kasan, mm: don't save alloc stacks twice

Patch series "kasan: optimizations and fixes for HW_TAGS", v4.

This patchset makes the HW_TAGS mode more efficient, mostly by reworking
poisoning approaches and simplifying/inlining some internal helpers.

With this change, the overhead of HW_TAGS annotations excluding setting
and checking memory tags is ~3%.  The performance impact caused by tags
will be unknown until we have hardware that supports MTE.

As a side-effect, this patchset speeds up generic KASAN by ~15%.

This patch (of 13):

Currently KASAN saves allocation stacks in both kasan_slab_alloc() and
kasan_kmalloc() annotations.  This patch changes KASAN to save allocation
stacks for slab objects from kmalloc caches in kasan_kmalloc() only, and
stacks for other slab objects in kasan_slab_alloc() only.

This change requires ____kasan_kmalloc() knowing whether the object
belongs to a kmalloc cache.  This is implemented by adding a flag field to
the kasan_info structure.  That flag is only set for kmalloc caches via a
new kasan_cache_create_kmalloc() annotation.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/7c673ebca8d00f40a7ad6f04ab9a2bddeeae2097.1612546384.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Branislav Rankov <[email protected]>
Cc: Kevin Brodsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions