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[PATCH] Off-by-one errors in gcc/config/arm/pr-support.c
- From: Mark Shinwell <shinwell at codesourcery dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 22 Jun 2006 21:00:01 +0100
- Subject: [PATCH] Off-by-one errors in gcc/config/arm/pr-support.c
I've decided to split this out on its own, since it is an obvious bugfix.
The _Unwind_VRS_Pop routine takes an "op" argument encoded within which
is the number of registers to be popped. The ARM EHABI encodes register
ranges using a start register and an end register; thus, there is scope
for an off-by-one error and indeed such errors manifest themselves in
the current code in pr-support.c. The patch fixes these errors, which
will cause failure to correctly unwind the stack in certain cases.
OK? (Could this even be eligible for mainline right now?)
Mark
--
gcc/ChangeLog:
2006-06-22 Mark Shinwell <shinwell@codesourcery.com>
* config/arm/pr-support.c (gnu_unwind_execute): Fix bug by inserting
" + 1" in necessary places to pass the correct "number of registers"
values to _Unwind_VRS_Pop.
Index: gcc/config/arm/pr-support.c
===================================================================
--- gcc/config/arm/pr-support.c (revision 114900)
+++ gcc/config/arm/pr-support.c (working copy)
@@ -224,7 +224,7 @@ __gnu_unwind_execute (_Unwind_Context *
{
/* Pop VFP registers with fldmx. */
op = next_unwind_byte (uws);
- op = ((op & 0xf0) << 12) | (op & 0xf);
+ op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_VFPX)
!= _UVRSR_OK)
return _URC_FAILURE;
@@ -253,7 +253,7 @@ __gnu_unwind_execute (_Unwind_Context *
{
/* Pop iWMMXt D registers. */
op = next_unwind_byte (uws);
- op = ((op & 0xf0) << 12) | (op & 0xf);
+ op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
if (_Unwind_VRS_Pop (context, _UVRSC_WMMXD, op, _UVRSD_UINT64)
!= _UVRSR_OK)
return _URC_FAILURE;
@@ -284,7 +284,7 @@ __gnu_unwind_execute (_Unwind_Context *
{
/* Pop FPA registers. */
op = next_unwind_byte (uws);
- op = ((op & 0xf0) << 12) | (op & 0xf);
+ op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
if (_Unwind_VRS_Pop (context, _UVRSC_FPA, op, _UVRSD_FPAX)
!= _UVRSR_OK)
return _URC_FAILURE;
@@ -294,7 +294,7 @@ __gnu_unwind_execute (_Unwind_Context *
{
/* Pop VFP registers with fldmd. */
op = next_unwind_byte (uws);
- op = ((op & 0xf0) << 12) | (op & 0xf);
+ op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_DOUBLE)
!= _UVRSR_OK)
return _URC_FAILURE;