diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/insn.c | 13 | ||||
| -rw-r--r-- | arch/x86/lib/x86-opcode-map.txt | 9 |
2 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c index 1313ae6b478b..8f72b334aea0 100644 --- a/arch/x86/lib/insn.c +++ b/arch/x86/lib/insn.c @@ -52,6 +52,13 @@ */ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64) { + /* + * Instructions longer than MAX_INSN_SIZE (15 bytes) are invalid + * even if the input buffer is long enough to hold them. + */ + if (buf_len > MAX_INSN_SIZE) + buf_len = MAX_INSN_SIZE; + memset(insn, 0, sizeof(*insn)); insn->kaddr = kaddr; insn->end_kaddr = kaddr + buf_len; @@ -164,6 +171,12 @@ found: /* VEX.W overrides opnd_size */ insn->opnd_bytes = 8; } else { + /* + * For VEX2, fake VEX3-like byte#2. + * Makes it easier to decode vex.W, vex.vvvv, + * vex.L and vex.pp. Masking with 0x7f sets vex.W == 0. + */ + insn->vex_prefix.bytes[2] = b2 & 0x7f; insn->vex_prefix.nbytes = 2; insn->next_byte += 2; } diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt index 1a2be7c6895d..816488c0b97e 100644 --- a/arch/x86/lib/x86-opcode-map.txt +++ b/arch/x86/lib/x86-opcode-map.txt @@ -273,6 +273,9 @@ dd: ESC de: ESC df: ESC # 0xe0 - 0xef +# Note: "forced64" is Intel CPU behavior: they ignore 0x66 prefix +# in 64-bit mode. AMD CPUs accept 0x66 prefix, it causes RIP truncation +# to 16 bits. In 32-bit mode, 0x66 is accepted by both Intel and AMD. e0: LOOPNE/LOOPNZ Jb (f64) e1: LOOPE/LOOPZ Jb (f64) e2: LOOP Jb (f64) @@ -281,6 +284,10 @@ e4: IN AL,Ib e5: IN eAX,Ib e6: OUT Ib,AL e7: OUT Ib,eAX +# With 0x66 prefix in 64-bit mode, for AMD CPUs immediate offset +# in "near" jumps and calls is 16-bit. For CALL, +# push of return address is 16-bit wide, RSP is decremented by 2 +# but is not truncated to 16 bits, unlike RIP. e8: CALL Jz (f64) e9: JMP-near Jz (f64) ea: JMP-far Ap (i64) @@ -456,6 +463,7 @@ AVXcode: 1 7e: movd/q Ey,Pd | vmovd/q Ey,Vy (66),(v1) | vmovq Vq,Wq (F3),(v1) 7f: movq Qq,Pq | vmovdqa Wx,Vx (66) | vmovdqu Wx,Vx (F3) # 0x0f 0x80-0x8f +# Note: "forced64" is Intel CPU behavior (see comment about CALL insn). 80: JO Jz (f64) 81: JNO Jz (f64) 82: JB/JC/JNAE Jz (f64) @@ -842,6 +850,7 @@ EndTable GrpTable: Grp5 0: INC Ev 1: DEC Ev +# Note: "forced64" is Intel CPU behavior (see comment about CALL insn). 2: CALLN Ev (f64) 3: CALLF Ep 4: JMPN Ev (f64) |