[src/trunk]: src/sys/kern be a bit more verbose about why we think a note is ...

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

details:   https://anonhg.NetBSD.org/src/rev/337019a75f76
branches:  trunk
changeset: 795987:337019a75f76
user:      christos <christos%NetBSD.org@localhost>
date:      Thu May 15 19:37:22 2014 +0000

description:
be a bit more verbose about why we think a note is bad.

diffstat:

 sys/kern/exec_elf.c |  38 ++++++++++++++++++++++++++++----------
 1 files changed, 28 insertions(+), 10 deletions(-)

diffs (123 lines):

diff -r 6a365d5a14fe -r 337019a75f76 sys/kern/exec_elf.c
--- a/sys/kern/exec_elf.c       Thu May 15 18:25:35 2014 +0000
+++ b/sys/kern/exec_elf.c       Thu May 15 19:37:22 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec_elf.c,v 1.65 2014/03/22 07:27:21 maxv Exp $       */
+/*     $NetBSD: exec_elf.c,v 1.66 2014/05/15 19:37:22 christos Exp $   */
 
 /*-
  * Copyright (c) 1994, 2000, 2005 The NetBSD Foundation, Inc.
@@ -57,7 +57,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: exec_elf.c,v 1.65 2014/03/22 07:27:21 maxv Exp $");
+__KERNEL_RCSID(1, "$NetBSD: exec_elf.c,v 1.66 2014/05/15 19:37:22 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_pax.h"
@@ -870,6 +870,12 @@
        int error;
        int isnetbsd = 0;
        char *ndata, *ndesc;
+#ifdef DIAGNOSTIC
+       const char *badnote;
+#define BADNOTE(n) badnote = (n)
+#else
+#define BADNOTE(n)
+#endif
 
        epp->ep_pax_flags = 0;
        if (eh->e_shnum > MAXSHNUM || eh->e_shnum == 0)
@@ -905,12 +911,16 @@
                 * Ensure this size is consistent with what is indicated
                 * in sh_size. The first check avoids integer overflows.
                 */
-               if (np->n_namesz > shp->sh_size || np->n_descsz > shp->sh_size)
+               if (np->n_namesz > shp->sh_size || np->n_descsz > shp->sh_size) {
+                       BADNOTE("note size limit");
                        goto bad;
+               }
                nsize = sizeof(*np) + roundup(np->n_namesz, 4) +
                    roundup(np->n_descsz, 4);
-               if (nsize != shp->sh_size)
+               if (nsize != shp->sh_size) {
+                       BADNOTE("note size");
                        goto bad;
+               }
                ndesc = ndata + roundup(np->n_namesz, 4);
 
                switch (np->n_type) {
@@ -934,7 +944,7 @@
                            memcmp(ndata, ELF_NOTE_SUSE_NAME,
                            ELF_NOTE_SUSE_NAMESZ) == 0)
                                break;
-
+                       BADNOTE("NetBSD tag");
                        goto bad;
 
                case ELF_NOTE_TYPE_PAX_TAG:
@@ -946,6 +956,7 @@
                                    sizeof(epp->ep_pax_flags));
                                break;
                        }
+                       BADNOTE("PaX tag");
                        goto bad;
 
                case ELF_NOTE_TYPE_MARCH_TAG:
@@ -954,19 +965,24 @@
                            && memcmp(ndata, ELF_NOTE_MARCH_NAME,
                                    ELF_NOTE_MARCH_NAMESZ) == 0) {
                                /* Do not truncate the buffer */
-                               if (np->n_descsz > sizeof(epp->ep_machine_arch))
+                               if (np->n_descsz > sizeof(epp->ep_machine_arch)) {
+                                       BADNOTE("description size limit");
                                        goto bad;
+                               }
                                /*
                                 * Ensure ndesc is NUL-terminated and of the
                                 * expected length.
                                 */
                                if (strnlen(ndesc, np->n_descsz) + 1 !=
-                                   np->n_descsz)
+                                   np->n_descsz) {
+                                       BADNOTE("description size");
                                        goto bad;
+                               }
                                strlcpy(epp->ep_machine_arch, ndesc,
                                    sizeof(epp->ep_machine_arch));
                                break;
                        }
+                       BADNOTE("march tag");
                        goto bad;
 
                case ELF_NOTE_TYPE_MCMODEL_TAG:
@@ -978,6 +994,7 @@
                                ELF_MD_MCMODEL_CHECK(epp, ndesc, np->n_descsz);
                                break;
                        }
+                       BADNOTE("mcmodel tag");
                        goto bad;
 #endif
                        break;
@@ -986,6 +1003,7 @@
                        break;
 
                default:
+                       BADNOTE("unknown tag");
 bad:
 #ifdef DIAGNOSTIC
                        /* Ignore GNU tags */
@@ -995,9 +1013,9 @@
                            break;
 
                        int ns = MIN(np->n_namesz, shp->sh_size - sizeof(*np));
-                       printf("%s: Unknown elf note type %d: "
-                           "[namesz=%d, descsz=%d name=%*.*s]\n",
-                           epp->ep_kname, np->n_type, np->n_namesz,
+                       printf("%s: Unknown elf note type %d (%s): "
+                           "[namesz=%d, descsz=%d name=%-*.*s]\n",
+                           epp->ep_kname, np->n_type, badnote, np->n_namesz,
                            np->n_descsz, ns, ns, ndata);
 #endif
                        break;