Messages in this thread | | | Date | Tue, 14 Jan 2014 16:38:27 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH -v1.1] x86, CPU, AMD: Add workaround for family 16h, erratum 793 |
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On 01/14/2014 03:07 PM, Borislav Petkov wrote: > From: Borislav Petkov <bp@suse.de> > > This adds the workaround for erratum 793 as a precaution in case not > every BIOS implements it. This addresses CVE-2013-6885. > > Signed-off-by: Borislav Petkov <bp@suse.de> > Tested-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com> > --- > arch/x86/include/uapi/asm/msr-index.h | 1 + > arch/x86/kernel/cpu/amd.c | 10 ++++++++++ > 2 files changed, 11 insertions(+) > > diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h > index 37813b5ddc37..59cea185ad1d 100644 > --- a/arch/x86/include/uapi/asm/msr-index.h > +++ b/arch/x86/include/uapi/asm/msr-index.h > @@ -184,6 +184,7 @@ > #define MSR_AMD64_PATCH_LOADER 0xc0010020 > #define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140 > #define MSR_AMD64_OSVW_STATUS 0xc0010141 > +#define MSR_AMD64_LS_CFG 0xc0011020 > #define MSR_AMD64_DC_CFG 0xc0011022 > #define MSR_AMD64_BU_CFG2 0xc001102a > #define MSR_AMD64_IBSFETCHCTL 0xc0011030 > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > index 4a48e8bbd857..a4bec9cd293a 100644 > --- a/arch/x86/kernel/cpu/amd.c > +++ b/arch/x86/kernel/cpu/amd.c > @@ -507,6 +507,16 @@ static void early_init_amd(struct cpuinfo_x86 *c) > set_cpu_cap(c, X86_FEATURE_EXTD_APICID); > } > #endif > + > + /* F16h erratum 793, CVE-2013-6885 */ > + if (c->x86 == 0x16 && c->x86_model <= 0xf) { > + u64 val; > + > + rdmsrl(MSR_AMD64_LS_CFG, val); > + if (!(val & BIT(15))) > + wrmsrl(MSR_AMD_LS_CFG, val | BIT(15)); > + } > + > } > > static const int amd_erratum_383[]; >
In file included from /home/hpa/kernel/distwork/arch/x86/include/asm/processor.h:20:0, from /home/hpa/kernel/distwork/arch/x86/include/asm/thread_info.h:22, from /home/hpa/kernel/distwork/include/linux/thread_info.h:54, from /home/hpa/kernel/distwork/arch/x86/include/asm/elf.h:7, from /home/hpa/kernel/distwork/include/linux/elf.h:4, from /home/hpa/kernel/distwork/arch/x86/kernel/cpu/amd.c:4: /home/hpa/kernel/distwork/arch/x86/kernel/cpu/amd.c: In function ‘early_init_amd’: /home/hpa/kernel/distwork/arch/x86/kernel/cpu/amd.c:518:11: error: ‘MSR_AMD_LS_CFG’ undeclared (first use in this function) wrmsrl(MSR_AMD_LS_CFG, val | BIT(15)); ^ /home/hpa/kernel/distwork/arch/x86/include/asm/msr.h:156:20: note: in definition of macro ‘wrmsrl’ native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32)) ^ /home/hpa/kernel/distwork/arch/x86/kernel/cpu/amd.c:518:11: note: each undeclared identifier is reported only once for each function it appear s in wrmsrl(MSR_AMD_LS_CFG, val | BIT(15)); ^ /home/hpa/kernel/distwork/arch/x86/include/asm/msr.h:156:20: note: in definition of macro ‘wrmsrl’ native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
-hpa
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