From 5120d167e21c674afd0630c65e7f6a00fa0667f1 Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Mon, 8 Apr 2024 10:51:40 -0700 Subject: [PATCH] rethook: Remove warning messages printed for finding return address of a frame. The function rethook_find_ret_addr() prints a warning message and returns 0 when the target task is running and is not the "current" task in order to prevent the incorrect return address, although it still may return an incorrect address. However, the warning message turns into noise when BPF profiling programs call bpf_get_task_stack() on running tasks in a firm with a large number of hosts. The callers should be aware and willing to take the risk of receiving an incorrect return address from a task that is currently running other than the "current" one. A warning is not needed here as the callers are intent on it. Link: https://lore.kernel.org/all/20240408175140.60223-1-thinker.li@gmail.com/ Acked-by: Andrii Nakryiko Acked-by: John Fastabend Signed-off-by: Kui-Feng Lee Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/rethook.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index fa03094e9e698..4297a132a7ae2 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -248,7 +248,7 @@ unsigned long rethook_find_ret_addr(struct task_struct *tsk, unsigned long frame if (WARN_ON_ONCE(!cur)) return 0; - if (WARN_ON_ONCE(tsk != current && task_is_running(tsk))) + if (tsk != current && task_is_running(tsk)) return 0; do { -- 2.30.2