[src/trunk]: src/sys/arch/arm/arm Fix crash(8) backtrace support.

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

details:   https://anonhg.NetBSD.org/src/rev/452c78f64f33
branches:  trunk
changeset: 805945:452c78f64f33
user:      skrll <skrll%NetBSD.org@localhost>
date:      Sat Jan 24 15:44:32 2015 +0000

description:
Fix crash(8) backtrace support.

diffstat:

 sys/arch/arm/arm/db_trace.c |  37 +++++++++++++++++++++++++------------
 1 files changed, 25 insertions(+), 12 deletions(-)

diffs (87 lines):

diff -r 885b9b389ec1 -r 452c78f64f33 sys/arch/arm/arm/db_trace.c
--- a/sys/arch/arm/arm/db_trace.c       Sat Jan 24 15:36:51 2015 +0000
+++ b/sys/arch/arm/arm/db_trace.c       Sat Jan 24 15:44:32 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: db_trace.c,v 1.30 2014/03/29 15:48:01 skrll Exp $      */
+/*     $NetBSD: db_trace.c,v 1.31 2015/01/24 15:44:32 skrll Exp $      */
 
 /*
  * Copyright (c) 2000, 2001 Ben Harris
@@ -31,7 +31,7 @@
 
 #include <sys/param.h>
 
-__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.30 2014/03/29 15:48:01 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.31 2015/01/24 15:44:32 skrll Exp $");
 
 #include <sys/proc.h>
 #include <arm/armreg.h>
@@ -155,9 +155,19 @@
                } else
                        frame = (uint32_t *)(addr);
        }
-       lastframe = NULL;
        scp_offset = -(get_pc_str_offset() >> 2);
 
+       if (frame == NULL)
+               return;
+
+       lastframe = frame;
+#ifndef _KERNEL
+       uint32_t frameb[4];
+       db_read_bytes((db_addr_t)(frame - 3), sizeof(frameb),
+           (char *)frameb);
+       frame = frameb + 3;
+#endif
+
        /*
         * In theory, the SCP isn't guaranteed to be in the function
         * that generated the stack frame.  We hope for the best.
@@ -169,7 +179,7 @@
 #endif
        pc = scp;
 
-       while (count-- && frame != NULL) {
+       while (count--) {
                uint32_t        savecode;
                int             r;
                uint32_t        *rp;
@@ -180,14 +190,8 @@
 #else
                scp = frame[FR_SCP];
 #endif
-               lastframe = frame;
-               (*pr)("%p: ", frame);
-#ifndef _KERNEL
-               uint32_t frameb[4];
-               db_read_bytes((db_addr_t)(frame - 3), sizeof(frameb),
-                   (char *)frameb);
-               frame = frameb + 3;
-#endif
+               (*pr)("%p: ", lastframe);
+
                db_printsym(pc, DB_STGY_PROC, pr);
                if (trace_full) {
                        (*pr)("\n\t");
@@ -244,6 +248,9 @@
 
                frame = (uint32_t *)(frame[FR_RFP]);
 
+               if (frame == NULL)
+                       break;
+
                if (INKERNEL((int)frame)) {
                        /* staying in kernel */
                        if (frame <= lastframe) {
@@ -262,5 +269,11 @@
                                break;
                        }
                }
+               lastframe = frame;
+#ifndef _KERNEL
+               db_read_bytes((db_addr_t)(frame - 3), sizeof(frameb),
+                   (char *)frameb);
+               frame = frameb + 3;
+#endif
        }
 }