diff options
Diffstat (limited to 'spectre-meltdown-checker.sh')
| -rwxr-xr-x | spectre-meltdown-checker.sh | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/spectre-meltdown-checker.sh b/spectre-meltdown-checker.sh index 906646a..9296dd3 100755 --- a/spectre-meltdown-checker.sh +++ b/spectre-meltdown-checker.sh @@ -885,6 +885,7 @@ check_variant2() load_msr fi if [ ! -e /dev/cpu/0/msr ]; then + spec_ctrl_msr=-1 pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?" else # the new MSR 'SPEC_CTRL' is at offset 0x48 @@ -893,8 +894,10 @@ check_variant2() # skip=9 because 8*9=72=0x48 dd if=/dev/cpu/0/msr of=/dev/null bs=8 count=1 skip=9 2>/dev/null if [ $? -eq 0 ]; then + spec_ctrl_msr=1 pstatus green YES else + spec_ctrl_msr=0 pstatus red NO fi fi @@ -987,6 +990,41 @@ check_variant2() fi fi + # STIBP + _info " * Single Thread Indirect Branch Predictors (STIBP)" + _info_nol " * SPEC_CTRL MSR is available: " + if [ "$spec_ctrl_msr" = 1 ]; then + pstatus green YES + elif [ "$spec_ctrl_msr" = 0 ]; then + pstatus red NO + else + pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?" + fi + + _info_nol " * CPU indicates STIBP capability: " + if [ ! -e /dev/cpu/0/cpuid ]; then + pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuidr, is cpuid support enabled in your kernel?" + else + # A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1 + if [ "$opt_verbose" -ge 3 ]; then + dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null + _debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?" + _debug "cpuid: leaf7 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n) + _debug "cpuid: leaf7 edx higher byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n) + fi + # getting high byte of edx on leaf7 of cpuinfo in decimal + edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}') + _debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)" + edx_bit27=$(( edx_hb & 8 )) + _debug "cpuid: edx_bit27=$edx_bit27" + if [ "$edx_bit27" -eq 8 ]; then + pstatus green YES "STIBP feature bit" + cpuid_stibp=1 + else + pstatus red NO + fi + fi + _info_nol " * Kernel is compiled with IBRS/IBPB support: " ibrs_can_tell=0 |