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Commit 80a208bd authored by Borislav Petkov's avatar Borislav Petkov Committed by H. Peter Anvin
Browse files

x86/cpufeature: Add bug flags to /proc/cpuinfo 



Dump the flags which denote we have detected and/or have applied bug
workarounds to the CPU we're executing on, in a similar manner to the
feature flags.

The advantage is that those are not accumulating over time like the CPU
features.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1403609105-8332-2-git-send-email-bp@alien8.de


Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 9b13a93d

arch/x86/include/asm/cpufeature.h

+8 −2
Original line number Diff line number Diff line
@@ -239,8 +239,8 @@ 
#define X86_BUG_F00F		X86_BUG(0) /* Intel F00F */

#define X86_BUG_FDIV		X86_BUG(1) /* FPU FDIV */

#define X86_BUG_COMA		X86_BUG(2) /* Cyrix 6x86 coma */

#define X86_BUG_AMD_TLB_MMATCH	X86_BUG(3) /* AMD Erratum 383 */

#define X86_BUG_AMD_APIC_C1E	X86_BUG(4) /* AMD Erratum 400 */

#define X86_BUG_AMD_TLB_MMATCH	X86_BUG(3) /* "tlb_mmatch" AMD Erratum 383 */

#define X86_BUG_AMD_APIC_C1E	X86_BUG(4) /* "apic_c1e" AMD Erratum 400 */

#define X86_BUG_11AP		X86_BUG(5) /* Bad local APIC aka 11AP */

#define X86_BUG_FXSAVE_LEAK	X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */

#define X86_BUG_CLFLUSH_MONITOR	X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
@@ -253,6 +253,12 @@ 
extern const char * const x86_cap_flags[NCAPINTS*32];

extern const char * const x86_power_flags[32];



/*

 * In order to save room, we index into this array by doing

 * X86_BUG_<name> - NCAPINTS*32.

 */

extern const char * const x86_bug_flags[NBUGINTS*32];



#define test_cpu_cap(c, bit)						\

	 test_bit(bit, (unsigned long *)((c)->x86_capability))

arch/x86/kernel/cpu/mkcapflags.sh

+37 −14
Original line number Diff line number Diff line 
#!/bin/sh

#

# Generate the x86_cap_flags[] array from include/asm/cpufeature.h

# Generate the x86_cap/bug_flags[] arrays from include/asm/cpufeature.h

#



IN=$1

OUT=$2



function dump_array()

{

	ARRAY=$1

	SIZE=$2

	PFX=$3

	POSTFIX=$4



	PFX_SZ=$(echo $PFX | wc -c)

	TABS="$(printf '\t\t\t\t\t')"

trap 'rm "$OUT"' EXIT



(

	echo "#ifndef _ASM_X86_CPUFEATURE_H"

	echo "#include <asm/cpufeature.h>"

	echo "#endif"

	echo ""

	echo "const char * const x86_cap_flags[NCAPINTS*32] = {"

	echo "const char * const $ARRAY[$SIZE] = {"



	# Iterate through any input lines starting with #define X86_FEATURE_

	sed -n -e 's/\t/ /g' -e 's/^ *# *define *X86_FEATURE_//p' $IN |

	# Iterate through any input lines starting with #define $PFX

	sed -n -e 's/\t/ /g' -e "s/^ *# *define *$PFX//p" $IN |

	while read i

	do

		# Name is everything up to the first whitespace
@@ -31,11 +33,32 @@ trap 'rm "$OUT"' EXIT 
		# Name is uppercase, VALUE is all lowercase

		VALUE="$(echo "$VALUE" | tr A-Z a-z)"



		TABCOUNT=$(( ( 5*8 - 14 - $(echo "$NAME" | wc -c) ) / 8 ))

		printf "\t[%s]%.*s = %s,\n" \

			"X86_FEATURE_$NAME" "$TABCOUNT" "$TABS" "$VALUE"

        if [ -n "$POSTFIX" ]; then

            T=$(( $PFX_SZ + $(echo $POSTFIX | wc -c) + 2 ))

	        TABS="$(printf '\t\t\t\t\t\t')"

		    TABCOUNT=$(( ( 6*8 - ($T + 1) - $(echo "$NAME" | wc -c) ) / 8 ))

		    printf "\t[%s - %s]%.*s = %s,\n" "$PFX$NAME" "$POSTFIX" "$TABCOUNT" "$TABS" "$VALUE"

        else

		    TABCOUNT=$(( ( 5*8 - ($PFX_SZ + 1) - $(echo "$NAME" | wc -c) ) / 8 ))

            printf "\t[%s]%.*s = %s,\n" "$PFX$NAME" "$TABCOUNT" "$TABS" "$VALUE"

        fi

	done

	echo "};"

}



trap 'rm "$OUT"' EXIT



(

	echo "#ifndef _ASM_X86_CPUFEATURE_H"

	echo "#include <asm/cpufeature.h>"

	echo "#endif"

	echo ""



	dump_array "x86_cap_flags" "NCAPINTS*32" "X86_FEATURE_" ""

	echo ""



	dump_array "x86_bug_flags" "NBUGINTS*32" "X86_BUG_" "NCAPINTS*32"



) > $OUT



trap - EXIT

arch/x86/kernel/cpu/proc.c

+8 −0
Original line number Diff line number Diff line
@@ -97,6 +97,14 @@ static int show_cpuinfo(struct seq_file *m, void *v) 
		if (cpu_has(c, i) && x86_cap_flags[i] != NULL)

			seq_printf(m, " %s", x86_cap_flags[i]);



	seq_printf(m, "\nbugs\t\t:");

	for (i = 0; i < 32*NBUGINTS; i++) {

		unsigned int bug_bit = 32*NCAPINTS + i;



		if (cpu_has_bug(c, bug_bit) && x86_bug_flags[i])

			seq_printf(m, " %s", x86_bug_flags[i]);

	}



	seq_printf(m, "\nbogomips\t: %lu.%02lu\n",

		   c->loops_per_jiffy/(500000/HZ),

		   (c->loops_per_jiffy/(5000/HZ)) % 100);