On Thu, 23 Jul 2015 08:31:39 -0700 Andy Lutomirski <l...@kernel.org> wrote:
> Switch from wrmsr to wrmsrl_safe to prepare to merge the 32-bit and > 64-bit code, and use __KERNEL_CS explicitly to initialize > MSR_IA32_SYSENTER_CS. While we're at it, tweak the whitespace a > bit. Saying "prepare to merge the 32-bit and 64-bit" isn't that informative to why this patch is needed. Can you please describe in the change log what can fault with the wrmsr call, when we do the merge? Thanks! -- Steve > > Signed-off-by: Andy Lutomirski <l...@kernel.org> > --- > arch/x86/kernel/cpu/common.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 922c5e0cea4c..9b3a43583f81 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1001,15 +1001,13 @@ void enable_sep_cpu(void) > * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field -- > * see the big comment in struct x86_hw_tss's definition. > */ > - > tss->x86_tss.ss1 = __KERNEL_CS; > - wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0); > - > - wrmsr(MSR_IA32_SYSENTER_ESP, > - (unsigned long)tss + offsetofend(struct tss_struct, > SYSENTER_stack), > - 0); > > - wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0); > + wrmsrl_safe(MSR_IA32_SYSENTER_CS, __KERNEL_CS); > + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, > + (unsigned long)tss + > + offsetofend(struct tss_struct, SYSENTER_stack)); > + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32); > > out: > put_cpu(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
