On Sat, 19 Apr 2025 at 08:15, Steven Rostedt <[email protected]> wrote: > > On Sat, 19 Apr 2025 03:44:41 +0530 > Devaansh Kumar <[email protected]> wrote: > > > diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c > > index 14c6f272c4d8..0f2253f3bc8c 100644 > > --- a/kernel/trace/trace_stack.c > > +++ b/kernel/trace/trace_stack.c > > @@ -542,7 +542,7 @@ 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); > > + strscpy(stack_trace_filter_buf, str + len, > > sizeof(stack_trace_filter_buf)); > > Is the sizeof() needed? > > From include/linux/string.h: > > /** > * strscpy - Copy a C-string into a sized buffer > * @dst: Where to copy the string to > * @src: Where to copy the string from > * @...: Size of destination buffer (optional) > * > * Copy the source string @src, or as much of it as fits, into the > * destination @dst buffer. The behavior is undefined if the string > * buffers overlap. The destination @dst buffer is always NUL terminated, > * unless it's zero-sized. > * > * The size argument @... is only required when @dst is not an array, or > * when the copy needs to be smaller than sizeof(@dst). > * > * Preferred to strncpy() since it always returns a valid string, and > * doesn't unnecessarily force the tail of the destination buffer to be > * zero padded. If padding is desired please use strscpy_pad(). > * > * Returns the number of characters copied in @dst (not including the > * trailing %NUL) or -E2BIG if @size is 0 or the copy from @src was > * truncated. > */ > #define strscpy(dst, src, ...) \ > CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) > > With stack_trace_filter_buf defined as: > > static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata; > > This looks like a text book example of just having that be: > > strscpy(stack_trace_filter_buf, str + len); >
Right I have tested it, just using strscpy(stack_trace_filter_buf, str + len) works. > -- Steve > > > > > > stack_tracer_enabled = 1; > > return 1;
