4 files changed, 33 insertions, 19 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 9ecfd856ce6e..c1173520f14d 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -952,14 +952,7 @@ extern int perf_event_overflow(struct perf_event *event, int nmi,
  */
 static inline int is_software_event(struct perf_event *event)
 {
-        switch (event->attr.type) {
-        case PERF_TYPE_SOFTWARE:
-        case PERF_TYPE_TRACEPOINT:
-        /* for now the breakpoint stuff also works as software event */
-        case PERF_TYPE_BREAKPOINT:
-                return 1;
-        }
-        return 0;
+        return event->pmu->task_ctx_nr == perf_sw_context;
 }
 
 extern atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 89d6023c6f82..eb3c1ceec06e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1163,6 +1163,7 @@ struct rcu_node;
 enum perf_event_task_context {
         perf_invalid_context = -1,
         perf_hw_context = 0,
+        perf_sw_context,
         perf_nr_task_contexts,
 };
 
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 6f150095cafe..3b2aaffb65f0 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -610,6 +610,8 @@ static void hw_breakpoint_stop(struct perf_event *bp, int flags)
 }
 
 static struct pmu perf_breakpoint = {
+        .task_ctx_nr    = perf_sw_context, /* could eventually get its own */
+
         .event_init     = hw_breakpoint_event_init,
         .add            = hw_breakpoint_add,
         .del            = hw_breakpoint_del,
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 7223ea875861..357ee8d5e8ae 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4709,6 +4709,8 @@ static int perf_swevent_init(struct perf_event *event)
 }
 
 static struct pmu perf_swevent = {
+        .task_ctx_nr    = perf_sw_context,
+
         .event_init     = perf_swevent_init,
         .add            = perf_swevent_add,
         .del            = perf_swevent_del,
@@ -4800,6 +4802,8 @@ static int perf_tp_event_init(struct perf_event *event)
 }
 
 static struct pmu perf_tracepoint = {
+        .task_ctx_nr    = perf_sw_context,
+
         .event_init     = perf_tp_event_init,
         .add            = perf_trace_add,
         .del            = perf_trace_del,
@@ -4988,6 +4992,8 @@ static int cpu_clock_event_init(struct perf_event *event)
 }
 
 static struct pmu perf_cpu_clock = {
+        .task_ctx_nr    = perf_sw_context,
+
         .event_init     = cpu_clock_event_init,
         .add            = cpu_clock_event_add,
         .del            = cpu_clock_event_del,
@@ -5063,6 +5069,8 @@ static int task_clock_event_init(struct perf_event *event)
 }
 
 static struct pmu perf_task_clock = {
+        .task_ctx_nr    = perf_sw_context,
+
         .event_init     = task_clock_event_init,
         .add            = task_clock_event_add,
         .del            = task_clock_event_del,
@@ -5490,6 +5498,7 @@ SYSCALL_DEFINE5(perf_event_open,
         struct perf_event_context *ctx;
         struct file *event_file = NULL;
         struct file *group_file = NULL;
+        struct pmu *pmu;
         int event_fd;
         int fput_needed = 0;
         int err;
@@ -5522,20 +5531,11 @@ SYSCALL_DEFINE5(perf_event_open,
                 goto err_fd;
         }
 
-        /*
-         * Get the target context (task or percpu):
-         */
-        ctx = find_get_context(event->pmu, pid, cpu);
-        if (IS_ERR(ctx)) {
-                err = PTR_ERR(ctx);
-                goto err_alloc;
-        }
-
         if (group_fd != -1) {
                 group_leader = perf_fget_light(group_fd, &fput_needed);
                 if (IS_ERR(group_leader)) {
                         err = PTR_ERR(group_leader);
-                        goto err_context;
+                        goto err_alloc;
                 }
                 group_file = group_leader->filp;
                 if (flags & PERF_FLAG_FD_OUTPUT)
@@ -5545,6 +5545,23 @@ SYSCALL_DEFINE5(perf_event_open,
         }
 
         /*
+         * Special case software events and allow them to be part of
+         * any hardware group.
+         */
+        pmu = event->pmu;
+        if ((pmu->task_ctx_nr == perf_sw_context) && group_leader)
+                pmu = group_leader->pmu;
+
+        /*
+         * Get the target context (task or percpu):
+         */
+        ctx = find_get_context(pmu, pid, cpu);
+        if (IS_ERR(ctx)) {
+                err = PTR_ERR(ctx);
+                goto err_group_fd;
+        }
+
+        /*
          * Look up the group leader (we will attach this event to it):
          */
         if (group_leader) {
@@ -5605,8 +5622,9 @@ SYSCALL_DEFINE5(perf_event_open,
         return event_fd;
 
 err_context:
-        fput_light(group_file, fput_needed);
         put_ctx(ctx);
+err_group_fd:
+        fput_light(group_file, fput_needed);
 err_alloc:
         free_event(event);
 err_fd: