diff options
| author | Mike Rapoport (Microsoft) <rppt@kernel.org> | 2025-04-23 17:48:07 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-12 23:50:33 -0700 |
| commit | 6bbf0e728528addd5f9dd140b03b06438f032166 (patch) | |
| tree | 6c72586e1d27775295a8fd955c049922271c86c2 /mm/execmem.c | |
| parent | b25f97d0f8043903a64e3a203b79219cc69f2f77 (diff) | |
execmem: enforce allocation size aligment to PAGE_SIZE
Before introduction of ROX cache execmem allocation size was always
implicitly aligned to PAGE_SIZE inside vmalloc.
However, when allocation happens from the ROX cache, this is not
enforced.
Make sure that the allocation size is always consistently aligned to
PAGE_SIZE.
Mike said:
: Right now it'll make the maple trees in execmem_cache more compact.
: And it's a precaution for the case when execmem callers would want to
: change permissions on unaligned range because that would WARN_ON()
: loudly.
Peter said
: It should not have a runtime effect -- currently all this code is used
: with PAGE_SIZE multiples and everything just works. But whilst I was
: perusing this code, I noticed that nothing actually enforced this. If
: someone were to break this assumption things will go sideways.
Link: https://lkml.kernel.org/r/20250423144808.1619863-1-rppt@kernel.org
Fixes: 2e45474ab14f ("execmem: add support for cache of large ROX pages")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/execmem.c')
| -rw-r--r-- | mm/execmem.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/execmem.c b/mm/execmem.c index e6c4f5076ca8..2b683e7d864d 100644 --- a/mm/execmem.c +++ b/mm/execmem.c @@ -377,6 +377,8 @@ void *execmem_alloc(enum execmem_type type, size_t size) pgprot_t pgprot = range->pgprot; void *p; + size = PAGE_ALIGN(size); + if (use_cache) p = execmem_cache_alloc(range, size); else |