Vlastimil Babka fa44968ac4 FROMGIT: mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO ... CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA. It was introduced by commit 1414c7f4f7 ("mm/page_poisoning.c: allow for zero poisoning"), noting that using zeroes retains the benefit of sanitizing content of freed pages, with the benefit of not having to zero them again on alloc, and the downside of making some forms of corruption (stray writes of NULLs) harder to detect than with the 0xAA pattern. Together with CONFIG_PAGE_POISONING_NO_SANITY it made possible to sanitize the contents on free without checking it back on alloc. These days we have the init_on_free() option to achieve sanitization with zeroes and to save clearing on alloc (and without checking on alloc). Arguably if someone does choose to check the poison for corruption on alloc, the savings of not clearing the page are secondary, and it makes sense to always use the 0xAA poison pattern. Thus, remove the CONFIG_PAGE_POISONING_ZERO option for being redundant. Link: https://lkml.kernel.org/r/20201113104033.22907-6-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <labbott@kernel.org> Cc: Mateusz Nosek <mateusznosek0@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit f289041ed4 https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm) Bug: 182930667 Signed-off-by: Alexander Potapenko <glider@google.com> Change-Id: I57e19d1dd77d3d5eec40f94c1b64a877c3710baa		2021-03-24 15:09:17 -07:00
..
asm	tools: Add missing stdio.h include to asm/bug.h header	2019-09-25 09:51:44 -03:00
asm-generic	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36	2019-05-24 17:27:11 +02:00
linux	FROMGIT: mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO	2021-03-24 15:09:17 -07:00
nolibc	tool headers nolibc: add RISCV support	2019-05-08 15:48:43 +02:00
tools	tools: bpf: fix license for a compat header file	2018-09-19 23:49:58 +02:00
trace/events	tools/lib/lockdep: Remove private kernel headers	2017-06-05 09:28:14 +02:00
uapi	tools headers UAPI: Sync linux/fscrypt.h with the kernel sources	2021-01-17 14:17:06 +01:00
vdso	tools headers: Synchronize linux/bits.h with the kernel sources	2020-04-14 11:40:05 -03:00