X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Flzms_common.c;h=57c17d4d3a5a1ba9bf3b5acff6edcbfeb0a0cb4b;hb=b41816aff9a66099bd44c93729c89bbd514f9c3f;hp=333beb5f9aad97626795412fa6d7808511f91a72;hpb=eb50d779c493f012b0622971643ee8f348bc8b5d;p=wimlib diff --git a/src/lzms_common.c b/src/lzms_common.c index 333beb5f..57c17d4d 100644 --- a/src/lzms_common.c +++ b/src/lzms_common.c @@ -446,26 +446,26 @@ translate_if_needed(u8 *data, u8 *p, s32 *last_x86_pos, /* * p[0] has one of the following values: - * 0xE8 0xE9 0x48 0x4C 0xF0 0xFF + * 0x48 0x4C 0xE8 0xE9 0xF0 0xFF */ - if ((p[0] & 0xFE) == 0xE8) { - if (p[0] & 0x01) { - /* 0xE9: Jump relative. Theoretically this would be - * useful to translate, but in fact it's explicitly - * excluded. Most likely it creates too many false - * positives for the detection algorithm. */ - p += 4; + if (p[0] >= 0xF0) { + if (p[0] & 0x0F) { + /* 0xFF (instruction group) */ + if (p[1] == 0x15) { + /* Call indirect relative */ + opcode_nbytes = 2; + goto have_opcode; + } } else { - /* 0xE8: Call relative. This is a common case, so it - * uses a reduced max_trans_offset. In other words, we - * have to be more confident that the data actually is - * x86 machine code before we'll do the translation. */ - opcode_nbytes = 1; - max_trans_offset >>= 1; - goto have_opcode; + /* 0xF0 (lock prefix) */ + if (p[1] == 0x83 && p[2] == 0x05) { + /* Lock add relative */ + opcode_nbytes = 3; + goto have_opcode; + } } - } else if ((p[0] & 0xFB) == 0x48) { + } else if (p[0] <= 0x4C) { /* 0x48 or 0x4C. In 64-bit code this is a REX prefix byte with * W=1, R=[01], X=0, and B=0, and it will be followed by the @@ -492,20 +492,20 @@ translate_if_needed(u8 *data, u8 *p, s32 *last_x86_pos, } } } else { - if (p[0] & 0x0F) { - /* 0xFF (instruction group) */ - if (p[1] == 0x15) { - /* Call indirect relative */ - opcode_nbytes = 2; - goto have_opcode; - } + if (p[0] & 0x01) { + /* 0xE9: Jump relative. Theoretically this would be + * useful to translate, but in fact it's explicitly + * excluded. Most likely it creates too many false + * positives for the detection algorithm. */ + p += 4; } else { - /* 0xF0 (lock prefix) */ - if (p[1] == 0x83 && p[2] == 0x05) { - /* Lock add relative */ - opcode_nbytes = 3; - goto have_opcode; - } + /* 0xE8: Call relative. This is a common case, so it + * uses a reduced max_trans_offset. In other words, we + * have to be more confident that the data actually is + * x86 machine code before we'll do the translation. */ + opcode_nbytes = 1; + max_trans_offset >>= 1; + goto have_opcode; } } @@ -516,15 +516,15 @@ have_opcode: p += opcode_nbytes; if (undo) { if (i - *last_x86_pos <= max_trans_offset) { - u32 n = get_unaligned_u32_le(p); - put_unaligned_u32_le(n - i, p); + u32 n = get_unaligned_le32(p); + put_unaligned_le32(n - i, p); } - target16 = i + get_unaligned_u16_le(p); + target16 = i + get_unaligned_le16(p); } else { - target16 = i + get_unaligned_u16_le(p); + target16 = i + get_unaligned_le16(p); if (i - *last_x86_pos <= max_trans_offset) { - u32 n = get_unaligned_u32_le(p); - put_unaligned_u32_le(n + i, p); + u32 n = get_unaligned_le32(p); + put_unaligned_le32(n + i, p); } }