On 7/12/14, 8:37 AM, Eric Sandeen wrote: > On 7/12/14, 1:13 AM, Arkadiusz Miśkiewicz wrote: >> On Saturday 12 of July 2014, Eric Sandeen wrote: >>> On 7/11/14, 2:34 PM, Arkadiusz Miśkiewicz wrote: >>>> cvtnum() and cvttime() silently ignore overflows. This leads to error >>>> conditions not being catched. Example: >>>> >>>> $ xfs_quota -x -c 'limit -u bsoft=987654321098765432199 \ >>>> >>>> bhard=987654321098765432199 999' / >>>> >>>> $ >>>> >>>> Fixed version: >>>> $ xfs_quota -x -c 'limit -u bsoft=987654321098765432199 \ >>>> >>>> bhard=987654321098765432199 999' / >>>> >>>> xfs_quota: Error: could not parse size 987654321098765432199. >>>> xfs_quota: unrecognised argument bsoft=987654321098765432199 >>> >>> So, strtol(3) suggests setting errno to 0 before the call: >>> >>> NOTES >>> Since strtol() can legitimately return 0, LONG_MAX, or >>> LONG_MIN (LLONG_MAX or LLONG_MIN for strtoll()) on both success and >>> failure, the calling program should set errno to 0 before the call, and >>> then deter- mine if an error occurred by checking whether errno has a >>> non-zero value after the call. >>> >>> Ditto for strtoul(). >> >> Hm, my man pages 3.70 don't have such notes, strtol(3): >> >> NOTES >> In locales other than the "C" locale, also other strings may be >> accepted. (For example, the thousands separator of the current locale may be >> supported.) >> >> BSD also has >> >> quad_t >> strtoq(const char *nptr, char **endptr, int base); >> >> with completely analogous definition. Depending on the wordsize of the >> current architecture, this may be equivalent to strtoll() or to strtol(). >> >>> >>> I guess that is just to ensure that there's not a leftover errno >>> when we make the call? Worth doing, maybe? >> >> ERANGE is checked in few other places already in input.c and none initialize >> errno before strtoul() call. > > http://c-faq.com/misc/errno.html suggests it too: > >> It's only necessary to detect errors with errno when a function does >> not have a unique, unambiguous, out-of-band error return (i.e. >> because all of its possible return values are valid; one example is >> atoi). In these cases (and in these cases only; check the >> documentation to be sure whether a function allows this), you can >> detect errors by setting errno to 0, calling the function, then >> testing errno. > > I wonder why it was removed from the man page Actually it seems to still be there: http://git.kernel.org/cgit/docs/man-pages/man-pages.git/tree/man3/strtol.3#n190 fiddly detail but probably worth doing... -Eric _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
