On Thu, Aug 27, 2020 at 09:12:06PM -0700, Joe Perches wrote: > Perhaps something like the below with a sample conversion > that uses single and multiple sysfs_emit uses. On quick review, I like it. :) > [...] > +int sysfs_emit(char *buf, char *pos, const char *fmt, ...) > +{ > + int len; > + va_list args; > + > + WARN(pos < buf, "pos < buf\n"); > + WARN(pos - buf >= PAGE_SIZE, "pos >= PAGE_SIZE (%tu > %lu)\n", > + pos - buf, PAGE_SIZE); > + if (pos < buf || pos - buf >= PAGE_SIZE) > + return 0; This can be: if (WARN(pos < buf, "pos < buf\n") || WARN(pos - buf >= PAGE_SIZE, "pos >= PAGE_SIZE (%tu > %lu)\n", pos - buf, PAGE_SIZE)) return 0; -- Kees Cook