diff options
| author | Keir Fraser <keir.fraser@citrix.com> | 2008-01-09 10:09:04 +0000 |
|---|---|---|
| committer | Keir Fraser <keir.fraser@citrix.com> | 2008-01-09 10:09:04 +0000 |
| commit | 98f4e2606f230327d128e88c3797a0744b512248 (patch) | |
| tree | e69f5b43da0654e101a3ca564f7f218fe90cfa17 | |
| parent | aa96438e580e76a181ae3ba923f9c204a8c1a3a5 (diff) | |
| download | xen-98f4e2606f230327d128e88c3797a0744b512248.tar.gz xen-98f4e2606f230327d128e88c3797a0744b512248.tar.bz2 xen-98f4e2606f230327d128e88c3797a0744b512248.zip | |
Fix x86_emulate() handling of imul with immediate operands.
This fixes a repeatable crash in RHEL 4.2 ext2 filesystem during boot.
Signed-off-by: Gary Grebus <ggrebus@virtualiron.com>
Signed-off-by: Ben Guthro <bguthro@virtualiron.com>
| -rw-r--r-- | xen/arch/x86/x86_emulate.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c index 66ea5a8454..f894047068 100644 --- a/xen/arch/x86/x86_emulate.c +++ b/xen/arch/x86/x86_emulate.c @@ -103,8 +103,8 @@ static uint8_t opcode_table[256] = { ImplicitOps, ImplicitOps, DstReg|SrcMem|ModRM, DstReg|SrcMem16|ModRM|Mov, 0, 0, 0, 0, /* 0x68 - 0x6F */ - ImplicitOps|Mov, DstMem|SrcImm|ModRM|Mov, - ImplicitOps|Mov, DstMem|SrcImmByte|ModRM|Mov, + ImplicitOps|Mov, DstReg|SrcImm|ModRM|Mov, + ImplicitOps|Mov, DstReg|SrcImmByte|ModRM|Mov, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, /* 0x70 - 0x77 */ ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, @@ -1331,34 +1331,37 @@ x86_emulate( case 0x69: /* imul imm16/32 */ case 0x6b: /* imul imm8 */ { - unsigned long reg = *(long *)decode_register(modrm_reg, &_regs, 0); + unsigned long src1; /* ModR/M source operand */ + if ( ea.type == OP_REG ) + src1 = *ea.reg; + else if ( (rc = ops->read(ea.mem.seg, ea.mem.off, + &src1, op_bytes, ctxt)) ) + goto done; _regs.eflags &= ~(EFLG_OF|EFLG_CF); switch ( dst.bytes ) { case 2: dst.val = ((uint32_t)(int16_t)src.val * - (uint32_t)(int16_t)reg); + (uint32_t)(int16_t)src1); if ( (int16_t)dst.val != (uint32_t)dst.val ) _regs.eflags |= EFLG_OF|EFLG_CF; break; #ifdef __x86_64__ case 4: dst.val = ((uint64_t)(int32_t)src.val * - (uint64_t)(int32_t)reg); + (uint64_t)(int32_t)src1); if ( (int32_t)dst.val != dst.val ) _regs.eflags |= EFLG_OF|EFLG_CF; break; #endif default: { - unsigned long m[2] = { src.val, reg }; + unsigned long m[2] = { src.val, src1 }; if ( imul_dbl(m) ) _regs.eflags |= EFLG_OF|EFLG_CF; dst.val = m[0]; break; } } - dst.type = OP_REG; - dst.reg = decode_register(modrm_reg, &_regs, 0); break; } |