Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:

include/linux/bpf.h
include/uapi/linux/bpf.h
kernel/bpf/btf.c
kernel/bpf/helpers.c
kernel/bpf/syscall.c
kernel/bpf/verifier.c
kernel/trace/bpf_trace.c
mm/slab_common.c
tools/include/uapi/linux/bpf.h
tools/testing/selftests/bpf/Makefile

Link: https://lore.kernel.org/all/20241024215724.60017-1-daniel@iogearbox.net/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 23 insertions, 8 deletions

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index d7d4fb403f6f..41e7a15dcb50 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1160,19 +1160,14 @@ void fgraph_update_pid_func(void)
 static int start_graph_tracing(void)
 {
 	unsigned long **ret_stack_list;
-	int ret, cpu;
+	int ret;
 
-	ret_stack_list = kmalloc(SHADOW_STACK_SIZE, GFP_KERNEL);
+	ret_stack_list = kcalloc(FTRACE_RETSTACK_ALLOC_SIZE,
+				 sizeof(*ret_stack_list), GFP_KERNEL);
 
 	if (!ret_stack_list)
 		return -ENOMEM;
 
-	/* The cpu_boot init_task->ret_stack will never be freed */
-	for_each_online_cpu(cpu) {
-		if (!idle_task(cpu)->ret_stack)
-			ftrace_graph_init_idle_task(idle_task(cpu), cpu);
-	}
-
 	do {
 		ret = alloc_retstack_tasklist(ret_stack_list);
 	} while (ret == -EAGAIN);
@@ -1242,14 +1237,34 @@ static void ftrace_graph_disable_direct(bool disable_branch)
 	fgraph_direct_gops = &fgraph_stub;
 }
 
+/* The cpu_boot init_task->ret_stack will never be freed */
+static int fgraph_cpu_init(unsigned int cpu)
+{
+	if (!idle_task(cpu)->ret_stack)
+		ftrace_graph_init_idle_task(idle_task(cpu), cpu);
+	return 0;
+}
+
 int register_ftrace_graph(struct fgraph_ops *gops)
 {
+	static bool fgraph_initialized;
 	int command = 0;
 	int ret = 0;
 	int i = -1;
 
 	mutex_lock(&ftrace_lock);
 
+	if (!fgraph_initialized) {
+		ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "fgraph_idle_init",
+					fgraph_cpu_init, NULL);
+		if (ret < 0) {
+			pr_warn("fgraph: Error to init cpu hotplug support\n");
+			return ret;
+		}
+		fgraph_initialized = true;
+		ret = 0;
+	}
+
 	if (!fgraph_array[0]) {
 		/* The array must always have real data on it */
 		for (i = 0; i < FGRAPH_ARRAY_SIZE; i++)