Bugzilla: https://bugzilla.redhat.com/2120966
commit adb8fa195efdfaac5852aaac24810b456ce43b04
Author: Mauricio Vásquez <mauricio@kinvolk.io>
Date: Tue Feb 15 17:58:50 2022 -0500
libbpf: Split bpf_core_apply_relo()
BTFGen needs to run the core relocation logic in order to understand
what are the types involved in a given relocation.
Currently bpf_core_apply_relo() calculates and **applies** a relocation
to an instruction. Having both operations in the same function makes it
difficult to only calculate the relocation without patching the
instruction. This commit splits that logic in two different phases: (1)
calculate the relocation and (2) patch the instruction.
For the first phase bpf_core_apply_relo() is renamed to
bpf_core_calc_relo_insn() who is now only on charge of calculating the
relocation, the second phase uses the already existing
bpf_core_patch_insn(). bpf_object__relocate_core() uses both of them and
the BTFGen will use only bpf_core_calc_relo_insn().
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com>
Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co>
Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220215225856.671072-2-mauricio@kinvolk.io
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120966
commit e4e835c87bb5ef7e7923e72da57c923bfcade418
Author: Mauricio Vásquez <mauricio@kinvolk.io>
Date: Mon Feb 7 09:50:50 2022 -0500
libbpf: Remove mode check in libbpf_set_strict_mode()
libbpf_set_strict_mode() checks that the passed mode doesn't contain
extra bits for LIBBPF_STRICT_* flags that don't exist yet.
It makes it difficult for applications to disable some strict flags as
something like "LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS"
is rejected by this check and they have to use a rather complicated
formula to calculate it.[0]
One possibility is to change LIBBPF_STRICT_ALL to only contain the bits
of all existing LIBBPF_STRICT_* flags instead of 0xffffffff. However
it's not possible because the idea is that applications compiled against
older libbpf_legacy.h would still be opting into latest
LIBBPF_STRICT_ALL features.[1]
The other possibility is to remove that check so something like
"LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS" is allowed. It's
what this commit does.
[0]: https://lore.kernel.org/bpf/20220204220435.301896-1-mauricio@kinvolk.io/
[1]: https://lore.kernel.org/bpf/CAEf4BzaTWa9fELJLh+bxnOb0P1EMQmaRbJVG0L+nXZdy0b8G3Q@mail.gmail.com/
Fixes: 93b8952d223a ("libbpf: deprecate legacy BPF map definitions")
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220207145052.124421-2-mauricio@kinvolk.io
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120966
commit 20eccf29e2979a18411517061998bac7d12c8543
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Jan 24 11:42:48 2022 -0800
libbpf: hide and discourage inconsistently named getters
Move a bunch of "getters" into libbpf_legacy.h to keep them there in
libbpf 1.0. See [0] for discussion of "Discouraged APIs". These getters
don't add any maintenance burden and are simple alias, but they are
inconsistent in naming. So keep them in libbpf_legacy.h instead of
libbpf.h to "hide" them in favor of preferred getters ([1]). Also add two
missing getters: bpf_program__type() and bpf_program__expected_attach_type().
[0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#handling-deprecation-of-apis-and-functionality
[1] Closes: https://github.com/libbpf/libbpf/issues/307
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120966
commit 93b8952d223af03c51fba0c6258173d2ffbd2cb7
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Jan 19 22:05:28 2022 -0800
libbpf: deprecate legacy BPF map definitions
Enact deprecation of legacy BPF map definition in SEC("maps") ([0]). For
the definitions themselves introduce LIBBPF_STRICT_MAP_DEFINITIONS flag
for libbpf strict mode. If it is set, error out on any struct
bpf_map_def-based map definition. If not set, libbpf will print out
a warning for each legacy BPF map to raise awareness that it goes away.
For any use of BPF_ANNOTATE_KV_PAIR() macro providing a legacy way to
associate BTF key/value type information with legacy BPF map definition,
warn through libbpf's pr_warn() error message (but don't fail BPF object
open).
BPF-side struct bpf_map_def is marked as deprecated. User-space struct
bpf_map_def has to be used internally in libbpf, so it is left
untouched. It should be enough for bpf_map__def() to be marked
deprecated to raise awareness that it goes away.
bpftool is an interesting case that utilizes libbpf to open BPF ELF
object to generate skeleton. As such, even though bpftool itself uses
full on strict libbpf mode (LIBBPF_STRICT_ALL), it has to relax it a bit
for BPF map definition handling to minimize unnecessary disruptions. So
opt-out of LIBBPF_STRICT_MAP_DEFINITIONS for bpftool. User's code that
will later use generated skeleton will make its own decision whether to
enforce LIBBPF_STRICT_MAP_DEFINITIONS or not.
There are few tests in selftests/bpf that are consciously using legacy
BPF map definitions to test libbpf functionality. For those, temporary
opt out of LIBBPF_STRICT_MAP_DEFINITIONS mode for the duration of those
tests.
[0] Closes: https://github.com/libbpf/libbpf/issues/272
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220120060529.1890907-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120966
commit a32ea51a3f17ce6524c9fc19d311e708331c8b5f
Author: Yafang Shao <laoar.shao@gmail.com>
Date: Sat Jan 8 13:47:39 2022 +0000
libbpf: Fix possible NULL pointer dereference when destroying skeleton
When I checked the code in skeleton header file generated with my own
bpf prog, I found there may be possible NULL pointer dereference when
destroying skeleton. Then I checked the in-tree bpf progs, finding that is
a common issue. Let's take the generated samples/bpf/xdp_redirect_cpu.skel.h
for example. Below is the generated code in
xdp_redirect_cpu__create_skeleton():
xdp_redirect_cpu__create_skeleton
struct bpf_object_skeleton *s;
s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));
if (!s)
goto error;
...
error:
bpf_object__destroy_skeleton(s);
return -ENOMEM;
After goto error, the NULL 's' will be deferenced in
bpf_object__destroy_skeleton().
We can simply fix this issue by just adding a NULL check in
bpf_object__destroy_skeleton().
Fixes: d66562fba1 ("libbpf: Add BPF object skeleton support")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220108134739.32541-1-laoar.shao@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 51a33c60f1c22c0d2dafad774315ba1537765442
Author: Qiang Wang <wangqiang.wq.frank@bytedance.com>
Date: Mon Dec 27 21:07:13 2021 +0800
libbpf: Support repeated legacy kprobes on same function
If repeated legacy kprobes on same function in one process,
libbpf will register using the same probe name and got -EBUSY
error. So append index to the probe name format to fix this
problem.
Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Qiang Wang <wangqiang.wq.frank@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211227130713.66933-2-wangqiang.wq.frank@bytedance.com
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 7218c28c87f57c131879a75a226b9033ac90b266
Author: Christy Lee <christylee@fb.com>
Date: Wed Dec 29 12:41:56 2021 -0800
libbpf: Deprecate bpf_perf_event_read_simple() API
With perf_buffer__poll() and perf_buffer__consume() APIs available,
there is no reason to expose bpf_perf_event_read_simple() API to
users. If users need custom perf buffer, they could re-implement
the function.
Mark bpf_perf_event_read_simple() and move the logic to a new
static function so it can still be called by other functions in the
same file.
[0] Closes: https://github.com/libbpf/libbpf/issues/310
Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211229204156.13569-1-christylee@fb.com
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 5b3d72987701d51bf31823b39db49d10970f5c2d
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Dec 22 15:10:03 2021 -0800
libbpf: Improve LINUX_VERSION_CODE detection
Ubuntu reports incorrect kernel version through uname(), which on older
kernels leads to kprobe BPF programs failing to load due to the version
check mismatch.
Accommodate Ubuntu's quirks with LINUX_VERSION_CODE by using
Ubuntu-specific /proc/version_code to fetch major/minor/patch versions
to form LINUX_VERSION_CODE.
While at it, consolide libbpf's kernel version detection code between
libbpf.c and libbpf_probes.c.
[0] Closes: https://github.com/libbpf/libbpf/issues/421
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211222231003.2334940-1-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit f97982398cc1c92f2e9bd0ef1ef870a5a729b0ac
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Dec 14 15:20:54 2021 -0800
libbpf: Avoid reading past ELF data section end when copying license
Fix possible read beyond ELF "license" data section if the license
string is not properly zero-terminated. Use the fact that libbpf_strlcpy
never accesses the (N-1)st byte of the source string because it's
replaced with '\0' anyways.
If this happens, it's a violation of contract between libbpf and a user,
but not handling this more robustly upsets CIFuzz, so given the fix is
trivial, let's fix the potential issue.
Fixes: 9fc205b413b3 ("libbpf: Add sane strncpy alternative and use it internally")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211214232054.3458774-1-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit e542f2c4cd16d49392abf3349341d58153d3c603
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Dec 14 11:59:03 2021 -0800
libbpf: Auto-bump RLIMIT_MEMLOCK if kernel needs it for BPF
The need to increase RLIMIT_MEMLOCK to do anything useful with BPF is
one of the first extremely frustrating gotchas that all new BPF users go
through and in some cases have to learn it a very hard way.
Luckily, starting with upstream Linux kernel version 5.11, BPF subsystem
dropped the dependency on memlock and uses memcg-based memory accounting
instead. Unfortunately, detecting memcg-based BPF memory accounting is
far from trivial (as can be evidenced by this patch), so in practice
most BPF applications still do unconditional RLIMIT_MEMLOCK increase.
As we move towards libbpf 1.0, it would be good to allow users to forget
about RLIMIT_MEMLOCK vs memcg and let libbpf do the sensible adjustment
automatically. This patch paves the way forward in this matter. Libbpf
will do feature detection of memcg-based accounting, and if detected,
will do nothing. But if the kernel is too old, just like BCC, libbpf
will automatically increase RLIMIT_MEMLOCK on behalf of user
application ([0]).
As this is technically a breaking change, during the transition period
applications have to opt into libbpf 1.0 mode by setting
LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK bit when calling
libbpf_set_strict_mode().
Libbpf allows to control the exact amount of set RLIMIT_MEMLOCK limit
with libbpf_set_memlock_rlim_max() API. Passing 0 will make libbpf do
nothing with RLIMIT_MEMLOCK. libbpf_set_memlock_rlim_max() has to be
called before the first bpf_prog_load(), bpf_btf_load(), or
bpf_object__load() call, otherwise it has no effect and will return
-EBUSY.
[0] Closes: https://github.com/libbpf/libbpf/issues/369
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211214195904.1785155-2-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 9fc205b413b3f3e9502fa92151fba63b91230454
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Fri Dec 10 16:40:43 2021 -0800
libbpf: Add sane strncpy alternative and use it internally
strncpy() has a notoriously error-prone semantics which makes GCC
complain about it a lot (and quite often completely completely falsely
at that). Instead of pleasing GCC all the time (-Wno-stringop-truncation
is unfortunately only supported by GCC, so it's a bit too messy to just
enable it in Makefile), add libbpf-internal libbpf_strlcpy() helper
which follows what FreeBSD's strlcpy() does and what most people would
expect from strncpy(): copies up to N-1 first bytes from source string
into destination string and ensures zero-termination afterwards.
Replace all the relevant uses of strncpy/strncat/memcpy in libbpf with
libbpf_strlcpy().
This also fixes the issue reported by Emmanuel Deloget in xsk.c where
memcpy() could access source string beyond its end.
Fixes: 2f6324a393 (libbpf: Support shared umems between queues and devices)
Reported-by: Emmanuel Deloget <emmanuel.deloget@eho.link>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211211004043.2374068-1-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Conflicts: upstream merge conflict resolved in be3158290db8
commit e7b924ca715f0d1c0be62b205c36c4076b335421
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Thu Dec 9 11:38:36 2021 -0800
libbpf: Deprecate bpf_object__load_xattr()
Deprecate non-extensible bpf_object__load_xattr() in v0.8 ([0]).
With log_level control through bpf_object_open_opts or
bpf_program__set_log_level(), we are finally at the point where
bpf_object__load_xattr() doesn't provide any functionality that can't be
accessed through other (better) ways. The other feature,
target_btf_path, is also controllable through bpf_object_open_opts.
[0] Closes: https://github.com/libbpf/libbpf/issues/289
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211209193840.1248570-9-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit b3ce907950350a58880b94fed2b6022f160b8b9a
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Thu Dec 9 11:38:35 2021 -0800
libbpf: Add per-program log buffer setter and getter
Allow to set user-provided log buffer on a per-program basis ([0]). This
gives great deal of flexibility in terms of which programs are loaded
with logging enabled and where corresponding logs go.
Log buffer set with bpf_program__set_log_buf() overrides kernel_log_buf
and kernel_log_size settings set at bpf_object open time through
bpf_object_open_opts, if any.
Adjust bpf_object_load_prog_instance() logic to not perform own log buf
allocation and load retry if custom log buffer is provided by the user.
[0] Closes: https://github.com/libbpf/libbpf/issues/418
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211209193840.1248570-8-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 2eda2145ebfc76569fd088f46356203fc0c785a1
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Thu Dec 9 11:38:34 2021 -0800
libbpf: Preserve kernel error code and remove kprobe prog type guessing
Instead of rewriting error code returned by the kernel of prog load with
libbpf-sepcific variants pass through the original error.
There is now also no need to have a backup generic -LIBBPF_ERRNO__LOAD
fallback error as bpf_prog_load() guarantees that errno will be properly
set no matter what.
Also drop a completely outdated and pretty useless BPF_PROG_TYPE_KPROBE
guess logic. It's not necessary and neither it's helpful in modern BPF
applications.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211209193840.1248570-7-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit ad9a7f96445b70c415d8e193f854321b110c890a
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Thu Dec 9 11:38:33 2021 -0800
libbpf: Improve logging around BPF program loading
Add missing "prog '%s': " prefixes in few places and use consistently
markers for beginning and end of program load logs. Here's an example of
log output:
libbpf: prog 'handler': BPF program load failed: Permission denied
libbpf: -- BEGIN PROG LOAD LOG ---
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
; out1 = in1;
0: (18) r1 = 0xffffc9000cdcc000
2: (61) r1 = *(u32 *)(r1 +0)
...
81: (63) *(u32 *)(r4 +0) = r5
R1_w=map_value(id=0,off=16,ks=4,vs=20,imm=0) R4=map_value(id=0,off=400,ks=4,vs=16,imm=0)
invalid access to map value, value_size=16 off=400 size=4
R4 min value is outside of the allowed memory range
processed 63 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: failed to load program 'handler'
libbpf: failed to load object 'test_skeleton'
The entire verifier log, including BEGIN and END markers are now always
youtput during a single print callback call. This should make it much
easier to post-process or parse it, if necessary. It's not an explicit
API guarantee, but it can be reasonably expected to stay like that.
Also __bpf_object__open is renamed to bpf_object_open() as it's always
an adventure to find the exact function that implements bpf_object's
open phase, so drop the double underscored and use internal libbpf
naming convention.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211209193840.1248570-6-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit e0e3ea888c69b4ea17133b8ac8dfd5066a759b5a
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Thu Dec 9 11:38:32 2021 -0800
libbpf: Allow passing user log setting through bpf_object_open_opts
Allow users to provide their own custom log_buf, log_size, and log_level
at bpf_object level through bpf_object_open_opts. This log_buf will be
used during BTF loading. Subsequent patch will use same log_buf during
BPF program loading, unless overriden at per-bpf_program level.
When such custom log_buf is provided, libbpf won't be attempting
retrying loading of BTF to try to provide its own log buffer to capture
kernel's error log output. User is responsible to provide big enough
buffer, otherwise they run a risk of getting -ENOSPC error from the
bpf() syscall.
See also comments in bpf_object_open_opts regarding log_level and
log_buf interactions.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211209193840.1248570-5-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit dbdd2c7f8cec2d09ae0e1bd707ae6050fa1c105f
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Dec 1 15:28:17 2021 -0800
libbpf: Add API to get/set log_level at per-program level
Add bpf_program__set_log_level() and bpf_program__log_level() to fetch
and adjust log_level sent during BPF_PROG_LOAD command. This allows to
selectively request more or less verbose output in BPF verifier log.
Also bump libbpf version to 0.7 and make these APIs the first in v0.7.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211201232824.3166325-3-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit d0e928876e30b18411b80fd2445424bc00e95745
Author: Alexei Starovoitov <ast@kernel.org>
Date: Wed Dec 1 10:10:32 2021 -0800
libbpf: Use CO-RE in the kernel in light skeleton.
Without lskel the CO-RE relocations are processed by libbpf before any other
work is done. Instead, when lskel is needed, remember relocation as RELO_CORE
kind. Then when loader prog is generated for a given bpf program pass CO-RE
relos of that program to gen loader via bpf_gen__record_relo_core(). The gen
loader will remember them as-is and pass it later as-is into the kernel.
The normal libbpf flow is to process CO-RE early before call relos happen. In
case of gen_loader the core relos have to be added to other relos to be copied
together when bpf static function is appended in different places to other main
bpf progs. During the copy the append_subprog_relos() will adjust insn_idx for
normal relos and for RELO_CORE kind too. When that is done each struct
reloc_desc has good relos for specific main prog.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-10-alexei.starovoitov@gmail.com
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 46334a0cd21bed70d6f1ddef1464f75a0ebe1774
Author: Alexei Starovoitov <ast@kernel.org>
Date: Wed Dec 1 10:10:27 2021 -0800
bpf: Define enum bpf_core_relo_kind as uapi.
enum bpf_core_relo_kind is generated by llvm and processed by libbpf.
It's a de-facto uapi.
With CO-RE in the kernel the bpf_core_relo_kind values become uapi de-jure.
Also rename them with BPF_CORE_ prefix to distinguish from conflicting names in
bpf_core_read.h. The enums bpf_field_info_kind, bpf_type_id_kind,
bpf_type_info_kind, bpf_enum_value_kind are passing different values from bpf
program into llvm.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-5-alexei.starovoitov@gmail.com
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit c291d0a4d169811898d723cfa5f1aa1fc60e607c
Author: Mehrdad Arshad Rad <arshad.rad@gmail.com>
Date: Sun Nov 28 11:33:37 2021 -0800
libbpf: Remove duplicate assignments
There is a same action when load_attr.attach_btf_id is initialized.
Signed-off-by: Mehrdad Arshad Rad <arshad.rad@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211128193337.10628-1-arshad.rad@gmail.com
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 2a6a9bf26170b4e156c18706cd230934ebd2f95f
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Nov 23 16:23:16 2021 -0800
libbpf: Don't call libc APIs with NULL pointers
Sanitizer complains about qsort(), bsearch(), and memcpy() being called
with NULL pointer. This can only happen when the associated number of
elements is zero, so no harm should be done. But still prevent this from
happening to keep sanitizer runs clean from extra noise.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124002325.1737739-5-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 992c4225419a38663d6239bc2f525b4ac0429188
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 24 11:32:30 2021 -0800
libbpf: Unify low-level map creation APIs w/ new bpf_map_create()
Mark the entire zoo of low-level map creation APIs for deprecation in
libbpf 0.7 ([0]) and introduce a new bpf_map_create() API that is
OPTS-based (and thus future-proof) and matches the BPF_MAP_CREATE
command name.
While at it, ensure that gen_loader sends map_extra field. Also remove
now unneeded btf_key_type_id/btf_value_type_id logic that libbpf is
doing anyways.
[0] Closes: https://github.com/libbpf/libbpf/issues/282
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124193233.3115996-2-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 8cccee9e91e19207671b94af40bacf7c1d2e74ef
Author: Florent Revest <revest@chromium.org>
Date: Fri Nov 19 19:00:35 2021 +0100
libbpf: Change bpf_program__set_extra_flags to bpf_program__set_flags
bpf_program__set_extra_flags has just been introduced so we can still
change it without breaking users.
This new interface is a bit more flexible (for example if someone wants
to clear a flag).
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211119180035.1396139-1-revest@chromium.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 7615209f42a1976894cd0df97a380a034911656a
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Thu Nov 18 09:40:54 2021 -0800
libbpf: Add runtime APIs to query libbpf version
Libbpf provided LIBBPF_MAJOR_VERSION and LIBBPF_MINOR_VERSION macros to
check libbpf version at compilation time. This doesn't cover all the
needs, though, because version of libbpf that application is compiled
against doesn't necessarily match the version of libbpf at runtime,
especially if libbpf is used as a shared library.
Add libbpf_major_version() and libbpf_minor_version() returning major
and minor versions, respectively, as integers. Also add a convenience
libbpf_version_string() for various tooling using libbpf to print out
libbpf version in a human-readable form. Currently it will return
"v0.6", but in the future it can contains some extra information, so the
format itself is not part of a stable API and shouldn't be relied upon.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20211118174054.2699477-1-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 4178893465774f91dcd49465ae6f4e3cc036b7b2
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 10 21:36:20 2021 -0800
libbpf: Make perf_buffer__new() use OPTS-based interface
Add new variants of perf_buffer__new() and perf_buffer__new_raw() that
use OPTS-based options for future extensibility ([0]). Given all the
currently used API names are best fits, re-use them and use
___libbpf_override() approach and symbol versioning to preserve ABI and
source code compatibility. struct perf_buffer_opts and struct
perf_buffer_raw_opts are kept as well, but they are restructured such
that they are OPTS-based when used with new APIs. For struct
perf_buffer_raw_opts we keep few fields intact, so we have to also
preserve the memory location of them both when used as OPTS and for
legacy API variants. This is achieved with anonymous padding for OPTS
"incarnation" of the struct. These pads can be eventually used for new
options.
[0] Closes: https://github.com/libbpf/libbpf/issues/311
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-6-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit a6ca71583137300f207343d5d950cb1c365ab911
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 10 21:17:57 2021 -0800
libbpf: Add ability to get/set per-program load flags
Add bpf_program__flags() API to retrieve prog_flags that will be (or
were) supplied to BPF_PROG_LOAD command.
Also add bpf_program__set_extra_flags() API to allow to set *extra*
flags, in addition to those determined by program's SEC() definition.
Such flags are logically OR'ed with libbpf-derived flags.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111051758.92283-2-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit d10ef2b825cffd0807dd733fdfd6a5bea32270d7
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 3 15:08:36 2021 -0700
libbpf: Unify low-level BPF_PROG_LOAD APIs into bpf_prog_load()
Add a new unified OPTS-based low-level API for program loading,
bpf_prog_load() ([0]). bpf_prog_load() accepts few "mandatory"
parameters as input arguments (program type, name, license,
instructions) and all the other optional (as in not required to specify
for all types of BPF programs) fields into struct bpf_prog_load_opts.
This makes all the other non-extensible APIs variant for BPF_PROG_LOAD
obsolete and they are slated for deprecation in libbpf v0.7:
- bpf_load_program();
- bpf_load_program_xattr();
- bpf_verify_program().
Implementation-wise, internal helper libbpf__bpf_prog_load is refactored
to become a public bpf_prog_load() API. struct bpf_prog_load_params used
internally is replaced by public struct bpf_prog_load_opts.
Unfortunately, while conceptually all this is pretty straightforward,
the biggest complication comes from the already existing bpf_prog_load()
*high-level* API, which has nothing to do with BPF_PROG_LOAD command.
We try really hard to have a new API named bpf_prog_load(), though,
because it maps naturally to BPF_PROG_LOAD command.
For that, we rename old bpf_prog_load() into bpf_prog_load_deprecated()
and mark it as COMPAT_VERSION() for shared library users compiled
against old version of libbpf. Statically linked users and shared lib
users compiled against new version of libbpf headers will get "rerouted"
to bpf_prog_deprecated() through a macro helper that decides whether to
use new or old bpf_prog_load() based on number of input arguments (see
___libbpf_overload in libbpf_common.h).
To test that existing
bpf_prog_load()-using code compiles and works as expected, I've compiled
and ran selftests as is. I had to remove (locally) selftest/bpf/Makefile
-Dbpf_prog_load=bpf_prog_test_load hack because it was conflicting with
the macro-based overload approach. I don't expect anyone else to do
something like this in practice, though. This is testing-specific way to
replace bpf_prog_load() calls with special testing variant of it, which
adds extra prog_flags value. After testing I kept this selftests hack,
but ensured that we use a new bpf_prog_load_deprecated name for this.
This patch also marks bpf_prog_load() and bpf_prog_load_xattr() as deprecated.
bpf_object interface has to be used for working with struct bpf_program.
Libbpf doesn't support loading just a bpf_program.
The silver lining is that when we get to libbpf 1.0 all these
complication will be gone and we'll have one clean bpf_prog_load()
low-level API with no backwards compatibility hackery surrounding it.
[0] Closes: https://github.com/libbpf/libbpf/issues/284
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-4-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 62554d52e71797eefa3fc15b54008038837bb2d4
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 3 10:32:11 2021 -0700
libbpf: Validate that .BTF and .BTF.ext sections contain data
.BTF and .BTF.ext ELF sections should have SHT_PROGBITS type and contain
data. If they are not, ELF is invalid or corrupted, so bail out.
Otherwise this can lead to data->d_buf being NULL and SIGSEGV later on.
Reported by oss-fuzz project.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-4-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2069046
Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit 88918dc12dc357a06d8d722a684617b1c87a4654
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 3 10:32:10 2021 -0700
libbpf: Improve sanity checking during BTF fix up
If BTF is corrupted DATASEC's variable type ID might be incorrect.
Prevent this easy to detect situation with extra NULL check.
Reported by oss-fuzz project.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-3-andrii@kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 689624f037ce219d42312534eff4dc470b54dec4
Author: Joe Burton <jevburton@google.com>
Date: Tue Oct 26 22:35:28 2021 +0000
libbpf: Deprecate bpf_objects_list
Add a flag to `enum libbpf_strict_mode' to disable the global
`bpf_objects_list', preventing race conditions when concurrent threads
call bpf_object__open() or bpf_object__close().
bpf_object__next() will return NULL if this option is set.
Callers may achieve the same workflow by tracking bpf_objects in
application code.
[0] Closes: https://github.com/libbpf/libbpf/issues/293
Signed-off-by: Joe Burton <jevburton@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026223528.413950-1-jevburton.kernel@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 65a7fa2e4e5381d205d3b0098da0fc8471fbbfb6
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Oct 25 15:45:29 2021 -0700
libbpf: Add ability to fetch bpf_program's underlying instructions
Add APIs providing read-only access to bpf_program BPF instructions ([0]).
This is useful for diagnostics purposes, but it also allows a cleaner
support for cloning BPF programs after libbpf did all the FD resolution
and CO-RE relocations, subprog instructions appending, etc. Currently,
cloning BPF program is possible only through hijacking a half-broken
bpf_program__set_prep() API, which doesn't really work well for anything
but most primitive programs. For instance, set_prep() API doesn't allow
adjusting BPF program load parameters which are necessary for loading
fentry/fexit BPF programs (the case where BPF program cloning is
a necessity if doing some sort of mass-attachment functionality).
Given bpf_program__set_prep() API is set to be deprecated, having
a cleaner alternative is a must. libbpf internally already keeps track
of linear array of struct bpf_insn, so it's not hard to expose it. The
only gotcha is that libbpf previously freed instructions array during
bpf_object load time, which would make this API much less useful overall,
because in between bpf_object__open() and bpf_object__load() a lot of
changes to instructions are done by libbpf.
So this patch makes libbpf hold onto prog->insns array even after BPF
program loading. I think this is a small price for added functionality
and improved introspection of BPF program code.
See retsnoop PR ([1]) for how it can be used in practice and code
savings compared to relying on bpf_program__set_prep().
[0] Closes: https://github.com/libbpf/libbpf/issues/298
[1] https://github.com/anakryiko/retsnoop/pull/1
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-3-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 229fae38d0fc0d6ff58d57cbeb1432da55e58d4f
Author: Shuyi Cheng <chengshuyi@linux.alibaba.com>
Date: Fri Dec 10 17:39:57 2021 +0800
libbpf: Add "bool skipped" to struct bpf_map
Fix error: "failed to pin map: Bad file descriptor, path:
/sys/fs/bpf/_rodata_str1_1."
In the old kernel, the global data map will not be created, see [0]. So
we should skip the pinning of the global data map to avoid
bpf_object__pin_maps returning error. Therefore, when the map is not
created, we mark “map->skipped" as true and then check during relocation
and during pinning.
Fixes: 16e0c35c6f7a ("libbpf: Load global data maps lazily on legacy kernels")
Signed-off-by: Shuyi Cheng <chengshuyi@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit ba05fd36b8512d6aeefe9c2c5b6a25b726c4bfff
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat Nov 13 04:50:22 2021 +0530
libbpf: Perform map fd cleanup for gen_loader in case of error
Alexei reported a fd leak issue in gen loader (when invoked from
bpftool) [0]. When adding ksym support, map fd allocation was moved from
stack to loader map, however I missed closing these fds (relevant when
cleanup label is jumped to on error). For the success case, the
allocated fd is returned in loader ctx, hence this problem is not
noticed.
Make three changes, first MAX_USED_MAPS in MAX_FD_ARRAY_SZ instead of
MAX_USED_PROGS, the braino was not a problem until now for this case as
we didn't try to close map fds (otherwise use of it would have tried
closing 32 additional fds in ksym btf fd range). Then, do a cleanup for
all nr_maps fds in cleanup label code, so that in case of error all
temporary map fds from bpf_gen__map_create are closed.
Then, adjust the cleanup label to only generate code for the required
number of program and map fds. To trim code for remaining program
fds, lay out prog_fd array in stack in the end, so that we can
directly skip the remaining instances. Still stack size remains same,
since changing that would require changes in a lot of places
(including adjustment of stack_off macro), so nr_progs_sz variable is
only used to track required number of iterations (and jump over
cleanup size calculated from that), stack offset calculation remains
unaffected.
The difference for test_ksyms_module.o is as follows:
libbpf: //prog cleanup iterations: before = 34, after = 5
libbpf: //maps cleanup iterations: before = 64, after = 2
Also, move allocation of gen->fd_array offset to bpf_gen__init. Since
offset can now be 0, and we already continue even if add_data returns 0
in case of failure, we do not need to distinguish between 0 offset and
failure case 0, as we rely on bpf_gen__finish to check errors. We can
also skip check for gen->fd_array in add_*_fd functions, since
bpf_gen__init will take care of it.
[0]: https://lore.kernel.org/bpf/CAADnVQJ6jSitKSNKyxOrUzwY2qDRX0sPkJ=VLGHuCLVJ=qOt9g@mail.gmail.com
Fixes: 18f4fccbf314 ("libbpf: Update gen_loader to emit BTF_KIND_FUNC relocations")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211112232022.899074-1-memxor@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 0d6988e16a12ebd41d3e268992211b0ceba44ed7
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Nov 3 10:32:12 2021 -0700
libbpf: Fix section counting logic
e_shnum does include section #0 and as such is exactly the number of ELF
sections that we need to allocate memory for to use section indices as
array indices. Fix the off-by-one error.
This is purely accounting fix, previously we were overallocating one
too many array items. But no correctness errors otherwise.
Fixes: 25bbbd7a444b ("libbpf: Remove assumptions about uniqueness of .rodata/.data/.bss maps")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211103173213.1376990-5-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 16e0c35c6f7a2e90d52f3035ecf942af21417b7b
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Nov 23 12:01:04 2021 -0800
libbpf: Load global data maps lazily on legacy kernels
Load global data maps lazily, if kernel is too old to support global
data. Make sure that programs are still correct by detecting if any of
the to-be-loaded programs have relocation against any of such maps.
This allows to solve the issue ([0]) with bpf_printk() and Clang
generating unnecessary and unreferenced .rodata.strX.Y sections, but it
also goes further along the CO-RE lines, allowing to have a BPF object
in which some code can work on very old kernels and relies only on BPF
maps explicitly, while other BPF programs might enjoy global variable
support. If such programs are correctly set to not load at runtime on
old kernels, bpf_object will load and function correctly now.
[0] https://lore.kernel.org/bpf/CAK-59YFPU3qO+_pXWOH+c1LSA=8WA1yabJZfREjOEXNHAqgXNg@mail.gmail.com/
Fixes: aed659170a31 ("libbpf: Support multiple .rodata.* and .data.* BPF maps")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211123200105.387855-1-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 92274e24b01b331ef7a4227135933e6163fe94aa
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu Oct 28 12:04:58 2021 +0530
libbpf: Use O_CLOEXEC uniformly when opening fds
There are some instances where we don't use O_CLOEXEC when opening an
fd, fix these up. Otherwise, it is possible that a parallel fork causes
these fds to leak into a child process on execve.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-6-memxor@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit c24941cd3766b6de682dbe6809bd6af12271ab5b
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu Oct 28 12:04:55 2021 +0530
libbpf: Add typeless ksym support to gen_loader
This uses the bpf_kallsyms_lookup_name helper added in previous patches
to relocate typeless ksyms. The return value ENOENT can be ignored, and
the value written to 'res' can be directly stored to the insn, as it is
overwritten to 0 on lookup failure. For repeating symbols, we can simply
copy the previously populated bpf_insn.
Also, we need to take care to not close fds for typeless ksym_desc, so
reuse the 'off' member's space to add a marker for typeless ksym and use
that to skip them in cleanup_relos.
We add a emit_ksym_relo_log helper that avoids duplicating common
logging instructions between typeless and weak ksym (for future commit).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-3-memxor@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 47512102cde2d252d7b984d9675cfd3420b48ad9
Author: Joanne Koong <joannekoong@fb.com>
Date: Wed Oct 27 16:45:01 2021 -0700
libbpf: Add "map_extra" as a per-map-type extra flag
This patch adds the libbpf infrastructure for supporting a
per-map-type "map_extra" field, whose definition will be
idiosyncratic depending on map type.
For example, for the bloom filter map, the lower 4 bits of
map_extra is used to denote the number of hash functions.
Please note that until libbpf 1.0 is here, the
"bpf_create_map_params" struct is used as a temporary
means for propagating the map_extra field to the kernel.
Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-3-joannekoong@fb.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit e21d585cb3db65a207cd338c74b9886090ef1ceb
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Oct 25 15:45:30 2021 -0700
libbpf: Deprecate multi-instance bpf_program APIs
Schedule deprecation of a set of APIs that are related to multi-instance
bpf_programs:
- bpf_program__set_prep() ([0]);
- bpf_program__{set,unset}_instance() ([1]);
- bpf_program__nth_fd().
These APIs are obscure, very niche, and don't seem to be used much in
practice. bpf_program__set_prep() is pretty useless for anything but the
simplest BPF programs, as it doesn't allow to adjust BPF program load
attributes, among other things. In short, it already bitrotted and will
bitrot some more if not removed.
With bpf_program__insns() API, which gives access to post-processed BPF
program instructions of any given entry-point BPF program, it's now
possible to do whatever necessary adjustments were possible with
set_prep() API before, but also more. Given any such use case is
automatically an advanced use case, requiring users to stick to
low-level bpf_prog_load() APIs and managing their own prog FDs is
reasonable.
[0] Closes: https://github.com/libbpf/libbpf/issues/299
[1] Closes: https://github.com/libbpf/libbpf/issues/300
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-4-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit a77f879ba1178437e5df87090165e5a45a91ba7f
Author: Stanislav Fomichev <sdf@google.com>
Date: Thu Oct 21 14:48:12 2021 -0700
libbpf: Use func name when pinning programs with LIBBPF_STRICT_SEC_NAME
We can't use section name anymore because they are not unique
and pinning objects with multiple programs with the same
progtype/secname will fail.
[0] Closes: https://github.com/libbpf/libbpf/issues/273
Fixes: 33a2c75c55 ("libbpf: add internal pin_name")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211021214814.1236114-2-sdf@google.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 6a886de070fad850d6cb74a787c9ed017303d9ac
Author: Hengqi Chen <hengqi.chen@gmail.com>
Date: Fri Oct 22 21:06:19 2021 +0800
libbpf: Add btf__type_cnt() and btf__raw_data() APIs
Add btf__type_cnt() and btf__raw_data() APIs and deprecate
btf__get_nr_type() and btf__get_raw_data() since the old APIs
don't follow the libbpf naming convention for getters which
omit 'get' in the name (see [0]). btf__raw_data() is just an
alias to the existing btf__get_raw_data(). btf__type_cnt()
now returns the number of all types of the BTF object
including 'void'.
[0] Closes: https://github.com/libbpf/libbpf/issues/279
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022130623.1548429-2-hengqi.chen@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit b96c07f3b5ae6944eb52fd96a322340aa80aef5d
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Oct 20 18:43:55 2021 -0700
libbpf: Deprecate btf__finalize_data() and move it into libbpf.c
There isn't a good use case where anyone but libbpf itself needs to call
btf__finalize_data(). It was implemented for internal use and it's not
clear why it was made into public API in the first place. To function, it
requires active ELF data, which is stored inside bpf_object for the
duration of opening phase only. But the only BTF that needs bpf_object's
ELF is that bpf_object's BTF itself, which libbpf fixes up automatically
during bpf_object__open() operation anyways. There is no need for any
additional fix up and no reasonable scenario where it's useful and
appropriate.
Thus, btf__finalize_data() is just an API atavism and is better removed.
So this patch marks it as deprecated immediately (v0.6+) and moves the
code from btf.c into libbpf.c where it's used in the context of
bpf_object opening phase. Such code co-location allows to make code
structure more straightforward and remove bpf_object__section_size() and
bpf_object__variable_offset() internal helpers from libbpf_internal.h,
making them static. Their naming is also adjusted to not create
a wrong illusion that they are some sort of method of bpf_object. They
are internal helpers and are called appropriately.
This is part of libbpf 1.0 effort ([0]).
[0] Closes: https://github.com/libbpf/libbpf/issues/276
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-2-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 26071635ac5ecd8276bf3bdfc3ea1128c93ac722
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Oct 20 18:44:03 2021 -0700
libbpf: Simplify look up by name of internal maps
Map name that's assigned to internal maps (.rodata, .data, .bss, etc)
consist of a small prefix of bpf_object's name and ELF section name as
a suffix. This makes it hard for users to "guess" the name to use for
looking up by name with bpf_object__find_map_by_name() API.
One proposal was to drop object name prefix from the map name and just
use ".rodata", ".data", etc, names. One downside called out was that
when multiple BPF applications are active on the host, it will be hard
to distinguish between multiple instances of .rodata and know which BPF
object (app) they belong to. Having few first characters, while quite
limiting, still can give a bit of a clue, in general.
Note, though, that btf_value_type_id for such global data maps (ARRAY)
points to DATASEC type, which encodes full ELF name, so tools like
bpftool can take advantage of this fact to "recover" full original name
of the map. This is also the reason why for custom .data.* and .rodata.*
maps libbpf uses only their ELF names and doesn't prepend object name at
all.
Another downside of such approach is that it is not backwards compatible
and, among direct use of bpf_object__find_map_by_name() API, will break
any BPF skeleton generated using bpftool that was compiled with older
libbpf version.
Instead of causing all this pain, libbpf will still generate map name
using a combination of object name and ELF section name, but it will
allow looking such maps up by their natural names, which correspond to
their respective ELF section names. This means non-truncated ELF section
names longer than 15 characters are going to be expected and supported.
With such set up, we get the best of both worlds: leave small bits of
a clue about BPF application that instantiated such maps, as well as
making it easy for user apps to lookup such maps at runtime. In this
sense it closes corresponding libbpf 1.0 issue ([0]).
BPF skeletons will continue using full names for lookups.
[0] Closes: https://github.com/libbpf/libbpf/issues/275
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-10-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit aed659170a3171e425913ae259d46396fb9c10ef
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Oct 20 18:44:01 2021 -0700
libbpf: Support multiple .rodata.* and .data.* BPF maps
Add support for having multiple .rodata and .data data sections ([0]).
.rodata/.data are supported like the usual, but now also
.rodata.<whatever> and .data.<whatever> are also supported. Each such
section will get its own backing BPF_MAP_TYPE_ARRAY, just like
.rodata and .data.
Multiple .bss maps are not supported, as the whole '.bss' name is
confusing and might be deprecated soon, as well as user would need to
specify custom ELF section with SEC() attribute anyway, so might as well
stick to just .data.* and .rodata.* convention.
User-visible map name for such new maps is going to be just their ELF
section names.
[0] https://github.com/libbpf/libbpf/issues/274
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-8-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 25bbbd7a444b1624000389830d46ffdc5b809ee8
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Oct 20 18:43:58 2021 -0700
libbpf: Remove assumptions about uniqueness of .rodata/.data/.bss maps
Remove internal libbpf assumption that there can be only one .rodata,
.data, and .bss map per BPF object. To achieve that, extend and
generalize the scheme that was used for keeping track of relocation ELF
sections. Now each ELF section has a temporary extra index that keeps
track of logical type of ELF section (relocations, data, read-only data,
BSS). Switch relocation to this scheme, as well as .rodata/.data/.bss
handling.
We don't yet allow multiple .rodata, .data, and .bss sections, but no
libbpf internal code makes an assumption that there can be only one of
each and thus they can be explicitly referenced by a single index. Next
patches will actually allow multiple .rodata and .data sections.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-5-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit ad23b7238474c6319bf692ae6ce037d9696df1d1
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Oct 20 18:43:57 2021 -0700
libbpf: Use Elf64-specific types explicitly for dealing with ELF
Minimize the usage of class-agnostic gelf_xxx() APIs from libelf. These
APIs require copying ELF data structures into local GElf_xxx structs and
have a more cumbersome API. BPF ELF file is defined to be always 64-bit
ELF object, even when intended to be run on 32-bit host architectures,
so there is no need to do class-agnostic conversions everywhere. BPF
static linker implementation within libbpf has been using Elf64-specific
types since initial implementation.
Add two simple helpers, elf_sym_by_idx() and elf_rel_by_idx(), for more
succinct direct access to ELF symbol and relocation records within ELF
data itself and switch all the GElf_xxx usage into Elf64_xxx
equivalents. The only remaining place within libbpf.c that's still using
gelf API is gelf_getclass(), as there doesn't seem to be a direct way to
get underlying ELF bitness.
No functional changes intended.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-4-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 29a30ff501518a49282754909543cef1ef49e4bc
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Oct 20 18:43:56 2021 -0700
libbpf: Extract ELF processing state into separate struct
Name currently anonymous internal struct that keeps ELF-related state
for bpf_object. Just a bit of clean up, no functional changes.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-3-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit ebc7b50a3849d73665013573cf3c09f27fb14fde
Author: Dave Marchevsky <davemarchevsky@fb.com>
Date: Mon Oct 11 01:20:28 2021 -0700
libbpf: Migrate internal use of bpf_program__get_prog_info_linear
In preparation for bpf_program__get_prog_info_linear deprecation, move
the single use in libbpf to call bpf_obj_get_info_by_fd directly.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211011082031.4148337-2-davemarchevsky@fb.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 223f903e9c832699f4e5f422281a60756c1c6cfe
Author: Yonghong Song <yhs@fb.com>
Date: Tue Oct 12 09:48:38 2021 -0700
bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG
Patch set [1] introduced BTF_KIND_TAG to allow tagging
declarations for struct/union, struct/union field, var, func
and func arguments and these tags will be encoded into
dwarf. They are also encoded to btf by llvm for the bpf target.
After BTF_KIND_TAG is introduced, we intended to use it
for kernel __user attributes. But kernel __user is actually
a type attribute. Upstream and internal discussion showed
it is not a good idea to mix declaration attribute and
type attribute. So we proposed to introduce btf_type_tag
as a type attribute and existing btf_tag renamed to
btf_decl_tag ([2]).
This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some
other declarations with *_tag to *_decl_tag to make it clear
the tag is for declaration. In the future, BTF_KIND_TYPE_TAG
might be introduced per [3].
[1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/
[2] https://reviews.llvm.org/D111588
[3] https://reviews.llvm.org/D111199
Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec003 ("bpftool: Add support for BTF_KIND_TAG")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit ccaf12d6215a56836472db220520cda8024d6c4f
Author: Hou Tao <houtao1@huawei.com>
Date: Mon Oct 4 17:48:56 2021 +0800
libbpf: Support detecting and attaching of writable tracepoint program
Program on writable tracepoint is BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
but its attachment is the same as BPF_PROG_TYPE_RAW_TRACEPOINT.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-3-hotforest@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 4a404a7e8a3902fc560527241a611186605efb4e
Author: Hengqi Chen <hengqi.chen@gmail.com>
Date: Sun Oct 3 00:10:00 2021 +0800
libbpf: Deprecate bpf_object__unload() API since v0.6
BPF objects are not reloadable after unload. Users are expected to use
bpf_object__close() to unload and free up resources in one operation.
No need to expose bpf_object__unload() as a public API, deprecate it
([0]). Add bpf_object__unload() as an alias to internal
bpf_object_unload() and replace all bpf_object__unload() uses to avoid
compilation errors.
[0] Closes: https://github.com/libbpf/libbpf/issues/290
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211002161000.3854559-1-hengqi.chen@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 2088a3a71d870115fdfb799c0f7de76d7383ba03
Author: Hengqi Chen <hengqi.chen@gmail.com>
Date: Mon Oct 4 00:58:43 2021 +0800
libbpf: Deprecate bpf_{map,program}__{prev,next} APIs since v0.7
Deprecate bpf_{map,program}__{prev,next} APIs. Replace them with
a new set of APIs named bpf_object__{prev,next}_{program,map} which
follow the libbpf API naming convention ([0]). No functionality changes.
[0] Closes: https://github.com/libbpf/libbpf/issues/296
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211003165844.4054931-2-hengqi.chen@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 18f4fccbf314fdb07d276f4cd3eaf53f1825550d
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat Oct 2 06:47:56 2021 +0530
libbpf: Update gen_loader to emit BTF_KIND_FUNC relocations
This change updates the BPF syscall loader to relocate BTF_KIND_FUNC
relocations, with support for weak kfunc relocations. The general idea
is to move map_fds to loader map, and also use the data for storing
kfunc BTF fds. Since both reuse the fd_array parameter, they need to be
kept together.
For map_fds, we reserve MAX_USED_MAPS slots in a region, and for kfunc,
we reserve MAX_KFUNC_DESCS. This is done so that insn->off has more
chances of being <= INT16_MAX than treating data map as a sparse array
and adding fd as needed.
When the MAX_KFUNC_DESCS limit is reached, we fall back to the sparse
array model, so that as long as it does remain <= INT16_MAX, we pass an
index relative to the start of fd_array.
We store all ksyms in an array where we try to avoid calling the
bpf_btf_find_by_name_kind helper, and also reuse the BTF fd that was
already stored. This also speeds up the loading process compared to
emitting calls in all cases, in later tests.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-9-memxor@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 466b2e13971ef65cd7b621ca3044be14028b002b
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat Oct 2 06:47:55 2021 +0530
libbpf: Resolve invalid weak kfunc calls with imm = 0, off = 0
Preserve these calls as it allows verifier to succeed in loading the
program if they are determined to be unreachable after dead code
elimination during program load. If not, the verifier will fail at
runtime. This is done for ext->is_weak symbols similar to the case for
variable ksyms.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-8-memxor@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 9dbe6015636c19f929a7f7b742f27f303ff6069d
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat Oct 2 06:47:54 2021 +0530
libbpf: Support kernel module function calls
This patch adds libbpf support for kernel module function call support.
The fd_array parameter is used during BPF program load to pass module
BTFs referenced by the program. insn->off is set to index into this
array, but starts from 1, because insn->off as 0 is reserved for
btf_vmlinux.
We try to use existing insn->off for a module, since the kernel limits
the maximum distinct module BTFs for kfuncs to 256, and also because
index must never exceed the maximum allowed value that can fit in
insn->off (INT16_MAX). In the future, if kernel interprets signed offset
as unsigned for kfunc calls, this limit can be increased to UINT16_MAX.
Also introduce a btf__find_by_name_kind_own helper to start searching
from module BTF's start id when we know that the BTF ID is not present
in vmlinux BTF (in find_ksym_btf_id).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-7-memxor@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit f731052325efc3726577feb743c7495f880ae07d
Author: Hengqi Chen <hengqi.chen@gmail.com>
Date: Fri Oct 1 00:14:55 2021 +0800
libbpf: Support uniform BTF-defined key/value specification across all BPF maps
A bunch of BPF maps do not support specifying BTF types for key and value.
This is non-uniform and inconvenient[0]. Currently, libbpf uses a retry
logic which removes BTF type IDs when BPF map creation failed. Instead
of retrying, this commit recognizes those specialized maps and removes
BTF type IDs when creating BPF map.
[0] Closes: https://github.com/libbpf/libbpf/issues/355
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210930161456.3444544-2-hengqi.chen@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 7c80c87ad56a05ec56069c3f5d7e60b5b1eb19b4
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 28 09:19:46 2021 -0700
selftests/bpf: Switch sk_lookup selftests to strict SEC("sk_lookup") use
Update "sk_lookup/" definition to be a stand-alone type specifier,
with backwards-compatible prefix match logic in non-libbpf-1.0 mode.
Currently in selftests all the "sk_lookup/<whatever>" uses just use
<whatever> for duplicated unique name encoding, which is redundant as
BPF program's name (C function name) uniquely and descriptively
identifies the intended use for such BPF programs.
With libbpf's SEC_DEF("sk_lookup") definition updated, switch existing
sk_lookup programs to use "unqualified" SEC("sk_lookup") section names,
with no random text after it.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-11-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit dd94d45cf0acb1d82748b17e1106b2c8b487b28b
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 28 09:19:45 2021 -0700
libbpf: Add opt-in strict BPF program section name handling logic
Implement strict ELF section name handling for BPF programs. It utilizes
`libbpf_set_strict_mode()` framework and adds new flag: LIBBPF_STRICT_SEC_NAME.
If this flag is set, libbpf will enforce exact section name matching for
a lot of program types that previously allowed just partial prefix
match. E.g., if previously SEC("xdp_whatever_i_want") was allowed, now
in strict mode only SEC("xdp") will be accepted, which makes SEC("")
definitions cleaner and more structured. SEC() now won't be used as yet
another way to uniquely encode BPF program identifier (for that
C function name is better and is guaranteed to be unique within
bpf_object). Now SEC() is strictly BPF program type and, depending on
program type, extra load/attach parameter specification.
Libbpf completely supports multiple BPF programs in the same ELF
section, so multiple BPF programs of the same type/specification easily
co-exist together within the same bpf_object scope.
Additionally, a new (for now internal) convention is introduced: section
name that can be a stand-alone exact BPF program type specificator, but
also could have extra parameters after '/' delimiter. An example of such
section is "struct_ops", which can be specified by itself, but also
allows to specify the intended operation to be attached to, e.g.,
"struct_ops/dctcp_init". Note, that "struct_ops_some_op" is not allowed.
Such section definition is specified as "struct_ops+".
This change is part of libbpf 1.0 effort ([0], [1]).
[0] Closes: https://github.com/libbpf/libbpf/issues/271
[1] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-10-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 15ea31fadd7f5b1076b4f91f75562bc319799c24
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 28 09:19:43 2021 -0700
libbpf: Refactor ELF section handler definitions
Refactor ELF section handler definitions table to use a set of flags and
unified SEC_DEF() macro. This allows for more succinct and table-like
set of definitions, and allows to more easily extend the logic without
adding more verbosity (this is utilized in later patches in the series).
This approach is also making libbpf-internal program pre-load callback
not rely on bpf_sec_def definition, which demonstrates that future
pluggable ELF section handlers will be able to achieve similar level of
integration without libbpf having to expose extra types and APIs.
For starters, update SEC_DEF() definitions and make them more succinct.
Also convert BPF_PROG_SEC() and BPF_APROG_COMPAT() definitions to
a common SEC_DEF() use.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-8-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 13d35a0cf1741431333ba4aa9bce9c5bbc88f63b
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 28 09:19:42 2021 -0700
libbpf: Reduce reliance of attach_fns on sec_def internals
Move closer to not relying on bpf_sec_def internals that won't be part
of public API, when pluggable SEC() handlers will be allowed. Drop
pre-calculated prefix length, and in various helpers don't rely on this
prefix length availability. Also minimize reliance on knowing
bpf_sec_def's prefix for few places where section prefix shortcuts are
supported (e.g., tp vs tracepoint, raw_tp vs raw_tracepoint).
Given checking some string for having a given string-constant prefix is
such a common operation and so annoying to be done with pure C code, add
a small macro helper, str_has_pfx(), and reuse it throughout libbpf.c
where prefix comparison is performed. With __builtin_constant_p() it's
possible to have a convenient helper that checks some string for having
a given prefix, where prefix is either string literal (or compile-time
known string due to compiler optimization) or just a runtime string
pointer, which is quite convenient and saves a lot of typing and string
literal duplication.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-7-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 12d9466d8bf3d1d4b4fd0f5733b6fa0cc5ee1013
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 28 09:19:41 2021 -0700
libbpf: Refactor internal sec_def handling to enable pluggability
Refactor internals of libbpf to allow adding custom SEC() handling logic
easily from outside of libbpf. To that effect, each SEC()-handling
registration sets mandatory program type/expected attach type for
a given prefix and can provide three callbacks called at different
points of BPF program lifetime:
- init callback for right after bpf_program is initialized and
prog_type/expected_attach_type is set. This happens during
bpf_object__open() step, close to the very end of constructing
bpf_object, so all the libbpf APIs for querying and updating
bpf_program properties should be available;
- pre-load callback is called right before BPF_PROG_LOAD command is
called in the kernel. This callbacks has ability to set both
bpf_program properties, as well as program load attributes, overriding
and augmenting the standard libbpf handling of them;
- optional auto-attach callback, which makes a given SEC() handler
support auto-attachment of a BPF program through bpf_program__attach()
API and/or BPF skeletons <skel>__attach() method.
Each callbacks gets a `long cookie` parameter passed in, which is
specified during SEC() handling. This can be used by callbacks to lookup
whatever additional information is necessary.
This is not yet completely ready to be exposed to the outside world,
mainly due to non-public nature of struct bpf_prog_load_params. Instead
of making it part of public API, we'll wait until the planned low-level
libbpf API improvements for BPF_PROG_LOAD and other typical bpf()
syscall APIs, at which point we'll have a public, probably OPTS-based,
way to fully specify BPF program load parameters, which will be used as
an interface for custom pre-load callbacks.
But this change itself is already a good first step to unify the BPF
program hanling logic even within the libbpf itself. As one example, all
the extra per-program type handling (sleepable bit, attach_btf_id
resolution, unsetting optional expected attach type) is now more obvious
and is gathered in one place.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-6-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit cc10623c681019c608c0cb30e2b38994e2c90b2a
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 21 14:00:36 2021 -0700
libbpf: Add legacy uprobe attaching support
Similarly to recently added legacy kprobe attach interface support
through tracefs, support attaching uprobes using the legacy interface if
host kernel doesn't support newer FD-based interface.
For uprobes event name consists of "libbpf_" prefix, PID, sanitized
binary path and offset within that binary. Structuraly the code is
aligned with kprobe logic refactoring in previous patch. struct
bpf_link_perf is re-used and all the same legacy_probe_name and
legacy_is_retprobe fields are used to ensure proper cleanup on
bpf_link__destroy().
Users should be aware, though, that on old kernels which don't support
FD-based interface for kprobe/uprobe attachment, if the application
crashes before bpf_link__destroy() is called, uprobe legacy
events will be left in tracefs. This is the same limitation as with
legacy kprobe interfaces.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-5-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 46ed5fc33db966aa1a46e8ae9d96b08b756a2546
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Tue Sep 21 14:00:35 2021 -0700
libbpf: Refactor and simplify legacy kprobe code
Refactor legacy kprobe handling code to follow the same logic as uprobe
legacy logic added in the next patchs:
- add append_to_file() helper that makes it simpler to work with
tracefs file-based interface for creating and deleting probes;
- move out probe/event name generation outside of the code that
adds/removes it, which simplifies bookkeeping significantly;
- change the probe name format to start with "libbpf_" prefix and
include offset within kernel function;
- switch 'unsigned long' to 'size_t' for specifying kprobe offsets,
which is consistent with how uprobes define that, simplifies
printf()-ing internally, and also avoids unnecessary complications on
architectures where sizeof(long) != sizeof(void *).
This patch also implicitly fixes the problem with invalid open() error
handling present in poke_kprobe_events(), which (the function) this
patch removes.
Fixes: ca304b40c20d ("libbpf: Introduce legacy kprobe events support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-4-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 91b555d73e53879fc6d4cf82c8c0e14c00ce212d
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Sep 15 18:58:35 2021 -0700
libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7
bpf_object_open_opts.attach_prog_fd makes a pretty strong assumption
that bpf_object contains either only single freplace BPF program or all
of BPF programs in BPF object are freplaces intended to replace
different subprograms of the same target BPF program. This seems both
a bit confusing, too assuming, and limiting.
We've had bpf_program__set_attach_target() API which allows more
fine-grained control over this, on a per-program level. As such, mark
open_opts.attach_prog_fd as deprecated starting from v0.7, so that we
have one more universal way of setting freplace targets. With previous
change to allow NULL attach_func_name argument, and especially combined
with BPF skeleton, arguable bpf_program__set_attach_target() is a more
convenient and explicit API as well.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-7-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 2d5ec1c66e25f0b4dd895a211e651a12dec2ef4f
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Sep 15 18:58:33 2021 -0700
libbpf: Allow skipping attach_func_name in bpf_program__set_attach_target()
Allow to use bpf_program__set_attach_target to only set target attach
program FD, while letting libbpf to use target attach function name from
SEC() definition. This might be useful for some scenarios where
bpf_object contains multiple related freplace BPF programs intended to
replace different sub-programs in target BPF program. In such case all
programs will have the same attach_prog_fd, but different
attach_func_name. It's convenient to specify such target function names
declaratively in SEC() definitions, but attach_prog_fd is a dynamic
runtime setting.
To simplify such scenario, allow bpf_program__set_attach_target() to
delay BTF ID resolution till the BPF program load time by providing NULL
attach_func_name. In that case the behavior will be similar to using
bpf_object_open_opts.attach_prog_fd (which is marked deprecated since
v0.7), but has the benefit of allowing more control by user in what is
attached to what. Such setup allows having BPF programs attached to
different target attach_prog_fd with target functions still declaratively
recorded in BPF source code in SEC() definitions.
Selftests changes in the next patch should make this more obvious.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-5-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit f11f86a3931b5d533aed1be1720fbd55bd63174d
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Wed Sep 15 18:58:30 2021 -0700
libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id()
Don't perform another search for sec_def inside
libbpf_find_attach_btf_id(), as each recognized bpf_program already has
prog->sec_def set.
Also remove unnecessary NULL check for prog->sec_name, as it can never
be NULL.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-2-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 5b84bd10363e36ceb7c4c1ae749a3fc8adf8df45
Author: Yonghong Song <yhs@fb.com>
Date: Tue Sep 14 15:30:25 2021 -0700
libbpf: Add support for BTF_KIND_TAG
Add BTF_KIND_TAG support for parsing and dedup.
Also added sanitization for BTF_KIND_TAG. If BTF_KIND_TAG is not
supported in the kernel, sanitize it to INTs.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223025.246687-1-yhs@fb.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit b6291a6f30d35bd4459dc35aac2f30669a4356ac
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Sep 13 18:47:33 2021 -0700
libbpf: Minimize explicit iterator of section definition array
Remove almost all the code that explicitly iterated BPF program section
definitions in favor of using find_sec_def(). The only remaining user of
section_defs is libbpf_get_type_names that has to iterate all of them to
construct its result.
Having one internal API entry point for section definitions will
simplify further refactorings around libbpf's program section
definitions parsing.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-5-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 5532dfd42e4846e84d346a6dfe01e477e35baa65
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Sep 13 18:47:32 2021 -0700
libbpf: Simplify BPF program auto-attach code
Remove the need to explicitly pass bpf_sec_def for auto-attachable BPF
programs, as it is already recorded at bpf_object__open() time for all
recognized type of BPF programs. This further reduces number of explicit
calls to find_sec_def(), simplifying further refactorings.
No functional changes are done by this patch.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-4-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 91b4d1d1d54431c72f3a7ff034f30a635f787426
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Mon Sep 13 18:47:31 2021 -0700
libbpf: Ensure BPF prog types are set before relocations
Refactor bpf_object__open() sequencing to perform BPF program type
detection based on SEC() definitions before we get to relocations
collection. This allows to have more information about BPF program by
the time we get to, say, struct_ops relocation gathering. This,
subsequently, simplifies struct_ops logic and removes the need to
perform extra find_sec_def() resolution.
With this patch libbpf will require all struct_ops BPF programs to be
marked with SEC("struct_ops") or SEC("struct_ops/xxx") annotations.
Real-world applications are already doing that through something like
selftests's BPF_STRUCT_OPS() macro. This change streamlines libbpf's
internal handling of SEC() definitions and is in the sprit of
upcoming libbpf-1.0 section strictness changes ([0]).
[0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-3-andrii@kernel.org
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit ca304b40c20d5750f08200f0ad3445384646620c
Author: Rafael David Tinoco <rafaeldtinoco@gmail.com>
Date: Sun Sep 12 03:48:44 2021 -0300
libbpf: Introduce legacy kprobe events support
Allow kprobe tracepoint events creation through legacy interface, as the
kprobe dynamic PMUs support, used by default, was only created in v4.17.
Store legacy kprobe name in struct bpf_perf_link, instead of creating
a new "subclass" off of bpf_perf_link. This is ok as it's just two new
fields, which are also going to be reused for legacy uprobe support in
follow up patches.
Signed-off-by: Rafael David Tinoco <rafaeldtinoco@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210912064844.3181742-1-rafaeldtinoco@gmail.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2069045
commit 03e601f48b2da6fb44d0f7b86957a8f6bacfb347
Author: Toke Høiland-Jørgensen <toke@redhat.com>
Date: Wed Sep 1 13:48:12 2021 +0200
libbpf: Don't crash on object files with no symbol tables
If libbpf encounters an ELF file that has been stripped of its symbol
table, it will crash in bpf_object__add_programs() when trying to
dereference the obj->efile.symbols pointer.
Fix this by erroring out of bpf_object__elf_collect() if it is not able
able to find the symbol table.
v2:
- Move check into bpf_object__elf_collect() and add nice error message
Fixes: 6245947c1b ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210901114812.204720-1-toke@redhat.com
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2041365
commit 4729445b47efebf089da4ccbcd1b116ffa2ad4af
Author: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu Sep 30 11:46:34 2021 +0530
libbpf: Fix segfault in light skeleton for objects without BTF
When fed an empty BPF object, bpftool gen skeleton -L crashes at
btf__set_fd() since it assumes presence of obj->btf, however for
the sequence below clang adds no .BTF section (hence no BTF).
Reproducer:
$ touch a.bpf.c
$ clang -O2 -g -target bpf -c a.bpf.c
$ bpftool gen skeleton -L a.bpf.o
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* THIS FILE IS AUTOGENERATED! */
struct a_bpf {
struct bpf_loader_ctx ctx;
Segmentation fault (core dumped)
The same occurs for files compiled without BTF info, i.e. without
clang's -g flag.
Fixes: 6723474373 (libbpf: Generate loader program out of BPF ELF file.)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210930061634.1840768-1-memxor@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2041365
commit 5e3b8356de3623987ace530b1977ffeb9ecf5a8a
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Sun Aug 15 00:06:08 2021 -0700
libbpf: Add uprobe ref counter offset support for USDT semaphores
When attaching to uprobes through perf subsystem, it's possible to specify
offset of a so-called USDT semaphore, which is just a reference counted u16,
used by kernel to keep track of how many tracers are attached to a given
location. Support for this feature was added in [0], so just wire this through
uprobe_opts. This is important to enable implementing USDT attachment and
tracing through libbpf's bpf_program__attach_uprobe_opts() API.
[0] a6ca88b241 ("trace_uprobe: support reference counter in fd-based uprobe")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-16-andrii@kernel.org
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Bugzilla: http://bugzilla.redhat.com/2041365
commit 47faff371755ba0f1ad76e2df7f5003377d974a5
Author: Andrii Nakryiko <andrii@kernel.org>
Date: Sun Aug 15 00:06:04 2021 -0700
libbpf: Add bpf_cookie to perf_event, kprobe, uprobe, and tp attach APIs
Wire through bpf_cookie for all attach APIs that use perf_event_open under the
hood:
- for kprobes, extend existing bpf_kprobe_opts with bpf_cookie field;
- for perf_event, uprobe, and tracepoint APIs, add their _opts variants and
pass bpf_cookie through opts.
For kernel that don't support BPF_LINK_CREATE for perf_events, and thus
bpf_cookie is not supported either, return error and log warning for user.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-12-andrii@kernel.org
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Jerome Marchand
Jiri Benc
Artem Savkov
Yauheni Kaliuta