[src/trunk]: src/sys/kern DTrace: Fix several bugs where the mod_ctf_get() fu...

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

details:   https://anonhg.NetBSD.org/src/rev/0d1978b9a517
branches:  trunk
changeset: 754537:0d1978b9a517
user:      darran <darran%NetBSD.org@localhost>
date:      Mon May 03 09:51:36 2010 +0000

description:
DTrace: Fix several bugs where the mod_ctf_get() function could return
success even though no CTF section was present in the kernel or module.
This fixes the panic that several people saw when trying out the FBT
provider without updating /boot or missing a CTF section in /netbsd.

diffstat:

 sys/kern/kern_ctf.c   |  14 ++++++++++----
 sys/kern/kern_ksyms.c |  11 +++++++++--
 2 files changed, 19 insertions(+), 6 deletions(-)

diffs (93 lines):

diff -r c598bf74132a -r 0d1978b9a517 sys/kern/kern_ctf.c
--- a/sys/kern/kern_ctf.c       Mon May 03 09:28:38 2010 +0000
+++ b/sys/kern/kern_ctf.c       Mon May 03 09:51:36 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_ctf.c,v 1.2 2010/03/13 01:41:14 christos Exp $    */
+/*     $NetBSD: kern_ctf.c,v 1.3 2010/05/03 09:51:36 darran Exp $      */
 /*-
  * Copyright (c) 2008 John Birrell <jb%freebsd.org@localhost>
  * All rights reserved.
@@ -82,8 +82,9 @@
        uint8_t *ctfaddr;
        size_t ctfsize;
 
-       if (mc == NULL)
+       if (mc == NULL) {
                return EINVAL;
+       }
 
        /* Set the defaults for no CTF present. That's not a crime! */
        memset(mc, 0, sizeof(*mc));
@@ -116,8 +117,9 @@
                mc->strcnt = 0;         /* XXX TBD */
                mc->nsym   = st->sd_symsize / sizeof(Elf_Sym);
        } else {
-               if (kobj_find_section(mod->mod_kobj, ".SUNW_ctf", (void **)&ctfaddr, &ctfsize))
+               if (kobj_find_section(mod->mod_kobj, ".SUNW_ctf", (void **)&ctfaddr, &ctfsize)) {
                        return ENOENT;
+               }
 
                mc->symtab = mod->mod_kobj->ko_symtab;
                mc->strtab = mod->mod_kobj->ko_strtab;
@@ -126,17 +128,21 @@
        }
 
        if (ctfaddr == NULL) {
+               error = ENOENT;
                goto out;
        }
 
        /* Check the CTF magic number. (XXX check for big endian!) */
        if (ctfaddr[0] != 0xf1 || ctfaddr[1] != 0xcf) {
+               error = EINVAL;
                goto out;
        }
 
        /* Check if version 2. */
-       if (ctfaddr[2] != 2)
+       if (ctfaddr[2] != 2) {
+               error = EINVAL;
                goto out;
+       }
 
        /* Check if the data is compressed. */
        if ((ctfaddr[3] & 0x1) != 0) {
diff -r c598bf74132a -r 0d1978b9a517 sys/kern/kern_ksyms.c
--- a/sys/kern/kern_ksyms.c     Mon May 03 09:28:38 2010 +0000
+++ b/sys/kern/kern_ksyms.c     Mon May 03 09:51:36 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_ksyms.c,v 1.58 2010/03/14 21:27:49 darran Exp $   */
+/*     $NetBSD: kern_ksyms.c,v 1.59 2010/05/03 09:51:36 darran Exp $   */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -71,7 +71,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_ksyms.c,v 1.58 2010/03/14 21:27:49 darran Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_ksyms.c,v 1.59 2010/05/03 09:51:36 darran Exp $");
 
 #if defined(_KERNEL) && defined(_KERNEL_OPT)
 #include "opt_ddb.h"
@@ -473,6 +473,9 @@
                char *shstr = (uint8_t*)start +
                                shdr[ehdr->e_shstrndx].sh_offset;
                for (i = 1; i < ehdr->e_shnum; i++) {
+#ifdef DEBUG
+                       printf("ksyms: checking %s\n", &shstr[shdr[i].sh_name]);
+#endif
                        if (shdr[i].sh_type != SHT_PROGBITS)
                                continue;
                        if (strncmp(".SUNW_ctf", &shstr[shdr[i].sh_name] ,10) != 0)
@@ -486,6 +489,10 @@
 #endif
                        break;
                }
+#ifdef DEBUG
+       } else {
+               printf("ksyms: e_shstrndx == 0\n");
+#endif
        }
 #endif