From 544e8dd7a8e49d22b4315fc232479bc02b417b46 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Tue, 8 Mar 2016 14:00:23 +0100 Subject: s390/cpum_sf: correctly set the PID and TID in perf samples The hardware sampler creates samples that are processed at a later point in time. The PID and TID values of the perf samples that are created for hardware samples are initialized with values from the current task. Hence, the PID and TID values are not correct and perf samples are associated with wrong processes. The PID and TID values are obtained from the Host Program Parameter (HPP) field in the basic-sampling data entries. These PIDs are valid in the init PID namespace. Ensure that the PIDs in the perf samples are resolved considering the PID namespace in which the perf event was created. To correct the PID and TID values in the created perf samples, a special overflow handler is installed. It replaces the default overflow handler and does not become effective if any other overflow handler is used. With the special overflow handler most of the perf samples are associated with the right processes. For processes, that are no longer exist, the association might still be wrong. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/mm/fault.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 14654007dce4..93faeca52284 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -728,7 +728,7 @@ static void pfault_interrupt(struct ext_code ext_code, return; inc_irq_stat(IRQEXT_PFL); /* Get the token (= pid of the affected task). */ - pid = param64 & LPP_PFAULT_PID_MASK; + pid = param64 & LPP_PID_MASK; rcu_read_lock(); tsk = find_task_by_pid_ns(pid, &init_pid_ns); if (tsk) -- cgit v1.2.3-59-g8ed1b