Messages in this thread Patch in this message | | | Date | Mon, 5 Dec 2011 16:10:16 +0100 | From | Borislav Petkov <> | Subject | Re: [GIT PULL] x86, microcode fixes for 3.2 |
| |
On Mon, Dec 05, 2011 at 10:26:12AM +0100, Ingo Molnar wrote: > Mind respinning this once more against latest -git? There's a > new conflict due to: > > 8e8da023f5af: x86: Fix boot failures on older AMD CPU's
Branch is updated, it also contains the following patch:
-- From: Borislav Petkov <borislav.petkov@amd.com> Date: Mon, 5 Dec 2011 14:28:37 +0100 Subject: [PATCH] x86: Document rdmsr_safe restrictions
Recently, I got bitten by using rdmsr_safe too early in the boot process. Document its shortcomings for future reference.
Link: http://lkml.kernel.org/r/4ED5B70F.606@lwfinger.net Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> --- arch/x86/include/asm/msr.h | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 084ef95..95203d4 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -169,7 +169,14 @@ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high) return native_write_msr_safe(msr, low, high); } -/* rdmsr with exception handling */ +/* + * rdmsr with exception handling. + * + * Please note that the exception handling works only after we've + * switched to the "smart" #GP handler in trap_init() which knows about + * exception tables - using this macro earlier than that causes machine + * hangs on boxes which do not implement the @msr in the first argument. + */ #define rdmsr_safe(msr, p1, p2) \ ({ \ int __err; \ -- 1.7.8.rc0 Thanks.
-- Regards/Gruss, Boris.
Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551
| |