Re: [libvirt] [PATCH]: don't harcode buffer for getgrnam_r

On Thu, Apr 16, 2009 at 09:56:27AM +0200, Daniel Veillard wrote: > On Thu, Apr 16, 2009 at 09:19:38AM +0200, Guido Günther wrote: > > Hi, > > determines the maximum needed buffersize for getgrnam_r using sysconf > > instead of hardcoding it to 1024 and increases the buffer on ERANGE. > > The latter is needed since sysconf is allowed to return -1. Furthermore > > some glibc versions seem to return a too small buffer on amd64 > > (http://bugs.debian.org/520744). O.k. to apply? > > It looks a bit weird, using sysconf but 1/ allowing it to fail so > doing the 2/ 1024 value and loop on ERANGE , but well if I understand > correctly taht's forced by some glibc broken behaviour. Yes, sysconf is allowed to return -1 here. > My take is that the *= 2 size loop should be bounded to avoid eating > all memory on some intermediate not size related error. Can we really glibc shouldn't return ERANGE then, but better safe than sorry. I've added that check in the attched patch.