From: Andi Kleen <ak@suse.de>
Date: Tue, 17 May 2005 04:53:29 +0000 (+0000)
Subject: [PATCH] x86_64: check if ptrace RIP is canonical
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=63a4a4f228c0de221779cd18c7ed9511d42c557b;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] x86_64: check if ptrace RIP is canonical

This works around an AMD Erratum.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Chris Wright <chrisw@osdl.org>
---

diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index eaa7250152f56..b2b7e347a6715 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -149,6 +149,11 @@ static int putreg(struct task_struct *child,
 				return -EIO;
 			value &= 0xffff;
 			break;
+		case offsetof(struct user_regs_struct, rip):
+			/* Check if the new RIP address is canonical */
+			if (value >= TASK_SIZE)
+				return -EIO;
+			break;
 	}
 	put_stack_long(child, regno - sizeof(struct pt_regs), value);
 	return 0;