Re: [PATCH] tracing: Replace deprecated strncpy() with memcpy() for stack_trace_filter_buf

[Devaansh Kumar]

On Fri, 4 Apr 2025 at 01:05, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Fri,  4 Apr 2025 00:43:40 +0530
> Devaansh Kumar <devaanshk840@xxxxxxxxx> wrote:
>
> > @@ -537,14 +538,16 @@ stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
> >       return ret;
> >  }
> >
> > -static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata;
> > +static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata __nonstring;
> >
> >  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)
> > +             memcpy(stack_trace_filter_buf, str + len, sizeof(stack_trace_filter_buf));
>
> Hmm, this location looks like it can just use strscpy().

Yes strscpy() also works. But since stack_trace_filter_buf is length
bounded, shouldn't memcpy be the right choice?

-- Devaansh Kumar