# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 53bb8c0d9639251b61b203b55f9e6b046f8d99d6
# Parent 78a72d42cfc19c06097a92b8d0f824d823813c79
Fix negation of unsigned quantities in the Xen x86 emulator.
This fixes the problems left behind by c/s 10171. Again pointed
out by Jan Beulich; and again different from his suggested patch.
Hopefully this one will be less embarrassing.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
xen-unstable changeset: 10241:2dd8e7c4472897a86cac635b6982fa55f1ab6e07
xen-unstable date: Thu Jun 01 16:31:37 2006 +0100
---
xen/arch/x86/traps.c | 4 ++--
xen/arch/x86/x86_emulate.c | 15 ++++++++-------
2 files changed, 10 insertions(+), 9 deletions(-)
diff -r 78a72d42cfc1 -r 53bb8c0d9639 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c Thu Jun 01 11:05:13 2006 +0100
+++ b/xen/arch/x86/traps.c Thu Jun 01 16:33:38 2006 +0100
@@ -873,7 +873,7 @@ static int emulate_privileged_op(struct
PAGE_FAULT(regs->edi, USER_WRITE_FAULT);
break;
}
- regs->edi += (regs->eflags & EF_DF) ? -(int)op_bytes : op_bytes;
+ regs->edi += (int)((regs->eflags & EF_DF) ? -op_bytes : op_bytes);
break;
case 0x6e: /* OUTSB */
@@ -899,7 +899,7 @@ static int emulate_privileged_op(struct
outl_user((u32)data, (u16)regs->edx, v, regs);
break;
}
- regs->esi += (regs->eflags & EF_DF) ? -(int)op_bytes : op_bytes;
+ regs->esi += (int)((regs->eflags & EF_DF) ? -op_bytes : op_bytes);
break;
}
diff -r 78a72d42cfc1 -r 53bb8c0d9639 xen/arch/x86/x86_emulate.c
--- a/xen/arch/x86/x86_emulate.c Thu Jun 01 11:05:13 2006 +0100
+++ b/xen/arch/x86/x86_emulate.c Thu Jun 01 16:33:38 2006 +0100
@@ -379,11 +379,12 @@ do{ __asm__ __volatile__ (
((reg) & ((1UL << (ad_bytes << 3)) - 1))))
#define register_address_increment(reg, inc) \
do { \
+ int _inc = (inc); /* signed type ensures sign extension to long */ \
if ( ad_bytes == sizeof(unsigned long) ) \
- (reg) += (inc); \
+ (reg) += _inc; \
else \
(reg) = ((reg) & ~((1UL << (ad_bytes << 3)) - 1)) | \
- (((reg) + (inc)) & ((1UL << (ad_bytes << 3)) - 1)); \
+ (((reg) + _inc) & ((1UL << (ad_bytes << 3)) - 1)); \
} while (0)
void *
@@ -857,7 +858,7 @@ x86_emulate_memop(
&dst.val, 8)) != 0 )
goto done;
}
- register_address_increment(_regs.esp, -(int)dst.bytes);
+ register_address_increment(_regs.esp, -dst.bytes);
if ( (rc = ops->write_std(register_address(_regs.ss, _regs.esp),
dst.val, dst.bytes)) != 0 )
goto done;
@@ -939,9 +940,9 @@ x86_emulate_memop(
goto done;
}
register_address_increment(
- _regs.esi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
+ _regs.esi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
register_address_increment(
- _regs.edi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
+ _regs.edi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
break;
case 0xa6 ... 0xa7: /* cmps */
DPRINTF("Urk! I don't handle CMPS.\n");
@@ -952,7 +953,7 @@ x86_emulate_memop(
dst.ptr = (unsigned long *)cr2;
dst.val = _regs.eax;
register_address_increment(
- _regs.edi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
+ _regs.edi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
break;
case 0xac ... 0xad: /* lods */
dst.type = OP_REG;
@@ -961,7 +962,7 @@ x86_emulate_memop(
if ( (rc = ops->read_emulated(cr2, &dst.val, dst.bytes)) != 0 )
goto done;
register_address_increment(
- _regs.esi, (_regs.eflags & EFLG_DF) ? -(int)dst.bytes : dst.bytes);
+ _regs.esi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
break;
case 0xae ... 0xaf: /* scas */
DPRINTF("Urk! I don't handle SCAS.\n");
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
Home