Messages in this thread | | | Date | Sun, 25 Mar 2012 12:27:23 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [GIT PULL] x86, microcode fixes for 3.2 |
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On 12/05/2011 07:10 AM, Borislav Petkov wrote: > > 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; \
I keep wondering if we couldn't have the early-static trap handlers be aware of exception tables, too; they wouldn't have to worry about modules and so it would be reasonably easy.
-hpa
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