6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zhang Rui <rui.zhang@xxxxxxxxx>
[ Upstream commit fed8511cc8996989178823052dc0200643e1389a ]
parse_cpu_string() parses the string input either from command line or
from /sys/fs/cgroup/cpuset.cpus.effective to get a list of CPUs that
turbostat can run with.
The cpu string returned by /sys/fs/cgroup/cpuset.cpus.effective contains
a trailing '\n', but strtoul() fails to treat this as an error.
That says, for the code below
val = ("\n", NULL, 10);
val returns 0, and errno is also not set.
As a result, CPU0 is erroneously considered as allowed CPU and this
causes failures when turbostat tries to run on CPU0.
get_counters: Could not migrate to CPU 0
...
turbostat: re-initialized with num_cpus 8, allowed_cpus 5
get_counters: Could not migrate to CPU 0
Add a check to return immediately if '\n' or '\0' is detected.
Fixes: 8c3dd2c9e542 ("tools/power/turbostat: Abstrct function for parsing cpu string")
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/power/x86/turbostat/turbostat.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 089220aaa5c92..aa9200319d0ea 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -5385,6 +5385,9 @@ static int parse_cpu_str(char *cpu_str, cpu_set_t *cpu_set, int cpu_set_size)
if (*next == '-') /* no negative cpu numbers */
return 1;
+ if (*next == '\0' || *next == '\n')
+ break;
+
start = strtoul(next, &next, 10);
if (start >= CPU_SUBSET_MAXCPUS)
--
2.43.0
