diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2022-08-26 10:18:07 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-09-11 16:22:29 -0700 |
| commit | 65d3440e8d2e9e024ef2357f8ff021611b068c99 (patch) | |
| tree | ac49d5f6d958a1ada1a0012320ad9b56b8863c8e | |
| parent | fd63612ae81159bd7e59762de478889315463ee8 (diff) | |
mm/memory-failure: fix detection of memory_failure() handlers
Some pagemap types, like MEMORY_DEVICE_GENERIC (device-dax) do not even
have pagemap ops which results in crash signatures like this:
BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 8000000205073067 P4D 8000000205073067 PUD 2062b3067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 22 PID: 4535 Comm: device-dax Tainted: G OE N 6.0.0-rc2+ #59
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:memory_failure+0x667/0xba0
[..]
Call Trace:
<TASK>
? _printk+0x58/0x73
do_madvise.part.0.cold+0xaf/0xc5
Check for ops before checking if the ops have a memory_failure()
handler.
Link: https://lkml.kernel.org/r/166153428781.2758201.1990616683438224741.stgit@dwillia2-xfh.jf.intel.com
Fixes: 33a8f7f2b3a3 ("pagemap,pmem: introduce ->memory_failure()")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/memremap.h | 5 | ||||
| -rw-r--r-- | mm/memory-failure.c | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 19010491a603..c3b4cc84877b 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -139,6 +139,11 @@ struct dev_pagemap { }; }; +static inline bool pgmap_has_memory_failure(struct dev_pagemap *pgmap) +{ + return pgmap->ops && pgmap->ops->memory_failure; +} + static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap) { if (pgmap->flags & PGMAP_ALTMAP_VALID) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 14439806b5ef..8a4294afbfa0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1928,7 +1928,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, * Call driver's implementation to handle the memory failure, otherwise * fall back to generic handler. */ - if (pgmap->ops->memory_failure) { + if (pgmap_has_memory_failure(pgmap)) { rc = pgmap->ops->memory_failure(pgmap, pfn, 1, flags); /* * Fall back to generic handler too if operation is not |