* Patch "mm/madvise.c: fix madvise() infinite loop under special circumstances" has been added to the 4.9-stable tree
@ 2017-12-04 8:49 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2017-12-04 8:49 UTC (permalink / raw)
To: chenjie6, aarcange, akpm, cotte, dan.j.williams, gregkh,
guoxuenan, khandual, kirill.shutemov, mgorman, mhocko, miaoxie,
minchan, riel, rientjes, rppt, shli, torvalds, yi.zhang
Cc: stable, stable-commits
This is a note to let you know that I've just added the patch titled
mm/madvise.c: fix madvise() infinite loop under special circumstances
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-madvise.c-fix-madvise-infinite-loop-under-special-circumstances.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From 6ea8d958a2c95a1d514015d4e29ba21a8c0a1a91 Mon Sep 17 00:00:00 2001
From: chenjie <chenjie6@huawei.com>
Date: Wed, 29 Nov 2017 16:10:54 -0800
Subject: mm/madvise.c: fix madvise() infinite loop under special circumstances
From: chenjie <chenjie6@huawei.com>
commit 6ea8d958a2c95a1d514015d4e29ba21a8c0a1a91 upstream.
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>
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>
---
mm/madvise.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -228,15 +228,14 @@ static long madvise_willneed(struct vm_a
{
struct file *file = vma->vm_file;
+ *prev = vma;
#ifdef CONFIG_SWAP
if (!file) {
- *prev = vma;
force_swapin_readahead(vma, start, end);
return 0;
}
if (shmem_mapping(file->f_mapping)) {
- *prev = vma;
force_shm_swapin_readahead(vma, start, end,
file->f_mapping);
return 0;
@@ -251,7 +250,6 @@ static long madvise_willneed(struct vm_a
return 0;
}
- *prev = vma;
start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
if (end > vma->vm_end)
end = vma->vm_end;
Patches currently in stable-queue which might be from chenjie6@huawei.com are
queue-4.9/mm-madvise.c-fix-madvise-infinite-loop-under-special-circumstances.patch
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2017-12-04 8:49 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-12-04 8:49 Patch "mm/madvise.c: fix madvise() infinite loop under special circumstances" has been added to the 4.9-stable tree gregkh
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.