[src/trunk]: src/lib/libexecinfo Don't subtract base if not pie.

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

details:   https://anonhg.NetBSD.org/src/rev/e91902e31789
branches:  trunk
changeset: 814934:e91902e31789
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Apr 20 14:00:16 2016 +0000

description:
Don't subtract base if not pie.

diffstat:

 lib/libexecinfo/symtab.c |  32 ++++++++++++++++++++++----------
 1 files changed, 22 insertions(+), 10 deletions(-)

diffs (92 lines):

diff -r 3c4605dc2d62 -r e91902e31789 lib/libexecinfo/symtab.c
--- a/lib/libexecinfo/symtab.c  Wed Apr 20 09:01:03 2016 +0000
+++ b/lib/libexecinfo/symtab.c  Wed Apr 20 14:00:16 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: symtab.c,v 1.4 2016/04/11 15:30:18 christos Exp $      */
+/*     $NetBSD: symtab.c,v 1.5 2016/04/20 14:00:16 christos Exp $      */
 
 /*-
  * Copyright (c) 2012 The NetBSD Foundation, Inc.
@@ -29,12 +29,13 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: symtab.c,v 1.4 2016/04/11 15:30:18 christos Exp $");
+__RCSID("$NetBSD: symtab.c,v 1.5 2016/04/20 14:00:16 christos Exp $");
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdint.h>
+#include <stdbool.h>
 #include <err.h>
 #include <dlfcn.h>
 
@@ -58,6 +59,7 @@
 struct symtab {
        size_t nsymbols;
        struct symbol *symbols;
+       bool ispie;
 };
 
 static int
@@ -85,6 +87,7 @@
        Elf *elf;
        symtab_t *st;
        Elf_Scn *scn = NULL;
+       GElf_Ehdr ehdr;
 
        if (elf_version(EV_CURRENT) == EV_NONE) {
                warnx("Elf Library is out of date.");
@@ -102,6 +105,13 @@
                elf_end(elf);
                return NULL;
        }
+       if (gelf_getehdr(elf, &ehdr) == NULL) {
+               warnx("Error getting ELF Ehdr");
+               elf_end(elf);
+               return NULL;
+       }
+
+       st->ispie = ehdr.e_type == ET_DYN;
 
        while ((scn = elf_nextscn(elf, scn)) != NULL) {
                GElf_Shdr shdr;
@@ -176,12 +186,14 @@
        size_t hi = ns;
        size_t lo = 0;
        size_t mid = ns / 2;
-       uintptr_t dd, sd, me = (uintptr_t)p - (uintptr_t)dli->dli_fbase;
-       uintptr_t ad = (uintptr_t)dli->dli_saddr - (uintptr_t)dli->dli_fbase;
+       uintptr_t fbase = st->ispie ? (uintptr_t)dli->dli_fbase : 0;
+       uintptr_t dd, sd, me = (uintptr_t)p - fbase;
+       uintptr_t ad = (uintptr_t)dli->dli_saddr - fbase;
 
 #ifdef SYMTAB_DEBUG
-       fprintf(stderr, "%s: [fbase=%p, saddr=%p, me=%#jx]\n", __func__,
-           dli->dli_fbase, dli->dli_saddr, (uintmax_t)me);
+       fprintf(stderr, "%s: [fbase=%#jx, saddr=%p, me=%#jx ad=%#jx]\n",
+           __func__, (uintmax_t)fbase, dli->dli_saddr, (uintmax_t)me,
+           (uintmax_t)ad);
 #endif
        for (;;) {
                if (s[mid].st_value < me)
@@ -202,14 +214,14 @@
                dli->dli_saddr = (void *)s[mid].st_value;
                dli->dli_sname = s[mid].st_name;
 #ifdef SYMTAB_DEBUG
-               fprintf(stderr, "%s: %p -> [%p, %s]\n", __func__,
-                   p, dli->dli_saddr, dli->dli_sname);
+               fprintf(stderr, "%s: me=%#jx -> [%#jx, %s]\n", __func__,
+                   (uintmax_t)me, (uintmax_t)sd, dli->dli_sname);
 #endif
        }
 #ifdef SYMTAB_DEBUG
        else
-               fprintf(stderr, "%s: %p -> [%p, ***]\n", __func__,
-                   p, dli->dli_saddr);
+               fprintf(stderr, "%s: %#jx -> [%#jx, ***]\n", __func__,
+                   (uintmax_t)me, (uintmax_t)sd);
 #endif
        return 1;
 }