3.16.68-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Borislav Petkov <bp@xxxxxxx> commit 80a208bd3948aceddf0429bd9f9b4cd858d526df upstream. 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: Borislav Petkov <bp@xxxxxxx> Link: http://lkml.kernel.org/r/1403609105-8332-2-git-send-email-bp@xxxxxxxxx Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- arch/x86/include/asm/cpufeature.h | 10 ++++-- arch/x86/kernel/cpu/mkcapflags.sh | 51 ++++++++++++++++++++++--------- arch/x86/kernel/cpu/proc.c | 8 +++++ 3 files changed, 53 insertions(+), 16 deletions(-) --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -268,8 +268,8 @@ #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_CPU_MELTDOWN X86_BUG(5) /* CPU is affected by meltdown attack and needs kernel page table isolation */ #define X86_BUG_SPECTRE_V1 X86_BUG(6) /* CPU is affected by Spectre variant 1 attack with conditional branches */ #define X86_BUG_SPECTRE_V2 X86_BUG(7) /* CPU is affected by Spectre variant 2 attack with indirect branches */ @@ -284,6 +284,12 @@ 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)) --- a/arch/x86/kernel/cpu/mkcapflags.sh +++ b/arch/x86/kernel/cpu/mkcapflags.sh @@ -1,23 +1,25 @@ #!/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=$2 -TABS="$(printf '\t\t\t\t\t')" -trap 'rm "$OUT"' EXIT +function dump_array() +{ + ARRAY=$1 + SIZE=$2 + PFX=$3 + POSTFIX=$4 -( - echo "#ifndef _ASM_X86_CPUFEATURE_H" - echo "#include <asm/cpufeature.h>" - echo "#endif" - echo "" - echo "const char * const x86_cap_flags[NCAPINTS*32] = {" + PFX_SZ=$(echo $PFX | wc -c) + TABS="$(printf '\t\t\t\t\t')" + + 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 --- a/arch/x86/kernel/cpu/proc.c +++ b/arch/x86/kernel/cpu/proc.c @@ -97,6 +97,14 @@ static int show_cpuinfo(struct seq_file 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);
