PATCH: Preserve the original p_align and p_flags if they are valid

[Ben Cheng]

Plain text of patch attached.

On Fri, May 4, 2012 at 1:59 PM, Ben Cheng <bccheng@google.com> wrote:
> Objcopy/strip will unconditionally change the flag to R and alignment
> to 1 for the PT_GNU_RELRO section, but sometimes the Gold linker mark
> them as RW with alignment of 4. This patch will preserve these
> attributes when they are marked as valid.
>
> Thanks,
> -Ben
>
> Index: bfd/ChangeLog
> ===================================================================
> RCS file: /cvs/src/src/bfd/ChangeLog,v
> retrieving revision 1.5667
> diff -u -r1.5667 ChangeLog
> --- bfd/ChangeLog 3 May 2012 13:11:53 -0000 1.5667
> +++ bfd/ChangeLog 4 May 2012 20:50:05 -0000
> @@ -1,3 +1,7 @@
> +2012-05-04  Ben Cheng  <bccheng@google.com>
> +
> +    * bfd/elf.c: Preserve the original p_align and p_flags if they are valid.
> +
>  2012-05-03  Sean Keys  <skeys@ipdatasys.com>
>
>   * cpu-xgate.c: New file. Added XGATE support.
> Index: bfd/elf.c
> ===================================================================
> RCS file: /cvs/src/src/bfd/elf.c,v
> retrieving revision 1.552
> diff -u -r1.552 elf.c
> --- bfd/elf.c 24 Apr 2012 05:12:30 -0000 1.552
> +++ bfd/elf.c 4 May 2012 20:50:05 -0000
> @@ -4931,8 +4931,14 @@
>        else
>   abort ();
>        p->p_memsz = p->p_filesz;
> -      p->p_align = 1;
> -      p->p_flags = (lp->p_flags & ~PF_W);
> +          /* Preserve the alignment and flags if they are valid. The gold
> +             linker generates RW/4 for the PT_GNU_RELRO section. It is better
> +             for objcopy/strip to honor these attributes otherwise gdb will
> +             choke when doing cross-debugging. */
> +          if (!m->p_align_valid)
> +            p->p_align = 1;
> +          if (!m->p_flags_valid)
> +            p->p_flags = (lp->p_flags & ~PF_W);
-------------- next part --------------
Index: bfd/ChangeLog
===================================================================
RCS file: /cvs/src/src/bfd/ChangeLog,v
retrieving revision 1.5667
diff -u -r1.5667 ChangeLog
--- bfd/ChangeLog	3 May 2012 13:11:53 -0000	1.5667
+++ bfd/ChangeLog	4 May 2012 21:13:27 -0000
@@ -1,3 +1,7 @@
+2012-05-04  Ben Cheng  <bccheng@google.com>
+
+    * bfd/elf.c: Preserve the original p_align and p_flags if they are valid.
+
 2012-05-03  Sean Keys  <skeys@ipdatasys.com>
 
 	* cpu-xgate.c: New file. Added XGATE support.
Index: bfd/elf.c
===================================================================
RCS file: /cvs/src/src/bfd/elf.c,v
retrieving revision 1.552
diff -u -r1.552 elf.c
--- bfd/elf.c	24 Apr 2012 05:12:30 -0000	1.552
+++ bfd/elf.c	4 May 2012 21:13:27 -0000
@@ -4931,8 +4931,14 @@
 	      else
 		abort ();
 	      p->p_memsz = p->p_filesz;
-	      p->p_align = 1;
-	      p->p_flags = (lp->p_flags & ~PF_W);
+          /* Preserve the alignment and flags if they are valid. The gold
+             linker generates RW/4 for the PT_GNU_RELRO section. It is better
+             for objcopy/strip to honor these attributes otherwise gdb will
+             choke when doing cross-debugging. */
+          if (!m->p_align_valid)
+            p->p_align = 1;
+          if (!m->p_flags_valid)
+            p->p_flags = (lp->p_flags & ~PF_W);
 	    }
 	  else
 	    {