@@ -786,32 +786,36 @@ static inline void clear_page_guard(stru
*/
void init_mem_debugging_and_hardening(void)
{
+ bool page_poisoning_requested = false;
+
+#ifdef CONFIG_PAGE_POISONING
+ /*
+ * Page poisoning is debug page alloc for some arches. If
+ * either of those options are enabled, enable poisoning.
+ */
+ if (page_poisoning_enabled() ||
+ (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
+ debug_pagealloc_enabled())) {
+ static_branch_enable(&_page_poisoning_enabled);
+ page_poisoning_requested = true;
+ }
+#endif
+
if (_init_on_alloc_enabled_early) {
- if (page_poisoning_enabled())
+ if (page_poisoning_requested)
pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
"will take precedence over init_on_alloc\n");
else
static_branch_enable(&init_on_alloc);
}
if (_init_on_free_enabled_early) {
- if (page_poisoning_enabled())
+ if (page_poisoning_requested)
pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
"will take precedence over init_on_free\n");
else
static_branch_enable(&init_on_free);
}
-#ifdef CONFIG_PAGE_POISONING
- /*
- * Page poisoning is debug page alloc for some arches. If
- * either of those options are enabled, enable poisoning.
- */
- if (page_poisoning_enabled() ||
- (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
- debug_pagealloc_enabled()))
- static_branch_enable(&_page_poisoning_enabled);
-#endif
-
#ifdef CONFIG_DEBUG_PAGEALLOC
if (!debug_pagealloc_enabled())
return;
The patch titled Subject: mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1 has been removed from the -mm tree. Its filename was mm-page_alloc-ignore-init_on_free=1-for-debug_pagealloc=1.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Sergei Trofimovich <slyfox@gentoo.org> Subject: mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1 On !ARCH_SUPPORTS_DEBUG_PAGEALLOC (like ia64) debug_pagealloc=1 implies page_poison=on: if (page_poisoning_enabled() || (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && debug_pagealloc_enabled())) static_branch_enable(&_page_poisoning_enabled); page_poison=on needs to override init_on_free=1. Before the change it did not work as expected for the following case: - have PAGE_POISONING=y - have page_poison unset - have !ARCH_SUPPORTS_DEBUG_PAGEALLOC arch (like ia64) - have init_on_free=1 - have debug_pagealloc=1 That way we get both keys enabled: - static_branch_enable(&init_on_free); - static_branch_enable(&_page_poisoning_enabled); which leads to poisoned pages returned for __GFP_ZERO pages. After the change we execute only: - static_branch_enable(&_page_poisoning_enabled); and ignore init_on_free=1. Link: https://lkml.kernel.org/r/20210329222555.3077928-1-slyfox@gentoo.org Link: https://lkml.org/lkml/2021/3/26/443 Fixes: 8db26a3d4735 ("mm, page_poison: use static key more efficiently") Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/page_alloc.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-)