[PATCH 3/5] tools/power turbostat: Fix offset overflow issue in index converting

From: Calvin Walton
Date: Fri Apr 23 2021 - 05:32:13 EST


The idx_to_offset() function returns type int (32-bit signed), but
MSR_PKG_ENERGY_STAT is greater than INT_MAX (or rather, would be
interpreted as a negative number). The end result is that it hits
the if (offset < 0) check in update_msr_sum() resulting in the timer
callback for updating the stat in the background when long durations
are used to not happen. The similar issue exists in offset_to_idx()
and update_msr_sum().

This patch fixes this issue by converting the 'int' type to 'off_t'
accordingly.

Fixes: 9972d5d84d76 ("tools/power turbostat: Enable accumulate RAPL display")
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
tools/power/x86/turbostat/turbostat.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index a211264b57fd..77557122b292 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -296,9 +296,9 @@ 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:
@@ -328,7 +328,7 @@ int idx_to_offset(int idx)
return offset;
}

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

@@ -3338,7 +3338,7 @@ 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;
@@ -3347,7 +3347,7 @@ 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", (long long int)offset);
continue;
}

thanks,
Chenyu
--
2.25.1


> --
> Calvin Walton <calvin.walton@xxxxxxxxxx>
>