There's no 1-byte operand size case to take care of here, and there's
no point doing the first writeback using dst fields - we can read rBP
and write rSP directly.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -3130,21 +3130,16 @@ x86_emulate(
case 0xc9: /* leave */
/* First writeback, to %%esp. */
- dst.type = OP_REG;
dst.bytes = (mode_64bit() && (op_bytes == 4)) ? 8 : op_bytes;
- dst.reg = (unsigned long *)&_regs.esp;
- dst.val = _regs.ebp;
-
- /* Flush first writeback, since there is a second. */
switch ( dst.bytes )
{
- case 1: *(uint8_t *)dst.reg = (uint8_t)dst.val; break;
- case 2: *(uint16_t *)dst.reg = (uint16_t)dst.val; break;
- case 4: *dst.reg = (uint32_t)dst.val; break; /* 64b: zero-ext */
- case 8: *dst.reg = dst.val; break;
+ case 2: *(uint16_t *)&_regs.esp = (uint16_t)_regs.ebp; break;
+ case 4: _regs.esp = (uint32_t)_regs.ebp; break; /* 64b: zero-ext */
+ case 8: _regs.esp = _regs.ebp; break;
}
/* Second writeback, to %%ebp. */
+ dst.type = OP_REG;
dst.reg = (unsigned long *)&_regs.ebp;
if ( (rc = read_ulong(x86_seg_ss, sp_post_inc(dst.bytes),
&dst.val, dst.bytes, ctxt, ops)) )
x86emul: simplify LEAVE handling
There's no 1-byte operand size case to take care of here, and there's
no point doing the first writeback using dst fields - we can read rBP
and write rSP directly.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -3130,21 +3130,16 @@ x86_emulate(
case 0xc9: /* leave */
/* First writeback, to %%esp. */
- dst.type = OP_REG;
dst.bytes = (mode_64bit() && (op_bytes == 4)) ? 8 : op_bytes;
- dst.reg = (unsigned long *)&_regs.esp;
- dst.val = _regs.ebp;
-
- /* Flush first writeback, since there is a second. */
switch ( dst.bytes )
{
- case 1: *(uint8_t *)dst.reg = (uint8_t)dst.val; break;
- case 2: *(uint16_t *)dst.reg = (uint16_t)dst.val; break;
- case 4: *dst.reg = (uint32_t)dst.val; break; /* 64b: zero-ext */
- case 8: *dst.reg = dst.val; break;
+ case 2: *(uint16_t *)&_regs.esp = (uint16_t)_regs.ebp; break;
+ case 4: _regs.esp = (uint32_t)_regs.ebp; break; /* 64b: zero-ext */
+ case 8: _regs.esp = _regs.ebp; break;
}
/* Second writeback, to %%ebp. */
+ dst.type = OP_REG;
dst.reg = (unsigned long *)&_regs.ebp;
if ( (rc = read_ulong(x86_seg_ss, sp_post_inc(dst.bytes),
&dst.val, dst.bytes, ctxt, ops)) )
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