x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM CPUID bit
authorBorislav Petkov <borislav.petkov@amd.com>
Mon, 31 Aug 2009 07:50:11 +0000 (09:50 +0200)
committerH. Peter Anvin <hpa@zytor.com>
Mon, 31 Aug 2009 22:14:29 +0000 (15:14 -0700)
commit6b0f43ddfa358dc71ad2a2d57bce5906c1c5dc1a
tree6c25cbfcd551a794678429979ac082f0c1f4251c
parent177fed1ee8d727c39601ce9fc2299b4cb25a718e
x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM CPUID bit

fbd8b1819e80ac5a176d085fdddc3a34d1499318 turns off the bit for
/proc/cpuinfo. However, a proper/full fix would be to additionally
turn off the bit in the CPUID output so that future callers get
correct CPU features info.

Do that by basically reversing what the BIOS wrongfully does at boot.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1251705011-18636-3-git-send-email-petkovbb@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
arch/x86/kernel/cpu/amd.c