From: Oleg Nesterov <oleg@redhat.com>
Date: Sun, 30 Dec 2012 14:21:22 +0000 (+0100)
Subject: uprobes/x86: Change __skip_sstep() to actually skip the whole insn
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cf31ec3f7fece93f3fce3ee5964e27857141ea47;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

uprobes/x86: Change __skip_sstep() to actually skip the whole insn

__skip_sstep() doesn't update regs->ip. Currently this is correct
but only "by accident" and it doesn't skip the whole insn. Change
it to advance ->ip by the length of the detected 0x66*0x90 sequence.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---

diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index c71025b67462..4e33a35d659e 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -680,8 +680,11 @@ static bool __skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
 		if (auprobe->insn[i] == 0x66)
 			continue;
 
-		if (auprobe->insn[i] == 0x90)
+		if (auprobe->insn[i] == 0x90) {
+			regs->ip = uprobe_get_swbp_addr(regs);
+			regs->ip += i + 1;
 			return true;
+		}
 
 		break;
 	}