Messages in this thread | | | Date | Wed, 7 Sep 2022 09:06:44 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/2] x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK |
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On Wed, Sep 07, 2022 at 09:55:21AM +0900, Masami Hiramatsu (Google) wrote:
> +/* Return the jump target address or 0 */ > +static inline unsigned long insn_get_branch_addr(struct insn *insn) > +{ > + switch (insn->opcode.bytes[0]) { > + case 0xe0: /* loopne */ > + case 0xe1: /* loope */ > + case 0xe2: /* loop */
Oh cute, objtool doesn't know about those, let me go add them.
> + case 0xe3: /* jcxz */ > + case 0xe9: /* near relative jump */
/* JMP.d32 */
> + case 0xeb: /* short relative jump */
/* JMP.d8 */
> + break; > + case 0x0f: > + if ((insn->opcode.bytes[1] & 0xf0) == 0x80) /* jcc near */
/* Jcc.d32 */
Are the GNU AS names for these things.
> + break; > + return 0;
> + default: > + if ((insn->opcode.bytes[0] & 0xf0) == 0x70) /* jcc short */ > + break; > + return 0;
You could write that as:
case 0x70 ... 0x7f: /* Jcc.d8 */ break;
default: return 0;
> + } > + return (unsigned long)insn->next_byte + insn->immediate.value; > +}
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