[PATCH] trace_kprobe: Remove warning message "Could not insert probe at..."

[PATCH] trace_kprobe: Remove warning message "Could not insert probe at..."

[Song Liu]

This warning message is not very helpful, as the return value should
already show information about the error. Also, this message will
flush dmesg if the user space do something silly in a loop, like:

    for x in {0..5}
    do
        echo p:xx xx+$x >> /sys/kernel/debug/tracing/kprobe_events
    done

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 kernel/trace/trace_kprobe.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1cd3fb4..02aed76 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -512,8 +512,6 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
 	if (ret == 0)
 		tk->tp.flags |= TP_FLAG_REGISTERED;
 	else {
-		pr_warn("Could not insert probe at %s+%lu: %d\n",
-			trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
 		if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
 			pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 			ret = 0;
-- 
2.9.5

[tip:perf/urgent] trace_kprobe: Remove warning message "Could not insert probe at..."

[tip-bot for Song Liu]

Commit-ID:  5c8dad48e4f53d6fd0a7e4f95d7c1c983374de88
Gitweb:     https://git.kernel.org/tip/5c8dad48e4f53d6fd0a7e4f95d7c1c983374de88
Author:     Song Liu <songliubraving@fb.com>
AuthorDate: Fri, 13 Apr 2018 11:55:13 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 17 Apr 2018 07:54:57 +0200

trace_kprobe: Remove warning message "Could not insert probe at..."

This warning message is not very helpful, as the return value should
already show information about the error. Also, this message will
spam dmesg if the user space does testing in a loop, like:

    for x in {0..5}
    do
        echo p:xx xx+$x >> /sys/kernel/debug/tracing/kprobe_events
    done

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Song Liu <songliubraving@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Link: http://lkml.kernel.org/r/20180413185513.3626052-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/trace/trace_kprobe.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1cd3fb4d70f8..02aed76e0978 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -512,8 +512,6 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
 	if (ret == 0)
 		tk->tp.flags |= TP_FLAG_REGISTERED;
 	else {
-		pr_warn("Could not insert probe at %s+%lu: %d\n",
-			trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
 		if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
 			pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
 			ret = 0;