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fix: rework read_msr for values > INT32_MAX (#507)

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Stéphane Lesimple
2026-03-30 20:53:13 +02:00
parent 72824deea5
commit 3d6acc460e
4 changed files with 41 additions and 30 deletions
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30
src/libs/340_cpu_msr.sh
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@@ -155,7 +155,7 @@ readonly READ_MSR_RET_KO=1
readonly READ_MSR_RET_ERR=2
# Read an MSR register value across one or all cores
# Args: $1=msr_address $2=cpu_index(optional, default 0)
# Sets: ret_read_msr_value, ret_read_msr_msg
# Sets: ret_read_msr_value, ret_read_msr_value_hi, ret_read_msr_value_lo, ret_read_msr_msg
# Returns: READ_MSR_RET_OK | READ_MSR_RET_KO | READ_MSR_RET_ERR
read_msr() {
local ret core first_core_ret first_core_value
@@ -187,21 +187,31 @@ read_msr() {
# Read an MSR register value from a single CPU core
# Args: $1=core $2=msr_address
# Sets: ret_read_msr_value, ret_read_msr_msg
# Sets: ret_read_msr_value, ret_read_msr_value_hi, ret_read_msr_value_lo, ret_read_msr_msg
# Returns: READ_MSR_RET_OK | READ_MSR_RET_KO | READ_MSR_RET_ERR
read_msr_one_core() {
local ret core msr msr_dec mockvarname msr_h msr_l
local ret core msr msr_dec mockvarname msr_h msr_l mockval
core="$1"
msr_dec=$(($2))
msr=$(printf "0x%x" "$msr_dec")
ret_read_msr_value=''
ret_read_msr_value_hi=''
ret_read_msr_value_lo=''
ret_read_msr_msg='unknown error'
mockvarname="SMC_MOCK_RDMSR_${msr}"
# shellcheck disable=SC2086,SC1083
if [ -n "$(eval echo \${$mockvarname:-})" ]; then
ret_read_msr_value="$(eval echo \$$mockvarname)"
mockval="$(eval echo \$$mockvarname)"
# accept both legacy decimal (small values) and new 16-char hex format
if [ "${#mockval}" -eq 16 ]; then
ret_read_msr_value="$mockval"
else
ret_read_msr_value=$(printf '%016x' "$mockval")
fi
ret_read_msr_value_hi=$((0x${ret_read_msr_value%????????}))
ret_read_msr_value_lo=$((0x${ret_read_msr_value#????????}))
pr_debug "read_msr: MOCKING enabled for msr $msr, returning $ret_read_msr_value"
g_mocked=1
return $READ_MSR_RET_OK
@@ -235,7 +245,7 @@ read_msr_one_core() {
# MSR 0x10: 0x000003e1 0xb106dded
msr_h=$(echo "$msr" | awk '{print $3}')
msr_l=$(echo "$msr" | awk '{print $4}')
ret_read_msr_value=$((msr_h << 32 | msr_l))
ret_read_msr_value=$(printf '%08x%08x' "$((msr_h))" "$((msr_l))")
else
# for Linux
if [ ! -r $CPU_DEV_BASE/"$core"/msr ]; then
@@ -245,15 +255,15 @@ read_msr_one_core() {
# if rdmsr is available, use it
elif command -v rdmsr >/dev/null 2>&1 && [ "${SMC_NO_RDMSR:-}" != 1 ]; then
pr_debug "read_msr: using rdmsr on $msr"
ret_read_msr_value=$(rdmsr -r $msr_dec 2>/dev/null | od -t u8 -A n)
ret_read_msr_value=$(rdmsr -r $msr_dec 2>/dev/null | od -A n -t x8)
# or if we have perl, use it, any 5.x version will work
elif command -v perl >/dev/null 2>&1 && [ "${SMC_NO_PERL:-}" != 1 ]; then
pr_debug "read_msr: using perl on $msr"
ret_read_msr_value=$(perl -e "open(M,'<','$CPU_DEV_BASE/$core/msr') and seek(M,$msr_dec,0) and read(M,\$_,8) and print" | od -t u8 -A n)
ret_read_msr_value=$(perl -e "open(M,'<','$CPU_DEV_BASE/$core/msr') and seek(M,$msr_dec,0) and read(M,\$_,8) and print" | od -A n -t x8)
# fallback to dd if it supports skip_bytes
elif dd if=/dev/null of=/dev/null bs=8 count=1 skip="$msr_dec" iflag=skip_bytes 2>/dev/null; then
pr_debug "read_msr: using dd on $msr"
ret_read_msr_value=$(dd if=$CPU_DEV_BASE/"$core"/msr bs=8 count=1 skip="$msr_dec" iflag=skip_bytes 2>/dev/null | od -t u8 -A n)
ret_read_msr_value=$(dd if=$CPU_DEV_BASE/"$core"/msr bs=8 count=1 skip="$msr_dec" iflag=skip_bytes 2>/dev/null | od -A n -t x8)
else
pr_debug "read_msr: got no rdmsr, perl or recent enough dd!"
g_mockme=$(printf "%b\n%b" "$g_mockme" "SMC_MOCK_RDMSR_${msr}_RET=$READ_MSR_RET_ERR")
@@ -266,8 +276,10 @@ read_msr_one_core() {
return $READ_MSR_RET_KO
fi
# remove sparse spaces od might give us
ret_read_msr_value=$((ret_read_msr_value))
ret_read_msr_value=$(printf '%s' "$ret_read_msr_value" | tr -d ' \t\n' | tr '[:upper:]' '[:lower:]')
fi
ret_read_msr_value_hi=$((0x${ret_read_msr_value%????????}))
ret_read_msr_value_lo=$((0x${ret_read_msr_value#????????}))
g_mockme=$(printf "%b\n%b" "$g_mockme" "SMC_MOCK_RDMSR_${msr}='$ret_read_msr_value'")
pr_debug "read_msr: MSR=$msr value is $ret_read_msr_value"
return $READ_MSR_RET_OK