On Thu, Aug 22, 2013 at 01:24:13AM +0400, Sergey Kandaurov wrote: > On Wed, Aug 21, 2013 at 10:27:25PM +0200, Jilles Tjoelker wrote: > > On Wed, Aug 21, 2013 at 11:03:10PM +0400, Sergey Kandaurov wrote: > > > On Wed, Aug 21, 2013 at 09:21:47PM +0400, Andrey Chernov wrote: > > > > On 21.08.2013 20:46, Sergey Kandaurov wrote: > > > > > number = strtoumax(buf, &endptr, 0); > > > > > > > > > > + if (number == UINTMAX_MAX && errno == ERANGE) { > > > > > + return (-1); > > > > > + }
> > > > You need to reset errno before strtoumax() call (errno = 0), because any > > > > of previous functions may left it as ERANGE. > > > Thanks for pointing out. > > > Does the patch look good? > > > Index: expand_number.c > > > =================================================================== > > > --- expand_number.c (revision 254600) > > > +++ expand_number.c (working copy) > > > @@ -53,6 +53,8 @@ > > > unsigned shift; > > > char *endptr; > > > > > > + errno = 0; > > > + > > > number = strtoumax(buf, &endptr, 0); > > > > > > if (number == UINTMAX_MAX && errno == ERANGE) { > > This may cause the function to set errno=0 if it is successful, which is > > not allowed for standard library functions from C and POSIX. There may > > be a problem not only if expand_number() is standardized but also if it > > is used in the implementation of a standard library function. The best > > solution is to save and restore errno around this (if [ERANGE] is > > detected, that is a valid errno value to keep). > > In an application it is acceptable to set errno=0 without further ado. > What about this change? > It changes errno only if it was modified from zero in strtoumax(). > Unconditionally restoring errno after strtoumax() unless ERANGE is > probably not good as strtoumax() might set different errno (e.g. EINVAL) > and we might want to keep it as well. Please correct me, if I'm wrong. > Index: lib/libutil/expand_number.c > =================================================================== > --- lib/libutil/expand_number.c (revision 254600) > +++ lib/libutil/expand_number.c (working copy) > @@ -50,15 +50,22 @@ > expand_number(const char *buf, uint64_t *num) > { > uint64_t number; > + int saved_errno; > unsigned shift; > char *endptr; > > + saved_errno = errno; > + errno = 0; > + > number = strtoumax(buf, &endptr, 0); > > if (number == UINTMAX_MAX && errno == ERANGE) { > return (-1); > } > > + if (errno == 0) > + errno = saved_errno; > + > if (endptr == buf) { > /* No valid digits. */ > errno = EINVAL; > This looks good to me. -- Jilles Tjoelker _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"