[src/trunk]: src/sys add KSTACK_CHECK_MAGIC. discussed on tech-kern.

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b0b6696da7dc
branches:  trunk
changeset: 533512:b0b6696da7dc
user:      yamt <yamt%NetBSD.org@localhost>
date:      Tue Jul 02 20:27:44 2002 +0000

description:
add KSTACK_CHECK_MAGIC. discussed on tech-kern.

diffstat:

 sys/arch/vax/include/proc.h |   8 +++-
 sys/conf/files              |   3 +-
 sys/kern/kern_proc.c        |  81 +++++++++++++++++++++++++++++++++++++++++++-
 sys/kern/kern_synch.c       |   9 +++-
 sys/sys/proc.h              |  21 +++++++++++-
 sys/uvm/uvm_glue.c          |  12 +++++-
 6 files changed, 125 insertions(+), 9 deletions(-)

diffs (244 lines):

diff -r 5fcccba99a3f -r b0b6696da7dc sys/arch/vax/include/proc.h
--- a/sys/arch/vax/include/proc.h       Tue Jul 02 19:52:16 2002 +0000
+++ b/sys/arch/vax/include/proc.h       Tue Jul 02 20:27:44 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: proc.h,v 1.2 1994/10/26 08:02:21 cgd Exp $     */
+/*     $NetBSD: proc.h,v 1.3 2002/07/02 20:27:44 yamt Exp $    */
 
 /*
  * Copyright (c) 1991 Regents of the University of California.
@@ -47,3 +47,9 @@
 
 /* md_flags */
 #define        MDP_AST         0x0001  /* async trap pending */
+
+/* kernel stack params */
+#define        KSTACK_LOWEST_ADDR(p)   \
+       ((caddr_t)(p)->p_addr + (REDZONEADDR + VAX_NBPG))
+#define        KSTACK_SIZE     \
+       (USPACE - (REDZONEADDR + VAX_NBPG))
diff -r 5fcccba99a3f -r b0b6696da7dc sys/conf/files
--- a/sys/conf/files    Tue Jul 02 19:52:16 2002 +0000
+++ b/sys/conf/files    Tue Jul 02 20:27:44 2002 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: files,v 1.539 2002/06/28 23:27:13 thorpej Exp $
+#      $NetBSD: files,v 1.540 2002/07/02 20:27:45 yamt Exp $
 
 #      @(#)files.newconf       7.5 (Berkeley) 5/10/93
 
@@ -139,6 +139,7 @@
                                KGDB_DEVADDR KGDB_DEVRATE KGDB_DEVMODE
 defflag                                LOCKDEBUG
 defflag                                SYSCALL_DEBUG
+defflag        opt_kstack.h            KSTACK_CHECK_MAGIC
 
 # memory (ram) disk options
 #
diff -r 5fcccba99a3f -r b0b6696da7dc sys/kern/kern_proc.c
--- a/sys/kern/kern_proc.c      Tue Jul 02 19:52:16 2002 +0000
+++ b/sys/kern/kern_proc.c      Tue Jul 02 20:27:44 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_proc.c,v 1.47 2002/04/12 17:02:33 christos Exp $  */
+/*     $NetBSD: kern_proc.c,v 1.48 2002/07/02 20:27:46 yamt Exp $      */
 
 /*-
  * Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -73,7 +73,9 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_proc.c,v 1.47 2002/04/12 17:02:33 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_proc.c,v 1.48 2002/07/02 20:27:46 yamt Exp $");
+
+#include "opt_kstack.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -571,3 +573,78 @@
        }
 }
 #endif /* DEBUG */
+
+#ifdef KSTACK_CHECK_MAGIC
+#include <sys/user.h>
+
+#define        KSTACK_MAGIC    0xdeadbeaf
+
+/* XXX should be per process basis? */
+int kstackleftmin = KSTACK_SIZE;
+int kstackleftthres = KSTACK_SIZE / 8; /* warn if remaining stack is less than this */
+
+void
+kstack_setup_magic(const struct proc *p)
+{
+       u_int32_t *ip;
+       u_int32_t const *end;
+
+       KASSERT(p != 0);
+       KASSERT(p != &proc0);
+
+       /*
+        * fill all the stack with magic number
+        * so that later modification on it can be detected.
+        */
+       ip = (u_int32_t *)KSTACK_LOWEST_ADDR(p);
+       end = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE); 
+       for (; ip < end; ip++) {
+               *ip = KSTACK_MAGIC;
+       }
+}
+
+void
+kstack_check_magic(const struct proc *p)
+{
+       u_int32_t const *ip, *end;
+       int stackleft;
+
+       KASSERT(p != 0);
+
+       /* don't check proc0 */ /*XXX*/
+       if (p == &proc0)
+               return;
+
+#ifdef __MACHINE_STACK_GROWS_UP
+       /* stack grows upwards (eg. hppa) */
+       ip = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE); 
+       end = (u_int32_t *)KSTACK_LOWEST_ADDR(p);
+       for (ip--; ip >= end; ip--)
+               if (*ip != KSTACK_MAGIC)
+                       break;
+               
+       stackleft = (caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE - (caddr_t)ip;
+#else /* __MACHINE_STACK_GROWS_UP */
+       /* stack grows downwards (eg. i386) */
+       ip = (u_int32_t *)KSTACK_LOWEST_ADDR(p);
+       end = (u_int32_t *)((caddr_t)KSTACK_LOWEST_ADDR(p) + KSTACK_SIZE); 
+       for (; ip < end; ip++)
+               if (*ip != KSTACK_MAGIC)
+                       break;
+
+       stackleft = (caddr_t)ip - KSTACK_LOWEST_ADDR(p);
+#endif /* __MACHINE_STACK_GROWS_UP */
+
+       if (kstackleftmin > stackleft) {
+               kstackleftmin = stackleft;
+               if (stackleft < kstackleftthres)
+                       printf("warning: kernel stack left %d bytes(pid %u)\n",
+                               stackleft, p->p_pid);
+       }
+
+       if (stackleft <= 0) {
+               panic("magic on the top of kernel stack changed for pid %u: "
+                   "maybe kernel stack overflow\n", p->p_pid);
+       }
+}
+#endif /*KSTACK_CHECK_MAGIC*/
diff -r 5fcccba99a3f -r b0b6696da7dc sys/kern/kern_synch.c
--- a/sys/kern/kern_synch.c     Tue Jul 02 19:52:16 2002 +0000
+++ b/sys/kern/kern_synch.c     Tue Jul 02 20:27:44 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_synch.c,v 1.108 2002/05/21 01:38:27 thorpej Exp $ */
+/*     $NetBSD: kern_synch.c,v 1.109 2002/07/02 20:27:46 yamt Exp $    */
 
 /*-
  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
@@ -78,10 +78,11 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.108 2002/05/21 01:38:27 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.109 2002/07/02 20:27:46 yamt Exp $");
 
 #include "opt_ddb.h"
 #include "opt_ktrace.h"
+#include "opt_kstack.h"
 #include "opt_lockdebug.h"
 #include "opt_multiprocessor.h"
 
@@ -848,6 +849,10 @@
         */
        spc->spc_flags &= ~SPCF_SWITCHCLEAR;
 
+#ifdef KSTACK_CHECK_MAGIC
+       kstack_check_magic(p);
+#endif
+
        /*
         * Pick a new current process and switch to it.  When we
         * run again, we'll return back here.
diff -r 5fcccba99a3f -r b0b6696da7dc sys/sys/proc.h
--- a/sys/sys/proc.h    Tue Jul 02 19:52:16 2002 +0000
+++ b/sys/sys/proc.h    Tue Jul 02 20:27:44 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: proc.h,v 1.138 2002/06/17 16:23:58 christos Exp $      */
+/*     $NetBSD: proc.h,v 1.139 2002/07/02 20:27:47 yamt Exp $  */
 
 /*-
  * Copyright (c) 1986, 1989, 1991, 1993
@@ -45,6 +45,7 @@
 
 #if defined(_KERNEL_OPT)
 #include "opt_multiprocessor.h"
+#include "opt_kstack.h"
 #endif
 
 #if defined(_KERNEL)
@@ -474,5 +475,23 @@
 void   proc_trampoline_mp(void);       /* XXX */
 #endif
 
+#ifdef KSTACK_CHECK_MAGIC
+void kstack_setup_magic(const struct proc *);
+void kstack_check_magic(const struct proc *);
+#endif
+
+/*
+ * kernel stack paramaters
+ * XXX require sizeof(struct user)
+ */
+/* the lowest address of kernel stack */
+#ifndef KSTACK_LOWEST_ADDR
+#define        KSTACK_LOWEST_ADDR(p)   ((caddr_t)ALIGN((p)->p_addr + 1))
+#endif
+/* size of kernel stack */
+#ifndef KSTACK_SIZE
+#define        KSTACK_SIZE     (USPACE - ALIGN(sizeof(struct user)))
+#endif
+
 #endif /* _KERNEL */
 #endif /* !_SYS_PROC_H_ */
diff -r 5fcccba99a3f -r b0b6696da7dc sys/uvm/uvm_glue.c
--- a/sys/uvm/uvm_glue.c        Tue Jul 02 19:52:16 2002 +0000
+++ b/sys/uvm/uvm_glue.c        Tue Jul 02 20:27:44 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_glue.c,v 1.58 2002/05/15 06:57:49 matt Exp $       */
+/*     $NetBSD: uvm_glue.c,v 1.59 2002/07/02 20:27:48 yamt Exp $       */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -67,9 +67,10 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.58 2002/05/15 06:57:49 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_glue.c,v 1.59 2002/07/02 20:27:48 yamt Exp $");
 
 #include "opt_kgdb.h"
+#include "opt_kstack.h"
 #include "opt_sysv.h"
 #include "opt_uvmhist.h"
 
@@ -295,6 +296,13 @@
        if (error)
                panic("uvm_fork: uvm_fault_wire failed: %d", error);
 
+#ifdef KSTACK_CHECK_MAGIC
+       /*
+        * fill stack with magic number
+        */
+       kstack_setup_magic(p2);
+#endif
+
        /*
         * p_stats currently points at a field in the user struct.  Copy
         * parts of p_stats, and zero out the rest.