This is a note to let you know that I've just added the patch titled tools/power turbostat: Fix trailing '\n' parsing to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tools-power-turbostat-fix-trailing-n-parsing.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 934f83de84c02f788ffb32cf5bd01c4871aa4576 Author: Zhang Rui <rui.zhang@xxxxxxxxx> Date: Tue Aug 27 13:07:51 2024 +0800 tools/power turbostat: Fix trailing '\n' parsing [ 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> 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)