diff options
| -rw-r--r-- | kernel/kcov.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c index 7cd05bd1fada..93b28ad2da28 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -746,26 +746,33 @@ static const struct file_operations kcov_fops = { * In turns kcov_remote_stop() clears those pointers from task_struct to stop * collecting coverage and copies all collected coverage into the kcov area. */ + +static inline bool kcov_mode_enabled(unsigned int mode) +{ + return (mode & ~KCOV_IN_CTXSW) != KCOV_MODE_DISABLED; +} + void kcov_remote_start(u64 handle) { + struct task_struct *t = current; struct kcov_remote *remote; struct kcov *kcov; + unsigned int mode; void *area; - struct task_struct *t; unsigned int size; - enum kcov_mode mode; int sequence; if (WARN_ON(!kcov_check_handle(handle, true, true, true))) return; if (WARN_ON(!in_task())) return; - t = current; + /* * Check that kcov_remote_start is not called twice * nor called by user tasks (with enabled kcov). */ - if (WARN_ON(t->kcov)) + mode = READ_ONCE(t->kcov_mode); + if (WARN_ON(kcov_mode_enabled(mode))) return; kcov_debug("handle = %llx\n", handle); @@ -863,13 +870,20 @@ static void kcov_move_area(enum kcov_mode mode, void *dst_area, void kcov_remote_stop(void) { struct task_struct *t = current; - struct kcov *kcov = t->kcov; - void *area = t->kcov_area; - unsigned int size = t->kcov_size; - int sequence = t->kcov_sequence; + struct kcov *kcov; + unsigned int mode; + void *area; + unsigned int size; + int sequence; - if (!kcov) + mode = READ_ONCE(t->kcov_mode); + barrier(); + if (!kcov_mode_enabled(mode)) return; + kcov = t->kcov; + area = t->kcov_area; + size = t->kcov_size; + sequence = t->kcov_sequence; kcov_stop(t); |