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check spec_ctrl support using cpuid

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This commit is contained in:
Stéphane Lesimple 2018-01-13 16:24:09 +01:00
parent dead0054a4
commit c483a2cf60
1 changed files with 40 additions and 3 deletions
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43
spectre-meltdown-checker.sh
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@ -8,7 +8,7 @@
#
# Stephane Lesimple
#
VERSION=0.29
VERSION='0.29+cpuid_spec_ctrl-test1'
show_usage()
{
@ -664,11 +664,11 @@ check_variant2()
sys_interface_available=1
else
_info "* Mitigation 1"
_info_nol "* Hardware (CPU microcode) support for mitigation: "
_info_nol "* Hardware / CPU microcode support for mitigation (SPEC_CTRL MSR): "
if [ ! -e /dev/cpu/0/msr ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
modprobe msr 2>/dev/null && insmod_msr=1
_debug "attempted to load module msr, ret=$insmod_msr"
_debug "attempted to load module msr, insmod_msr=$insmod_msr"
fi
if [ ! -e /dev/cpu/0/msr ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
@ -690,6 +690,43 @@ check_variant2()
_debug "attempted to unload module msr, ret=$?"
fi
# CPUID test
_info_nol "* Hardware / CPU microcode support for mitigation (CPUID bit): "
# $(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}'); echo $z; echo $(($z & 32))
if [ ! -e /dev/cpu/0/cpuid ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
modprobe cpuid 2>/dev/null && insmod_cpuid=1
_debug "attempted to load module cpuid, insmod_cpuid=$insmod_cpuid"
fi
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuidr, is cpuid support enabled in your kernel?"
else
# from kernel src: { X86_FEATURE_SPEC_CTRL, CPUID_EDX,26, 0x00000007, 0 },
if [ "$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=$?"
_debug "cpuid: leaf7 eax-ebx-ecd-edx: "$(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-half 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: $edx_hb (decimal)"
edx_bit26=$(( edx_hb & 8 ))
_debug "cpuid: edx_bit26=$edx_bit26"
if [ "$edx_bit26" -eq 8 ]; then
pstatus green YES
else
pstatus red NO
fi
fi
if [ "$insmod_cpuid" = 1 ]; then
# if we used modprobe ourselves, rmmod the module
rmmod cpuid 2>/dev/null
_debug "attempted to unload module cpuid, ret=$?"
fi
# /CPUID test
_info_nol "* Kernel support for IBRS: "
if [ "$opt_live" = 1 ]; then
mount_debugfs