Marco Elver 747c0f35f2 kfence: fix stack trace pruning ... Commit b140513524 ("mm/sl[au]b: generalize kmalloc subsystem") refactored large parts of the kmalloc subsystem, resulting in the stack trace pruning logic done by KFENCE to no longer work. While b140513524 attempted to fix the situation by including '__kmem_cache_free' in the list of functions KFENCE should skip through, this only works when the compiler actually optimized the tail call from kfree() to __kmem_cache_free() into a jump (and thus kfree() _not_ appearing in the full stack trace to begin with). In some configurations, the compiler no longer optimizes the tail call into a jump, and __kmem_cache_free() appears in the stack trace. This means that the pruned stack trace shown by KFENCE would include kfree() which is not intended - for example: | BUG: KFENCE: invalid free in kfree+0x7c/0x120 | | Invalid free of 0xffff8883ed8fefe0 (in kfence-#126): | kfree+0x7c/0x120 | test_double_free+0x116/0x1a9 | kunit_try_run_case+0x90/0xd0 | [...] Fix it by moving __kmem_cache_free() to the list of functions that may be tail called by an allocator entry function, making the pruning logic work in both the optimized and unoptimized tail call cases. Link: https://lkml.kernel.org/r/20221118152216.3914899-1-elver@google.com Fixes: b140513524 ("mm/sl[au]b: generalize kmalloc subsystem") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2022-11-22 18:50:44 -08:00
..
.kunitconfig	kfence: test: use new suite_{init/exit} support, add .kunitconfig	2022-05-02 12:35:57 -06:00
core.c	- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in	2022-10-10 17:53:04 -07:00
kfence.h	mm, kfence: support kmem_dump_obj() for KFENCE objects	2022-04-15 14:49:55 -07:00
kfence_test.c	Yang Shi has improved the behaviour of khugepaged collapsing of readonly	2022-05-26 12:32:41 -07:00
Makefile	mm/kfence: remove unnecessary CONFIG_KFENCE option	2022-03-22 15:57:11 -07:00
report.c	kfence: fix stack trace pruning	2022-11-22 18:50:44 -08:00