On Fri, 4 Apr 2025 19:28:48 +0530
Devaansh Kumar <[email protected]> wrote:
> --- a/kernel/trace/trace_stack.c
> +++ b/kernel/trace/trace_stack.c
> @@ -543,8 +543,10 @@ static __init int enable_stacktrace(char *str)
> {
> int len;
>
> - if ((len = str_has_prefix(str, "_filter=")))
> - strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE);
> + len = str_has_prefix(str, "_filter=");
> +
> + if (len)
> + strscpy(stack_trace_filter_buf, str + len,
> sizeof(stack_trace_filter_buf));
>
> stack_tracer_enabled = 1;
> return 1;
BTW, why separate out the len? I use this notation quite a bit for
str_has_prefix() checks.
$ git grep '(len = str_has_pref' kernel/trace
kernel/trace/trace_events.c: if (!(len = str_has_prefix(fmt, "REC->")))
kernel/trace/trace_events_filter.c: if ((len = str_has_prefix(str + i,
".ustring"))) {
kernel/trace/trace_events_filter.c: if ((len = str_has_prefix(str + i,
".function"))) {
kernel/trace/trace_events_hist.c: if ((len = str_has_prefix(str, "key="))
||
kernel/trace/trace_events_hist.c: (len = str_has_prefix(str,
"keys="))) {
kernel/trace/trace_events_hist.c: } else if ((len = str_has_prefix(str,
"val=")) ||
kernel/trace/trace_events_hist.c: (len = str_has_prefix(str,
"vals=")) ||
kernel/trace/trace_events_hist.c: (len = str_has_prefix(str,
"values="))) {
kernel/trace/trace_events_hist.c: } else if ((len = str_has_prefix(str,
"sort="))) {
kernel/trace/trace_events_hist.c: } else if ((len = str_has_prefix(str,
"clock="))) {
kernel/trace/trace_events_hist.c: } else if ((len = str_has_prefix(str,
"size="))) {
kernel/trace/trace_events_hist.c: if ((len = str_has_prefix(str,
"onmatch(")))
kernel/trace/trace_events_hist.c: else if ((len =
str_has_prefix(str, "onmax(")))
kernel/trace/trace_events_hist.c: else if ((len =
str_has_prefix(str, "onchange(")))
kernel/trace/trace_stack.c: if ((len = str_has_prefix(str, "_filter=")))
It's fine being in the if statement as the if is more about "does this have
this prefix" and the length is just a side effect of it to use it to
extract the rest.
This patch is only about removing strncpy(), it doesn't need to modify the
format.
-- Steve
