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| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-01-19 10:57:41 -0500 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-02-02 21:39:33 -0500 |
| commit | 915e7f58eb59530412595b69e9511c5933014c0c (patch) | |
| tree | f6aa9ae8c68029629362070f38fb1f64a842afc5 | |
| parent | 624551ee4690ea61d8cbc2edb63324768329db82 (diff) | |
| download | libtracefs-915e7f58eb59530412595b69e9511c5933014c0c.tar.gz | |
libtracefs: Do not count CPUs beyond set size in get_affinity
If the string of CPUs has bits set that are beyond the size that the
passed in cpu_set_t size can hold, do not set them.
This relies on the _S version of the CPU_SET macros from not crashing if
the size if too big. One would think that the _S versions would be made
specifically to protect against being too big.
If a CPU is set in the string but is outside the size limit of the
cpu_set_t passed in, then do not add it to the count that is returned by
tracefs_instance_get_affinity_set().
Link: https://lore.kernel.org/linux-trace-devel/20220119155741.1766541-5-rostedt@goodmis.org
Link: https://lore.kernel.org/all/CAPpZLN4n=L-ZHCXM+LDRiQu0XwR4iCnGeCKJOuOWenkz2EhESA@mail.gmail.com/
Reported-by: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | src/tracefs-instance.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/tracefs-instance.c b/src/tracefs-instance.c index db51af3..1493938 100644 --- a/src/tracefs-instance.c +++ b/src/tracefs-instance.c @@ -1000,7 +1000,16 @@ static inline int update_cpu_set(int cpus, int cpu_set, int cpu, return 0; CPU_SET_S(cpu_set + cpu, set_size, set); - return 1; + + /* + * It is possible that the passed in set_size is not big enough + * to hold the cpu we just set. If that's the case, do not report + * it as being set. + * + * The CPU_ISSET_S() should return false if the CPU given to it + * is bigger than the set itself. + */ + return CPU_ISSET_S(cpu_set + cpu, set_size, set) ? 1 : 0; } /** |