On Wed, Nov 26, 2014 at 09:27:06AM -0500, Steven Rostedt wrote: > On Wed, 26 Nov 2014 17:06:21 +0300 > Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > > This check says "goto out;" if we had to truncate the string. > > > > The "tbuffer" buffer has TRACE_BUF_SIZE bytes. The vsnprintf() function > > returns the number of characters (not counting the NUL char) which would > > have been printed if there were space. If we we tried to print > > TRACE_BUF_SIZE characters, the last character would have been truncated > > to make space for the NUL character so we should "goto out;". > > > > Oh, and the NUL character is never copied. We copy the string into the > buffer with: > > memcpy(&entry->buf, tbuffer, len); > > Where len does not include NUL, and why we add it ourselves. Yeah. I noticed that. Probably we should change the memcpy() to: memcpy(&entry->buf, tbuffer, len + 1); and remove separate NUL assignment? It's a speedup! I'll do it in v2. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
