Re: [libvirt] [PATCH] tests: Lower stack usage below 4096 bytes

2011/4/25 Eric Blake <eblake(a)redhat.com&gt;: > On 04/24/2011 04:26 PM, Matthias Bolte wrote: >> Make virtTestLoadFile allocate the buffer to read the file into. >> >> Fix logic error in virtTestLoadFile, stop reading on the an empty line. >> >> Use virFileReadLimFD in virtTestCaptureProgramOutput. >> --- >> +++ b/tests/commandhelper.c >> @@ -99,8 +99,8 @@ int main(int argc, char **argv) { >>      } >> >>      fprintf(log, "DAEMON:%s\n", getpgrp() == getsid(0) ? "yes" : "no"); >> -    char cwd[1024]; >> -    if (!getcwd(cwd, sizeof(cwd))) >> +    char *cwd = NULL; >> +    if (!(cwd = getcwd(NULL, 0))) > > Ouch.  This is not portable to POSIX, and while gnulib can guarantee > that it works, the current gnulib getcwd module is GPL (and relies on > openat, which is a rather heavy-weight replacement!). > > I'm going to work on a gnulib module getcwd-lgpl which doesn't fix all > the known bugs in getcwd, but at least guarantees that getcwd(NULL,0) > will malloc insofar as the underlying getcwd is not buggy; we'll need to > import that into libvirt before applying the rest of this patch. > > I haven't closely reviewed the rest of this patch yet, but like the > general idea once we have getcwd sorted out. > Oops. At first I used getcwd(NULL, 0) to replace the getcwd(cwd, sizeof(cwd)) calls in the main functions, but then decided to just move the cwd buffer to global scope instead. I just missed this one in the second rewrite round. Matthias