[Bug libc/17250] New: static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[Bug libc/17250] New: static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[vapier at gentoo dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

            Bug ID: 17250
           Summary: static linking breaks nss loading
                    (getaddrinfo/getpwnam/etc...)
           Product: glibc
           Version: 2.19
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
          Assignee: unassigned at sourceware dot org
          Reporter: vapier at gentoo dot org
                CC: drepper.fsp at gmail dot com, macro@linux-mips.org

it looks like the change landed for bug 16046 broke static dlopening of nss
modules.  if you try to use getaddrinfo/getpwnam/etc..., they just return
errors immediately.

example tests:
$ cat test.c
#include <sys/types.h>
#include <pwd.h>
#include <stdio.h>
int main() {
    void *p = getpwnam("root");
    printf("%p\n", p);
    return p == NULL ? 1 : 0;
}

$ gcc test.c && ./a.out
0x7f6aec59a0e0
$ gcc -static test.c && ./a.out
(nil)

$ cat test.c
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <net/if.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netdb.h>
#include <string.h>

int main(int argc, char *argv[])
{
        const char *host = argv[1];
        int rc;
        struct addrinfo *result = NULL;
        struct addrinfo hint;

        memset(&hint, 0 , sizeof(hint));
        hint.ai_family = AF_INET;
        hint.ai_socktype = SOCK_STREAM;
        hint.ai_flags = AF_UNSPEC;
        rc = getaddrinfo(host, NULL, &hint, &result);
        if (rc || !result) {
                printf("bad address '%s'\n", host);
                return 1;
        } else
                return 0;
}

$ gcc test.c && ./a.out localhost
$ gcc -static test.c && ./a.out localhost
bad address 'localhost'

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[vapier at gentoo dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

Mike Frysinger <vapier at gentoo dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://sourceware.org/bugz
                   |                            |illa/show_bug.cgi?id=16046,
                   |                            |https://bugs.gentoo.org/sho
                   |                            |w_bug.cgi?id=518650,
                   |                            |https://bugs.gentoo.org/sho
                   |                            |w_bug.cgi?id=509748

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[vapier at gentoo dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

--- Comment #1 from Mike Frysinger <vapier at gentoo dot org> ---
bisecting more, it looks like it's specifically the change to
elf/dl-iteratephdr.c that breaks things (where it changes from a custom
dl_iterate_phdr to a weak alias of __dl_iterate_phdr).  if i revert that change
alone, the tests start working again.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[aurelien at aurel32 dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

Aurelien Jarno <aurelien at aurel32 dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aurelien at aurel32 dot net
           See Also|                            |http://bugs.debian.org/7595
                   |                            |30

--- Comment #2 from Aurelien Jarno <aurelien at aurel32 dot net> ---
I confirm that the breakage has been introduced by the following commit:

commit 0d23a5c1b1908700d25b7e3c6cece148e19dded4
Author: Maciej W. Rozycki <macro@codesourcery.com>
Date:   Fri Jan 31 17:51:31 2014 +0000

    [BZ #16046] Static dlopen correction fallout fixes.

    Fixes to address issues from BZ #15022 resolution, as follows:

    * TLS updates to csu/libc-tls.c -- we now have a proper main map, so
      there's no longer a need to create a separate fake one to keep TLS
      structures,

    * random updates to elf/dl-close.c -- LM_ID_BASE is now a valid name
      space ID for static executables as well, so assert that we don't
      unload the main map.  Similarly dl_nns isn't supposed to be 0 for
      static executables anymore,

    * actual BZ #16046 fix to elf/dl-iteratephdr.c -- the dl_iterate_phdr
      special function for static executables isn't needed anymore, provided
      that l_phdr and l_phnum members of the main map have been properly
      initialized (done in _dl_non_dynamic_init in elf/dl-support.c now),

    * ld.so.cache loader update to elf/dl-load.c --
      GL(dl_ns)[LM_ID_BASE]._ns_loaded is now always initialized in static
      executables so can become the fallback loader map to check for
      DF_1_NODEFLIB, provided that the l_flags_1 member of the main map has
      been properly initialized (done in elf/dl-support.c now); this also
      ensures previous semantics elsewhere in elf/dl-load.c,

    * matching updates to elf/dl-support.c -- to complement the two fixes
      above.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[aurelien at aurel32 dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

Aurelien Jarno <aurelien at aurel32 dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |http://bugs.debian.org/7646
                   |                            |92

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[aurelien at aurel32 dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

--- Comment #3 from Aurelien Jarno <aurelien at aurel32 dot net> ---
The problem seems to be related to the trusted directories. As long as the
generated file elf/trusted-dirs.h contains a path matching the NSS modules
location, they are not even load. Changing these paths to not match the NSS
modules location make the NSS modules to work again.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[aurelien at aurel32 dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

--- Comment #4 from Aurelien Jarno <aurelien at aurel32 dot net> ---
Looking more at the code the new behaviour is actually wanted. Statically
linked binaries do not lookup in the default lib search patch by default
(DF_1_NODEFLIB is defined as "Ignore default lib search path."):

--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -91,6 +91,7 @@ static struct link_map _dl_main_map =
     .l_scope = _dl_main_map.l_scope_mem,
     .l_local_scope = { &_dl_main_map.l_searchlist },
     .l_used = 1,
+    .l_flags_1 = DF_1_NODEFLIB,
     .l_tls_offset = NO_TLS_OFFSET,
     .l_serial = 1,
   };

This means that the dlopen calls from nss/nsswitch.c do not look for the
default search path. In addition to that it means that the dlopen behavior for
static binaries also has changed and doesn't support loading objects without an
absolute path. This is conform to the POSIX specification ("Otherwise, file is
used in an implementation-defined manner to yield a pathname."), but do we
really want such a behavior change?

Concerning the NSS support we should probably switch it to an absolute path. In
the meantime this can be workarounded by using LD_LIBRARY_PATH

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug nss/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[jsm28 at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

Joseph Myers <jsm28 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|libc                        |nss

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug nss/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

--- Comment #5 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".

The branch, master has been updated
       via  93bad7c97c7047ecaf7664859e2b49c0fe995443 (commit)
      from  f6987f5aa4c2ef7270bcb0a828808bd3db53520b (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=93bad7c97c7047ecaf7664859e2b49c0fe995443

commit 93bad7c97c7047ecaf7664859e2b49c0fe995443
Author: Maciej W. Rozycki <macro@imgtec.com>
Date:   Fri Sep 25 09:37:12 2015 +0100

    [BZ #17250] Fix static dlopen default library search path

    Fix a regression introduced with commit 0d23a5c1 [Static dlopen
    correction fallout fixes] that caused the default library search path to
    be ignored for modules loaded with dlopen from static executables.

        [BZ #17250]
        * elf/dl-support.c (_dl_main_map): Don't initialize l_flags_1
        member.

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog        |    6 ++++++
 NEWS             |   12 ++++++------
 elf/dl-support.c |    1 -
 3 files changed, 12 insertions(+), 7 deletions(-)

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug dynamic-link/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[macro@linux-mips.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

Maciej W. Rozycki <macro@linux-mips.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
          Component|nss                         |dynamic-link
         Resolution|---                         |FIXED
           Assignee|unassigned at sourceware dot org   |macro@linux-mips.org

--- Comment #6 from Maciej W. Rozycki <macro@linux-mips.org> ---
Fixed on trunk as per the commit message.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug dynamic-link/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[vapier at gentoo dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

Mike Frysinger <vapier at gentoo dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |2.23

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug dynamic-link/17250] static linking breaks nss loading (getaddrinfo/getpwnam/etc...)

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17250

--- Comment #7 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".

The branch, gentoo/2.22 has been updated
       via  adf228f91c11a1bcdf7563d104a2a370d054e482 (commit)
      from  ca6a9ce6151759981cc2efd58e053148c7db2fea (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=adf228f91c11a1bcdf7563d104a2a370d054e482

commit adf228f91c11a1bcdf7563d104a2a370d054e482
Author: Maciej W. Rozycki <macro@imgtec.com>
Date:   Fri Sep 25 09:37:12 2015 +0100

    [BZ #17250] Fix static dlopen default library search path

    Fix a regression introduced with commit 0d23a5c1 [Static dlopen
    correction fallout fixes] that caused the default library search path to
    be ignored for modules loaded with dlopen from static executables.

        [BZ #17250]
        * elf/dl-support.c (_dl_main_map): Don't initialize l_flags_1
        member.

    (cherry picked from commit 93bad7c97c7047ecaf7664859e2b49c0fe995443)

-----------------------------------------------------------------------

Summary of changes:
 elf/dl-support.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

-- 
You are receiving this mail because:
You are on the CC list for the bug.