Module Name: src
Committed By: snj
Date: Sat Mar 25 16:57:40 UTC 2017
Modified Files:
src/sys/arch/amd64/amd64 [netbsd-7]: trap.c
src/sys/arch/i386/i386 [netbsd-7]: trap.c
Log Message:
Pull up following revision(s) (requested by maxv in ticket #1391):
sys/arch/amd64/amd64/trap.c: revision 1.94
sys/arch/i386/i386/trap.c: revision 1.287
Mmh, allow iret to be handled when an #SS fault (T_STKFLT) happens. Even
if the sdm is far from being clear, it appears that iret can trigger an #SS
fault if %ss points to a writable but non-present segment; in which case
the kernel would panic, thinking the fault was internal to it.
In particular, userland can create a broken segment in the ldt with
USER_LDT, update its %ss with setcontext and trigger the panic. I don't
think amd64 is affected since USER_LDT does not exist there, and the
changes on tf_ss seem correct - but I'm still adding T_STKFLT for safety.
To generate a diff of this commit:
cvs rdiff -u -r1.78 -r1.78.4.1 src/sys/arch/amd64/amd64/trap.c
cvs rdiff -u -r1.272 -r1.272.4.1 src/sys/arch/i386/i386/trap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/trap.c
diff -u src/sys/arch/amd64/amd64/trap.c:1.78 src/sys/arch/amd64/amd64/trap.c:1.78.4.1
--- src/sys/arch/amd64/amd64/trap.c:1.78 Tue Mar 11 20:54:29 2014
+++ src/sys/arch/amd64/amd64/trap.c Sat Mar 25 16:57:39 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.78 2014/03/11 20:54:29 para Exp $ */
+/* $NetBSD: trap.c,v 1.78.4.1 2017/03/25 16:57:39 snj Exp $ */
/*-
* Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.78 2014/03/11 20:54:29 para Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.78.4.1 2017/03/25 16:57:39 snj Exp $");
#include "opt_ddb.h"
#include "opt_kgdb.h"
@@ -301,6 +301,7 @@ trap(struct trapframe *frame)
case T_PROTFLT:
case T_SEGNPFLT:
case T_ALIGNFLT:
+ case T_STKFLT:
case T_TSSFLT:
if (p == NULL)
goto we_re_toast;
Index: src/sys/arch/i386/i386/trap.c
diff -u src/sys/arch/i386/i386/trap.c:1.272 src/sys/arch/i386/i386/trap.c:1.272.4.1
--- src/sys/arch/i386/i386/trap.c:1.272 Wed Mar 12 18:59:07 2014
+++ src/sys/arch/i386/i386/trap.c Sat Mar 25 16:57:40 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.272 2014/03/12 18:59:07 martin Exp $ */
+/* $NetBSD: trap.c,v 1.272.4.1 2017/03/25 16:57:40 snj Exp $ */
/*-
* Copyright (c) 1998, 2000, 2005, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.272 2014/03/12 18:59:07 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.272.4.1 2017/03/25 16:57:40 snj Exp $");
#include "opt_ddb.h"
#include "opt_kgdb.h"
@@ -349,6 +349,7 @@ trap(struct trapframe *frame)
case T_PROTFLT:
case T_SEGNPFLT:
case T_ALIGNFLT:
+ case T_STKFLT:
case T_TSSFLT:
if (p == NULL)
goto we_re_toast;
