s390/perf: fix bug when creating per-thread event
A per-thread event could not be created correctly like below:
perf record --per-thread -e rB0000 -- sleep 1
Error:
The sys_perf_event_open() syscall returned with 19 (No such device) for event (rB0000).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
This bug was introduced by:
commit c311c797998c1e70eade463dd60b843da4f1a203
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon May 8 15:56:15 2017 -0700
cpumask: make "nr_cpumask_bits" unsigned
If a per-thread event is not attached to any CPU, the cpu field
in struct perf_event is -1. The above commit converts the CPU number
to unsigned int, which result in an illegal CPU number.
Fixes: c311c797998c ("cpumask: make "nr_cpumask_bits" unsigned")
Cc: <stable@vger.kernel.org> # v4.12+
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Pu Hou <bjhoupu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index c1bf75f..7e1e403 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -823,9 +823,12 @@
}
/* Check online status of the CPU to which the event is pinned */
- if ((unsigned int)event->cpu >= nr_cpumask_bits ||
- (event->cpu >= 0 && !cpu_online(event->cpu)))
- return -ENODEV;
+ if (event->cpu >= 0) {
+ if ((unsigned int)event->cpu >= nr_cpumask_bits)
+ return -ENODEV;
+ if (!cpu_online(event->cpu))
+ return -ENODEV;
+ }
/* Force reset of idle/hv excludes regardless of what the
* user requested.