Re: [musl] Re: musl bugs found through gnulib

[Rich Felker]

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