From 65fc985b37dc241c4db7cd32adcbc989193fe3c8 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 20 Mar 2013 15:07:23 +0100 Subject: [PATCH] x86, cpu: Expand cpufeature facility to include cpu bugs We add another 32-bit vector at the end of the ->x86_capability bitvector which collects bugs present in CPUs. After all, a CPU bug is a kind of a capability, albeit a strange one. Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/1363788448-31325-2-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/cpufeature.h | 13 +++++++++++++ arch/x86/include/asm/processor.h | 2 +- arch/x86/kernel/alternative.c | 2 +- arch/x86/kernel/cpu/common.c | 4 ++++ 4 files changed, 19 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 93fe929..16190ab 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -9,6 +9,7 @@ #endif #define NCAPINTS 10 /* N 32-bit words worth of info */ +#define NBUGINTS 1 /* N 32-bit bug flags */ /* * Note: If the comment begins with a quoted string, that string is used @@ -216,6 +217,11 @@ #define X86_FEATURE_ADX (9*32+19) /* The ADCX and ADOX instructions */ #define X86_FEATURE_SMAP (9*32+20) /* Supervisor Mode Access Prevention */ +/* + * BUG word(s) + */ +#define X86_BUG(x) (NCAPINTS*32 + (x)) + #if defined(__KERNEL__) && !defined(__ASSEMBLY__) #include @@ -401,6 +407,13 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) #define static_cpu_has(bit) boot_cpu_has(bit) #endif +#define cpu_has_bug(c, bit) cpu_has(c, (bit)) +#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) +#define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit)); + +#define static_cpu_has_bug(bit) static_cpu_has((bit)) +#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) + #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ #endif /* _ASM_X86_CPUFEATURE_H */ diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 3270116..23c8081d 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -107,7 +107,7 @@ struct cpuinfo_x86 { __u32 extended_cpuid_level; /* Maximum supported CPUID level, -1=no CPUID: */ int cpuid_level; - __u32 x86_capability[NCAPINTS]; + __u32 x86_capability[NCAPINTS + NBUGINTS]; char x86_vendor_id[16]; char x86_model_id[64]; /* in KB - valid for CPUS which support this call: */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ef5ccca..c15cf9a 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -271,7 +271,7 @@ void __init_or_module apply_alternatives(struct alt_instr *start, replacement = (u8 *)&a->repl_offset + a->repl_offset; BUG_ON(a->replacementlen > a->instrlen); BUG_ON(a->instrlen > sizeof(insnbuf)); - BUG_ON(a->cpuid >= NCAPINTS*32); + BUG_ON(a->cpuid >= (NCAPINTS + NBUGINTS) * 32); if (!boot_cpu_has(a->cpuid)) continue; diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index d814772..22018f7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -920,6 +920,10 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) /* AND the already accumulated flags with these */ for (i = 0; i < NCAPINTS; i++) boot_cpu_data.x86_capability[i] &= c->x86_capability[i]; + + /* OR, i.e. replicate the bug flags */ + for (i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++) + c->x86_capability[i] |= boot_cpu_data.x86_capability[i]; } /* Init Machine Check Exception if available. */ -- 2.7.4