Adding support to emulate nop5 as the original uprobe instruction.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
arch/x86/kernel/uprobes.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 5ee2cce4c63e..1661e0ab2a3d 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -308,6 +308,11 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool
return -ENOTSUPP;
}
+static int is_nop5_insn(uprobe_opcode_t *insn)
+{
+ return !memcmp(insn, x86_nops[5], 5);
+}
+
#ifdef CONFIG_X86_64
asm (
@@ -865,6 +870,11 @@ void arch_uprobe_clear_state(struct mm_struct *mm)
hlist_for_each_entry_safe(tramp, n, &state->head_tramps, node)
destroy_uprobe_trampoline(tramp);
}
+
+static bool emulate_nop5_insn(struct arch_uprobe *auprobe)
+{
+ return is_nop5_insn((uprobe_opcode_t *) &auprobe->insn);
+}
#else /* 32-bit: */
/*
* No RIP-relative addressing on 32-bit
@@ -878,6 +888,10 @@ static void riprel_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
static void riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
}
+static bool emulate_nop5_insn(struct arch_uprobe *auprobe)
+{
+ return false;
+}
#endif /* CONFIG_X86_64 */
struct uprobe_xol_ops {
@@ -1109,6 +1123,8 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn)
break;
case 0x0f:
+ if (emulate_nop5_insn(auprobe))
+ goto setup;
if (insn->opcode.nbytes != 2)
return -ENOSYS;
/*
--
2.49.0
