[PATCH] bfd: Handle bmmap failure in _bfd_mmap_read_temporary

[H.J. Lu]

On Thu, Apr 4, 2024 at 12:15 AM Alan Modra <amodra@gmail.com> wrote:
>
> On Wed, Apr 03, 2024 at 03:37:44PM -0700, H.J. Lu wrote:
> > bmmap may return MAP_FAILED.  _bfd_mmap_readonly_temporary returns
> > MAP_FAILED when called from GDB on an object with opncls_iovec.  Update
> > _bfd_mmap_read_temporary to handle bmmap failure.
> >
> >       * libbfd.c (_bfd_mmap_read_temporary): Handle bmmap failure.
> > ---
> >  bfd/libbfd.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/bfd/libbfd.c b/bfd/libbfd.c
> > index 869f0ed5c66..34197b75b5e 100644
> > --- a/bfd/libbfd.c
> > +++ b/bfd/libbfd.c
> > @@ -1207,7 +1207,11 @@ _bfd_mmap_read_temporary (void **data_p, size_t *size_p,
> >      {
> >        data = _bfd_mmap_readonly_temporary (abfd, size, mmap_base,
> >                                          size_p);
> > -      if (data == NULL || data == MAP_FAILED)
> > +      /* MAP_FAILED is returned when called from GDB on an object with
> > +      opncls_iovec.  Use bfd_read in this case.  */
> > +      if (data == MAP_FAILED)
> > +     goto mmap_failed;
> > +      if (data == NULL)
> >       abort ();
> >        *data_p = data;
> >        return true;
> > @@ -1216,6 +1220,7 @@ _bfd_mmap_read_temporary (void **data_p, size_t *size_p,
> >
> >    if (data == NULL)
> >      {
> > +mmap_failed:
>
> Will this give an unused label warning when !USE_MMAP?  I'm sure you
> can rewrite the patch without needing a label if you use another temp
> rather than "data" inside the use_mmap block.  That would be a good
> idea anyway as it saves anyone wondering whether the !final_link case
> can have "data" non-NULL and thus malloc is not needed.
>

The v2 patch:

https://sourceware.org/pipermail/binutils/2024-April/133374.html

-- 
H.J.