lkml.org 
[lkml]   [2017]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] mm/cma: fix alloc_contig_range ret code/potential leak
On Wed, Nov 22, 2017 at 10:52:14AM -0800, Mike Kravetz wrote:
> If the call __alloc_contig_migrate_range() in alloc_contig_range
> returns -EBUSY, processing continues so that test_pages_isolated()
> is called where there is a tracepoint to identify the busy pages.
> However, it is possible for busy pages to become available between
> the calls to these two routines. In this case, the range of pages
> may be allocated. Unfortunately, the original return code (ret
> == -EBUSY) is still set and returned to the caller. Therefore,
> the caller believes the pages were not allocated and they are leaked.
>
> Update comment to indicate that allocation is still possible even if
> __alloc_contig_migrate_range returns -EBUSY. Also, clear return code
> in this case so that it is not accidentally used or returned to caller.
>
> Fixes: 8ef5849fa8a2 ("mm/cma: always check which page caused allocation failure")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

\
 
 \ /
  Last update: 2017-11-27 18:04    [W:0.087 / U:7.360 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site