From: JaeSang Yoo js.yoo.5b@gmail.com
stable inclusion from linux-4.19.231 commit 8f8c9e71e192823e4d76fdc53b4391642291bafc
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[ 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: Yongqiang Liu liuyongqiang13@huawei.com Signed-off-by: Laibin Qiu qiulaibin@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 119dd5fd5840..feed30698280 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;