[Linux-ia64] [patch] 2.4.21-pre5 ia64 unwind.c - allow unw_access_gr(r0)

[Linux-ia64] [patch] 2.4.21-pre5 ia64 unwind.c - allow unw_access_gr(r0)

[Keith Owens]

Patch is against 2.4.21-pre5 + ia64-021210 + unwind patches from bk
tree (it would be nice to have a released 2.4.21-pre5-ia64 version).
The patch allows unw_access_gr() to read from r0, to support unwind
directives such as .save ar.pfs,r0 and .save rp,r0.

diff -urN 2.4.21-pre5-ia64/arch/ia64/kernel/unwind.c 2.4.21-pre5-ia64/arch/ia64/kernel/unwind.c
--- 2.4.21-pre5-ia64/arch/ia64/kernel/unwind.c	Fri Mar 14 15:24:18 2003
+++ 2.4.21-pre5-ia64/arch/ia64/kernel/unwind.c	Fri Mar 14 15:23:17 2003
@@ -253,6 +253,11 @@
 	struct pt_regs *pt;
 
 	if ((unsigned) regnum - 1 >= 127) {
+		if (regnum = 0 && !write) {
+			*val = 0;	/* read r0 always returns 0 */
+			*nat = 0;
+			return 0;
+		}
 		UNW_DPRINT(0, "unwind.%s: trying to access non-existent r%u\n",
 			   __FUNCTION__, regnum);
 		return -1;

Re: [Linux-ia64] [patch] 2.4.21-pre5 ia64 unwind.c - allow unw_access_gr(r0)

[David Mosberger]

>>>>> On Fri, 14 Mar 2003 15:37:46 +1100, Keith Owens <kaos@sgi.com> said:

  Keith> Patch is against 2.4.21-pre5 + ia64-021210 + unwind patches
  Keith> from bk tree (it would be nice to have a released
  Keith> 2.4.21-pre5-ia64 version).  The patch allows unw_access_gr()
  Keith> to read from r0, to support unwind directives such as .save
  Keith> ar.pfs,r0 and .save rp,r0.

I applied this patch in the 2.5 tree.

Thanks,

	--david