Change branch_setup_xol_ops() to simply use opc1 = OPCODE2(insn) - 0x10 if OPCODE1() == 0x0f; this matches the "short" jmp which checks the same condition.
Thanks to lib/insn.c, it does the rest correctly. branch->ilen/offs are correct no matter if this jmp is "near" or "short". Reported-by: Jonathan Lebon <[email protected]> Signed-off-by: Oleg Nesterov <[email protected]> Reviewed-by: Jim Keniston <[email protected]> --- arch/x86/kernel/uprobes.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index b5f2fa4..d7e9d04 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -599,6 +599,14 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn) branch_clear_offset(auprobe, insn); break; + case 0x0f: + if (insn->opcode.nbytes != 2) + return -ENOSYS; + /* + * If it is a "near" conditional jmp, OPCODE2() - 0x10 matches + * OPCODE1() of the "short" jmp which checks the same condition. + */ + opc1 = OPCODE2(insn) - 0x10; default: if (!is_cond_jmp_opcode(opc1)) return -ENOSYS; -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
