Module Name: src
Committed By: hans
Date: Fri Feb 28 20:11:21 UTC 2025
Modified Files:
src/sys/arch/vax/vax: vm_machdep.c
Log Message:
vax: explicitly zero AP and FP in the CALLS frame in cpu_lwp_fork()
This prevents a recursive panic when ddb(4) tries to trace the stack
back across cpu_lwp_bootstrap(). The CALLS frame in question is put
in place by cpu_lwp_fork() to make it look as if cpu_lwp_bootstrap()
was called from sret, which is detected by db_dump_stack() but only
if the FP of the frame is also 0.
To generate a diff of this commit:
cvs rdiff -u -r1.118 -r1.119 src/sys/arch/vax/vax/vm_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/vax/vax/vm_machdep.c
diff -u src/sys/arch/vax/vax/vm_machdep.c:1.118 src/sys/arch/vax/vax/vm_machdep.c:1.119
--- src/sys/arch/vax/vax/vm_machdep.c:1.118 Mon May 22 16:53:05 2017
+++ src/sys/arch/vax/vax/vm_machdep.c Fri Feb 28 20:11:21 2025
@@ -1,4 +1,4 @@
-/* $NetBSD: vm_machdep.c,v 1.118 2017/05/22 16:53:05 ragge Exp $ */
+/* $NetBSD: vm_machdep.c,v 1.119 2025/02/28 20:11:21 hans Exp $ */
/*
* Copyright (c) 1994 Ludd, University of Lule}, Sweden.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.118 2017/05/22 16:53:05 ragge Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.119 2025/02/28 20:11:21 hans Exp $");
#include "opt_execfmt.h"
#include "opt_compat_ultrix.h"
@@ -124,6 +124,8 @@ cpu_lwp_fork(struct lwp *l1, struct lwp
cf = (struct callsframe *)tf - 1;
cf->ca_cond = 0;
cf->ca_maskpsw = 0x20000000; /* CALLS stack frame, no registers */
+ cf->ca_ap = 0;
+ cf->ca_fp = 0;
cf->ca_pc = (uintptr_t)&sret; /* return PC; userspace trampoline */
cf->ca_argno = 1;
cf->ca_arg1 = 0; /* unused */
