This is the mail archive of the
glibc-bugs@sourceware.org
mailing list for the glibc project.
[Bug dynamic-link/16046] New: dl_iterate_phdr should not expose internal stub
- From: "ppluzhnikov at google dot com" <sourceware-bugzilla at sourceware dot org>
- To: glibc-bugs at sourceware dot org
- Date: Mon, 14 Oct 2013 20:34:05 +0000
- Subject: [Bug dynamic-link/16046] New: dl_iterate_phdr should not expose internal stub
- Auto-submitted: auto-generated
https://sourceware.org/bugzilla/show_bug.cgi?id=16046
Bug ID: 16046
Summary: dl_iterate_phdr should not expose internal stub
Product: glibc
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: dynamic-link
Assignee: unassigned at sourceware dot org
Reporter: ppluzhnikov at google dot com
Test case:
#define _GNU_SOURCE
#include <stdio.h>
#include <link.h>
int callback(struct dl_phdr_info *info, size_t size, void *data) {
printf("addr=%p name=%s phdr=%p phnum=%d\n",
(void*)info->dlpi_addr, info->dlpi_name, info->dlpi_phdr,
info->dlpi_phnum);
return 0;
}
int main() {
int status;
status = dl_iterate_phdr(callback, NULL);
return 0;
}
Using current git trunk, dynamically linked binary shows:
addr=(nil) name= phdr=0x400040 phnum=9
addr=0x7fff2a613000 name=linux-vdso.so.1 phdr=0x7fff29d13040 phnum=4
addr=0x7f73a76d4000 name=./libc.so.6 phdr=0x7f73a76d4040 phnum=10
addr=0x7f73a7a87000 name=./elf/ld.so phdr=0x7f73a7a87040 phnum=7
Statically linked binary:
addr=(nil) name= phdr=0x400040 phnum=6
addr=(nil) name= phdr=(nil) phnum=0
addr=0x7ffffd5e1000 name=linux-vdso.so.1 phdr=0x7ffffcce1040 phnum=4
Same with glibc-2.15:
addr=(nil) name= phdr=0x400040 phnum=6
What is the second entry? People calling dl_iterate_phdr may legitimately
expect only real ELF images to appear.
At a minimum, this internal entry should be hidden from dl_iterate_phdr.
AFAICT, this was added in commit:
commit f91f1c0fb89056995f1c9c6a06c361efdf5139e7
Author: Maciej W. Rozycki <macro@codesourcery.com>
Date: Fri Jun 28 16:20:26 2013 +0100
[BZ #15022] Correct global-scope dlopen issues in static executables.
This change creates a link map in static executables to serve as the
global search list for dlopen. It fixes a problem with the inability
to access the global symbol object and a crash on an attempt to map a
DSO into the global scope. Some code that has become dead after the
addition of this link map is removed too and test cases are provided.
--
You are receiving this mail because:
You are on the CC list for the bug.