From: Qian Cai <cai@lca.pw>
To: akpm@linux-foundation.org
Cc: mingo@kernel.org, mhocko@suse.com, hpa@zytor.com,
mgorman@techsingularity.net, tglx@linutronix.de,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Qian Cai <cai@lca.pw>
Subject: [PATCH] mm: skip checking poison pattern for page_to_nid()
Date: Tue, 18 Dec 2018 20:57:32 -0500 [thread overview]
Message-ID: <20181219015732.26179-1-cai@lca.pw> (raw)
In-Reply-To: <1545172285.18411.26.camel@lca.pw>
Kernel panic with page_owner=on
CONFIG_DEBUG_VM_PGFLAGS=y
PAGE_OWNER=y
NODE_NOT_IN_PAGE_FLAGS=n
This is due to f165b378bbd (mm: uninitialized struct page poisoning
sanity checking) shoots itself in the foot.
[ 11.917212] page:ffffea0004200000 is uninitialized and poisoned
[ 11.917220] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff
ffffffffffffffff
[ 11.921745] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff
ffffffffffffffff
[ 11.924523] page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
[ 11.926498] page_owner info is not active (free page?)
[ 12.329560] kernel BUG at include/linux/mm.h:990!
[ 12.337632] RIP: 0010:init_page_owner+0x486/0x520
At first,
start_kernel
setup_arch
pagetable_init
paging_init
sparse_init
sparse_init_nid
sparse_buffer_init
memblock_virt_alloc_try_nid_raw
It poisons all the allocated pages there.
memset(ptr, PAGE_POISON_PATTERN, size)
Later,
page_ext_init
invoke_init_callbacks
init_section_page_ext
init_page_owner
init_early_allocated_pages
init_zones_in_node
init_pages_in_zone
lookup_page_ext
page_to_nid
PF_POISONED_CHECK <--- panic here.
This because all allocated pages are not initialized until later.
init_pages_in_zone
__set_page_owner_handle
Fixes: f165b378bbd (mm: uninitialized struct page poisoning
sanity checking)
Signed-off-by: Qian Cai <cai@lca.pw>
---
include/linux/mm.h | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411de93a363..f083f366ea90 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -985,9 +985,7 @@ extern int page_to_nid(const struct page *page);
#else
static inline int page_to_nid(const struct page *page)
{
- struct page *p = (struct page *)page;
-
- return (PF_POISONED_CHECK(p)->flags >> NODES_PGSHIFT) & NODES_MASK;
+ return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
}
#endif
--
2.17.2 (Apple Git-113)
next parent reply other threads:[~2018-12-19 1:57 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1545172285.18411.26.camel@lca.pw>
2018-12-19 1:57 ` Qian Cai [this message]
2018-12-19 10:20 ` [PATCH] mm: skip checking poison pattern for page_to_nid() Michal Hocko
2018-12-19 12:46 ` Qian Cai
2018-12-20 6:03 ` [PATCH] mm/page_owner: fix for deferred struct page init Qian Cai
2018-12-20 9:22 ` Michal Hocko
2018-12-20 18:50 ` [PATCH v2] " Qian Cai
2018-12-20 20:31 ` [PATCH v3] " Qian Cai
2018-12-20 21:00 ` William Kucharski
2018-12-20 21:04 ` Qian Cai
2019-01-03 11:51 ` Michal Hocko
2019-01-03 16:38 ` Qian Cai
2019-01-03 16:59 ` Michal Hocko
2019-01-03 17:38 ` Qian Cai
2019-01-03 19:07 ` Michal Hocko
2019-01-03 19:53 ` Qian Cai
2019-01-03 20:22 ` Michal Hocko
2019-01-03 22:22 ` Qian Cai
2019-01-04 13:09 ` Michal Hocko
2019-01-04 15:01 ` Qian Cai
2019-01-04 15:17 ` Michal Hocko
2019-01-04 15:25 ` Qian Cai
2019-01-04 15:32 ` Michal Hocko
2019-01-04 20:18 ` Qian Cai
2019-01-07 18:43 ` Michal Hocko
2019-01-08 1:53 ` Qian Cai
2019-01-08 8:20 ` Michal Hocko
2019-01-08 13:19 ` Qian Cai
2019-01-08 22:02 ` Andrew Morton
2019-01-08 22:13 ` Qian Cai
2019-01-08 22:40 ` Michal Hocko
2019-01-09 7:34 ` [PATCH v2] " Michal Hocko
2019-01-15 20:28 ` [PATCH] Revert "mm: use early_pfn_to_nid in page_ext_init" Qian Cai
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