6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Huafei <lihuafei1@xxxxxxxxxx> [ Upstream commit bd3734db86e01e20dd239a40b419059a0ce9c901 ] Use guard(mutex)() to acquire and automatically release ftrace_lock, fixing the issue of not unlocking when calling cpuhp_setup_state() fails. Fixes smatch warning: kernel/trace/fgraph.c:1317 register_ftrace_graph() warn: inconsistent returns '&ftrace_lock'. Link: https://lore.kernel.org/20241024155917.1019580-1-lihuafei1@xxxxxxxxxx Fixes: 2c02f7375e65 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Closes: https://lore.kernel.org/r/202410220121.wxg0olfd-lkp@xxxxxxxxx/ Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Signed-off-by: Li Huafei <lihuafei1@xxxxxxxxxx> Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/trace/fgraph.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 41e7a15dcb50c..cd1c2946018c8 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -1252,7 +1252,7 @@ int register_ftrace_graph(struct fgraph_ops *gops) int ret = 0; int i = -1; - mutex_lock(&ftrace_lock); + guard(mutex)(&ftrace_lock); if (!fgraph_initialized) { ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "fgraph_idle_init", @@ -1273,10 +1273,8 @@ int register_ftrace_graph(struct fgraph_ops *gops) } i = fgraph_lru_alloc_index(); - if (i < 0 || WARN_ON_ONCE(fgraph_array[i] != &fgraph_stub)) { - ret = -ENOSPC; - goto out; - } + if (i < 0 || WARN_ON_ONCE(fgraph_array[i] != &fgraph_stub)) + return -ENOSPC; gops->idx = i; ftrace_graph_active++; @@ -1313,8 +1311,6 @@ int register_ftrace_graph(struct fgraph_ops *gops) gops->saved_func = NULL; fgraph_lru_release_index(i); } -out: - mutex_unlock(&ftrace_lock); return ret; } -- 2.43.0
