1 files changed, 46 insertions, 23 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 110b38a58493..e5aaa806702d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1469,7 +1469,6 @@ ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
 static void
 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
 {
-
         lockdep_assert_held(&ctx->lock);
 
         WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
@@ -1624,6 +1623,8 @@ static void perf_group_attach(struct perf_event *event)
 {
         struct perf_event *group_leader = event->group_leader, *pos;
 
+        lockdep_assert_held(&event->ctx->lock);
+
         /*
          * We can have double attach due to group movement in perf_event_open.
          */
@@ -1697,6 +1698,8 @@ static void perf_group_detach(struct perf_event *event)
         struct perf_event *sibling, *tmp;
         struct list_head *list = NULL;
 
+        lockdep_assert_held(&event->ctx->lock);
+
         /*
          * We can have double detach due to exit/hot-unplug + close.
          */
@@ -1895,9 +1898,29 @@ __perf_remove_from_context(struct perf_event *event,
  */
 static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
 {
-        lockdep_assert_held(&event->ctx->mutex);
+        struct perf_event_context *ctx = event->ctx;
+
+        lockdep_assert_held(&ctx->mutex);
 
         event_function_call(event, __perf_remove_from_context, (void *)flags);
+
+        /*
+         * The above event_function_call() can NO-OP when it hits
+         * TASK_TOMBSTONE. In that case we must already have been detached
+         * from the context (by perf_event_exit_event()) but the grouping
+         * might still be in-tact.
+         */
+        WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
+        if ((flags & DETACH_GROUP) &&
+            (event->attach_state & PERF_ATTACH_GROUP)) {
+                /*
+                 * Since in that case we cannot possibly be scheduled, simply
+                 * detach now.
+                 */
+                raw_spin_lock_irq(&ctx->lock);
+                perf_group_detach(event);
+                raw_spin_unlock_irq(&ctx->lock);
+        }
 }
 
 /*
@@ -6609,6 +6632,27 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
         char *buf = NULL;
         char *name;
 
+        if (vma->vm_flags & VM_READ)
+                prot |= PROT_READ;
+        if (vma->vm_flags & VM_WRITE)
+                prot |= PROT_WRITE;
+        if (vma->vm_flags & VM_EXEC)
+                prot |= PROT_EXEC;
+
+        if (vma->vm_flags & VM_MAYSHARE)
+                flags = MAP_SHARED;
+        else
+                flags = MAP_PRIVATE;
+
+        if (vma->vm_flags & VM_DENYWRITE)
+                flags |= MAP_DENYWRITE;
+        if (vma->vm_flags & VM_MAYEXEC)
+                flags |= MAP_EXECUTABLE;
+        if (vma->vm_flags & VM_LOCKED)
+                flags |= MAP_LOCKED;
+        if (vma->vm_flags & VM_HUGETLB)
+                flags |= MAP_HUGETLB;
+
         if (file) {
                 struct inode *inode;
                 dev_t dev;
@@ -6635,27 +6679,6 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
                 maj = MAJOR(dev);
                 min = MINOR(dev);
 
-                if (vma->vm_flags & VM_READ)
-                        prot |= PROT_READ;
-                if (vma->vm_flags & VM_WRITE)
-                        prot |= PROT_WRITE;
-                if (vma->vm_flags & VM_EXEC)
-                        prot |= PROT_EXEC;
-
-                if (vma->vm_flags & VM_MAYSHARE)
-                        flags = MAP_SHARED;
-                else
-                        flags = MAP_PRIVATE;
-
-                if (vma->vm_flags & VM_DENYWRITE)
-                        flags |= MAP_DENYWRITE;
-                if (vma->vm_flags & VM_MAYEXEC)
-                        flags |= MAP_EXECUTABLE;
-                if (vma->vm_flags & VM_LOCKED)
-                        flags |= MAP_LOCKED;
-                if (vma->vm_flags & VM_HUGETLB)
-                        flags |= MAP_HUGETLB;
-
                 goto got_name;
         } else {
                 if (vma->vm_ops && vma->vm_ops->name) {