diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_event.c | 22 | ||||
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 11 |
2 files changed, 23 insertions, 10 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 574ee58a3046..681af806d76b 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1164,11 +1164,9 @@ void perf_event_task_sched_out(struct task_struct *task, struct perf_event_context *ctx = task->perf_event_ctxp; struct perf_event_context *next_ctx; struct perf_event_context *parent; - struct pt_regs *regs; int do_switch = 1; - regs = task_pt_regs(task); - perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0); + perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0); if (likely(!ctx || !cpuctx->task_ctx)) return; @@ -2786,12 +2784,11 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) return NULL; } -#ifdef CONFIG_EVENT_TRACING __weak void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip) { } -#endif + /* * Output @@ -3378,15 +3375,23 @@ static void perf_event_task_output(struct perf_event *event, struct perf_task_event *task_event) { struct perf_output_handle handle; - int size; struct task_struct *task = task_event->task; - int ret; + unsigned long flags; + int size, ret; + + /* + * If this CPU attempts to acquire an rq lock held by a CPU spinning + * in perf_output_lock() from interrupt context, it's game over. + */ + local_irq_save(flags); size = task_event->event_id.header.size; ret = perf_output_begin(&handle, event, size, 0, 0); - if (ret) + if (ret) { + local_irq_restore(flags); return; + } task_event->event_id.pid = perf_event_pid(event, task); task_event->event_id.ppid = perf_event_pid(event, current); @@ -3397,6 +3402,7 @@ static void perf_event_task_output(struct perf_event *event, perf_output_put(&handle, task_event->event_id); perf_output_end(&handle); + local_irq_restore(flags); } static int perf_event_task_match(struct perf_event *event) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 81f691eb3a30..0565bb42566f 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -17,7 +17,12 @@ EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs); static char *perf_trace_buf; static char *perf_trace_buf_nmi; -typedef typeof(char [PERF_MAX_TRACE_SIZE]) perf_trace_t ; +/* + * Force it to be aligned to unsigned long to avoid misaligned accesses + * suprises + */ +typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)]) + perf_trace_t; /* Count the events in use (per event id, not per instance) */ static int total_ref_count; @@ -130,6 +135,8 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, char *trace_buf, *raw_data; int pc, cpu; + BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long)); + pc = preempt_count(); /* Protect the per cpu buffer, begin the rcu read side */ @@ -152,7 +159,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, raw_data = per_cpu_ptr(trace_buf, cpu); /* zero the dead bytes from align to not leak stack to user */ - *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64)); entry = (struct trace_entry *)raw_data; tracing_generic_entry_update(entry, *irq_flags, pc); |