tracing: Fix return value of __setup handlers

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>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bb15059020445f252022d9599167415166ed833e..24683115eade25cb23cb994f0d04a365e5fd007d 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -235,7 +235,7 @@ static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata;
 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);
 
@@ -246,7 +246,7 @@ static int __init set_trace_boot_clock(char *str)
 {
        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);
 

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1bb85f7a4593a4be08487d10a1d6131ba5d57cac..bc2a2bc5a453fb8ca59f5e47f065d437f96f703e 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -31,7 +31,7 @@ static int __init set_kprobe_boot_events(char *str)
        strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
        disable_tracing_selftest("running kprobe events");
 
-       return 0;
+       return 1;
 }
 __setup("kprobe_event=", set_kprobe_boot_events);