From: Christoph Lameter <clameter@sgi.com>
Date: Thu, 9 Jun 2005 19:29:00 +0000 (-0700)
Subject: [IA64] Fix race condition in the rt_sigprocmask fastcall
X-Git-Tag: v2.6.12~47^2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a2a64769d0d3cc0380b4b6ecdcb781a2f790a69e;p=pandora-kernel.git

[IA64] Fix race condition in the rt_sigprocmask fastcall

current->blocked will be set to the value of current->thread_info->flags if the
cmpxchg to update thread_info->flags fails. For performance reasons the store into
current->blocked was placed in the cmpxchg loop. However, the cmpxchg overwrites the
register holding the value to be stored. In the rare case of a retry the value of
thread_info->flags will be written into current->blocked.

The fix is to use another register so that the register containing the current->blocked
value is not overwritten.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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