Module Name: src
Committed By: rin
Date: Mon Aug 10 09:38:48 UTC 2020
Modified Files:
src/sys/arch/m68k/m68k: process_machdep.c
Log Message:
Forbid to set odd address to PC in process_write_regs() and process_set_pc().
Otherwise, address error occurs in kernel at rte instruction when returning
to the user level.
Found by tests/lib/libc/t_ptrace_*:access_regs_set_unaligned_pc_0x[137].
To generate a diff of this commit:
cvs rdiff -u -r1.30 -r1.31 src/sys/arch/m68k/m68k/process_machdep.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/m68k/m68k/process_machdep.c
diff -u src/sys/arch/m68k/m68k/process_machdep.c:1.30 src/sys/arch/m68k/m68k/process_machdep.c:1.31
--- src/sys/arch/m68k/m68k/process_machdep.c:1.30 Sat Jan 4 00:10:02 2014
+++ src/sys/arch/m68k/m68k/process_machdep.c Mon Aug 10 09:38:48 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: process_machdep.c,v 1.30 2014/01/04 00:10:02 dsl Exp $ */
+/* $NetBSD: process_machdep.c,v 1.31 2020/08/10 09:38:48 rin Exp $ */
/*
* Copyright (c) 1993 Christopher G. Demetriou
@@ -53,7 +53,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: process_machdep.c,v 1.30 2014/01/04 00:10:02 dsl Exp $");
+__KERNEL_RCSID(0, "$NetBSD: process_machdep.c,v 1.31 2020/08/10 09:38:48 rin Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -114,13 +114,10 @@ process_write_regs(struct lwp *l, const
struct frame *frame = process_frame(l);
/*
- * in the hp300 machdep.c _write_regs, PC alignment wasn't
- * checked. If an odd address is placed in the PC and the
- * program is allowed to run, it will cause an Address Error
- * which will be transmitted to the process by a SIGBUS.
- * No reasonable debugger would let this happen, but
- * it's not our problem.
+ * Avoid kernel address error at rte instruction.
*/
+ if (regs->r_pc & 1)
+ return EINVAL;
/*
* XXX
@@ -171,14 +168,10 @@ process_set_pc(struct lwp *l, void *addr
struct frame *frame = process_frame(l);
/*
- * in the hp300 machdep.c _set_pc, PC alignment is guaranteed
- * by chopping off the low order bit of the new pc.
- * If an odd address was placed in the PC and the program
- * is allowed to run, it will cause an Address Error
- * which will be transmitted to the process by a SIGBUS.
- * No reasonable debugger would let this happen, but
- * it's not our problem.
+ * Avoid kernel address error at rte instruction.
*/
+ if ((u_int)addr & 1)
+ return EINVAL;
frame->f_pc = (u_int)addr;
return 0;
