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Commit 65fc985b authored by Borislav Petkov's avatar Borislav Petkov Committed by H. Peter Anvin
Browse files

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: default avatarBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1363788448-31325-2-git-send-email-bp@alien8.de


Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 07961ac7

arch/x86/include/asm/cpufeature.h

+13 −0
Original line number Diff line number Diff line
@@ -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 <asm/asm.h>
@@ -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 */

arch/x86/include/asm/processor.h

+1 −1
Original line number Diff line number Diff line
@@ -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: */

arch/x86/kernel/alternative.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

arch/x86/kernel/cpu/common.c

+4 −0
Original line number Diff line number Diff line
@@ -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. */