Marco Elver 4933295622 kfence: shorten critical sections of alloc/free ... Initializing memory and setting/checking the canary bytes is relatively expensive, and doing so in the meta->lock critical sections extends the duration with preemption and interrupts disabled unnecessarily. Any reads to meta->addr and meta->size in kfence_guarded_alloc() and kfence_guarded_free() don't require locking meta->lock as long as the object is removed from the freelist: only kfence_guarded_alloc() sets meta->addr and meta->size after removing it from the freelist, which requires a preceding kfence_guarded_free() returning it to the list or the initial state. Therefore move reads to meta->addr and meta->size, including expensive memory initialization using them, out of meta->lock critical sections. Link: https://lkml.kernel.org/r/20210930153706.2105471-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-11-06 13:30:43 -07:00
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core.c	kfence: shorten critical sections of alloc/free	2021-11-06 13:30:43 -07:00
kfence.h	kfence: limit currently covered allocations when pool nearly full	2021-11-06 13:30:43 -07:00
kfence_test.c	kfence: test: use kunit_skip() to skip tests	2021-11-06 13:30:43 -07:00
Makefile	kfence: add test suite	2021-02-26 09:41:02 -08:00
report.c	Merge branch 'akpm' (patches from Andrew)	2021-09-08 12:55:35 -07:00