[PATCH 2/2] tools/power turbostat: Fix offset overflow issue in index converting

From: Chen Yu
Date: Wed Apr 28 2021 - 05:05:54 EST


From: Calvin Walton <calvin.walton@xxxxxxxxxx>

The idx_to_offset() function returns type int (32-bit signed), but
MSR_PKG_ENERGY_STAT is u32 and would be interpreted as a negative number.
The end result is that it hits the if (offset < 0) check in update_msr_sum()
which prevents the timer callback from updating the stat in the background when
long durations are used. The similar issue exists in offset_to_idx() and
update_msr_sum(). Fix this issue by converting the 'int' to 'off_t' accordingly.

Fixes: 9972d5d84d76 ("tools/power turbostat: Enable accumulate RAPL display")
Signed-off-by: Calvin Walton <calvin.walton@xxxxxxxxxx>
---
tools/power/x86/turbostat/turbostat.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 37759d6c463d..085057daef86 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -291,9 +291,9 @@ struct msr_sum_array {
/* The percpu MSR sum array.*/
struct msr_sum_array *per_cpu_msr_sum;

-int idx_to_offset(int idx)
+off_t idx_to_offset(int idx)
{
- int offset;
+ off_t offset;

switch (idx) {
case IDX_PKG_ENERGY:
@@ -323,7 +323,7 @@ int idx_to_offset(int idx)
return offset;
}

-int offset_to_idx(int offset)
+int offset_to_idx(off_t offset)
{
int idx;

@@ -3276,7 +3276,7 @@ static int update_msr_sum(struct thread_data *t, struct core_data *c, struct pkg

for (i = IDX_PKG_ENERGY; i < IDX_COUNT; i++) {
unsigned long long msr_cur, msr_last;
- int offset;
+ off_t offset;

if (!idx_valid(i))
continue;
@@ -3285,7 +3285,8 @@ static int update_msr_sum(struct thread_data *t, struct core_data *c, struct pkg
continue;
ret = get_msr(cpu, offset, &msr_cur);
if (ret) {
- fprintf(outf, "Can not update msr(0x%x)\n", offset);
+ fprintf(outf, "Can not update msr(0x%llx)\n",
+ (unsigned long long)offset);
continue;
}

--
2.25.1