lkml.org 
[lkml]   [2015]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] lib: fix data race in rhashtable_rehash_one
On 09/22/15 at 10:51am, Dmitry Vyukov wrote:
> rhashtable_rehash_one() uses complex logic to update entry->next field,
> after INIT_RHT_NULLS_HEAD and NULLS_MARKER expansion:
>
> entry->next = 1 | ((base + off) << 1)
>
> This can be compiled along the lines of:
>
> entry->next = base + off
> entry->next <<= 1
> entry->next |= 1
>
> Which will break concurrent readers.
>
> NULLS value recomputation is not needed here, so just remove
> the complex logic.
>
> The data race was found with KernelThreadSanitizer (KTSAN).
>
> Signed-off-by: Dmitry Vyukov <dvyukov@google.com>

Acked-by: Thomas Graf <tgraf@suug.ch>


\
 
 \ /
  Last update: 2015-09-22 11:41    [W:0.048 / U:2.332 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site