Conflicts:
fs/exec.c - We already have
33a2d6bc3480 ("Revert "fs/exec: allow to unshare a time namespace on vfork+exec"")
so don't add call to timens_on_fork back in
include/linux/mmzone.h - We already have
e6ad640bc404 ("mm: deduplicate cacheline padding code")
so keep CACHELINE_PADDING(_pad2_) over ZONE_PADDING(_pad2_)
mm/vmscan.c - The backport of
badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs")
added an #include <linux/debugfs.h>. Keep it.
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit bd74fdaea146029e4fa12c6de89adbe0779348a9
Author: Yu Zhao <yuzhao@google.com>
Date: Sun Sep 18 02:00:05 2022 -0600
mm: multi-gen LRU: support page table walks
To further exploit spatial locality, the aging prefers to walk page tables
to search for young PTEs and promote hot pages. A kill switch will be
added in the next patch to disable this behavior. When disabled, the
aging relies on the rmap only.
NB: this behavior has nothing similar with the page table scanning in the
2.4 kernel [1], which searches page tables for old PTEs, adds cold pages
to swapcache and unmaps them.
To avoid confusion, the term "iteration" specifically means the traversal
of an entire mm_struct list; the term "walk" will be applied to page
tables and the rmap, as usual.
An mm_struct list is maintained for each memcg, and an mm_struct follows
its owner task to the new memcg when this task is migrated. Given an
lruvec, the aging iterates lruvec_memcg()->mm_list and calls
walk_page_range() with each mm_struct on this list to promote hot pages
before it increments max_seq.
When multiple page table walkers iterate the same list, each of them gets
a unique mm_struct; therefore they can run concurrently. Page table
walkers ignore any misplaced pages, e.g., if an mm_struct was migrated,
pages it left in the previous memcg will not be promoted when its current
memcg is under reclaim. Similarly, page table walkers will not promote
pages from nodes other than the one under reclaim.
This patch uses the following optimizations when walking page tables:
1. It tracks the usage of mm_struct's between context switches so that
page table walkers can skip processes that have been sleeping since
the last iteration.
2. It uses generational Bloom filters to record populated branches so
that page table walkers can reduce their search space based on the
query results, e.g., to skip page tables containing mostly holes or
misplaced pages.
3. It takes advantage of the accessed bit in non-leaf PMD entries when
CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG=y.
4. It does not zigzag between a PGD table and the same PMD table
spanning multiple VMAs. IOW, it finishes all the VMAs within the
range of the same PMD table before it returns to a PGD table. This
improves the cache performance for workloads that have large
numbers of tiny VMAs [2], especially when CONFIG_PGTABLE_LEVELS=5.
Server benchmark results:
Single workload:
fio (buffered I/O): no change
Single workload:
memcached (anon): +[8, 10]%
Ops/sec KB/sec
patch1-7: 1147696.57 44640.29
patch1-8: 1245274.91 48435.66
Configurations:
no change
Client benchmark results:
kswapd profiles:
patch1-7
48.16% lzo1x_1_do_compress (real work)
8.20% page_vma_mapped_walk (overhead)
7.06% _raw_spin_unlock_irq
2.92% ptep_clear_flush
2.53% __zram_bvec_write
2.11% do_raw_spin_lock
2.02% memmove
1.93% lru_gen_look_around
1.56% free_unref_page_list
1.40% memset
patch1-8
49.44% lzo1x_1_do_compress (real work)
6.19% page_vma_mapped_walk (overhead)
5.97% _raw_spin_unlock_irq
3.13% get_pfn_folio
2.85% ptep_clear_flush
2.42% __zram_bvec_write
2.08% do_raw_spin_lock
1.92% memmove
1.44% alloc_zspage
1.36% memset
Configurations:
no change
Thanks to the following developers for their efforts [3].
kernel test robot <lkp@intel.com>
[1] https://lwn.net/Articles/23732/
[2] https://llvm.org/docs/ScudoHardenedAllocator.html
[3] https://lore.kernel.org/r/202204160827.ekEARWQo-lkp@intel.com/
Link: https://lkml.kernel.org/r/20220918080010.2920238-9-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Brian Geffon <bgeffon@google.com>
Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Steven Barrett <steven@liquorix.net>
Acked-by: Suleiman Souhlal <suleiman@google.com>
Tested-by: Daniel Byrne <djbyrne@mtu.edu>
Tested-by: Donald Carr <d@chaos-reins.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
Tested-by: Sofia Trinh <sofia.trinh@edi.works>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2060283
commit d243b34459cea30cfe5f3a9b2feb44e7daff9938
Author: Wander Lairson Costa <wander@redhat.com>
Date: Wed Jun 14 09:23:21 2023 -0300
kernel/fork: beware of __put_task_struct() calling context
Under PREEMPT_RT, __put_task_struct() indirectly acquires sleeping
locks. Therefore, it can't be called from an non-preemptible context.
One practical example is splat inside inactive_task_timer(), which is
called in a interrupt context:
CPU: 1 PID: 2848 Comm: life Kdump: loaded Tainted: G W ---------
Hardware name: HP ProLiant DL388p Gen8, BIOS P70 07/15/2012
Call Trace:
dump_stack_lvl+0x57/0x7d
mark_lock_irq.cold+0x33/0xba
mark_lock+0x1e7/0x400
mark_usage+0x11d/0x140
__lock_acquire+0x30d/0x930
lock_acquire.part.0+0x9c/0x210
rt_spin_lock+0x27/0xe0
refill_obj_stock+0x3d/0x3a0
kmem_cache_free+0x357/0x560
inactive_task_timer+0x1ad/0x340
__run_hrtimer+0x8a/0x1a0
__hrtimer_run_queues+0x91/0x130
hrtimer_interrupt+0x10f/0x220
__sysvec_apic_timer_interrupt+0x7b/0xd0
sysvec_apic_timer_interrupt+0x4f/0xd0
asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0033:0x7fff196bf6f5
Instead of calling __put_task_struct() directly, we defer it using
call_rcu(). A more natural approach would use a workqueue, but since
in PREEMPT_RT, we can't allocate dynamic memory from atomic context,
the code would become more complex because we would need to put the
work_struct instance in the task_struct and initialize it when we
allocate a new task_struct.
The issue is reproducible with stress-ng:
while true; do
stress-ng --sched deadline --sched-period 1000000000 \
--sched-runtime 800000000 --sched-deadline \
1000000000 --mmapfork 23 -t 20
done
Reported-by: Hu Chunyu <chuhu@redhat.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Valentin Schneider <vschneid@redhat.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230614122323.37957-2-wander@redhat.com
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
commit 8d9bfb2608145cf3e408428c224099e1585471af
Author: Mike Kravetz <mike.kravetz@oracle.com>
Date: Wed Sep 14 15:18:07 2022 -0700
hugetlb: add vma based lock for pmd sharing
Allocate a new hugetlb_vma_lock structure and hang off vm_private_data for
synchronization use by vmas that could be involved in pmd sharing. This
data structure contains a rw semaphore that is the primary tool used for
synchronization.
This new structure is ref counted, so that it can exist when NOT attached
to a vma. This is only helpful in resolving lock ordering issues where
code may need to obtain the vma_lock while there are no guarantees the vma
may go away. By obtaining a ref on the structure, it can be guaranteed
that at least the rw semaphore will not go away.
Only add infrastructure for the new lock here. Actual use will be added
in subsequent patches.
[mike.kravetz@oracle.com: fix build issue for missing hugetlb_vma_lock_release]
Link: https://lkml.kernel.org/r/YyNUtA1vRASOE4+M@monkey
Link: https://lkml.kernel.org/r/20220914221810.95771-7-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2168372
Signed-off-by: Nico Pache <npache@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2169516
commit 434c9eefb959c36331a93617ea95df903469b99f
Author: Paul E. McKenney <paulmck@kernel.org>
Date: Mon, 16 May 2022 17:56:16 -0700
rcu-tasks: Add data structures for lightweight grace periods
This commit adds fields to task_struct and to rcu_tasks_percpu that will
be used to avoid the task-list scan for RCU Tasks Trace grace periods,
and also initializes these fields.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: KP Singh <kpsingh@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit d2081b2bf8195b8239c67fdd61518e077da7cbec
Author: Yang Shi <shy828301@gmail.com>
Date: Thu May 19 14:08:49 2022 -0700
mm: khugepaged: make khugepaged_enter() void function
The most callers of khugepaged_enter() don't care about the return value.
Only dup_mmap(), anonymous THP page fault and MADV_HUGEPAGE handle the
error by returning -ENOMEM. Actually it is not harmful for them to ignore
the error case either. It also sounds overkilling to fail fork() and page
fault early due to khugepaged_enter() error, and MADV_HUGEPAGE does set
VM_HUGEPAGE flag regardless of the error.
Link: https://lkml.kernel.org/r/20220510203222.24246-6-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Vlastmil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2175212
commit f05837ed73d0c73e950b2d9f2612febb0d3d451e
Author: Christoph Hellwig <hch@lst.de>
Date: Fri Feb 3 16:03:48 2023 +0100
blk-cgroup: store a gendisk to throttle in struct task_struct
Switch from a request_queue pointer and reference to a gendisk once
for the throttle information in struct task_struct.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Link: https://lore.kernel.org/r/20230203150400.3199230-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2116442
commit 2b5f9dad32ed19e8db3b0f10a84aa824a219803b
Author: Andrei Vagin <avagin@gmail.com>
Date: Tue Sep 20 17:31:19 2022 -0700
fs/exec: switch timens when a task gets a new mm
Changing a time namespace requires remapping a vvar page, so we don't want
to allow doing that if any other tasks can use the same mm.
Currently, we install a time namespace when a task is created with a new
vm. exec() is another case when a task gets a new mm and so it can switch
a time namespace safely, but it isn't handled now.
One more issue of the current interface is that clone() with CLONE_VM isn't
allowed if the current task has unshared a time namespace
(timens_for_children doesn't match the current timens).
Both these issues make some inconvenience for users. For example, Alexey
and Florian reported that posix_spawn() uses vfork+exec and this pattern
doesn't work with time namespaces due to the both described issues.
LXC needed to workaround the exec() issue by calling setns.
In the commit 133e2d3e81de5 ("fs/exec: allow to unshare a time namespace on
vfork+exec"), we tried to fix these issues with minimal impact on UAPI. But
it adds extra complexity and some undesirable side effects. Eric suggested
fixing the issues properly because here are all the reasons to suppose that
there are no users that depend on the old behavior.
Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Origin-author: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220921003120.209637-1-avagin@google.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2129758
commit 792575348ff70e05c6040d02fce38e949ef92c37
From: Daniel Bristot de Oliveira <bristot@kernel.org>
Date: Fri, 29 Jul 2022 11:38:43 +0200
rv/include: Add deterministic automata monitor definition via C macros
In Linux terms, the runtime verification monitors are encapsulated
inside the "RV monitor" abstraction. The "RV monitor" includes a set
of instances of the monitor (per-cpu monitor, per-task monitor, and
so on), the helper functions that glue the monitor to the system
reference model, and the trace output as a reaction for event parsing
and exceptions, as depicted below:
Linux +----- RV Monitor ----------------------------------+ Formal
Realm | | Realm
+-------------------+ +----------------+ +-----------------+
| Linux kernel | | Monitor | | Reference |
| Tracing | -> | Instance(s) | <- | Model |
| (instrumentation) | | (verification) | | (specification) |
+-------------------+ +----------------+ +-----------------+
| | |
| V |
| +----------+ |
| | Reaction | |
| +--+--+--+-+ |
| | | | |
| | | +-> trace output ? |
+------------------------|--|----------------------+
| +----> panic ?
+-------> <user-specified>
Add the rv/da_monitor.h, enabling automatic code generation for the
*Monitor Instance(s)* using C macros, and code to support it.
The benefits of the usage of macro for monitor synthesis are 3-fold as it:
- Reduces the code duplication;
- Facilitates the bug fix/improvement;
- Avoids the case of developers changing the core of the monitor code
to manipulate the model in a (let's say) non-standard way.
This initial implementation presents three different types of monitor
instances:
- DECLARE_DA_MON_GLOBAL(name, type)
- DECLARE_DA_MON_PER_CPU(name, type)
- DECLARE_DA_MON_PER_TASK(name, type)
The first declares the functions for a global deterministic automata monitor,
the second for monitors with per-cpu instances, and the third with per-task
instances.
Link: https://lkml.kernel.org/r/51b0bf425a281e226dfeba7401d2115d6091f84e.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alessandro Carminati <acarmina@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120966
commit 54ecbe6f1ed5138c895bdff55608cf502755b20e
Author: Masami Hiramatsu <mhiramat@kernel.org>
Date: Tue Mar 15 23:00:50 2022 +0900
rethook: Add a generic return hook
Add a return hook framework which hooks the function return. Most of the
logic came from the kretprobe, but this is independent from kretprobe.
Note that this is expected to be used with other function entry hooking
feature, like ftrace, fprobe, adn kprobes. Eventually this will replace
the kretprobe (e.g. kprobe + rethook = kretprobe), but at this moment,
this is just an additional hook.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735285066.1084943.9259661137330166643.stgit@devnote2
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Merge conflicts:
-----------------
Conflicts with !1142(merged) "io_uring: update to v5.15"
fs/io-wq.c
- static bool io_wqe_create_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
!1142 already contains backport of 3146cba99aa2 ("io-wq: make worker creation resilient against signals")
along with other commits which are not present in !1370. Resolved in favor of HEAD(!1142)
- static int io_wqe_worker(void *data)
!1370 does not contain 767a65e9f317 ("io-wq: fix potential race of acct->nr_workers")
Resolved in favor of HEAD(!1142)
- static void io_init_new_worker(struct io_wqe *wqe, struct io_worker *worker,
HEAD(!1142) does not contain e32cf5dfbe22 ("kthread: Generalize pf_io_worker so it can point to struct kthread")
Resolved in favor of !1370
- static void create_worker_cont(struct callback_head *cb)
!1370 does not contain 66e70be72288 ("io-wq: fix memory leak in create_io_worker()")
Resolved in favor of HEAD(!1142)
- static void io_workqueue_create(struct work_struct *work)
!1370 does not contain 66e70be72288 ("io-wq: fix memory leak in create_io_worker()")
Resolved in favor of HEAD(!1142)
- static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
!1370 does not contain 66e70be72288 ("io-wq: fix memory leak in create_io_worker()")
Resolved in favor of HEAD(!1142)
- static bool io_wq_work_match_item(struct io_wq_work *work, void *data)
!1370 does not contain 713b9825a4c4 ("io-wq: fix cancellation on create-worker failure")
Resolved in favor of HEAD(!1142)
- static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
!1370 is missing 713b9825a4c4 ("io-wq: fix cancellation on create-worker failure")
removed wrongly merged run_cancel label
Resolved in favor of HEAD(!1142)
- static bool io_task_work_match(struct callback_head *cb, void *data)
!1370 is missing 3b33e3f4a6c0 ("io-wq: fix silly logic error in io_task_work_match()")
Resolved in favor of HEAD(!1142)
- static void io_wq_exit_workers(struct io_wq *wq)
!1370 is missing 3b33e3f4a6c0 ("io-wq: fix silly logic error in io_task_work_match()")
Resolved in favor of HEAD(!1142)
- int io_wq_max_workers(struct io_wq *wq, int *new_count)
!1370 is missing 3b33e3f4a6c0 ("io-wq: fix silly logic error in io_task_work_match()")
fs/io_uring.c
- static int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
!1370 is missing bunch of commits after 2e480058ddc2 ("io-wq: provide a way to limit max number of workers")
Resolved in favor of HEAD(!1142)
include/uapi/linux/io_uring.h
- !1370 is missing dd47c104533d ("io-wq: provide IO_WQ_* constants for IORING_REGISTER_IOWQ_MAX_WORKERS arg items")
just a comment conflict
Resolved in favor of HEAD(!1142)
kernel/exit.c
- void __noreturn do_exit(long code)
- !1370 contains bunch of commits after f552a27afe67 ("io_uring: remove files pointer in cancellation functions")
Resolved in favor of !1370
Conflicts with !1357(merged) "NFS refresh for RHEL-9.2"
fs/nfs/callback.c
- nfs4_callback_svc(void *vrqstp)
!1370 is missing f49169c97fce ("NFSD: Remove svc_serv_ops::svo_module") where the module_put_and_kthread_exit() was removed
Resolved in favor of HEAD(!1357)
fs/nfs/file.c
!1357 is missing 187c82cb0380 ("fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio")
Resolved in favor of HEAD(!1370)
fs/nfsd/nfssvc.c
- nfsd(void *vrqstp)
!1370 is missing f49169c97fce ("NFSD: Remove svc_serv_ops::svo_module")
Resolved in favor of HEAD(!1357)
-----------------
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/1370
Bugzilla: https://bugzilla.redhat.com/2120352
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2099722
Patches 1-9 are changes to selftests
Patches 10-31 are reverts of RHEL-only patches to address COR CVE
Patches 32-320 are the machine dependent mm changes ported by Rafael
Patch 321 reverts the backport of 6692c98c7df5. See below.
Patches 322-981 are the machine independent mm changes
Patches 982-1016 are David Hildebrand's upstream changes to address the COR CVE
RHEL commit b23c298982 fork: Stop protecting back_fork_cleanup_cgroup_lock with CONFIG_NUMA
which is a backport of upstream 6692c98c7df5 and is reverted early in this series. 6692c98c7df5
is a fix for upstream 40966e316f86 which was not in RHEL until this series. 6692c98c7df5 is re-added
after 40966e316f86.
Omitted-fix: 310d1344e3c5 ("Revert "powerpc: Remove unused FW_FEATURE_NATIVE references"")
to be fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2131716
Omitted-fix: 465d0eb0dc31 ("Docs/admin-guide/mm/damon/usage: fix the example code snip")
to be fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2131716
Omitted-fix: 317314527d17 ("mm/hugetlb: correct demote page offset logic")
to be fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2131716
Omitted-fix: 37dcc673d065 ("frontswap: don't call ->init if no ops are registered")
to be fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2131716
Omitted-fix: 30c19366636f ("mm: fix BUG splat with kvmalloc + GFP_ATOMIC")
to be fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2131716
Omitted: fix: fa84693b3c89 io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: 009ad9f0c6ee io_uring: drop ctx->uring_lock before acquiring sqd->lock
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: bc369921d670 io-wq: max_worker fixes
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107743
Omitted-fix: e139a1ec92f8 io_uring: apply max_workers limit to all future users
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107743
Omitted-fix: 71c9ce27bb57 io-wq: fix max-workers not correctly set on multi-node system
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107743
Omitted-fix: 41d3a6bd1d37 io_uring: pin SQPOLL data before unlocking ring lock
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: bad119b9a000 io_uring: honour zeroes as io-wq worker limits
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107743
Omitted-fix: 08bdbd39b584 io-wq: ensure that hash wait lock is IRQ disabling
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: 713b9825a4c4 io-wq: fix cancellation on create-worker failure
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: 3b33e3f4a6c0 io-wq: fix silly logic error in io_task_work_match()
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: 71e1cef2d794 io-wq: Remove duplicate code in io_workqueue_create()
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=210774
Omitted-fix: a226abcd5d42 io-wq: don't retry task_work creation failure on fatal conditions
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107743
Omitted-fix: fa84693b3c89 io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: dd47c104533d io-wq: provide IO_WQ_* constants for IORING_REGISTER_IOWQ_MAX_WORKERS arg items
fixed under https://bugzilla.redhat.com/show_bug.cgi?id=2107656
Omitted-fix: 4f0712ccec09 hexagon: Fix function name in die()
unsupported arch
Omitted-fix: 751971af2e36 csky: Fix function name in csky_alignment() and die()
unsupported arch
Omitted-fix: dcbc65aac283 ptrace: Remove duplicated include in ptrace.c
unsupported arch
Omitted-fix: eb48d4219879 drm/i915: Fix oops due to missing stack depot
fixed in RHEL commit 105d2d4832 Merge DRM changes from upstream v5.16..v5.17
Omitted-fix: 751a9d69b197 drm/i915: Fix oops due to missing stack depot
fixed in RHEL commit 99fc716fc4 Merge DRM changes from upstream v5.17..v5.18
Omitted-fix: eb48d4219879 drm/i915: Fix oops due to missing stack depot
fixed in RHEL commit 105d2d4832 Merge DRM changes from upstream v5.16..v5.17
Omitted-fix: 751a9d69b197 drm/i915: Fix oops due to missing stack depot
fixed in RHEL commit 99fc716fc4 Merge DRM changes from upstream v5.17..v5.18
Omitted-fix: b95dc06af3e6 drm/amdgpu: disable runpm if we are the primary adapter
reverted later
Omitted-fix: 5a90c24ad028 Revert "drm/amdgpu: disable runpm if we are the primary adapter"
revert of above omitted fix
Omitted-fix: 724bbe49c5e4 fs/ntfs3: provide block_invalidate_folio to fix memory leak
unsupported fs
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Approved-by: John W. Linville <linville@redhat.com>
Approved-by: Jiri Benc <jbenc@redhat.com>
Approved-by: Jarod Wilson <jarod@redhat.com>
Approved-by: Prarit Bhargava <prarit@redhat.com>
Approved-by: Lyude Paul <lyude@redhat.com>
Approved-by: Donald Dutile <ddutile@redhat.com>
Approved-by: Rafael Aquini <aquini@redhat.com>
Approved-by: Phil Auld <pauld@redhat.com>
Approved-by: Waiman Long <longman@redhat.com>
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 343f4c49f2438d8920f1f76fa823ee59b91f02e4
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Mon Apr 11 11:40:14 2022 -0500
kthread: Don't allocate kthread_struct for init and umh
If kthread_is_per_cpu runs concurrently with free_kthread_struct the
kthread_struct that was just freed may be read from.
This bug was introduced by commit 40966e316f86 ("kthread: Ensure
struct kthread is present for all kthreads"). When kthread_struct
started to be allocated for all tasks that have PF_KTHREAD set. This
in turn required the kthread_struct to be freed in kernel_execve and
violated the assumption that kthread_struct will have the same
lifetime as the task.
Looking a bit deeper this only applies to callers of kernel_execve
which is just the init process and the user mode helper processes.
These processes really don't want to be kernel threads but are for
historical reasons. Mostly that copy_thread does not know how to take
a kernel mode function to the process with for processes without
PF_KTHREAD or PF_IO_WORKER set.
Solve this by not allocating kthread_struct for the init process and
the user mode helper processes.
This is done by adding a kthread member to struct kernel_clone_args.
Setting kthread in fork_idle and kernel_thread. Adding
user_mode_thread that works like kernel_thread except it does not set
kthread. In fork only allocating the kthread_struct if .kthread is set.
I have looked at kernel/kthread.c and since commit 40966e316f86
("kthread: Ensure struct kthread is present for all kthreads") there
have been no assumptions added that to_kthread or __to_kthread will
not return NULL.
There are a few callers of to_kthread or __to_kthread that assume a
non-NULL struct kthread pointer will be returned. These functions are
kthread_data(), kthread_parmme(), kthread_exit(), kthread(),
kthread_park(), kthread_unpark(), kthread_stop(). All of those functions
can reasonably expected to be called when it is know that a task is a
kthread so that assumption seems reasonable.
Cc: stable@vger.kernel.org
Fixes: 40966e316f86 ("kthread: Ensure struct kthread is present for all kthreads")
Reported-by: Максим Кутявин <maximkabox13@gmail.com>
Link: https://lkml.kernel.org/r/20220506141512.516114-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 51fb34de2a4c8fa0f221246313700bfe3b6c586d
Author: Andrey Konovalov <andreyknvl@gmail.com>
Date: Thu Mar 24 18:11:10 2022 -0700
kasan, arm64: reset pointer tags of vmapped stacks
Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.
Reset the tag of kernel stack pointers after allocation in
arch_alloc_vmap_stack().
For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.
For HW_TAGS KASAN, there's no instrumentation-related issues. However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.
Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.
[andreyknvl@google.com: fix case when a stack is retrieved from cached_stacks]
Link: https://lkml.kernel.org/r/f50c5f96ef896d7936192c888b0c0a7674e33184.1644943792.git.andreyknvl@google.com
[dan.carpenter@oracle.com: remove unnecessary check in alloc_thread_stack_node()]
Link: https://lkml.kernel.org/r/20220301080706.GB17208@kili
Link: https://lkml.kernel.org/r/698c5ab21743c796d46c15d075b9481825973e34.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit c08e6a1206e6876c66e0528b3ec717f557b07dd4
Author: Andrey Konovalov <andreyknvl@gmail.com>
Date: Thu Mar 24 18:11:07 2022 -0700
kasan, fork: reset pointer tags of vmapped stacks
Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.
Reset the tag of kernel stack pointers after allocation in
alloc_thread_stack_node().
For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.
For HW_TAGS KASAN, there's no instrumentation-related issues. However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.
Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.
Link: https://lkml.kernel.org/r/c6c96f012371ecd80e1936509ebcd3b07a5956f7.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 17fca131cee21724ee953a17c185c14e9533af5b
Author: Arnd Bergmann <arnd@arndb.de>
Date: Fri Jan 14 14:06:07 2022 -0800
mm: move anon_vma declarations to linux/mm_inline.h
The patch to add anonymous vma names causes a build failure in some
configurations:
include/linux/mm_types.h: In function 'is_same_vma_anon_name':
include/linux/mm_types.h:924:37: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
924 | return name && vma_name && !strcmp(name, vma_name);
| ^~~~~~
include/linux/mm_types.h:22:1: note: 'strcmp' is defined in header '<string.h>'; did you forget to '#include <string.h>'?
This should not really be part of linux/mm_types.h in the first place,
as that header is meant to only contain structure defintions and need a
minimum set of indirect includes itself.
While the header clearly includes more than it should at this point,
let's not make it worse by including string.h as well, which would pull
in the expensive (compile-speed wise) fortify-string logic.
Move the new functions into a separate header that only needs to be
included in a couple of locations.
Link: https://lkml.kernel.org/r/20211207125710.2503446-1-arnd@kernel.org
Fixes: "mm: add a field to store names for private anonymous memory"
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Colin Cross <ccross@google.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 9a10064f5625d5572c3626c1516e0bebc6c9fe9b
Author: Colin Cross <ccross@google.com>
Date: Fri Jan 14 14:05:59 2022 -0800
mm: add a field to store names for private anonymous memory
In many userspace applications, and especially in VM based applications
like Android uses heavily, there are multiple different allocators in
use. At a minimum there is libc malloc and the stack, and in many cases
there are libc malloc, the stack, direct syscalls to mmap anonymous
memory, and multiple VM heaps (one for small objects, one for big
objects, etc.). Each of these layers usually has its own tools to
inspect its usage; malloc by compiling a debug version, the VM through
heap inspection tools, and for direct syscalls there is usually no way
to track them.
On Android we heavily use a set of tools that use an extended version of
the logic covered in Documentation/vm/pagemap.txt to walk all pages
mapped in userspace and slice their usage by process, shared (COW) vs.
unique mappings, backing, etc. This can account for real physical
memory usage even in cases like fork without exec (which Android uses
heavily to share as many private COW pages as possible between
processes), Kernel SamePage Merging, and clean zero pages. It produces
a measurement of the pages that only exist in that process (USS, for
unique), and a measurement of the physical memory usage of that process
with the cost of shared pages being evenly split between processes that
share them (PSS).
If all anonymous memory is indistinguishable then figuring out the real
physical memory usage (PSS) of each heap requires either a pagemap
walking tool that can understand the heap debugging of every layer, or
for every layer's heap debugging tools to implement the pagemap walking
logic, in which case it is hard to get a consistent view of memory
across the whole system.
Tracking the information in userspace leads to all sorts of problems.
It either needs to be stored inside the process, which means every
process has to have an API to export its current heap information upon
request, or it has to be stored externally in a filesystem that somebody
needs to clean up on crashes. It needs to be readable while the process
is still running, so it has to have some sort of synchronization with
every layer of userspace. Efficiently tracking the ranges requires
reimplementing something like the kernel vma trees, and linking to it
from every layer of userspace. It requires more memory, more syscalls,
more runtime cost, and more complexity to separately track regions that
the kernel is already tracking.
This patch adds a field to /proc/pid/maps and /proc/pid/smaps to show a
userspace-provided name for anonymous vmas. The names of named
anonymous vmas are shown in /proc/pid/maps and /proc/pid/smaps as
[anon:<name>].
Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name)
Setting the name to NULL clears it. The name length limit is 80 bytes
including NUL-terminator and is checked to contain only printable ascii
characters (including space), except '[',']','\','$' and '`'.
Ascii strings are being used to have a descriptive identifiers for vmas,
which can be understood by the users reading /proc/pid/maps or
/proc/pid/smaps. Names can be standardized for a given system and they
can include some variable parts such as the name of the allocator or a
library, tid of the thread using it, etc.
The name is stored in a pointer in the shared union in vm_area_struct
that points to a null terminated string. Anonymous vmas with the same
name (equivalent strings) and are otherwise mergeable will be merged.
The name pointers are not shared between vmas even if they contain the
same name. The name pointer is stored in a union with fields that are
only used on file-backed mappings, so it does not increase memory usage.
CONFIG_ANON_VMA_NAME kernel configuration is introduced to enable this
feature. It keeps the feature disabled by default to prevent any
additional memory overhead and to avoid confusing procfs parsers on
systems which are not ready to support named anonymous vmas.
The patch is based on the original patch developed by Colin Cross, more
specifically on its latest version [1] posted upstream by Sumit Semwal.
It used a userspace pointer to store vma names. In that design, name
pointers could be shared between vmas. However during the last
upstreaming attempt, Kees Cook raised concerns [2] about this approach
and suggested to copy the name into kernel memory space, perform
validity checks [3] and store as a string referenced from
vm_area_struct.
One big concern is about fork() performance which would need to strdup
anonymous vma names. Dave Hansen suggested experimenting with
worst-case scenario of forking a process with 64k vmas having longest
possible names [4]. I ran this experiment on an ARM64 Android device
and recorded a worst-case regression of almost 40% when forking such a
process.
This regression is addressed in the followup patch which replaces the
pointer to a name with a refcounted structure that allows sharing the
name pointer between vmas of the same name. Instead of duplicating the
string during fork() or when splitting a vma it increments the refcount.
[1] https://lore.kernel.org/linux-mm/20200901161459.11772-4-sumit.semwal@linaro.org/
[2] https://lore.kernel.org/linux-mm/202009031031.D32EF57ED@keescook/
[3] https://lore.kernel.org/linux-mm/202009031022.3834F692@keescook/
[4] https://lore.kernel.org/linux-mm/5d0358ab-8c47-2f5f-8e43-23b89d6a8e95@intel.com/
Changes for prctl(2) manual page (in the options section):
PR_SET_VMA
Sets an attribute specified in arg2 for virtual memory areas
starting from the address specified in arg3 and spanning the
size specified in arg4. arg5 specifies the value of the attribute
to be set. Note that assigning an attribute to a virtual memory
area might prevent it from being merged with adjacent virtual
memory areas due to the difference in that attribute's value.
Currently, arg2 must be one of:
PR_SET_VMA_ANON_NAME
Set a name for anonymous virtual memory areas. arg5 should
be a pointer to a null-terminated string containing the
name. The name length including null byte cannot exceed
80 bytes. If arg5 is NULL, the name of the appropriate
anonymous virtual memory areas will be reset. The name
can contain only printable ascii characters (including
space), except '[',']','\','$' and '`'.
This feature is available only if the kernel is built with
the CONFIG_ANON_VMA_NAME option enabled.
[surenb@google.com: docs: proc.rst: /proc/PID/maps: fix malformed table]
Link: https://lkml.kernel.org/r/20211123185928.2513763-1-surenb@google.com
[surenb: rebased over v5.15-rc6, replaced userpointer with a kernel copy,
added input sanitization and CONFIG_ANON_VMA_NAME config. The bulk of the
work here was done by Colin Cross, therefore, with his permission, keeping
him as the author]
Link: https://lkml.kernel.org/r/20211019215511.3771969-2-surenb@google.com
Signed-off-by: Colin Cross <ccross@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Glauber <jan.glauber@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Landley <rob@landley.net>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Shaohua Li <shli@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 2873cd31a20c25b5e763b35e5fb886f0938c6dd5
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Sat Jan 8 10:03:24 2022 -0600
exit: Remove profile_handoff_task
All profile_handoff_task does is notify the task_free_notifier chain.
The helpers task_handoff_register and task_handoff_unregister are used
to add and delete entries from that chain and are never called.
So remove the dead code and make it much easier to read and reason
about __put_task_struct.
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/87fspyw6m0.fsf@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit e32cf5dfbe227b355776948b2c9b5691b84d1cbd
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Wed Dec 22 22:10:09 2021 -0600
kthread: Generalize pf_io_worker so it can point to struct kthread
The point of using set_child_tid to hold the kthread pointer was that
it already did what is necessary. There are now restrictions on when
set_child_tid can be initialized and when set_child_tid can be used in
schedule_tail. Which indicates that continuing to use set_child_tid
to hold the kthread pointer is a bad idea.
Instead of continuing to use the set_child_tid field of task_struct
generalize the pf_io_worker field of task_struct and use it to hold
the kthread pointer.
Rename pf_io_worker (which is a void * pointer) to worker_private so
it can be used to store kthreads struct kthread pointer. Update the
kthread code to store the kthread pointer in the worker_private field.
Remove the places where set_child_tid had to be dealt with carefully
because kthreads also used it.
Link: https://lkml.kernel.org/r/CAHk-=wgtFAA9SbVYg0gR1tqPMC17-NYcs0GQkaYg1bGhh1uJQQ@mail.gmail.com
Link: https://lkml.kernel.org/r/87a6grvqy8.fsf_-_@email.froward.int.ebiederm.org
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit ff8288ff475e47544569359772f88f2b39fd2cf9
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Mon Dec 20 10:42:18 2021 -0600
fork: Rename bad_fork_cleanup_threadgroup_lock to bad_fork_cleanup_delayacct
I just fixed a bug in copy_process when using the label
bad_fork_cleanup_threadgroup_lock. While fixing the bug I looked
closer at the label and realized it has been misnamed since
568ac88821 ("cgroup: reduce read locked section of
cgroup_threadgroup_rwsem during fork").
Fix the name so that fork is easier to understand.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 6692c98c7df53502adb8b8b73ab9bcbd399f7a06
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Mon Dec 20 10:20:14 2021 -0600
fork: Stop protecting back_fork_cleanup_cgroup_lock with CONFIG_NUMA
Mark Brown <broonie@kernel.org> reported:
> This is also causing further build errors including but not limited to:
>
> /tmp/next/build/kernel/fork.c: In function 'copy_process':
> /tmp/next/build/kernel/fork.c:2106:4: error: label 'bad_fork_cleanup_threadgroup_lock' used but not defined
> 2106 | goto bad_fork_cleanup_threadgroup_lock;
> | ^~~~
It turns out that I messed up and was depending upon a label protected
by an ifdef. Move the label out of the ifdef as the ifdef around the label
no longer makes sense (if it ever did).
Link: https://lkml.kernel.org/r/YbugCP144uxXvRsk@sirena.org.uk
Fixes: 40966e316f86 ("kthread: Ensure struct kthread is present for all kthreads")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 40966e316f86b8cfd83abd31ccb4df729309d3e7
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Thu Dec 2 09:56:14 2021 -0600
kthread: Ensure struct kthread is present for all kthreads
Today the rules are a bit iffy and arbitrary about which kernel
threads have struct kthread present. Both idle threads and thread
started with create_kthread want struct kthread present so that is
effectively all kernel threads. Make the rule that if PF_KTHREAD
and the task is running then struct kthread is present.
This will allow the kernel thread code to using tsk->exit_code
with different semantics from ordinary processes.
To make ensure that struct kthread is present for all
kernel threads move it's allocation into copy_process.
Add a deallocation of struct kthread in exec for processes
that were kernel threads.
Move the allocation of struct kthread for the initial thread
earlier so that it is not repeated for each additional idle
thread.
Move the initialization of struct kthread into set_kthread_struct
so that the structure is always and reliably initailized.
Clear set_child_tid in free_kthread_struct to ensure the kthread
struct is reliably freed during exec. The function
free_kthread_struct does not need to clear vfork_done during exec as
exec_mm_release called from exec_mmap has already cleared vfork_done.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 0258b5fd7c7124b87e185a1a9322d2c66b1876b7
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Wed Sep 22 11:24:02 2021 -0500
coredump: Limit coredumps to a single thread group
Today when a signal is delivered with a handler of SIG_DFL whose
default behavior is to generate a core dump not only that process but
every process that shares the mm is killed.
In the case of vfork this looks like a real world problem. Consider
the following well defined sequence.
if (vfork() == 0) {
execve(...);
_exit(EXIT_FAILURE);
}
If a signal that generates a core dump is received after vfork but
before the execve changes the mm the process that called vfork will
also be killed (as the mm is shared).
Similarly if the execve fails after the point of no return the kernel
delivers SIGSEGV which will kill both the exec'ing process and because
the mm is shared the process that called vfork as well.
As far as I can tell this behavior is a violation of people's
reasonable expectations, POSIX, and is unnecessarily fragile when the
system is low on memory.
Solve this by making a userspace visible change to only kill a single
process/thread group. This is possible because Jann Horn recently
modified[1] the coredump code so that the mm can safely be modified
while the coredump is happening. With LinuxThreads long gone I don't
expect anyone to have a notice this behavior change in practice.
To accomplish this move the core_state pointer from mm_struct to
signal_struct, which allows different thread groups to coredump
simultatenously.
In zap_threads remove the work to kill anything except for the current
thread group.
v2: Remove core_state from the VM_BUG_ON_MM print to fix
compile failure when CONFIG_DEBUG_VM is enabled.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
[1] a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3")
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133
Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 92307383082daff5df884a25df9e283efb7ef261
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Wed Sep 1 11:33:50 2021 -0500
coredump: Don't perform any cleanups before dumping core
Rename coredump_exit_mm to coredump_task_exit and call it from do_exit
before PTRACE_EVENT_EXIT, and before any cleanup work for a task
happens. This ensures that an accurate copy of the process can be
captured in the coredump as no cleanup for the process happens before
the coredump completes. This also ensures that PTRACE_EVENT_EXIT
will not be visited by any thread until the coredump is complete.
Add a new flag PF_POSTCOREDUMP so that tasks that have passed through
coredump_task_exit can be recognized and ignored in zap_process.
Now that all of the coredumping happens before exit_mm remove code to
test for a coredump in progress from mm_release.
Replace "may_ptrace_stop()" with a simple test of "current->ptrace".
The other tests in may_ptrace_stop all concern avoiding stopping
during a coredump. These tests are no longer necessary as it is now
guaranteed that fatal_signal_pending will be set if the code enters
ptrace_stop during a coredump. The code in ptrace_stop is guaranteed
not to stop if fatal_signal_pending returns true.
Until this change "ptrace_event(PTRACE_EVENT_EXIT)" could call
ptrace_stop without fatal_signal_pending being true, as signals are
dequeued in get_signal before calling do_exit. This is no longer
an issue as "ptrace_event(PTRACE_EVENT_EXIT)" is no longer reached
until after the coredump completes.
Link: https://lkml.kernel.org/r/874kaax26c.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
Upstream status: RHEL only
6692c98c7df5 is a fix for upstream 40966e316f86 which was not in RHEL until
this series. We'll re-add 6692c98c7df5 after 40966e316f86.
This reverts commit b23c298982.
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120665
commit 85eaeb5058f0f04dffb124c97c86b4f18db0b833
Author: Yishai Hadas <yishaih@nvidia.com>
Date: Wed Aug 24 09:10:36 2022 +0300
IB/core: Fix a nested dead lock as part of ODP flow
Fix a nested dead lock as part of ODP flow by using mmput_async().
From the below call trace [1] can see that calling mmput() once we have
the umem_odp->umem_mutex locked as required by
ib_umem_odp_map_dma_and_lock() might trigger in the same task the
exit_mmap()->__mmu_notifier_release()->mlx5_ib_invalidate_range() which
may dead lock when trying to lock the same mutex.
Moving to use mmput_async() will solve the problem as the above
exit_mmap() flow will be called in other task and will be executed once
the lock will be available.
[1]
[64843.077665] task:kworker/u133:2 state:D stack: 0 pid:80906 ppid:
2 flags:0x00004000
[64843.077672] Workqueue: mlx5_ib_page_fault mlx5_ib_eqe_pf_action [mlx5_ib]
[64843.077719] Call Trace:
[64843.077722] <TASK>
[64843.077724] __schedule+0x23d/0x590
[64843.077729] schedule+0x4e/0xb0
[64843.077735] schedule_preempt_disabled+0xe/0x10
[64843.077740] __mutex_lock.constprop.0+0x263/0x490
[64843.077747] __mutex_lock_slowpath+0x13/0x20
[64843.077752] mutex_lock+0x34/0x40
[64843.077758] mlx5_ib_invalidate_range+0x48/0x270 [mlx5_ib]
[64843.077808] __mmu_notifier_release+0x1a4/0x200
[64843.077816] exit_mmap+0x1bc/0x200
[64843.077822] ? walk_page_range+0x9c/0x120
[64843.077828] ? __cond_resched+0x1a/0x50
[64843.077833] ? mutex_lock+0x13/0x40
[64843.077839] ? uprobe_clear_state+0xac/0x120
[64843.077860] mmput+0x5f/0x140
[64843.077867] ib_umem_odp_map_dma_and_lock+0x21b/0x580 [ib_core]
[64843.077931] pagefault_real_mr+0x9a/0x140 [mlx5_ib]
[64843.077962] pagefault_mr+0xb4/0x550 [mlx5_ib]
[64843.077992] pagefault_single_data_segment.constprop.0+0x2ac/0x560
[mlx5_ib]
[64843.078022] mlx5_ib_eqe_pf_action+0x528/0x780 [mlx5_ib]
[64843.078051] process_one_work+0x22b/0x3d0
[64843.078059] worker_thread+0x53/0x410
[64843.078065] ? process_one_work+0x3d0/0x3d0
[64843.078073] kthread+0x12a/0x150
[64843.078079] ? set_kthread_struct+0x50/0x50
[64843.078085] ret_from_fork+0x22/0x30
[64843.078093] </TASK>
Fixes: 36f30e486d ("IB/core: Improve ODP to use hmm_range_fault()")
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/74d93541ea533ef7daec6f126deb1072500aeb16.1661251841.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Kamal Heib <kheib@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2113044
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 2667ed10d9f01e250ba806276740782c89d77fda
Author: Fenghua Yu <fenghua.yu@intel.com>
Date: Thu Apr 28 11:00:41 2022 -0700
mm: Fix PASID use-after-free issue
The PASID is being freed too early. It needs to stay around until after
device drivers that might be using it have had a chance to clear it out
of the hardware.
The relevant refcounts are:
mmget() /mmput() refcount the mm's address space
mmgrab()/mmdrop() refcount the mm itself
The PASID is currently tied to the life of the mm's address space and freed
in __mmput(). This makes logical sense because the PASID can't be used
once the address space is gone.
But, this misses an important point: even after the address space is gone,
the PASID will still be programmed into a device. Device drivers might,
for instance, still need to flush operations that are outstanding and need
to use that PASID. They do this at file->release() time.
Device drivers call the IOMMU driver to hold a reference on the mm itself
and drop it at file->release() time. But, the IOMMU driver holds a
reference on the mm itself, not the address space. The address space (and
the PASID) is long gone by the time the driver tries to clean up. This is
effectively a use-after-free bug on the PASID.
To fix this, move the PASID free operation from __mmput() to __mmdrop().
This ensures that the IOMMU driver's existing mmgrab() keeps the PASID
allocated until it drops its mm reference.
Fixes: 701fac40384f ("iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit")
Reported-by: Zhangfei Gao <zhangfei.gao@foxmail.com>
Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Suggested-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Zhangfei Gao <zhangfei.gao@foxmail.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20220428180041.806809-1-fenghua.yu@intel.com
(cherry picked from commit 2667ed10d9f01e250ba806276740782c89d77fda)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2078906
commit ca7752caeaa70bd31d1714af566c9809688544af
Author: Michael Pratt <mpratt@google.com>
Date: Mon Nov 1 17:06:15 2021 -0400
posix-cpu-timers: Clear task::posix_cputimers_work in copy_process()
copy_process currently copies task_struct.posix_cputimers_work as-is. If a
timer interrupt arrives while handling clone and before dup_task_struct
completes then the child task will have:
1. posix_cputimers_work.scheduled = true
2. posix_cputimers_work.work queued.
copy_process clears task_struct.task_works, so (2) will have no effect and
posix_cpu_timers_work will never run (not to mention it doesn't make sense
for two tasks to share a common linked list).
Since posix_cpu_timers_work never runs, posix_cputimers_work.scheduled is
never cleared. Since scheduled is set, future timer interrupts will skip
scheduling work, with the ultimate result that the task will never receive
timer expirations.
Together, the complete flow is:
1. Task 1 calls clone(), enters kernel.
2. Timer interrupt fires, schedules task work on Task 1.
2a. task_struct.posix_cputimers_work.scheduled = true
2b. task_struct.posix_cputimers_work.work added to
task_struct.task_works.
3. dup_task_struct() copies Task 1 to Task 2.
4. copy_process() clears task_struct.task_works for Task 2.
5. Future timer interrupts on Task 2 see
task_struct.posix_cputimers_work.scheduled = true and skip scheduling
work.
Fix this by explicitly clearing contents of task_struct.posix_cputimers_work
in copy_process(). This was never meant to be shared or inherited across
tasks in the first place.
Fixes: 1fb497dd00 ("posix-cpu-timers: Provide mechanisms to defer timer handling to task_work")
Reported-by: Rhys Hiltner <rhys@justin.tv>
Signed-off-by: Michael Pratt <mpratt@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211101210615.716522-1-mpratt@google.com
Signed-off-by: Phil Auld <pauld@redhat.com>
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/754
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2076594
Tested: Sanity tested with scheduler stress tests.
This is a handful of commits to help the RT merge. Keeping the differences
as small as possible reduces the maintenance.
Signed-off-by: Phil Auld <pauld@redhat.com>
Approved-by: Fernando Pacheco <fpacheco@redhat.com>
Approved-by: Waiman Long <longman@redhat.com>
Approved-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Patrick Talbert <ptalbert@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2041365
Conflicts: Minor conflict with commit a2baf4e8bb ("bpf: Fix
potentially incorrect results with bpf_get_local_storage()")
commit c7603cfa04e7c3a435b31d065f7cbdc829428f6e
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Jul 12 16:06:15 2021 -0700
bpf: Add ambient BPF runtime context stored in current
b910eaaaa4 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage()
helper") fixed the problem with cgroup-local storage use in BPF by
pre-allocating per-CPU array of 8 cgroup storage pointers to accommodate
possible BPF program preemptions and nested executions.
While this seems to work good in practice, it introduces new and unnecessary
failure mode in which not all BPF programs might be executed if we fail to
find an unused slot for cgroup storage, however unlikely it is. It might also
not be so unlikely when/if we allow sleepable cgroup BPF programs in the
future.
Further, the way that cgroup storage is implemented as ambiently-available
property during entire BPF program execution is a convenient way to pass extra
information to BPF program and helpers without requiring user code to pass
around extra arguments explicitly. So it would be good to have a generic
solution that can allow implementing this without arbitrary restrictions.
Ideally, such solution would work for both preemptable and sleepable BPF
programs in exactly the same way.
This patch introduces such solution, bpf_run_ctx. It adds one pointer field
(bpf_ctx) to task_struct. This field is maintained by BPF_PROG_RUN family of
macros in such a way that it always stays valid throughout BPF program
execution. BPF program preemption is handled by remembering previous
current->bpf_ctx value locally while executing nested BPF program and
restoring old value after nested BPF program finishes. This is handled by two
helper functions, bpf_set_run_ctx() and bpf_reset_run_ctx(), which are
supposed to be used before and after BPF program runs, respectively.
Restoring old value of the pointer handles preemption, while bpf_run_ctx
pointer being a property of current task_struct naturally solves this problem
for sleepable BPF programs by "following" BPF program execution as it is
scheduled in and out of CPU. It would even allow CPU migration of BPF
programs, even though it's not currently allowed by BPF infra.
This patch cleans up cgroup local storage handling as a first application. The
design itself is generic, though, with bpf_run_ctx being an empty struct that
is supposed to be embedded into a specific struct for a given BPF program type
(bpf_cg_run_ctx in this case). Follow up patches are planned that will expand
this mechanism for other uses within tracing BPF programs.
To verify that this change doesn't revert the fix to the original cgroup
storage issue, I ran the same repro as in the original report ([0]) and didn't
get any problems. Replacing bpf_reset_run_ctx(old_run_ctx) with
bpf_reset_run_ctx(NULL) triggers the issue pretty quickly (so repro does work).
[0] https://lore.kernel.org/bpf/YEEvBUiJl2pJkxTd@krava/
Fixes: b910eaaaa4 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210712230615.3525979-1-andrii@kernel.org
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/627
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2062831
Upstream Status: Linux
Tested: By me with a series of scheduler stress and performance tests
Scheduler updates and fixes from 5.17 and 5.18-rc1. This series
keeps the scheduler up to date and addresses a handful of potential
issues.
Signed-off-by: Phil Auld <pauld@redhat.com>
Approved-by: Waiman Long <longman@redhat.com>
Approved-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Patrick Talbert <ptalbert@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit 0ce055f85335e48bc571114d61a70ae217039362
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:06 2022 +0100
fork: Use IS_ENABLED() in account_kernel_stack()
Not strickly needed but checking CONFIG_VMAP_STACK instead of
task_stack_vm_area()' result allows the compiler the remove the else
path in the CONFIG_VMAP_STACK case where the pointer can't be NULL.
Check for CONFIG_VMAP_STACK in order to use the proper path.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-9-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit e540bf3162e822d7a1f07e69e3bb1b4f925ca368
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:05 2022 +0100
fork: Only cache the VMAP stack in finish_task_switch()
The task stack could be deallocated later, but for fork()/exec() kind of
workloads (say a shell script executing several commands) it is important
that the stack is released in finish_task_switch() so that in VMAP_STACK
case it can be cached and reused in the new task.
For PREEMPT_RT it would be good if the wake-up in vfree_atomic() could
be avoided in the scheduling path. Far worse are the other
free_thread_stack() implementations which invoke __free_pages()/
kmem_cache_free() with disabled preemption.
Cache the stack in free_thread_stack() in the VMAP_STACK case and
RCU-delay the free path otherwise. Free the stack in the RCU callback.
In the VMAP_STACK case this is another opportunity to fill the cache.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-8-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
Conflicts: Fuzz in one hunk of dup_task_struct due to context diff.
commit 1a03d3f13ffe5dd24142d6db629e72c11b704d99
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:04 2022 +0100
fork: Move task stack accounting to do_exit()
There is no need to perform the stack accounting of the outgoing task in
its final schedule() invocation which happens with preemption disabled.
The task is leaving, the resources will be freed and the accounting can
happen in do_exit() before the actual schedule invocation which
frees the stack memory.
Move the accounting of the stack memory from release_task_stack() to
exit_task_stack_account() which then can be invoked from do_exit().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-7-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit f1c1a9ee00e4c53c9ccc03ec1aff4792948a25eb
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:03 2022 +0100
fork: Move memcg_charge_kernel_stack() into CONFIG_VMAP_STACK
memcg_charge_kernel_stack() is only used in the CONFIG_VMAP_STACK case.
Move memcg_charge_kernel_stack() into the CONFIG_VMAP_STACK block and
invoke it from within alloc_thread_stack_node().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-6-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit 7865aba3ade4cf30f0ac08e015550084a50d9afb
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:02 2022 +0100
fork: Don't assign the stack pointer in dup_task_struct()
All four versions of alloc_thread_stack_node() assign now
task_struct::stack in case the allocation was successful.
Let alloc_thread_stack_node() return an error code instead of the stack
pointer and remove the stack assignment in dup_task_struct().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-5-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit 2bb0529c0bc0698f3baf3e88ffd61a18eef252a7
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:01 2022 +0100
fork, IA64: Provide alloc_thread_stack_node() for IA64
Provide a generic alloc_thread_stack_node() for IA64 and
CONFIG_ARCH_THREAD_STACK_ALLOCATOR which returns stack pointer and sets
task_struct::stack so it behaves exactly like the other implementations.
Rename IA64's alloc_thread_stack_node() and add the generic version to the
fork code so it is in one place _and_ to drastically lower the chances of
fat fingering the IA64 code. Do the same for free_thread_stack().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-4-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit 546c42b2c5c161619736dd730d3df709181999d0
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:24:00 2022 +0100
fork: Duplicate task_struct before stack allocation
alloc_thread_stack_node() already populates the task_struct::stack
member except on IA64. The stack pointer is saved and populated again
because IA64 needs it and arch_dup_task_struct() overwrites it.
Allocate thread's stack after task_struct has been duplicated as a
preparation for further changes.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-3-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2076594
commit be9a2277cafd318976d59c41a7f45a934ec43b26
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Feb 17 11:23:59 2022 +0100
fork: Redo ifdefs around task stack handling
The use of ifdef CONFIG_VMAP_STACK is confusing in terms what is
actually happenning and what can happen.
For instance from reading free_thread_stack() it appears that in the
CONFIG_VMAP_STACK case it may receive a non-NULL vm pointer but it may also
be NULL in which case __free_pages() is used to free the stack. This is
however not the case because in the VMAP case a non-NULL pointer is always
returned here. Since it looks like this might happen, the compiler creates
the correct dead code with the invocation to __free_pages() and everything
around it. Twice.
Add spaces between the ifdef and the identifer to recognize the ifdef
level which is currently in scope.
Add the current identifer as a comment behind #else and #endif.
Move the code within free_thread_stack() and alloc_thread_stack_node()
into the relevant ifdef blocks.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-2-bigeasy@linutronix.de
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2066297
commit 88c9a2ce520ba381bb70658c80ec704f4d60f728
Author: Christoph Hellwig <hch@lst.de>
Date: Fri Nov 26 12:58:05 2021 +0100
fork: move copy_io to block/blk-ioc.c
Move the copying of the I/O context to the block layer as that is where
we can use the proper low-level interfaces.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211126115817.2087431-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2004573
Upstream Status: kernel/git/torvalds/linux.git
Conflict: RH_KABI work around for addition to task_struct
commit a3d29e8291b622780eb6e4e3eeaf2b24ec78fd43
Author: Peter Zijlstra <peterz@infradead.org>
Date: Mon Feb 7 15:02:50 2022 -0800
sched: Define and initialize a flag to identify valid PASID in the task
Add a new single bit field to the task structure to track whether this task
has initialized the IA32_PASID MSR to the mm's PASID.
Initialize the field to zero when creating a new task with fork/clone.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-8-fenghua.yu@intel.com
(cherry picked from commit a3d29e8291b622780eb6e4e3eeaf2b24ec78fd43)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2004573
Upstream Status: kernel/git/torvalds/linux.git
Conflict: 30209b93177a ("iommu: Fix some W=1 warnings") not backported yet.
commit 701fac40384f07197b106136012804c3cae0b3de
Author: Fenghua Yu <fenghua.yu@intel.com>
Date: Mon Feb 7 15:02:48 2022 -0800
iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit
PASIDs are process-wide. It was attempted to use refcounted PASIDs to
free them when the last thread drops the refcount. This turned out to
be complex and error prone. Given the fact that the PASID space is 20
bits, which allows up to 1M processes to have a PASID associated
concurrently, PASID resource exhaustion is not a realistic concern.
Therefore, it was decided to simplify the approach and stick with lazy
on demand PASID allocation, but drop the eager free approach and make an
allocated PASID's lifetime bound to the lifetime of the process.
Get rid of the refcounting mechanisms and replace/rename the interfaces
to reflect this new approach.
[ bp: Massage commit message. ]
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-6-fenghua.yu@intel.com
(cherry picked from commit 701fac40384f07197b106136012804c3cae0b3de)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2004573
Upstream Status: kernel/git/torvalds/linux.git
commit a6cbd44093ef305b02ad5f80ed54abf0148a696c
Author: Fenghua Yu <fenghua.yu@intel.com>
Date: Mon Feb 7 15:02:47 2022 -0800
kernel/fork: Initialize mm's PASID
A new mm doesn't have a PASID yet when it's created. Initialize
the mm's PASID on fork() or for init_mm to INVALID_IOASID (-1).
INIT_PASID (0) is reserved for kernel legacy DMA PASID. It cannot be
allocated to a user process. Initializing the process's PASID to 0 may
cause confusion that's why the process uses the reserved kernel legacy
DMA PASID. Initializing the PASID to INVALID_IOASID (-1) explicitly
tells the process doesn't have a valid PASID yet.
Even though the only user of mm_pasid_init() is in fork.c, define it in
<linux/sched/mm.h> as the first of three mm/pasid life cycle functions
(init/set/drop) to keep these all together.
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-5-fenghua.yu@intel.com
(cherry picked from commit a6cbd44093ef305b02ad5f80ed54abf0148a696c)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2004573
Upstream Status: kernel/git/torvalds/linux.git
commit 7a853c2d5951419fdf3c1c9d2b6f5a38f6a6857d
Author: Fenghua Yu <fenghua.yu@intel.com>
Date: Mon Feb 7 15:02:45 2022 -0800
mm: Change CONFIG option for mm->pasid field
This currently depends on CONFIG_IOMMU_SUPPORT. But it is only
needed when CONFIG_IOMMU_SVA option is enabled.
Change the CONFIG guards around definition and initialization
of mm->pasid field.
Suggested-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220207230254.3342514-3-fenghua.yu@intel.com
(cherry picked from commit 7a853c2d5951419fdf3c1c9d2b6f5a38f6a6857d)
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2062831
commit 6692c98c7df53502adb8b8b73ab9bcbd399f7a06
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Mon Dec 20 10:20:14 2021 -0600
fork: Stop protecting back_fork_cleanup_cgroup_lock with CONFIG_NUMA
Mark Brown <broonie@kernel.org> reported:
> This is also causing further build errors including but not limited to:
>
> /tmp/next/build/kernel/fork.c: In function 'copy_process':
> /tmp/next/build/kernel/fork.c:2106:4: error: label 'bad_fork_cleanup_threadgroup_lock' used but not defined
> 2106 | goto bad_fork_cleanup_threadgroup_lock;
> | ^~~~
It turns out that I messed up and was depending upon a label protected
by an ifdef. Move the label out of the ifdef as the ifdef around the label
no longer makes sense (if it ever did).
Link: https://lkml.kernel.org/r/YbugCP144uxXvRsk@sirena.org.uk
Fixes: 40966e316f86 ("kthread: Ensure struct kthread is present for all kthreads")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2062836
commit b1e8206582f9d680cff7d04828708c8b6ab32957
Author: Peter Zijlstra <peterz@infradead.org>
Date: Mon Feb 14 10:16:57 2022 +0100
sched: Fix yet more sched_fork() races
Where commit 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an
invalid sched_task_group") fixed a fork race vs cgroup, it opened up a
race vs syscalls by not placing the task on the runqueue before it
gets exposed through the pidhash.
Commit 13765de8148f ("sched/fair: Fix fault in reweight_entity") is
trying to fix a single instance of this, instead fix the whole class
of issues, effectively reverting this commit.
Fixes: 4ef0c5c6b5ba ("kernel/sched: Fix sched_fork() access an invalid sched_task_group")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Tested-by: Zhang Qiao <zhangqiao22@huawei.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/YgoeCbwj5mbCR0qA@hirez.programming.kicks-ass.net
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2061724
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 8f2f9c4d82f24f172ae439e5035fc1e0e4c229dd
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Wed Feb 9 20:03:19 2022 -0600
ucounts: Enforce RLIMIT_NPROC not RLIMIT_NPROC+1
Michal Koutný <mkoutny@suse.com> wrote:
> It was reported that v5.14 behaves differently when enforcing
> RLIMIT_NPROC limit, namely, it allows one more task than previously.
> This is consequence of the commit 21d1c5e386 ("Reimplement
> RLIMIT_NPROC on top of ucounts") that missed the sharpness of
> equality in the forking path.
This can be fixed either by fixing the test or by moving the increment
to be before the test. Fix it my moving copy_creds which contains
the increment before is_ucounts_overlimit.
In the case of CLONE_NEWUSER the ucounts in the task_cred changes.
The function is_ucounts_overlimit needs to use the final version of
the ucounts for the new process. Which means moving the
is_ucounts_overlimit test after copy_creds is necessary.
Both the test in fork and the test in set_user were semantically
changed when the code moved to ucounts. The change of the test in
fork was bad because it was before the increment. The test in
set_user was wrong and the change to ucounts fixed it. So this
fix only restores the old behavior in one lcation not two.
Link: https://lkml.kernel.org/r/20220204181144.24462-1-mkoutny@suse.com
Link: https://lkml.kernel.org/r/20220216155832.680775-2-ebiederm@xmission.com
Cc: stable@vger.kernel.org
Reported-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Fixes: 21d1c5e386 ("Reimplement RLIMIT_NPROC on top of ucounts")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Alexey Gladkov <agladkov@redhat.com>
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/217
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2020279
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2029640
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1921343
Upstream Status: Linux
Tested: By me, with scheduler stress and sanity tests. Boot tested
on Alderlake for topology changes.
5.16+ scheduler fixes. This includes some commits requested by
the Livepatch team and some AlderLake topology changes. A few
additional patches were pulled in to make the rest apply. With
those and the dependency all patches apply cleanly.
v2: added 3 more commits from sched/urgent.
Added one last (hopefully) fix from sched/urgent.
Signed-off-by: Phil Auld <pauld@redhat.com>
RH-Acked-by: David Arcari <darcari@redhat.com>
RH-Acked-by: Rafael Aquini <aquini@redhat.com>
RH-Acked-by: Wander Lairson Costa <wander@redhat.com>
RH-Acked-by: Waiman Long <longman@redhat.com>
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2020279
commit 4ef0c5c6b5ba1f38f0ea1cedad0cad722f00c14a
Author: Zhang Qiao <zhangqiao22@huawei.com>
Date: Wed Sep 15 14:40:30 2021 +0800
kernel/sched: Fix sched_fork() access an invalid sched_task_group
There is a small race between copy_process() and sched_fork()
where child->sched_task_group point to an already freed pointer.
parent doing fork() | someone moving the parent
| to another cgroup
-------------------------------+-------------------------------
copy_process()
+ dup_task_struct()<1>
parent move to another cgroup,
and free the old cgroup. <2>
+ sched_fork()
+ __set_task_cpu()<3>
+ task_fork_fair()
+ sched_slice()<4>
In the worst case, this bug can lead to "use-after-free" and
cause panic as shown above:
(1) parent copy its sched_task_group to child at <1>;
(2) someone move the parent to another cgroup and free the old
cgroup at <2>;
(3) the sched_task_group and cfs_rq that belong to the old cgroup
will be accessed at <3> and <4>, which cause a panic:
[] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[] PGD 8000001fa0a86067 P4D 8000001fa0a86067 PUD 2029955067 PMD 0
[] Oops: 0000 [#1] SMP PTI
[] CPU: 7 PID: 648398 Comm: ebizzy Kdump: loaded Tainted: G OE --------- - - 4.18.0.x86_64+ #1
[] RIP: 0010:sched_slice+0x84/0xc0
[] Call Trace:
[] task_fork_fair+0x81/0x120
[] sched_fork+0x132/0x240
[] copy_process.part.5+0x675/0x20e0
[] ? __handle_mm_fault+0x63f/0x690
[] _do_fork+0xcd/0x3b0
[] do_syscall_64+0x5d/0x1d0
[] entry_SYSCALL_64_after_hwframe+0x65/0xca
[] RIP: 0033:0x7f04418cd7e1
Between cgroup_can_fork() and cgroup_post_fork(), the cgroup
membership and thus sched_task_group can't change. So update child's
sched_task_group at sched_post_fork() and move task_fork() and
__set_task_cpu() (where accees the sched_task_group) from sched_fork()
to sched_post_fork().
Fixes: 8323f26ce3 ("sched: Fix race in task_group")
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lkml.kernel.org/r/20210915064030.2231-1-zhangqiao22@huawei.com
Signed-off-by: Phil Auld <pauld@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2018403
commit 545c6647d2d9f3bf8a086d5ff47fb85e5c5dca28
Author: Christoph Hellwig <hch@lst.de>
Date: Mon Sep 20 14:33:17 2021 +0200
kernel: remove spurious blkdev.h includes
Various files have acquired spurious includes of <linux/blkdev.h> over
time. Remove them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit 13db8c50477d83ad3e3b9b0ae247e5cd833a7ae4
Author: Liu Zixian <liuzixian4@huawei.com>
Date: Wed Sep 8 18:10:05 2021 -0700
mm/hugetlb: initialize hugetlb_usage in mm_init
After fork, the child process will get incorrect (2x) hugetlb_usage. If
a process uses 5 2MB hugetlb pages in an anonymous mapping,
HugetlbPages: 10240 kB
and then forks, the child will show,
HugetlbPages: 20480 kB
The reason for double the amount is because hugetlb_usage will be copied
from the parent and then increased when we copy page tables from parent
to child. Child will have 2x actual usage.
Fix this by adding hugetlb_count_init in mm_init.
Link: https://lkml.kernel.org/r/20210826071742.877-1-liuzixian4@huawei.com
Fixes: 5d317b2b65 ("mm: hugetlb: proc: add HugetlbPages field to /proc/PID/status")
Signed-off-by: Liu Zixian <liuzixian4@huawei.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit 8d0920bde5eb8ec7e567939b85e65a0596c8580d
Author: David Hildenbrand <david@redhat.com>
Date: Thu Apr 22 12:08:20 2021 +0200
mm: remove VM_DENYWRITE
All in-tree users of MAP_DENYWRITE are gone. MAP_DENYWRITE cannot be
set from user space, so all users are gone; let's remove it.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit fe69d560b5bd9ec77b5d5749bd7027344daef47e
Author: David Hildenbrand <david@redhat.com>
Date: Fri Apr 23 10:29:59 2021 +0200
kernel/fork: always deny write access to current MM exe_file
We want to remove VM_DENYWRITE only currently only used when mapping the
executable during exec. During exec, we already deny_write_access() the
executable, however, after exec completes the VMAs mapped
with VM_DENYWRITE effectively keeps write access denied via
deny_write_access().
Let's deny write access when setting or replacing the MM exe_file. With
this change, we can remove VM_DENYWRITE for mapping executables.
Make set_mm_exe_file() return an error in case deny_write_access()
fails; note that this should never happen, because exec code does a
deny_write_access() early and keeps write access denied when calling
set_mm_exe_file. However, it makes the code easier to read and makes
set_mm_exe_file() and replace_mm_exe_file() look more similar.
This represents a minor user space visible change:
sys_prctl(PR_SET_MM_MAP/EXE_FILE) can now fail if the file is already
opened writable. Also, after sys_prctl(PR_SET_MM_MAP/EXE_FILE) the file
cannot be opened writable. Note that we can already fail with -EACCES if
the file doesn't have execute permissions.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit 35d7bdc86031a2c1ae05ac27dfa93b2acdcbaecc
Author: David Hildenbrand <david@redhat.com>
Date: Fri Apr 23 10:20:25 2021 +0200
kernel/fork: factor out replacing the current MM exe_file
Let's factor the main logic out into replace_mm_exe_file(), such that
all mm->exe_file logic is contained in kernel/fork.c.
While at it, perform some simple cleanups that are possible now that
we're simplifying the individual functions.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1992256
commit b90ca8badbd11488e5f762346b028666808164e7
Author: Will Deacon <will@kernel.org>
Date: Fri Jul 30 12:24:33 2021 +0100
sched: Introduce task_struct::user_cpus_ptr to track requested affinity
In preparation for saving and restoring the user-requested CPU affinity
mask of a task, add a new cpumask_t pointer to 'struct task_struct'.
If the pointer is non-NULL, then the mask is copied across fork() and
freed on task exit.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-7-will@kernel.org
Signed-off-by: Phil Auld <pauld@redhat.com>
"Ma, XinjianX" <xinjianx.ma@intel.com> reported:
> When lkp team run kernel selftests, we found after these series of patches, testcase mqueue: mq_perf_tests
> in kselftest failed with following message.
>
> # selftests: mqueue: mq_perf_tests
> #
> # Initial system state:
> # Using queue path: /mq_perf_tests
> # RLIMIT_MSGQUEUE(soft): 819200
> # RLIMIT_MSGQUEUE(hard): 819200
> # Maximum Message Size: 8192
> # Maximum Queue Size: 10
> # Nice value: 0
> #
> # Adjusted system state for testing:
> # RLIMIT_MSGQUEUE(soft): (unlimited)
> # RLIMIT_MSGQUEUE(hard): (unlimited)
> # Maximum Message Size: 16777216
> # Maximum Queue Size: 65530
> # Nice value: -20
> # Continuous mode: (disabled)
> # CPUs to pin: 3
> # ./mq_perf_tests: mq_open() at 296: Too many open files
> not ok 2 selftests: mqueue: mq_perf_tests # exit=1
> ```
>
> Test env:
> rootfs: debian-10
> gcc version: 9
After investigation the problem turned out to be that ucount_max for
the rlimits in init_user_ns was being set to the initial rlimit value.
The practical problem is that ucount_max provides a limit that
applications inside the user namespace can not exceed. Which means in
practice that rlimits that have been converted to use the ucount
infrastructure were not able to exceend their initial rlimits.
Solve this by setting the relevant values of ucount_max to
RLIM_INIFINITY. A limit in init_user_ns is pointless so the code
should allow the values to grow as large as possible without riscking
an underflow or an overflow.
As the ltp test case was a bit of a pain I have reproduced the rlimit failure
and tested the fix with the following little C program:
> #include <stdio.h>
> #include <fcntl.h>
> #include <sys/stat.h>
> #include <mqueue.h>
> #include <sys/time.h>
> #include <sys/resource.h>
> #include <errno.h>
> #include <string.h>
> #include <stdlib.h>
> #include <limits.h>
> #include <unistd.h>
>
> int main(int argc, char **argv)
> {
> struct mq_attr mq_attr;
> struct rlimit rlim;
> mqd_t mqd;
> int ret;
>
> ret = getrlimit(RLIMIT_MSGQUEUE, &rlim);
> if (ret != 0) {
> fprintf(stderr, "getrlimit(RLIMIT_MSGQUEUE) failed: %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
> printf("RLIMIT_MSGQUEUE %lu %lu\n",
> rlim.rlim_cur, rlim.rlim_max);
> rlim.rlim_cur = RLIM_INFINITY;
> rlim.rlim_max = RLIM_INFINITY;
> ret = setrlimit(RLIMIT_MSGQUEUE, &rlim);
> if (ret != 0) {
> fprintf(stderr, "setrlimit(RLIMIT_MSGQUEUE, RLIM_INFINITY) failed: %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
>
> memset(&mq_attr, 0, sizeof(struct mq_attr));
> mq_attr.mq_maxmsg = 65536 - 1;
> mq_attr.mq_msgsize = 16*1024*1024 - 1;
>
> mqd = mq_open("/mq_rlimit_test", O_RDONLY|O_CREAT, 0600, &mq_attr);
> if (mqd == (mqd_t)-1) {
> fprintf(stderr, "mq_open failed: %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
> ret = mq_close(mqd);
> if (ret) {
> fprintf(stderr, "mq_close failed; %s\n", strerror(errno));
> exit(EXIT_FAILURE);
> }
>
> return EXIT_SUCCESS;
> }
Fixes: 6e52a9f053 ("Reimplement RLIMIT_MSGQUEUE on top of ucounts")
Fixes: d7c9e99aee ("Reimplement RLIMIT_MEMLOCK on top of ucounts")
Fixes: d646969055 ("Reimplement RLIMIT_SIGPENDING on top of ucounts")
Fixes: 21d1c5e386 ("Reimplement RLIMIT_NPROC on top of ucounts")
Reported-by: kernel test robot lkp@intel.com
Acked-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/87eeajswfc.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Merge misc updates from Andrew Morton:
"191 patches.
Subsystems affected by this patch series: kthread, ia64, scripts,
ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
pagealloc, and memory-failure)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
mm,hwpoison: make get_hwpoison_page() call get_any_page()
mm,hwpoison: send SIGBUS with error virutal address
mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
docs: remove description of DISCONTIGMEM
arch, mm: remove stale mentions of DISCONIGMEM
mm: remove CONFIG_DISCONTIGMEM
m68k: remove support for DISCONTIGMEM
arc: remove support for DISCONTIGMEM
arc: update comment about HIGHMEM implementation
alpha: remove DISCONTIGMEM and NUMA
mm/page_alloc: move free_the_page
mm/page_alloc: fix counting of managed_pages
mm/page_alloc: improve memmap_pages dbg msg
mm: drop SECTION_SHIFT in code comments
mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
mm/page_alloc: scale the number of pages that are batch freed
...
has_pinned 32bit can be packed in the MMF_HAS_PINNED bit as a noop
cleanup.
Any atomic_inc/dec to the mm cacheline shared by all threads in pin-fast
would reintroduce a loss of SMP scalability to pin-fast, so there's no
future potential usefulness to keep an atomic in the mm for this.
set_bit(MMF_HAS_PINNED) will be theoretically a bit slower than WRITE_ONCE
(atomic_set is equivalent to WRITE_ONCE), but the set_bit (just like
atomic_set after this commit) has to be still issued only once per "mm",
so the difference between the two will be lost in the noise.
will-it-scale "mmap2" shows no change in performance with enterprise
config as expected.
will-it-scale "pin_fast" retains the > 4000% SMP scalability performance
improvement against upstream as expected.
This is a noop as far as overall performance and SMP scalability are
concerned.
[peterx@redhat.com: pack has_pinned in MMF_HAS_PINNED]
Link: https://lkml.kernel.org/r/YJqWESqyxa8OZA+2@t490s
[akpm@linux-foundation.org: coding style fixes]
[peterx@redhat.com: fix build for task_mmu.c, introduce mm_set_has_pinned_flag, fix comments]
Link: https://lkml.kernel.org/r/20210507150553.208763-4-peterx@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull user namespace rlimit handling update from Eric Biederman:
"This is the work mainly by Alexey Gladkov to limit rlimits to the
rlimits of the user that created a user namespace, and to allow users
to have stricter limits on the resources created within a user
namespace."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
cred: add missing return error code when set_cred_ucounts() failed
ucounts: Silence warning in dec_rlimit_ucounts
ucounts: Set ucount_max to the largest positive value the type can hold
kselftests: Add test to check for rlimit changes in different user namespaces
Reimplement RLIMIT_MEMLOCK on top of ucounts
Reimplement RLIMIT_SIGPENDING on top of ucounts
Reimplement RLIMIT_MSGQUEUE on top of ucounts
Reimplement RLIMIT_NPROC on top of ucounts
Use atomic_t for ucounts reference counting
Add a reference to ucounts for each cred
Increase size of ucounts to atomic_long_t
- Changes to core scheduling facilities:
- Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
coordinated scheduling across SMT siblings. This is a much
requested feature for cloud computing platforms, to allow
the flexible utilization of SMT siblings, without exposing
untrusted domains to information leaks & side channels, plus
to ensure more deterministic computing performance on SMT
systems used by heterogenous workloads.
There's new prctls to set core scheduling groups, which
allows more flexible management of workloads that can share
siblings.
- Fix task->state access anti-patterns that may result in missed
wakeups and rename it to ->__state in the process to catch new
abuses.
- Load-balancing changes:
- Tweak newidle_balance for fair-sched, to improve
'memcache'-like workloads.
- "Age" (decay) average idle time, to better track & improve workloads
such as 'tbench'.
- Fix & improve energy-aware (EAS) balancing logic & metrics.
- Fix & improve the uclamp metrics.
- Fix task migration (taskset) corner case on !CONFIG_CPUSET.
- Fix RT and deadline utilization tracking across policy changes
- Introduce a "burstable" CFS controller via cgroups, which allows
bursty CPU-bound workloads to borrow a bit against their future
quota to improve overall latencies & batching. Can be tweaked
via /sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us.
- Rework assymetric topology/capacity detection & handling.
- Scheduler statistics & tooling:
- Disable delayacct by default, but add a sysctl to enable
it at runtime if tooling needs it. Use static keys and
other optimizations to make it more palatable.
- Use sched_clock() in delayacct, instead of ktime_get_ns().
- Misc cleanups and fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler udpates from Ingo Molnar:
- Changes to core scheduling facilities:
- Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
coordinated scheduling across SMT siblings. This is a much
requested feature for cloud computing platforms, to allow the
flexible utilization of SMT siblings, without exposing untrusted
domains to information leaks & side channels, plus to ensure more
deterministic computing performance on SMT systems used by
heterogenous workloads.
There are new prctls to set core scheduling groups, which allows
more flexible management of workloads that can share siblings.
- Fix task->state access anti-patterns that may result in missed
wakeups and rename it to ->__state in the process to catch new
abuses.
- Load-balancing changes:
- Tweak newidle_balance for fair-sched, to improve 'memcache'-like
workloads.
- "Age" (decay) average idle time, to better track & improve
workloads such as 'tbench'.
- Fix & improve energy-aware (EAS) balancing logic & metrics.
- Fix & improve the uclamp metrics.
- Fix task migration (taskset) corner case on !CONFIG_CPUSET.
- Fix RT and deadline utilization tracking across policy changes
- Introduce a "burstable" CFS controller via cgroups, which allows
bursty CPU-bound workloads to borrow a bit against their future
quota to improve overall latencies & batching. Can be tweaked via
/sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us.
- Rework assymetric topology/capacity detection & handling.
- Scheduler statistics & tooling:
- Disable delayacct by default, but add a sysctl to enable it at
runtime if tooling needs it. Use static keys and other
optimizations to make it more palatable.
- Use sched_clock() in delayacct, instead of ktime_get_ns().
- Misc cleanups and fixes.
* tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
sched/doc: Update the CPU capacity asymmetry bits
sched/topology: Rework CPU capacity asymmetry detection
sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag
psi: Fix race between psi_trigger_create/destroy
sched/fair: Introduce the burstable CFS controller
sched/uclamp: Fix uclamp_tg_restrict()
sched/rt: Fix Deadline utilization tracking during policy change
sched/rt: Fix RT utilization tracking during policy change
sched: Change task_struct::state
sched,arch: Remove unused TASK_STATE offsets
sched,timer: Use __set_current_state()
sched: Add get_current_state()
sched,perf,kvm: Fix preemption condition
sched: Introduce task_is_running()
sched: Unbreak wakeups
sched/fair: Age the average idle time
sched/cpufreq: Consider reduced CPU capacity in energy calculation
sched/fair: Take thermal pressure into account while estimating energy
thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure
sched/fair: Return early from update_tg_cfs_load() if delta == 0
...
This reverts commits 4bad58ebc8 (and
399f8dd9a8, which tried to fix it).
I do not believe these are correct, and I'm about to release 5.13, so am
reverting them out of an abundance of caution.
The locking is odd, and appears broken.
On the allocation side (in __sigqueue_alloc()), the locking is somewhat
straightforward: it depends on sighand->siglock. Since one caller
doesn't hold that lock, it further then tests 'sigqueue_flags' to avoid
the case with no locks held.
On the freeing side (in sigqueue_cache_or_free()), there is no locking
at all, and the logic instead depends on 'current' being a single
thread, and not able to race with itself.
To make things more exciting, there's also the data race between freeing
a signal and allocating one, which is handled by using WRITE_ONCE() and
READ_ONCE(), and being mutually exclusive wrt the initial state (ie
freeing will only free if the old state was NULL, while allocating will
obviously only use the value if it was non-NULL, so only one or the
other will actually act on the value).
However, while the free->alloc paths do seem mutually exclusive thanks
to just the data value dependency, it's not clear what the memory
ordering constraints are on it. Could writes from the previous
allocation possibly be delayed and seen by the new allocation later,
causing logical inconsistencies?
So it's all very exciting and unusual.
And in particular, it seems that the freeing side is incorrect in
depending on "current" being single-threaded. Yes, 'current' is a
single thread, but in the presense of asynchronous events even a single
thread can have data races.
And such asynchronous events can and do happen, with interrupts causing
signals to be flushed and thus free'd (for example - sending a
SIGCONT/SIGSTOP can happen from interrupt context, and can flush
previously queued process control signals).
So regardless of all the other questions about the memory ordering and
locking for this new cached allocation, the sigqueue_cache_or_free()
assumptions seem to be fundamentally incorrect.
It may be that people will show me the errors of my ways, and tell me
why this is all safe after all. We can reinstate it if so. But my
current belief is that the WRITE_ONCE() that sets the cached entry needs
to be a smp_store_release(), and the READ_ONCE() that finds a cached
entry needs to be a smp_load_acquire() to handle memory ordering
correctly.
And the sequence in sigqueue_cache_or_free() would need to either use a
lock or at least be interrupt-safe some way (perhaps by using something
like the percpu 'cmpxchg': it doesn't need to be SMP-safe, but like the
percpu operations it needs to be interrupt-safe).
Fixes: 399f8dd9a8 ("signal: Prevent sigqueue caching after task got released")
Fixes: 4bad58ebc8 ("signal: Allow tasks to cache one sigqueue struct")
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the type and name of task_struct::state. Drop the volatile and
shrink it to an 'unsigned int'. Rename it in order to find all uses
such that we can use READ_ONCE/WRITE_ONCE as appropriate.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
Commit:
00b89fe019 ("sched: Make the idle task quack like a per-CPU kthread")
... added PF_KTHREAD | PF_NO_SETAFFINITY to the idle kernel threads.
Unfortunately these properties are inherited to the init/0 children
through kernel_thread() calls: init/1 and kthreadd. There are several
side effects to that:
1) kthreadd affinity can not be reset anymore from userspace. Also
PF_NO_SETAFFINITY propagates to all kthreadd children, including
the unbound kthreads Therefore it's not possible anymore to overwrite
the affinity of any of them. Here is an example of warning reported
by rcutorture:
WARNING: CPU: 0 PID: 116 at kernel/rcu/tree_nocb.h:1306 rcu_bind_current_to_nocb+0x31/0x40
Call Trace:
rcu_torture_fwd_prog+0x62/0x730
kthread+0x122/0x140
ret_from_fork+0x22/0x30
2) init/1 does an exec() in the end which clears both
PF_KTHREAD and PF_NO_SETAFFINITY so we are fine once kernel_init()
escapes to userspace. But until then, no initcall or init code can
successfully call sched_setaffinity() to init/1.
Also PF_KTHREAD looks legit on init/1 before it calls exec() but
we better be careful with unknown introduced side effects.
One way to solve the PF_NO_SETAFFINITY issue is to not inherit this flag
on copy_process() at all. The cases where it matters are:
* fork_idle(): explicitly set the flag already.
* fork() syscalls: userspace tasks that shouldn't be concerned by that.
* create_io_thread(): the callers explicitly attribute the flag to the
newly created tasks.
* kernel_thread():
- Fix the issues on init/1 and kthreadd
- Fix the issues on kthreadd children.
- Usermode helper created by an unbound workqueue. This shouldn't
matter. In the worst case it gives more control to userspace
on setting affinity to these short living tasks although this can
be tuned with inherited unbound workqueues affinity already.
Fixes: 00b89fe019 ("sched: Make the idle task quack like a per-CPU kthread")
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20210525235849.441842-1-frederic@kernel.org
As pointed out by commit
de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")
init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.
As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().
Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().
Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().
Secondary startups were patched via coccinelle:
@begone@
@@
-preempt_disable();
...
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Note that sched_core_fork() is called from under tasklist_lock, and
not from sched_fork() earlier. This avoids a few races later.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Don Hiatt <dhiatt@digitalocean.com>
Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210422123308.980003687@infradead.org
In order to not have to use pid_struct, create a new, smaller,
structure to manage task cookies for core scheduling.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Don Hiatt <dhiatt@digitalocean.com>
Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210422123308.919768100@infradead.org
All this can happen without a single goto.
Link: https://lkml.kernel.org/r/2072685.XptgVkyDqn@devpool47
Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ns->ucount_max[] is signed long which is less than the rlimit size.
We have to protect ucount_max[] from overflow and only use the largest
value that we can hold.
On 32bit using "long" instead of "unsigned long" to hold the counts has
the downside that RLIMIT_MSGQUEUE and RLIMIT_MEMLOCK are limited to 2GiB
instead of 4GiB. I don't think anyone cares but it should be mentioned
in case someone does.
The RLIMIT_NPROC and RLIMIT_SIGPENDING used atomic_t so their maximum
hasn't changed.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/1825a5dfa18bc5a570e79feb05e2bd07fd57e7e3.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The rlimit counter is tied to uid in the user_namespace. This allows
rlimit values to be specified in userns even if they are already
globally exceeded by the user. However, the value of the previous
user_namespaces cannot be exceeded.
Changelog
v11:
* Fix issue found by lkp robot.
v8:
* Fix issues found by lkp-tests project.
v7:
* Keep only ucounts for RLIMIT_MEMLOCK checks instead of struct cred.
v6:
* Fix bug in hugetlb_file_setup() detected by trinity.
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/970d50c70c71bfd4496e0e8d2a0a32feebebb350.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The rlimit counter is tied to uid in the user_namespace. This allows
rlimit values to be specified in userns even if they are already
globally exceeded by the user. However, the value of the previous
user_namespaces cannot be exceeded.
Changelog
v11:
* Revert most of changes to fix performance issues.
v10:
* Fix memory leak on get_ucounts failure.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/df9d7764dddd50f28616b7840de74ec0f81711a8.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The rlimit counter is tied to uid in the user_namespace. This allows
rlimit values to be specified in userns even if they are already
globally exceeded by the user. However, the value of the previous
user_namespaces cannot be exceeded.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/2531f42f7884bbfee56a978040b3e0d25cdf6cde.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The rlimit counter is tied to uid in the user_namespace. This allows
rlimit values to be specified in userns even if they are already
globally exceeded by the user. However, the value of the previous
user_namespaces cannot be exceeded.
To illustrate the impact of rlimits, let's say there is a program that
does not fork. Some service-A wants to run this program as user X in
multiple containers. Since the program never fork the service wants to
set RLIMIT_NPROC=1.
service-A
\- program (uid=1000, container1, rlimit_nproc=1)
\- program (uid=1000, container2, rlimit_nproc=1)
The service-A sets RLIMIT_NPROC=1 and runs the program in container1.
When the service-A tries to run a program with RLIMIT_NPROC=1 in
container2 it fails since user X already has one running process.
We cannot use existing inc_ucounts / dec_ucounts because they do not
allow us to exceed the maximum for the counter. Some rlimits can be
overlimited by root or if the user has the appropriate capability.
Changelog
v11:
* Change inc_rlimit_ucounts() which now returns top value of ucounts.
* Drop inc_rlimit_ucounts_and_test() because the return code of
inc_rlimit_ucounts() can be checked.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/c5286a8aa16d2d698c222f7532f3d735c82bc6bc.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
For RLIMIT_NPROC and some other rlimits the user_struct that holds the
global limit is kept alive for the lifetime of a process by keeping it
in struct cred. Adding a pointer to ucounts in the struct cred will
allow to track RLIMIT_NPROC not only for user in the system, but for
user in the user_namespace.
Updating ucounts may require memory allocation which may fail. So, we
cannot change cred.ucounts in the commit_creds() because this function
cannot fail and it should always return 0. For this reason, we modify
cred.ucounts before calling the commit_creds().
Changelog
v6:
* Fix null-ptr-deref in is_ucounts_overlimit() detected by trinity. This
error was caused by the fact that cred_alloc_blank() left the ucounts
pointer empty.
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/b37aaef28d8b9b0d757e07ba6dd27281bbe39259.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
For simplification commit 991e767385 ("mm: memcontrol: account kernel
stack per node") changed the per zone vmalloc backed stack pages
accounting to per node.
By doing that we have lost a certain precision because those pages might
live in different NUMA nodes. In the end NR_KERNEL_STACK_KB exported to
the userspace might be over estimated on some nodes while underestimated
on others. But this is not a real world problem, just a problem found
by reading the code. So there is no actual data to showing how much
impact it has on users.
This doesn't impose any real problem to correctnes of the kernel
behavior as the counter is not used for any internal processing but it
can cause some confusion to the userspace.
Address the problem by accounting each vmalloc backing page to its own
node.
Link: https://lkml.kernel.org/r/20210303151843.81156-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Core:
- bpf:
- allow bpf programs calling kernel functions (initially to
reuse TCP congestion control implementations)
- enable task local storage for tracing programs - remove the
need to store per-task state in hash maps, and allow tracing
programs access to task local storage previously added for
BPF_LSM
- add bpf_for_each_map_elem() helper, allowing programs to
walk all map elements in a more robust and easier to verify
fashion
- sockmap: support UDP and cross-protocol BPF_SK_SKB_VERDICT
redirection
- lpm: add support for batched ops in LPM trie
- add BTF_KIND_FLOAT support - mostly to allow use of BTF
on s390 which has floats in its headers files
- improve BPF syscall documentation and extend the use of kdoc
parsing scripts we already employ for bpf-helpers
- libbpf, bpftool: support static linking of BPF ELF files
- improve support for encapsulation of L2 packets
- xdp: restructure redirect actions to avoid a runtime lookup,
improving performance by 4-8% in microbenchmarks
- xsk: build skb by page (aka generic zerocopy xmit) - improve
performance of software AF_XDP path by 33% for devices
which don't need headers in the linear skb part (e.g. virtio)
- nexthop: resilient next-hop groups - improve path stability
on next-hops group changes (incl. offload for mlxsw)
- ipv6: segment routing: add support for IPv4 decapsulation
- icmp: add support for RFC 8335 extended PROBE messages
- inet: use bigger hash table for IP ID generation
- tcp: deal better with delayed TX completions - make sure we don't
give up on fast TCP retransmissions only because driver is
slow in reporting that it completed transmitting the original
- tcp: reorder tcp_congestion_ops for better cache locality
- mptcp:
- add sockopt support for common TCP options
- add support for common TCP msg flags
- include multiple address ids in RM_ADDR
- add reset option support for resetting one subflow
- udp: GRO L4 improvements - improve 'forward' / 'frag_list'
co-existence with UDP tunnel GRO, allowing the first to take
place correctly even for encapsulated UDP traffic
- micro-optimize dev_gro_receive() and flow dissection, avoid
retpoline overhead on VLAN and TEB GRO
- use less memory for sysctls, add a new sysctl type, to allow using
u8 instead of "int" and "long" and shrink networking sysctls
- veth: allow GRO without XDP - this allows aggregating UDP
packets before handing them off to routing, bridge, OvS, etc.
- allow specifing ifindex when device is moved to another namespace
- netfilter:
- nft_socket: add support for cgroupsv2
- nftables: add catch-all set element - special element used
to define a default action in case normal lookup missed
- use net_generic infra in many modules to avoid allocating
per-ns memory unnecessarily
- xps: improve the xps handling to avoid potential out-of-bound
accesses and use-after-free when XPS change race with other
re-configuration under traffic
- add a config knob to turn off per-cpu netdev refcnt to catch
underflows in testing
Device APIs:
- add WWAN subsystem to organize the WWAN interfaces better and
hopefully start driving towards more unified and vendor-
-independent APIs
- ethtool:
- add interface for reading IEEE MIB stats (incl. mlx5 and
bnxt support)
- allow network drivers to dump arbitrary SFP EEPROM data,
current offset+length API was a poor fit for modern SFP
which define EEPROM in terms of pages (incl. mlx5 support)
- act_police, flow_offload: add support for packet-per-second
policing (incl. offload for nfp)
- psample: add additional metadata attributes like transit delay
for packets sampled from switch HW (and corresponding egress
and policy-based sampling in the mlxsw driver)
- dsa: improve support for sandwiched LAGs with bridge and DSA
- netfilter:
- flowtable: use direct xmit in topologies with IP
forwarding, bridging, vlans etc.
- nftables: counter hardware offload support
- Bluetooth:
- improvements for firmware download w/ Intel devices
- add support for reading AOSP vendor capabilities
- add support for virtio transport driver
- mac80211:
- allow concurrent monitor iface and ethernet rx decap
- set priority and queue mapping for injected frames
- phy: add support for Clause-45 PHY Loopback
- pci/iov: add sysfs MSI-X vector assignment interface
to distribute MSI-X resources to VFs (incl. mlx5 support)
New hardware/drivers:
- dsa: mv88e6xxx: add support for Marvell mv88e6393x -
11-port Ethernet switch with 8x 1-Gigabit Ethernet
and 3x 10-Gigabit interfaces.
- dsa: support for legacy Broadcom tags used on BCM5325, BCM5365
and BCM63xx switches
- Microchip KSZ8863 and KSZ8873; 3x 10/100Mbps Ethernet switches
- ath11k: support for QCN9074 a 802.11ax device
- Bluetooth: Broadcom BCM4330 and BMC4334
- phy: Marvell 88X2222 transceiver support
- mdio: add BCM6368 MDIO mux bus controller
- r8152: support RTL8153 and RTL8156 (USB Ethernet) chips
- mana: driver for Microsoft Azure Network Adapter (MANA)
- Actions Semi Owl Ethernet MAC
- can: driver for ETAS ES58X CAN/USB interfaces
Pure driver changes:
- add XDP support to: enetc, igc, stmmac
- add AF_XDP support to: stmmac
- virtio:
- page_to_skb() use build_skb when there's sufficient tailroom
(21% improvement for 1000B UDP frames)
- support XDP even without dedicated Tx queues - share the Tx
queues with the stack when necessary
- mlx5:
- flow rules: add support for mirroring with conntrack,
matching on ICMP, GTP, flex filters and more
- support packet sampling with flow offloads
- persist uplink representor netdev across eswitch mode
changes
- allow coexistence of CQE compression and HW time-stamping
- add ethtool extended link error state reporting
- ice, iavf: support flow filters, UDP Segmentation Offload
- dpaa2-switch:
- move the driver out of staging
- add spanning tree (STP) support
- add rx copybreak support
- add tc flower hardware offload on ingress traffic
- ionic:
- implement Rx page reuse
- support HW PTP time-stamping
- octeon: support TC hardware offloads - flower matching on ingress
and egress ratelimitting.
- stmmac:
- add RX frame steering based on VLAN priority in tc flower
- support frame preemption (FPE)
- intel: add cross time-stamping freq difference adjustment
- ocelot:
- support forwarding of MRP frames in HW
- support multiple bridges
- support PTP Sync one-step timestamping
- dsa: mv88e6xxx, dpaa2-switch: offload bridge port flags like
learning, flooding etc.
- ipa: add IPA v4.5, v4.9 and v4.11 support (Qualcomm SDX55, SM8350,
SC7280 SoCs)
- mt7601u: enable TDLS support
- mt76:
- add support for 802.3 rx frames (mt7915/mt7615)
- mt7915 flash pre-calibration support
- mt7921/mt7663 runtime power management fixes
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core:
- bpf:
- allow bpf programs calling kernel functions (initially to
reuse TCP congestion control implementations)
- enable task local storage for tracing programs - remove the
need to store per-task state in hash maps, and allow tracing
programs access to task local storage previously added for
BPF_LSM
- add bpf_for_each_map_elem() helper, allowing programs to walk
all map elements in a more robust and easier to verify fashion
- sockmap: support UDP and cross-protocol BPF_SK_SKB_VERDICT
redirection
- lpm: add support for batched ops in LPM trie
- add BTF_KIND_FLOAT support - mostly to allow use of BTF on
s390 which has floats in its headers files
- improve BPF syscall documentation and extend the use of kdoc
parsing scripts we already employ for bpf-helpers
- libbpf, bpftool: support static linking of BPF ELF files
- improve support for encapsulation of L2 packets
- xdp: restructure redirect actions to avoid a runtime lookup,
improving performance by 4-8% in microbenchmarks
- xsk: build skb by page (aka generic zerocopy xmit) - improve
performance of software AF_XDP path by 33% for devices which don't
need headers in the linear skb part (e.g. virtio)
- nexthop: resilient next-hop groups - improve path stability on
next-hops group changes (incl. offload for mlxsw)
- ipv6: segment routing: add support for IPv4 decapsulation
- icmp: add support for RFC 8335 extended PROBE messages
- inet: use bigger hash table for IP ID generation
- tcp: deal better with delayed TX completions - make sure we don't
give up on fast TCP retransmissions only because driver is slow in
reporting that it completed transmitting the original
- tcp: reorder tcp_congestion_ops for better cache locality
- mptcp:
- add sockopt support for common TCP options
- add support for common TCP msg flags
- include multiple address ids in RM_ADDR
- add reset option support for resetting one subflow
- udp: GRO L4 improvements - improve 'forward' / 'frag_list'
co-existence with UDP tunnel GRO, allowing the first to take place
correctly even for encapsulated UDP traffic
- micro-optimize dev_gro_receive() and flow dissection, avoid
retpoline overhead on VLAN and TEB GRO
- use less memory for sysctls, add a new sysctl type, to allow using
u8 instead of "int" and "long" and shrink networking sysctls
- veth: allow GRO without XDP - this allows aggregating UDP packets
before handing them off to routing, bridge, OvS, etc.
- allow specifing ifindex when device is moved to another namespace
- netfilter:
- nft_socket: add support for cgroupsv2
- nftables: add catch-all set element - special element used to
define a default action in case normal lookup missed
- use net_generic infra in many modules to avoid allocating
per-ns memory unnecessarily
- xps: improve the xps handling to avoid potential out-of-bound
accesses and use-after-free when XPS change race with other
re-configuration under traffic
- add a config knob to turn off per-cpu netdev refcnt to catch
underflows in testing
Device APIs:
- add WWAN subsystem to organize the WWAN interfaces better and
hopefully start driving towards more unified and vendor-
independent APIs
- ethtool:
- add interface for reading IEEE MIB stats (incl. mlx5 and bnxt
support)
- allow network drivers to dump arbitrary SFP EEPROM data,
current offset+length API was a poor fit for modern SFP which
define EEPROM in terms of pages (incl. mlx5 support)
- act_police, flow_offload: add support for packet-per-second
policing (incl. offload for nfp)
- psample: add additional metadata attributes like transit delay for
packets sampled from switch HW (and corresponding egress and
policy-based sampling in the mlxsw driver)
- dsa: improve support for sandwiched LAGs with bridge and DSA
- netfilter:
- flowtable: use direct xmit in topologies with IP forwarding,
bridging, vlans etc.
- nftables: counter hardware offload support
- Bluetooth:
- improvements for firmware download w/ Intel devices
- add support for reading AOSP vendor capabilities
- add support for virtio transport driver
- mac80211:
- allow concurrent monitor iface and ethernet rx decap
- set priority and queue mapping for injected frames
- phy: add support for Clause-45 PHY Loopback
- pci/iov: add sysfs MSI-X vector assignment interface to distribute
MSI-X resources to VFs (incl. mlx5 support)
New hardware/drivers:
- dsa: mv88e6xxx: add support for Marvell mv88e6393x - 11-port
Ethernet switch with 8x 1-Gigabit Ethernet and 3x 10-Gigabit
interfaces.
- dsa: support for legacy Broadcom tags used on BCM5325, BCM5365 and
BCM63xx switches
- Microchip KSZ8863 and KSZ8873; 3x 10/100Mbps Ethernet switches
- ath11k: support for QCN9074 a 802.11ax device
- Bluetooth: Broadcom BCM4330 and BMC4334
- phy: Marvell 88X2222 transceiver support
- mdio: add BCM6368 MDIO mux bus controller
- r8152: support RTL8153 and RTL8156 (USB Ethernet) chips
- mana: driver for Microsoft Azure Network Adapter (MANA)
- Actions Semi Owl Ethernet MAC
- can: driver for ETAS ES58X CAN/USB interfaces
Pure driver changes:
- add XDP support to: enetc, igc, stmmac
- add AF_XDP support to: stmmac
- virtio:
- page_to_skb() use build_skb when there's sufficient tailroom
(21% improvement for 1000B UDP frames)
- support XDP even without dedicated Tx queues - share the Tx
queues with the stack when necessary
- mlx5:
- flow rules: add support for mirroring with conntrack, matching
on ICMP, GTP, flex filters and more
- support packet sampling with flow offloads
- persist uplink representor netdev across eswitch mode changes
- allow coexistence of CQE compression and HW time-stamping
- add ethtool extended link error state reporting
- ice, iavf: support flow filters, UDP Segmentation Offload
- dpaa2-switch:
- move the driver out of staging
- add spanning tree (STP) support
- add rx copybreak support
- add tc flower hardware offload on ingress traffic
- ionic:
- implement Rx page reuse
- support HW PTP time-stamping
- octeon: support TC hardware offloads - flower matching on ingress
and egress ratelimitting.
- stmmac:
- add RX frame steering based on VLAN priority in tc flower
- support frame preemption (FPE)
- intel: add cross time-stamping freq difference adjustment
- ocelot:
- support forwarding of MRP frames in HW
- support multiple bridges
- support PTP Sync one-step timestamping
- dsa: mv88e6xxx, dpaa2-switch: offload bridge port flags like
learning, flooding etc.
- ipa: add IPA v4.5, v4.9 and v4.11 support (Qualcomm SDX55, SM8350,
SC7280 SoCs)
- mt7601u: enable TDLS support
- mt76:
- add support for 802.3 rx frames (mt7915/mt7615)
- mt7915 flash pre-calibration support
- mt7921/mt7663 runtime power management fixes"
* tag 'net-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2451 commits)
net: selftest: fix build issue if INET is disabled
net: netrom: nr_in: Remove redundant assignment to ns
net: tun: Remove redundant assignment to ret
net: phy: marvell: add downshift support for M88E1240
net: dsa: ksz: Make reg_mib_cnt a u8 as it never exceeds 255
net/sched: act_ct: Remove redundant ct get and check
icmp: standardize naming of RFC 8335 PROBE constants
bpf, selftests: Update array map tests for per-cpu batched ops
bpf: Add batched ops support for percpu array
bpf: Implement formatted output helpers with bstr_printf
seq_file: Add a seq_bprintf function
sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues
net:nfc:digital: Fix a double free in digital_tg_recv_dep_req
net: fix a concurrency bug in l2tp_tunnel_register()
net/smc: Remove redundant assignment to rc
mpls: Remove redundant assignment to err
llc2: Remove redundant assignment to rc
net/tls: Remove redundant initialization of record
rds: Remove redundant assignment to nr_sig
dt-bindings: net: mdio-gpio: add compatible for microchip,mdio-smi0
...
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Merge tag 'for-5.13/io_uring-2021-04-27' of git://git.kernel.dk/linux-block
Pull io_uring updates from Jens Axboe:
- Support for multi-shot mode for POLL requests
- More efficient reference counting. This is shamelessly stolen from
the mm side. Even though referencing is mostly single/dual user, the
128 count was retained to keep the code the same. Maybe this
should/could be made generic at some point.
- Removal of the need to have a manager thread for each ring. The
manager threads only job was checking and creating new io-threads as
needed, instead we handle this from the queue path.
- Allow SQPOLL without CAP_SYS_ADMIN or CAP_SYS_NICE. Since 5.12, this
thread is "just" a regular application thread, so no need to restrict
use of it anymore.
- Cleanup of how internal async poll data lifetime is managed.
- Fix for syzbot reported crash on SQPOLL cancelation.
- Make buffer registration more like file registrations, which includes
flexibility in avoiding full set unregistration and re-registration.
- Fix for io-wq affinity setting.
- Be a bit more defensive in task->pf_io_worker setup.
- Various SQPOLL fixes.
- Cleanup of SQPOLL creds handling.
- Improvements to in-flight request tracking.
- File registration cleanups.
- Tons of cleanups and little fixes
* tag 'for-5.13/io_uring-2021-04-27' of git://git.kernel.dk/linux-block: (156 commits)
io_uring: maintain drain logic for multishot poll requests
io_uring: Check current->io_uring in io_uring_cancel_sqpoll
io_uring: fix NULL reg-buffer
io_uring: simplify SQPOLL cancellations
io_uring: fix work_exit sqpoll cancellations
io_uring: Fix uninitialized variable up.resv
io_uring: fix invalid error check after malloc
io_uring: io_sq_thread() no longer needs to reset current->pf_io_worker
kernel: always initialize task->pf_io_worker to NULL
io_uring: update sq_thread_idle after ctx deleted
io_uring: add full-fledged dynamic buffers support
io_uring: implement fixed buffers registration similar to fixed files
io_uring: prepare fixed rw for dynanic buffers
io_uring: keep table of pointers to ubufs
io_uring: add generic rsrc update with tags
io_uring: add IORING_REGISTER_RSRC
io_uring: enumerate dynamic resources
io_uring: add generic path for rsrc update
io_uring: preparation for rsrc tagging
io_uring: decouple CQE filling from requests
...
- Clean up SCHED_DEBUG: move the decades old mess of sysctl, procfs and debugfs interfaces
to a unified debugfs interface.
- Signals: Allow caching one sigqueue object per task, to improve performance & latencies.
- Improve newidle_balance() irq-off latencies on systems with a large number of CPU cgroups.
- Improve energy-aware scheduling
- Improve the PELT metrics for certain workloads
- Reintroduce select_idle_smt() to improve load-balancing locality - but without the previous
regressions
- Add 'scheduler latency debugging': warn after long periods of pending need_resched. This
is an opt-in feature that requires the enabling of the LATENCY_WARN scheduler feature,
or the use of the resched_latency_warn_ms=xx boot parameter.
- CPU hotplug fixes for HP-rollback, and for the 'fail' interface. Fix remaining
balance_push() vs. hotplug holes/races
- PSI fixes, plus allow /proc/pressure/ files to be written by CAP_SYS_RESOURCE tasks as well
- Fix/improve various load-balancing corner cases vs. capacity margins
- Fix sched topology on systems with NUMA diameter of 3 or above
- Fix PF_KTHREAD vs to_kthread() race
- Minor rseq optimizations
- Misc cleanups, optimizations, fixes and smaller updates
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Clean up SCHED_DEBUG: move the decades old mess of sysctl, procfs and
debugfs interfaces to a unified debugfs interface.
- Signals: Allow caching one sigqueue object per task, to improve
performance & latencies.
- Improve newidle_balance() irq-off latencies on systems with a large
number of CPU cgroups.
- Improve energy-aware scheduling
- Improve the PELT metrics for certain workloads
- Reintroduce select_idle_smt() to improve load-balancing locality -
but without the previous regressions
- Add 'scheduler latency debugging': warn after long periods of pending
need_resched. This is an opt-in feature that requires the enabling of
the LATENCY_WARN scheduler feature, or the use of the
resched_latency_warn_ms=xx boot parameter.
- CPU hotplug fixes for HP-rollback, and for the 'fail' interface. Fix
remaining balance_push() vs. hotplug holes/races
- PSI fixes, plus allow /proc/pressure/ files to be written by
CAP_SYS_RESOURCE tasks as well
- Fix/improve various load-balancing corner cases vs. capacity margins
- Fix sched topology on systems with NUMA diameter of 3 or above
- Fix PF_KTHREAD vs to_kthread() race
- Minor rseq optimizations
- Misc cleanups, optimizations, fixes and smaller updates
* tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
cpumask/hotplug: Fix cpu_dying() state tracking
kthread: Fix PF_KTHREAD vs to_kthread() race
sched/debug: Fix cgroup_path[] serialization
sched,psi: Handle potential task count underflow bugs more gracefully
sched: Warn on long periods of pending need_resched
sched/fair: Move update_nohz_stats() to the CONFIG_NO_HZ_COMMON block to simplify the code & fix an unused function warning
sched/debug: Rename the sched_debug parameter to sched_verbose
sched,fair: Alternative sched_slice()
sched: Move /proc/sched_debug to debugfs
sched,debug: Convert sysctl sched_domains to debugfs
debugfs: Implement debugfs_create_str()
sched,preempt: Move preempt_dynamic to debug.c
sched: Move SCHED_DEBUG sysctl to debugfs
sched: Don't make LATENCYTOP select SCHED_DEBUG
sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG
sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG
sched: Use cpu_dying() to fix balance_push vs hotplug-rollback
cpumask: Introduce DYING mask
cpumask: Make cpu_{online,possible,present,active}() inline
rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs()
...
- Improve Intel uncore PMU support:
- Parse uncore 'discovery tables' - a new hardware capability enumeration method
introduced on the latest Intel platforms. This table is in a well-defined PCI
namespace location and is read via MMIO. It is organized in an rbtree.
These uncore tables will allow the discovery of standard counter blocks, but
fancier counters still need to be enumerated explicitly.
- Add Alder Lake support
- Improve IIO stacks to PMON mapping support on Skylake servers
- Add Intel Alder Lake PMU support - which requires the introduction of 'hybrid' CPUs
and PMUs. Alder Lake is a mix of Golden Cove ('big') and Gracemont ('small' - Atom derived)
cores.
The CPU-side feature set is entirely symmetrical - but on the PMU side there's
core type dependent PMU functionality.
- Reduce data loss with CPU level hardware tracing on Intel PT / AUX profiling, by
fixing the AUX allocation watermark logic.
- Improve ring buffer allocation on NUMA systems
- Put 'struct perf_event' into their separate kmem_cache pool
- Add support for synchronous signals for select perf events. The immediate motivation
is to support low-overhead sampling-based race detection for user-space code. The
feature consists of the following main changes:
- Add thread-only event inheritance via perf_event_attr::inherit_thread, which limits
inheritance of events to CLONE_THREAD.
- Add the ability for events to not leak through exec(), via perf_event_attr::remove_on_exec.
- Allow the generation of SIGTRAP via perf_event_attr::sigtrap, extend siginfo with an u64
::si_perf, and add the breakpoint information to ::si_addr and ::si_perf if the event is
PERF_TYPE_BREAKPOINT.
The siginfo support is adequate for breakpoints right now - but the new field can be used
to introduce support for other types of metadata passed over siginfo as well.
- Misc fixes, cleanups and smaller updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event updates from Ingo Molnar:
- Improve Intel uncore PMU support:
- Parse uncore 'discovery tables' - a new hardware capability
enumeration method introduced on the latest Intel platforms. This
table is in a well-defined PCI namespace location and is read via
MMIO. It is organized in an rbtree.
These uncore tables will allow the discovery of standard counter
blocks, but fancier counters still need to be enumerated
explicitly.
- Add Alder Lake support
- Improve IIO stacks to PMON mapping support on Skylake servers
- Add Intel Alder Lake PMU support - which requires the introduction of
'hybrid' CPUs and PMUs. Alder Lake is a mix of Golden Cove ('big')
and Gracemont ('small' - Atom derived) cores.
The CPU-side feature set is entirely symmetrical - but on the PMU
side there's core type dependent PMU functionality.
- Reduce data loss with CPU level hardware tracing on Intel PT / AUX
profiling, by fixing the AUX allocation watermark logic.
- Improve ring buffer allocation on NUMA systems
- Put 'struct perf_event' into their separate kmem_cache pool
- Add support for synchronous signals for select perf events. The
immediate motivation is to support low-overhead sampling-based race
detection for user-space code. The feature consists of the following
main changes:
- Add thread-only event inheritance via
perf_event_attr::inherit_thread, which limits inheritance of
events to CLONE_THREAD.
- Add the ability for events to not leak through exec(), via
perf_event_attr::remove_on_exec.
- Allow the generation of SIGTRAP via perf_event_attr::sigtrap,
extend siginfo with an u64 ::si_perf, and add the breakpoint
information to ::si_addr and ::si_perf if the event is
PERF_TYPE_BREAKPOINT.
The siginfo support is adequate for breakpoints right now - but the
new field can be used to introduce support for other types of
metadata passed over siginfo as well.
- Misc fixes, cleanups and smaller updates.
* tag 'perf-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
signal, perf: Add missing TRAP_PERF case in siginfo_layout()
signal, perf: Fix siginfo_t by avoiding u64 on 32-bit architectures
perf/x86: Allow for 8<num_fixed_counters<16
perf/x86/rapl: Add support for Intel Alder Lake
perf/x86/cstate: Add Alder Lake CPU support
perf/x86/msr: Add Alder Lake CPU support
perf/x86/intel/uncore: Add Alder Lake support
perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
perf/x86/intel: Add Alder Lake Hybrid support
perf/x86: Support filter_match callback
perf/x86/intel: Add attr_update for Hybrid PMUs
perf/x86: Add structures for the attributes of Hybrid PMUs
perf/x86: Register hybrid PMUs
perf/x86: Factor out x86_pmu_show_pmu_cap
perf/x86: Remove temporary pmu assignment in event_init
perf/x86/intel: Factor out intel_pmu_check_extra_regs
perf/x86/intel: Factor out intel_pmu_check_event_constraints
perf/x86/intel: Factor out intel_pmu_check_num_counters
perf/x86: Hybrid PMU support for extra_regs
perf/x86: Hybrid PMU support for event constraints
...
Otherwise io_wq_worker_{running,sleeping}() may dereference an
invalid pointer (in future). Currently all users of create_io_thread()
are fine and get task->pf_io_worker = NULL implicitly from the
wq_manager, which got it either from the userspace thread
of the sq_thread, which explicitly reset it to NULL.
I think it's safer to always reset it in order to avoid future
problems.
Fixes: 3bfe610669 ("io-wq: fork worker threads from original task")
cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Adds bit perf_event_attr::inherit_thread, to restricting inheriting
events only if the child was cloned with CLONE_THREAD.
This option supports the case where an event is supposed to be
process-wide only (including subthreads), but should not propagate
beyond the current process's shared environment.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/YBvj6eJR%2FDY2TsEB@hirez.programming.kicks-ass.net/
The idea for this originates from the real time tree to make signal
delivery for realtime applications more efficient. In quite some of these
application scenarios a control tasks signals workers to start their
computations. There is usually only one signal per worker on flight. This
works nicely as long as the kmem cache allocations do not hit the slow path
and cause latencies.
To cure this an optimistic caching was introduced (limited to RT tasks)
which allows a task to cache a single sigqueue in a pointer in task_struct
instead of handing it back to the kmem cache after consuming a signal. When
the next signal is sent to the task then the cached sigqueue is used
instead of allocating a new one. This solved the problem for this set of
application scenarios nicely.
The task cache is not preallocated so the first signal sent to a task goes
always to the cache allocator. The cached sigqueue stays around until the
task exits and is freed when task::sighand is dropped.
After posting this solution for mainline the discussion came up whether
this would be useful in general and should not be limited to realtime
tasks: https://lore.kernel.org/r/m11rcu7nbr.fsf@fess.ebiederm.org
One concern leading to the original limitation was to avoid a large amount
of pointlessly cached sigqueues in alive tasks. The other concern was
vs. RLIMIT_SIGPENDING as these cached sigqueues are not accounted for.
The accounting problem is real, but on the other hand slightly academic.
After gathering some statistics it turned out that after boot of a regular
distro install there are less than 10 sigqueues cached in ~1500 tasks.
In case of a 'mass fork and fire signal to child' scenario the extra 80
bytes of memory per task are well in the noise of the overall memory
consumption of the fork bomb.
If this should be limited then this would need an extra counter in struct
user, more atomic instructions and a seperate rlimit. Yet another tunable
which is mostly unused.
The caching is actually used. After boot and a full kernel compile on a
64CPU machine with make -j128 the number of 'allocations' looks like this:
From slab: 23996
From task cache: 52223
I.e. it reduces the number of slab cache operations by ~68%.
A typical pattern there is:
<...>-58490 __sigqueue_alloc: for 58488 from slab ffff8881132df460
<...>-58488 __sigqueue_free: cache ffff8881132df460
<...>-58488 __sigqueue_alloc: for 1149 from cache ffff8881103dc550
bash-1149 exit_task_sighand: free ffff8881132df460
bash-1149 __sigqueue_free: cache ffff8881103dc550
The interesting sequence is that the exiting task 58488 grabs the sigqueue
from bash's task cache to signal exit and bash sticks it back into it's own
cache. Lather, rinse and repeat.
The caching is probably not noticable for the general use case, but the
benefit for latency sensitive applications is clear. While kmem caches are
usually just serving from the fast path the slab merging (default) can
depending on the usage pattern of the merged slabs cause occasional slow
path allocations.
The time spared per cached entry is a few micro seconds per signal which is
not relevant for e.g. a kernel build, but for signal heavy workloads it's
measurable.
As there is no real downside of this caching mechanism making it
unconditionally available is preferred over more conditional code or new
magic tunables.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/87sg4lbmxo.fsf@nanos.tec.linutronix.de
fork() fails if signal_pending() is true, but there are two conditions
that can lead to that:
1) An actual signal is pending. We want fork to fail for that one, like
we always have.
2) TIF_NOTIFY_SIGNAL is pending, because the task has pending task_work.
We don't need to make it fail for that case.
Allow fork() to proceed if just task_work is pending, by changing the
signal_pending() check to task_sigpending().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Conflicts:
MAINTAINERS
- keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
- simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
- trivial
include/linux/ethtool.h
- trivial, fix kdoc while at it
include/linux/skmsg.h
- move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
- add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
- trivial
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'io_uring-5.12-2021-03-27' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
- Use thread info versions of flag testing, as discussed last week.
- The series enabling PF_IO_WORKER to just take signals, instead of
needing to special case that they do not in a bunch of places. Ends
up being pretty trivial to do, and then we can revert all the special
casing we're currently doing.
- Kill dead pointer assignment
- Fix hashed part of async work queue trace
- Fix sign extension issue for IORING_OP_PROVIDE_BUFFERS
- Fix a link completion ordering regression in this merge window
- Cancellation fixes
* tag 'io_uring-5.12-2021-03-27' of git://git.kernel.dk/linux-block:
io_uring: remove unsued assignment to pointer io
io_uring: don't cancel extra on files match
io_uring: don't cancel-track common timeouts
io_uring: do post-completion chore on t-out cancel
io_uring: fix timeout cancel return code
Revert "signal: don't allow STOP on PF_IO_WORKER threads"
Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing"
Revert "kernel: treat PF_IO_WORKER like PF_KTHREAD for ptrace/signals"
Revert "signal: don't allow sending any signals to PF_IO_WORKER threads"
kernel: stop masking signals in create_io_thread()
io_uring: handle signals for IO threads like a normal thread
kernel: don't call do_exit() for PF_IO_WORKER threads
io_uring: maintain CQE order of a failed link
io-wq: fix race around pending work on teardown
io_uring: do ctx sqd ejection in a clear context
io_uring: fix provide_buffers sign extension
io_uring: don't skip file_end_write() on reissue
io_uring: correct io_queue_async_work() traces
io_uring: don't use {test,clear}_tsk_thread_flag() for current
This is racy - move the blocking into when the task is created and
we're marking it as PF_IO_WORKER anyway. The IO threads are now
prepared to handle signals like SIGSTOP as well, so clear that from
the mask to allow proper stopping of IO threads.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'io_uring-5.12-2021-03-19' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"Quieter week this time, which was both expected and desired. About
half of the below is fixes for this release, the other half are just
fixes in general. In detail:
- Fix the freezing of IO threads, by making the freezer not send them
fake signals. Make them freezable by default.
- Like we did for personalities, move the buffer IDR to xarray. Kills
some code and avoids a use-after-free on teardown.
- SQPOLL cleanups and fixes (Pavel)
- Fix linked timeout race (Pavel)
- Fix potential completion post use-after-free (Pavel)
- Cleanup and move internal structures outside of general kernel view
(Stefan)
- Use MSG_SIGNAL for send/recv from io_uring (Stefan)"
* tag 'io_uring-5.12-2021-03-19' of git://git.kernel.dk/linux-block:
io_uring: don't leak creds on SQO attach error
io_uring: use typesafe pointers in io_uring_task
io_uring: remove structures from include/linux/io_uring.h
io_uring: imply MSG_NOSIGNAL for send[msg]()/recv[msg]() calls
io_uring: fix sqpoll cancellation via task_work
io_uring: add generic callback_head helpers
io_uring: fix concurrent parking
io_uring: halt SQO submission on ctx exit
io_uring: replace sqd rw_semaphore with mutex
io_uring: fix complete_post use ctx after free
io_uring: fix ->flags races by linked timeouts
io_uring: convert io_buffer_idr to XArray
io_uring: allow IO worker threads to be frozen
kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing
Merge misc fixes from Andrew Morton:
"28 patches.
Subsystems affected by this series: mm (memblock, pagealloc, hugetlb,
highmem, kfence, oom-kill, madvise, kasan, userfaultfd, memcg, and
zram), core-kernel, kconfig, fork, binfmt, MAINTAINERS, kbuild, and
ia64"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
zram: fix broken page writeback
zram: fix return value on writeback_store
mm/memcg: set memcg when splitting page
mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
mm/userfaultfd: fix memory corruption due to writeprotect
kasan: fix KASAN_STACK dependency for HW_TAGS
kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
mm/madvise: replace ptrace attach requirement for process_madvise
include/linux/sched/mm.h: use rcu_dereference in in_vfork()
kfence: fix reports if constant function prefixes exist
kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations
kfence: fix printk format for ptrdiff_t
linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*
MAINTAINERS: exclude uapi directories in API/ABI section
binfmt_misc: fix possible deadlock in bm_register_write
mm/highmem.c: fix zero_user_segments() with start > end
hugetlb: do early cow when page pinned on src mm
mm: use is_cow_mapping() across tree where proper
...
When a new mm is created, its PASID should be cleared, i.e. the PASID is
initialized to its init state 0 on both ARM and X86.
This patch was part of the series introducing mm->pasid, but got lost
along the way [1]. It still makes sense to have it, because each address
space has a different PASID. And the IOMMU code in
iommu_sva_alloc_pasid() expects the pasid field of a new mm struct to be
cleared.
[1] https://lore.kernel.org/linux-iommu/YDgh53AcQHT+T3L0@otcwcpicx3.sc.intel.com/
Link: https://lkml.kernel.org/r/20210302103837.2562625-1-jean-philippe@linaro.org
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the freezer using the proper signaling to notify us of when it's
time to freeze a thread, we can re-enable normal freezer usage for the
IO threads. Ensure that SQPOLL, io-wq, and the io-wq manager call
try_to_freeze() appropriately, and remove the default setting of
PF_NOFREEZE from create_io_thread().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The io-wq threads were already marked as no-freeze, but the manager was
not. On resume, we perpetually have signal_pending() being true, and
hence the manager will loop and spin 100% of the time.
Just mark the tasks created by create_io_thread() as PF_NOFREEZE by
default, and remove any knowledge of it in io-wq and io_uring.
Reported-by: Kevin Locke <kevin@kevinlocke.name>
Tested-by: Kevin Locke <kevin@kevinlocke.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Chris von Recklinghausen
Wander Lairson Costa
Viktor Malik
Nico Pache
Waiman Long
Ming Lei
Oleg Nesterov
Herton R. Krzesinski
Alessandro Carminati
Jerome Marchand
Frantisek Hrbata
Kamal Heib
Jerry Snitselaar
Phil Auld
Patrick Talbert
Alexey Gladkov
Rafael Aquini
Eric W. Biederman
Linus Torvalds
Andrea Arcangeli
Peter Zijlstra
Frederic Weisbecker
Valentin Schneider
Xiaofeng Cao
Rolf Eike Beer
Alexey Gladkov
Muchun Song
Stefan Metzmacher
Ingo Molnar
Marco Elver
Thomas Gleixner
Jens Axboe
Jakub Kicinski
David S. Miller
Fenghua Yu