From: JaeSang Yoo <js.yoo.5b@gmail.com> stable inclusion from stable-v5.10.102 commit 15616ba17d02b5139408cc86a92a9b8ed323dbb1 bugzilla: https://gitee.com/openeuler/kernel/issues/I567K6 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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@gmail.com Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> [ Fixed up change log and added space after if condition ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- kernel/trace/trace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 19cdb7869bdc..364659978d83 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -250,6 +250,10 @@ __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; -- 2.20.1