Re: Re: musl bugs found through gnulib

[Rich Felker <dalias@aerifal.cx>]

On Wed, Jun 20, 2012 at 03:28:02PM -0400, Rich Felker wrote:
> > Replacement of getcwd, because of
> >   checking whether getcwd handles long file names properly... no, but it is partly working

This test is failing because musl uses the kernel to resolve the
current directory name, and the kernel does not support pathnames
longer than PATH_MAX. For some reason, the test only considers this an
error if AT_FDCWD is defined.

Does gnulib aim to provide a getcwd that always works regardless of
path depth? If so, replacing getcwd is the right action for gnulib on
musl.

> >   checking whether getcwd aborts when 4k < cwd_length < 16k... no

No is the correct result here. This test is looking for a bug that
only exists on some archs with large page sizes (>4k), and no means it
did not find the bug.

> > Replacement of mktime, because of
> >   checking for working mktime... no

This test is buggy; it goes into an infinite loop due to integer
overflow UB, because the condition to break out of the loop is only
checked when the test does not fail:

      for (j = 1; ; j <<= 1)
        if (! bigtime_test (j))
          result |= 4;
        else if (INT_MAX / 2 < j)
          break;

However this does indicate a bug in musl. The relevant code is very
old and I suspect it's not checking for integer overflows at all, just
generating huge time_t values that get truncated rather than mapped to
(time_t)-1.

Both need to be fixed.

> > test-fcntl.c:382: assertion failed
> > FAIL: test-fcntl
> 
> Pending; intend to fix.

Fixed.

> > test-fma2.h:116: assertion failed
> > FAIL: test-fma2
> 
> Unknown. Asking nsz..

Fixed by nsz. :-)

Rich