summaryrefslogtreecommitdiff
path: root/mm/page-writeback.c
diff options
context:
space:
mode:
authorchenjie <chenjie6@huawei.com>2017-11-30 03:10:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-30 05:40:43 +0300
commit6ea8d958a2c95a1d514015d4e29ba21a8c0a1a91 (patch)
treece8cb7704e78795e561d07aabb43f22718745f8f /mm/page-writeback.c
parent04e35f4495dd560db30c25efca4eecae8ec8c375 (diff)
downloadlinux-6ea8d958a2c95a1d514015d4e29ba21a8c0a1a91.tar.xz
mm/madvise.c: fix madvise() infinite loop under special circumstances
MADVISE_WILLNEED has always been a noop for DAX (formerly XIP) mappings. Unfortunately madvise_willneed() doesn't communicate this information properly to the generic madvise syscall implementation. The calling convention is quite subtle there. madvise_vma() is supposed to either return an error or update &prev otherwise the main loop will never advance to the next vma and it will keep looping for ever without a way to get out of the kernel. It seems this has been broken since introduction. Nobody has noticed because nobody seems to be using MADVISE_WILLNEED on these DAX mappings. [mhocko@suse.com: rewrite changelog] Link: http://lkml.kernel.org/r/20171127115318.911-1-guoxuenan@huawei.com Fixes: fe77ba6f4f97 ("[PATCH] xip: madvice/fadvice: execute in place") Signed-off-by: chenjie <chenjie6@huawei.com> Signed-off-by: guoxuenan <guoxuenan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: zhangyi (F) <yi.zhang@huawei.com> Cc: Miao Xie <miaoxie@huawei.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Shaohua Li <shli@fb.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
0 files changed, 0 insertions, 0 deletions