tracing: Fix return value of __setup handlers

__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>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3050892d1812a5cc5db482d9323f843c1280bf9b..eb44418574f9ca5edea3a36b70eb911da13c7bd9 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 508f14af4f2c7eb3ddad503adb2701baf05fb8fb..b62fd785b599b25ea3a2308907a843b07ebc2990 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -32,7 +32,7 @@ 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);