diff options
Diffstat (limited to 'src/long_mode')
| -rw-r--r-- | src/long_mode/mod.rs | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/long_mode/mod.rs b/src/long_mode/mod.rs index 3062783..d6ad7df 100644 --- a/src/long_mode/mod.rs +++ b/src/long_mode/mod.rs @@ -8918,11 +8918,26 @@ fn read_operands< instruction.regs[0] = RegSpec::fs(); instruction.operands[0] = OperandSpec::RegRRR; instruction.operand_count = 1; + + // good grief. from the SDM: + // + // > If the source operand is a segment register (16 bits) and the operand size is + // > 64-bits, a zeroextended value is pushed on the stack; if the operand size is + // > 32-bits, either a zero-extended value is pushed on the stack or the segment selector + // > s written on the stack using a 16-bit move + // + // the memory size here really depends on the `Default` bit in the CS descriptor. if + // the default operand size is 64 bits (basically every long-mode code), the acccess is + // 8 bytes (zero extended). if the default operand size is 32 bits, this is more complex. + instruction.mem_size = 8; } OperandCase::GS => { instruction.regs[0] = RegSpec::gs(); instruction.operands[0] = OperandSpec::RegRRR; instruction.operand_count = 1; + + // see the comment on mem size as written in OperandCase::FS + instruction.mem_size = 8; } OperandCase::AL_Ib => { instruction.regs[0] = |