From a63fbed776c7124ce9f606234267c3c095b2680e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 24 May 2017 10:15:34 +0200 Subject: perf/tracing/cpuhotplug: Fix locking order perf, tracing, kprobes and jump_labels have a gazillion of ways to create dependency lock chains. Some of those involve nested invocations of get_online_cpus(). The conversion of the hotplug locking to a percpu rwsem requires to avoid such nested calls. sys_perf_event_open() protects most of the syscall logic against cpu hotplug. This causes nested calls and lock inversions versus ftrace and kprobes in various interesting ways. It's impossible to move the hotplug locking to the outer end of all call chains in the involved facilities, so the hotplug protection in sys_perf_event_open() needs to be solved differently. Introduce 'pmus_mutex' which protects a perf private online cpumask. This mutex is taken when the mask is updated in the cpu hotplug callbacks and can be taken in sys_perf_event_open() to protect the swhash setup/teardown code and when the final judgement about a valid event has to be made. [ tglx: Produced changelog and fixed the swhash interaction ] Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Acked-by: Ingo Molnar Cc: Paul E. McKenney Cc: Sebastian Siewior Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Masami Hiramatsu Link: http://lkml.kernel.org/r/20170524081548.930941109@linutronix.de --- include/linux/perf_event.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 24a635887f28..7d6aa29094b2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -801,6 +801,8 @@ struct perf_cpu_context { struct list_head sched_cb_entry; int sched_cb_usage; + + int online; }; struct perf_output_handle { -- cgit v1.2.3 From f91840a32deef5cb1bf73338bc5010f843b01426 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Fri, 2 Jun 2017 21:03:52 -0700 Subject: perf, bpf: Add BPF support to all perf_event types Allow BPF_PROG_TYPE_PERF_EVENT program types to attach to all perf_event types, including HW_CACHE, RAW, and dynamic pmu events. Only tracepoint/kprobe events are treated differently which require BPF_PROG_TYPE_TRACEPOINT/BPF_PROG_TYPE_KPROBE program types accordingly. Also add support for reading all event counters using bpf_perf_event_read() helper. Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/linux/perf_event.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 24a635887f28..8fc5f0fada5e 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -896,7 +896,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, void *context); extern void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu); -extern u64 perf_event_read_local(struct perf_event *event); +int perf_event_read_local(struct perf_event *event, u64 *value); extern u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running); @@ -1301,7 +1301,10 @@ static inline const struct perf_event_attr *perf_event_attrs(struct perf_event * { return ERR_PTR(-EINVAL); } -static inline u64 perf_event_read_local(struct perf_event *event) { return -EINVAL; } +static inline int perf_event_read_local(struct perf_event *event, u64 *value) +{ + return -EINVAL; +} static inline void perf_event_print_debug(void) { } static inline int perf_event_task_disable(void) { return -EINVAL; } static inline int perf_event_task_enable(void) { return -EINVAL; } -- cgit v1.2.3