From: Kees Jongenburger <keesj@minix3.org>
Date: Tue, 19 Feb 2013 12:17:54 +0000 (+0100)
Subject: kernel:handle improper svc calls gracefully.
X-Git-Tag: v3.3.0~1141
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/expt.png?a=commitdiff_plain;h=d47f512a136ee5ec672097fc3f33a47928e9b14a;p=minix.git

kernel:handle improper svc calls gracefully.

Change-Id: Id0f694dd2a8c5981900601fcdb2112ee266d0d76
---

diff --git a/kernel/arch/earm/mpx.S b/kernel/arch/earm/mpx.S
index 96bf3f538..622bc83f9 100644
--- a/kernel/arch/earm/mpx.S
+++ b/kernel/arch/earm/mpx.S
@@ -192,7 +192,11 @@ ENTRY(svc_entry)
 	beq	kernel_call_entry
 	cmp	r3, #IPCVEC
 	beq	ipc_entry
-	b	invalid_svc
+
+	/* return -1 to the current process as an invalid SWI was called .*/
+	mov	r0, #-1
+	str	r0, [fp, #REG0]
+	b	_C_LABEL(switch_to_user)
 
 /*
  * kernel call is only from a process to kernel
@@ -244,7 +248,7 @@ ENTRY(ipc_entry)
 	b	_C_LABEL(switch_to_user)
 
 ENTRY(invalid_svc)
-	b .
+	b	.
 
 ENTRY(restore_user_context)
 	/* sp holds the proc ptr */