From: JaeSang Yoo <js.yoo.5b@xxxxxxxxx>
[ Upstream commit 3203ce39ac0b2a57a84382ec184c7d4a0bede175 ]
The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is
the same as another kernel parameter "tp_printk". If "tp_printk" setup is
called before the "tp_printk_stop_on_boot", it will override the latter
and keep it from being set.
This is similar to other kernel parameter issues, such as:
Commit 745a600cf1a6 ("um: console: Ignore console= option")
or init/do_mounts.c:45 (setup function of "ro" kernel param)
Fix it by checking for a "_" right after the "tp_printk" and if that
exists do not process the parameter.
Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@xxxxxxxxx
Signed-off-by: JaeSang Yoo <jsyoo5b@xxxxxxxxx>
[ Fixed up change log and added space after if condition ]
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/trace/trace.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 17e337a22c239..19a6b088f1e72 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -232,6 +232,10 @@ __setup("trace_clock=", set_trace_boot_clock);
static int __init set_tracepoint_printk(char *str)
{
+ /* Ignore the "tp_printk_stop_on_boot" param */
+ if (*str == '_')
+ return 0;
+
if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
tracepoint_printk = 1;
return 1;
--
2.34.1
