diff options
author | Rokudo Yan <wu-yan@tcl.com> | 2021-02-05 05:32:20 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-10 11:25:31 +0300 |
commit | 56d61cd652dd75bf35c61c05303c40cd59356879 (patch) | |
tree | 8c061db368538fa04e9d7d6550aebbd3c86899d8 /mm | |
parent | 90ef21e5806f992daf1be603f2b9643eabe14866 (diff) | |
download | linux-56d61cd652dd75bf35c61c05303c40cd59356879.tar.xz |
mm, compaction: move high_pfn to the for loop scope
commit 74e21484e40bb8ce0f9828bbfe1c9fc9b04249c6 upstream.
In fast_isolate_freepages, high_pfn will be used if a prefered one (ie
PFN >= low_fn) not found.
But the high_pfn is not reset before searching an free area, so when it
was used as freepage, it may from another free area searched before. As
a result move_freelist_head(freelist, freepage) will have unexpected
behavior (eg corrupt the MOVABLE freelist)
Unable to handle kernel paging request at virtual address dead000000000200
Mem abort info:
ESR = 0x96000044
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000044
CM = 0, WnR = 1
[dead000000000200] address between user and kernel address ranges
-000|list_cut_before(inline)
-000|move_freelist_head(inline)
-000|fast_isolate_freepages(inline)
-000|isolate_freepages(inline)
-000|compaction_alloc(?, ?)
-001|unmap_and_move(inline)
-001|migrate_pages([NSD:0xFFFFFF80088CBBD0] from = 0xFFFFFF80088CBD88, [NSD:0xFFFFFF80088CBBC8] get_new_p
-002|__read_once_size(inline)
-002|static_key_count(inline)
-002|static_key_false(inline)
-002|trace_mm_compaction_migratepages(inline)
-002|compact_zone(?, [NSD:0xFFFFFF80088CBCB0] capc = 0x0)
-003|kcompactd_do_work(inline)
-003|kcompactd([X19] p = 0xFFFFFF93227FBC40)
-004|kthread([X20] _create = 0xFFFFFFE1AFB26380)
-005|ret_from_fork(asm)
The issue was reported on an smart phone product with 6GB ram and 3GB
zram as swap device.
This patch fixes the issue by reset high_pfn before searching each free
area, which ensure freepage and freelist match when call
move_freelist_head in fast_isolate_freepages().
Link: http://lkml.kernel.org/r/20190118175136.31341-12-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210112094720.1238444-1-wu-yan@tcl.com
Fixes: 5a811889de10f1eb ("mm, compaction: use free lists to quickly locate a migration target")
Signed-off-by: Rokudo Yan <wu-yan@tcl.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/compaction.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 92470625f0b1..88c3f6bad1ab 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1276,7 +1276,7 @@ fast_isolate_freepages(struct compact_control *cc) { unsigned int limit = min(1U, freelist_scan_limit(cc) >> 1); unsigned int nr_scanned = 0; - unsigned long low_pfn, min_pfn, high_pfn = 0, highest = 0; + unsigned long low_pfn, min_pfn, highest = 0; unsigned long nr_isolated = 0; unsigned long distance; struct page *page = NULL; @@ -1321,6 +1321,7 @@ fast_isolate_freepages(struct compact_control *cc) struct page *freepage; unsigned long flags; unsigned int order_scanned = 0; + unsigned long high_pfn = 0; if (!area->nr_free) continue; |