Re: RFA: ia64 portion of libunwind patch

["J. Johnston" <jjohnstn at redhat dot com>]

Kevin Buettner wrote:
> On Oct 23,  8:11pm, J. Johnston wrote:
>
>
> > Ok to commit?  Questions regarding this in conjunction with the generic 
> > libunwind frame code?
>
>
> > +#ifdef HAVE_LIBUNWIND_IA64_H
> > +
> > +# ifndef __NR_getunwind
> > +#  define __NR_getunwind	1215
> > +# endif
>
>
> Is this part still needed?

Not if we include <sys/syscall.h>

>                         ...........
>
>
> > +static void *
> > +map_segment (bfd *bfd, Elf_Internal_Phdr *p_text, struct map_info *mi)
> > +  {
> > +  size_t page_mask = getpagesize () - 1, nbytes;
> > +  char *buf, *cp;
> > +  ssize_t nread;
> > +  int fd;
> > +  
> > +  if (bfd->iostream)
> > +    fd = fileno (bfd->iostream);
> > +  else
> > +    fd = open (bfd_get_filename (bfd), O_RDONLY);
> > +  
> > +  if (fd < 0)
> > +    return NULL;
> > +
> > +  buf = mmap (0, p_text->p_filesz, PROT_READ, MAP_PRIVATE, fd,
> > +	      p_text->p_offset & ~page_mask);
> > +  if (buf != (char *) -1)
> > +    {
> > +      mi->buf = buf;
> > +      mi->length = p_text->p_filesz;
> > +      mi->mapped = 1;
> > +      buf += p_text->p_offset & page_mask;
> > +    }
> > +  else
> > +    {
> > +      /* mmap () failed, try reading the file: */
> > +      mi->mapped = 0;
> > +      
> > +      if (lseek (fd, p_text->p_offset, SEEK_SET) < 0)
> > +	{
> > +	  if (!bfd->iostream)
> > +	    close (fd);
> > +	  return NULL;
> > +	}
> > +      
> > +      nbytes = p_text->p_filesz;
> > +      cp = buf = xmalloc (nbytes);
> > +      while ((nbytes > 0) && (nread = read (fd, cp, nbytes)) > 0)
> > +	{
> > +	  cp += nread;
> > +	  nbytes -= nread;
> > +  	}
> > +      if (nbytes > 0)
> > +	{
> > +	  /* premature end-of-file or some error */
> > +	  xfree (buf);
> > +	  buf = 0;
> > +	}
> > +      mi->buf = buf;
> > +    }
> > +  if (!bfd->iostream)
> > +    close (fd);
> > +  
> > +  return buf;
> > +}
>
>
> For the above, why isn't bfd being employed to read the segment?

Are you referring to using bfd_bread() if the mmap fails or do you mean 
something higher level?

-- Jeff J.