path: root/kernel
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authorOleg Nesterov <oleg@redhat.com>2011-01-18 17:10:08 +0100
committerIngo Molnar <mingo@elte.hu>2011-01-18 19:34:23 +0100
commit22a4ec729017ba613337a28f306f94ba5023fe2e (patch)
treea0e6ad7131088b4e1cf1072f76f9b34ead7e9065 /kernel
parentc5ed5145591774bd9a2960ba4ca45a02fc70aad1 (diff)
perf: Find_get_context: fix the per-cpu-counter check
If task == NULL, find_get_context() should always check that cpu is correct. Afaics, the bug was introduced by 38a81da2 "perf events: Clean up pid passing", but even before that commit "&& cpu != -1" was not exactly right, -ESRCH from find_task_by_vpid() is not accurate. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Cc: gregkh@suse.de Cc: stable@kernel.org LKML-Reference: <20110118161008.GB693@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 76be4c7bf08..a962b1962ee 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2228,7 +2228,7 @@ find_get_context(struct pmu *pmu, struct task_struct *task, int cpu)
unsigned long flags;
int ctxn, err;
- if (!task && cpu != -1) {
+ if (!task) {
/* Must be root to operate on a CPU event: */
if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);