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x86-asm: Reject some invalid arith imm8 instruction

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There were two errors in the arithmetic imm8 instruction.  They accept
only REGW, and in case the user write a xxxb opcode that variant
needs to be rejected as well (it's not automatically rejected by REGW
in case the destination is memory).
This commit is contained in:
Michael Matz 2016-05-16 05:10:21 +02:00
parent 0f36f60faa
commit f2a4cb0a0e
4 changed files with 25 additions and 2 deletions
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7
i386-asm.c
View File

@ -552,7 +552,14 @@ ST_FUNC void asm_opcode(TCCState *s1, int opcode)
continue;
s = (opcode - pa->sym) % NBWLX;
if ((pa->instr_type & OPC_BWLX) == OPC_WLX)
{
/* We need to reject the xxxb opcodes that we accepted above.
Note that pa->sym for WLX opcodes is the 'w' token,
to get the 'b' token subtract one. */
if (((opcode - pa->sym + 1) % NBWLX) == 0)
continue;
s++;
}
} else if (pa->instr_type & OPC_SHIFT) {
if (!(opcode >= pa->sym && opcode < pa->sym + 7*NBWLX))
continue;

2
i386-asm.h
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@ -157,7 +157,7 @@ ALT(DEF_ASM_OP2(lgs, 0x0fb5, 0, OPC_MODRM, OPT_EA, OPT_REG32))
ALT(DEF_ASM_OP2(addb, 0x00, 0, OPC_ARITH | OPC_MODRM | OPC_BWLX, OPT_REG, OPT_EA | OPT_REG)) /* XXX: use D bit ? */
ALT(DEF_ASM_OP2(addb, 0x02, 0, OPC_ARITH | OPC_MODRM | OPC_BWLX, OPT_EA | OPT_REG, OPT_REG))
ALT(DEF_ASM_OP2(addb, 0x04, 0, OPC_ARITH | OPC_BWLX, OPT_IM, OPT_EAX))
ALT(DEF_ASM_OP2(addw, 0x83, 0, OPC_ARITH | OPC_MODRM | OPC_WLX, OPT_IM8S, OPT_EA | OPT_REG))
ALT(DEF_ASM_OP2(addw, 0x83, 0, OPC_ARITH | OPC_MODRM | OPC_WLX, OPT_IM8S, OPT_EA | OPT_REGW))
ALT(DEF_ASM_OP2(addb, 0x80, 0, OPC_ARITH | OPC_MODRM | OPC_BWLX, OPT_IM, OPT_EA | OPT_REG))
ALT(DEF_ASM_OP2(testb, 0x84, 0, OPC_MODRM | OPC_BWLX, OPT_REG, OPT_EA | OPT_REG))

16
tests/asmtest.S
View File

@ -158,6 +158,22 @@ addl $0x123, %eax
add $0x123, %ebx
add $-16, %ecx
add $-0x123, %esi
add $1, %bx
add $1, %ebx
add $-1, %bx
add $-1, %ebx
add $127, %bx
addl $127, %ebx
addl $-128, %ebx
addl $-128, %ebx
addl $-129, %ebx
addl $128, %ebx
addl $255, %ebx
addl $256, %ebx
andb $0xf, %ah
andb $-15, %cl
xorb $127, %dh
cmpb $42, (%eax)
addl $0x123, 0x100
addl $0x123, 0x100(%ebx)
addl $0x123, 0x100(%ebx,%edx,2)

2
x86_64-asm.h
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@ -166,7 +166,7 @@ ALT(DEF_ASM_OP2(lgs, 0x0fb5, 0, OPC_MODRM, OPT_EA, OPT_REG32))
ALT(DEF_ASM_OP2(addb, 0x00, 0, OPC_ARITH | OPC_MODRM | OPC_BWLX, OPT_REG, OPT_EA | OPT_REG)) /* XXX: use D bit ? */
ALT(DEF_ASM_OP2(addb, 0x02, 0, OPC_ARITH | OPC_MODRM | OPC_BWLX, OPT_EA | OPT_REG, OPT_REG))
ALT(DEF_ASM_OP2(addb, 0x04, 0, OPC_ARITH | OPC_BWLX, OPT_IM, OPT_EAX))
ALT(DEF_ASM_OP2(addw, 0x83, 0, OPC_ARITH | OPC_MODRM | OPC_WLX, OPT_IM8S, OPT_EA | OPT_REG))
ALT(DEF_ASM_OP2(addw, 0x83, 0, OPC_ARITH | OPC_MODRM | OPC_WLX, OPT_IM8S, OPT_EA | OPT_REGW))
ALT(DEF_ASM_OP2(addb, 0x80, 0, OPC_ARITH | OPC_MODRM | OPC_BWLX, OPT_IM, OPT_EA | OPT_REG))
ALT(DEF_ASM_OP2(testb, 0x84, 0, OPC_MODRM | OPC_BWLX, OPT_REG, OPT_EA | OPT_REG))