aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorQian Cai <cai@lca.pw>2019-02-12 15:36:03 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-12 16:33:18 -0800
commit2f1ee0913ce58efe7f18fbd518bd54c598559b89 (patch)
treec1959338eb8f79370256f1c20cda38cf9021baf5
parent414fd080d125408cb15d04ff4907e1dd8145c8c7 (diff)
downloadlinux-stericsson-2f1ee0913ce58efe7f18fbd518bd54c598559b89.tar.gz
Revert "mm: use early_pfn_to_nid in page_ext_init"
This reverts commit fe53ca54270a ("mm: use early_pfn_to_nid in page_ext_init"). When booting a system with "page_owner=on", start_kernel 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 The issue here is that page_to_nid() will not work since some page flags have no node information until later in page_alloc_init_late() due to DEFERRED_STRUCT_PAGE_INIT. Hence, it could trigger an out-of-bounds access with an invalid nid. UBSAN: Undefined behaviour in ./include/linux/mm.h:1104:50 index 7 is out of range for type 'zone [5]' Also, kernel will panic since flags were poisoned earlier with, CONFIG_DEBUG_VM_PGFLAGS=y CONFIG_NODE_NOT_IN_PAGE_FLAGS=n start_kernel setup_arch pagetable_init paging_init sparse_init sparse_init_nid memblock_alloc_try_nid_raw It did not handle it well in init_pages_in_zone() which ends up calling page_to_nid(). page:ffffea0004200000 is uninitialized and poisoned raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) page_owner info is not active (free page?) kernel BUG at include/linux/mm.h:990! RIP: 0010:init_page_owner+0x486/0x520 This means that assumptions behind commit fe53ca54270a ("mm: use early_pfn_to_nid in page_ext_init") are incomplete. Therefore, revert the commit for now. A proper way to move the page_owner initialization to sooner is to hook into memmap initialization. Link: http://lkml.kernel.org/r/20190115202812.75820-1-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Yang Shi <yang.shi@linaro.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--init/main.c3
-rw-r--r--mm/page_ext.c4
2 files changed, 3 insertions, 4 deletions
diff --git a/init/main.c b/init/main.c
index e2e80ca3165a..c86a1c8f19f4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -695,7 +695,6 @@ asmlinkage __visible void __init start_kernel(void)
initrd_start = 0;
}
#endif
- page_ext_init();
kmemleak_init();
setup_per_cpu_pageset();
numa_policy_init();
@@ -1131,6 +1130,8 @@ static noinline void __init kernel_init_freeable(void)
sched_init_smp();
page_alloc_init_late();
+ /* Initialize page ext after all struct pages are initialized. */
+ page_ext_init();
do_basic_setup();
diff --git a/mm/page_ext.c b/mm/page_ext.c
index ae44f7adbe07..8c78b8d45117 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -398,10 +398,8 @@ void __init page_ext_init(void)
* We know some arch can have a nodes layout such as
* -------------pfn-------------->
* N0 | N1 | N2 | N0 | N1 | N2|....
- *
- * Take into account DEFERRED_STRUCT_PAGE_INIT.
*/
- if (early_pfn_to_nid(pfn) != nid)
+ if (pfn_to_nid(pfn) != nid)
continue;
if (init_section_page_ext(pfn, nid))
goto oom;