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 @@ -233,7 +233,7 @@ 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);
@@ -244,7 +244,7 @@ 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 @@ -31,7 +31,7 @@ static int __init set_kprobe_boot_events 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);