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| author | Andy Lutomirski <[email protected]> | 2015-04-26 23:47:59 +0000 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2015-04-27 00:57:38 +0000 |
| commit | 61f01dd941ba9e06d2bf05994450ecc3d61b6b8b (patch) | |
| tree | 3a4a4ef2d5e4d44bb4cb1708f9fc4749e9c9824a /scripts/kconfig/expr.c | |
| parent | Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux (diff) | |
| download | kernel-61f01dd941ba9e06d2bf05994450ecc3d61b6b8b.tar.gz kernel-61f01dd941ba9e06d2bf05994450ecc3d61b6b8b.zip | |
x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue
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 <[email protected]>
Cc: Peter Anvin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Brian Gerst <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'scripts/kconfig/expr.c')
0 files changed, 0 insertions, 0 deletions