linux-kernelorg-stable/rust/helpers/mm.c

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mm: rust: add abstraction for struct mm_struct Patch series "Rust support for mm_struct, vm_area_struct, and mmap", v16. This updates the vm_area_struct support to use the approach we discussed at LPC where there are several different Rust wrappers for vm_area_struct depending on the kind of access you have to the vma. Each case allows a different set of operations on the vma. This includes an MM MAINTAINERS entry as proposed by Lorenzo: https://lore.kernel.org/all/33e64b12-aa07-4e78-933a-b07c37ff1d84@lucifer.local/ This patch (of 9): These abstractions allow you to reference a `struct mm_struct` using both mmgrab and mmget refcounts. This is done using two Rust types: * Mm - represents an mm_struct where you don't know anything about the value of mm_users. * MmWithUser - represents an mm_struct where you know at compile time that mm_users is non-zero. This allows us to encode in the type system whether a method requires that mm_users is non-zero or not. For instance, you can always call `mmget_not_zero` but you can only call `mmap_read_lock` when mm_users is non-zero. The struct is called Mm to keep consistency with the C side. The ability to obtain `current->mm` is added later in this series. The mm module is defined to only exist when CONFIG_MMU is set. This avoids various errors due to missing types and functions when CONFIG_MMU is disabled. More fine-grained cfgs can be considered in the future. See the thread at [1] for more info. Link: https://lkml.kernel.org/r/20250408-vma-v16-9-d8b446e885d9@google.com Link: https://lkml.kernel.org/r/20250408-vma-v16-1-d8b446e885d9@google.com Link: https://lore.kernel.org/all/202503091916.QousmtcY-lkp@intel.com/ Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Balbir Singh <balbirs@nvidia.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benno Lossin <benno.lossin@proton.me> Cc: Björn Roy Baron <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jann Horn <jannh@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Trevor Gross <tmgross@umich.edu> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-08 09:22:38 +00:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/mm.h>
#include <linux/sched/mm.h>
void rust_helper_mmgrab(struct mm_struct *mm)
{
mmgrab(mm);
}
void rust_helper_mmdrop(struct mm_struct *mm)
{
mmdrop(mm);
}
void rust_helper_mmget(struct mm_struct *mm)
{
mmget(mm);
}
bool rust_helper_mmget_not_zero(struct mm_struct *mm)
{
return mmget_not_zero(mm);
}
void rust_helper_mmap_read_lock(struct mm_struct *mm)
{
mmap_read_lock(mm);
}
bool rust_helper_mmap_read_trylock(struct mm_struct *mm)
{
return mmap_read_trylock(mm);
}
void rust_helper_mmap_read_unlock(struct mm_struct *mm)
{
mmap_read_unlock(mm);
}