[ Upstream commit fed8511cc8 ]
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: 8c3dd2c9e5 ("tools/power/turbostat: Abstrct function for parsing cpu string")
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2409cf42bc