From d22d0efe52ec456d383d7140df6523a09b30d3ca Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] tools/power turbostat: Fix trailing '\n' parsing BugLink: https://bugs.launchpad.net/bugs/2101915 [ 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 Signed-off-by: Len Brown Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- 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 7f780ae8f22a..0e2c7cb4c357 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -3652,6 +3652,9 @@ 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)