The patch titled
Subject: mm/page_alloc.c: call kernel_map_pages in unset_migrateype_isolate
has been added to the -mm tree. Its filename is
mm-page_alloc-call-kernel_map_pages-in-unset_migrateype_isolate.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-call-kernel_map_pages-in-unset_migrateype_isolate.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-call-kernel_map_pages-in-unset_migrateype_isolate.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Laura Abbott <[email protected]>
Subject: mm/page_alloc.c: call kernel_map_pages in unset_migrateype_isolate
Commit 3c605096d315 ("mm/page_alloc: restrict max order of merging on
isolated pageblock") changed the logic of unset_migratetype_isolate to
check the buddy allocator and explicitly call __free_pages to merge. The
page that is being freed in this path never had prep_new_page called so
set_page_refcounted is called explicitly but there is no call to
kernel_map_pages. With the default kernel_map_pages this is mostly
harmless but if kernel_map_pages does any manipulation of the page tables
(unmapping or setting pages to read only) this may trigger a fault:
alloc_contig_range test_pages_isolated(ceb00, ced00) failed
Unable to handle kernel paging request at virtual address ffffffc0cec00000
pgd = ffffffc045fc4000
[ffffffc0cec00000] *pgd=0000000000000000
Internal error: Oops: 9600004f [#1] PREEMPT SMP
Modules linked in: exfatfs
CPU: 1 PID: 23237 Comm: TimedEventQueue Not tainted 3.10.49-gc72ad36-dirty
#1
task: ffffffc03de52100 ti: ffffffc015388000 task.ti: ffffffc015388000
PC is at memset+0xc8/0x1c0
LR is at kernel_map_pages+0x1ec/0x244
Fix this by calling kernel_map_pages to ensure the page is set in the
page table properly
Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated
pageblock")
Signed-off-by: Laura Abbott <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Mel Gorman <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Cc: Zhang Yanfei <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Acked-by: Joonsoo Kim <[email protected]>
Cc: Gioh Kim <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
mm/page_isolation.c | 1 +
1 file changed, 1 insertion(+)
diff -puN
mm/page_isolation.c~mm-page_alloc-call-kernel_map_pages-in-unset_migrateype_isolate
mm/page_isolation.c
---
a/mm/page_isolation.c~mm-page_alloc-call-kernel_map_pages-in-unset_migrateype_isolate
+++ a/mm/page_isolation.c
@@ -103,6 +103,7 @@ void unset_migratetype_isolate(struct pa
if (!is_migrate_isolate_page(buddy)) {
__isolate_free_page(page, order);
+ kernel_map_pages(page, (1 << order), 1);
set_page_refcounted(page);
isolated_page = page;
}
_
Patches currently in -mm which might be from [email protected] are
mm-page_alloc-call-kernel_map_pages-in-unset_migrateype_isolate.patch
mm-cma-debugfs-interface.patch
mm-cma-allocation-trigger.patch
mm-cma-release-trigger.patch
mm-cma-allocation-trigger-fix.patch
cma-debug-document-new-debugfs-interface.patch
mm-dont-offset-memmap-for-flatmem.patch
seccomp-allow-compat-sigreturn-overrides.patch
arm-use-asm-generic-for-seccomph.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
