commit: 22a4ec729017ba613337a28f306f94ba5023fe2e From: Oleg Nesterov <[email protected]> Date: Tue, 18 Jan 2011 17:10:08 +0100 Subject: [PATCH] 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 <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Cc: Alan Stern <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Prasad <[email protected]> Cc: Roland McGrath <[email protected]> Cc: [email protected] Cc: [email protected] LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> --- kernel/perf_event.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 76be4c7..a962b19 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); _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
