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mm: enable page poisoning early at boot

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On SPARSEMEM systems page poisoning is enabled after buddy is up,
because of the dependency on page extension init.  This causes the pages
released by free_all_bootmem not to be poisoned.  This either delays or
misses the identification of some issues because the pages have to
undergo another cycle of alloc-free-alloc for any corruption to be
detected.

Enable page poisoning early by getting rid of the PAGE_EXT_DEBUG_POISON
flag.  Since all the free pages will now be poisoned, the flag need not
be verified before checking the poison during an alloc.

[vinmenon@codeaurora.org: fix Kconfig]
  Link: http://lkml.kernel.org/r/1490878002-14423-1-git-send-email-vinmenon@codeaurora.org
Link: http://lkml.kernel.org/r/1490358246-11001-1-git-send-email-vinmenon@codeaurora.org
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Acked-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vinayak Menon
2017-05-03 14:54:42 -07:00
committed by Linus Torvalds
parent 2872bb2d0a
commit bd33ef3681
5 changed files with 17 additions and 88 deletions
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13
mm/page_alloc.c
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@@ -1689,10 +1689,10 @@ static inline int check_new_page(struct page *page)
return 1;
}
static inline bool free_pages_prezeroed(bool poisoned)
static inline bool free_pages_prezeroed(void)
{
return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
page_poisoning_enabled() && poisoned;
page_poisoning_enabled();
}
#ifdef CONFIG_DEBUG_VM
@@ -1746,17 +1746,10 @@ static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags
unsigned int alloc_flags)
{
int i;
bool poisoned = true;
for (i = 0; i < (1 << order); i++) {
struct page *p = page + i;
if (poisoned)
poisoned &= page_is_poisoned(p);
}
post_alloc_hook(page, order, gfp_flags);
if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO))
for (i = 0; i < (1 << order); i++)
clear_highpage(page + i);