[PATCH 5.4 59/64] tracing: Fix return value of __setup handlers

Greg Kroah-Hartman
2022-03-07T09:41:14Z

From: Randy Dunlap <rdunlap@infradead.org>

commit 1d02b444b8d1345ea4708db3bab4db89a7784b55 upstream.

__setup() handlers should generally return 1 to indicate that the
boot options have been handled.

Using invalid option values causes the entire kernel boot option
string to be reported as Unknown and added to init's environment
strings, polluting it.

Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
kprobe_event=p,syscall_any,$arg1 trace_options=quiet
trace_clock=jiffies", will be passed to user space.

Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc6
kprobe_event=p,syscall_any,$arg1
trace_options=quiet
trace_clock=jiffies

Return 1 from the __setup() handlers so that init's environment is not
polluted with kernel boot options.

Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org

Cc: stable@vger.kernel.org
Fixes: 7bcfaf54f591 ("tracing: Add trace_options kernel command line parameter")
Fixes: e1e232ca6b8f ("tracing: Add trace_clock=<clock> kernel parameter")
Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace.c | 4 ++--
kernel/trace/trace_kprobe.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -219,7 +219,7 @@ static char trace_boot_options_buf[MAX_T
static int __init set_trace_boot_options(char *str)
{
strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
- return 0;
+ return 1;
}
__setup("trace_options=", set_trace_boot_options);

@@ -230,7 +230,7 @@ static int __init set_trace_boot_clock(c
{
strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
trace_boot_clock = trace_boot_clock_buf;
- return 0;
+ return 1;
}
__setup("trace_clock=", set_trace_boot_clock);

--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -430,7 +430,7 @@ static int disable_trace_kprobe(struct t
*/
trace_probe_remove_file(tp, file);

- return 0;
+ return 1;
}

#if defined(CONFIG_DYNAMIC_FTRACE) && \