Revision 61f01dd941ba9e06d2bf05994450ecc3d61b6b8b authored by Andy Lutomirski on 26 April 2015, 23:47:59 UTC, committed by Linus Torvalds on 27 April 2015, 00:57:38 UTC
AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
SS == 0 results in an invalid usermode state in which SS is apparently
equal to __USER_DS but causes #SS if used.

Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
ensuring that SYSRET never happens with SS set to NULL.

This was exposed by a recent vDSO cleanup.

Fixes: e7d6eefaaa44 x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1190944
History
File Mode Size
include
Kconfig -rw-r--r-- 5.1 KB
Makefile -rw-r--r-- 533 bytes
Makefile.boot -rw-r--r-- 642 bytes
adssphere.c -rw-r--r-- 1.2 KB
clock.c -rw-r--r-- 14.0 KB
core.c -rw-r--r-- 30.4 KB
crunch-bits.S -rw-r--r-- 8.4 KB
crunch.c -rw-r--r-- 2.0 KB
dma.c -rw-r--r-- 3.7 KB
edb93xx.c -rw-r--r-- 10.3 KB
gesbc9312.c -rw-r--r-- 1.2 KB
micro9.c -rw-r--r-- 3.5 KB
simone.c -rw-r--r-- 2.2 KB
snappercl15.c -rw-r--r-- 4.6 KB
soc.h -rw-r--r-- 8.3 KB
ts72xx.c -rw-r--r-- 6.3 KB
ts72xx.h -rw-r--r-- 2.3 KB
vision_ep9307.c -rw-r--r-- 9.1 KB

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