x86-32, espfix: Remove filter for espfix32 due to race
authorH. Peter Anvin <hpa@linux.intel.com>
Wed, 30 Apr 2014 21:03:25 +0000 (14:03 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 1 Jul 2014 03:09:45 +0000 (20:09 -0700)
commit7a1d06c86697d727ef095f6e675e378ee9caae1a
treede19e5c5f65a57b74478b6dd0d4ce7b6b4c1593c
parent43507abd621cb72b55142e7b18a4aa77a19aa3f3
x86-32, espfix: Remove filter for espfix32 due to race

commit 246f2d2ee1d715e1077fc47d61c394569c8ee692 upstream.

It is not safe to use LAR to filter when to go down the espfix path,
because the LDT is per-process (rather than per-thread) and another
thread might change the descriptors behind our back.  Fortunately it
is always *safe* (if a bit slow) to go down the espfix path, and a
32-bit LDT stack segment is extremely rare.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kernel/entry_32.S