Re: GNU C Library master sources branch master updated. glibc-2.16-ports-merge-437-g53cea63

[Thomas Schwinge <thomas at codesourcery dot com>]

Hi!

On 5 Oct 2012 17:39:33 -0000, hjl@sourceware.org wrote:
> http://sources.redhat.com/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=9cee55856438b714fa1efa45d8b7c1857467f4ca
> 
> commit 9cee55856438b714fa1efa45d8b7c1857467f4ca
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date:   Fri Oct 5 10:20:39 2012 -0700
> 
>     Set up the data structures for vDSO in libc.a

> +	[BZ #14557]
> +	* elf/dl-support.c (_dl_sysinfo_map): New.
> +	Include "get-dynamic-info.h" and "setup-vdso.h".
> +	(_dl_non_dynamic_init): Call setup_vdso.
> +	* elf/dynamic-link.h: Don't include <assert.h>.
> +	(elf_get_dynamic_info): Moved to ...
> +	* elf/get-dynamic-info.h: Here.  New file.
> +	* elf/dynamic-link.h: Include "get-dynamic-info.h".
> +	* elf/rtld.c (dl_main): Break out vDSO setup code into ...
> +	* elf/setup-vdso.h: Here.  New file.
> +	* elf/rtld.c: Include "setup-vdso.h".
> +	(dl_main): Call setup_vdso.

> diff --git a/elf/dl-support.c b/elf/dl-support.c
> index 2bb468a..424ca6d 100644
> --- a/elf/dl-support.c
> +++ b/elf/dl-support.c
> @@ -161,6 +161,11 @@ uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT;
>  #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
>  /* Address of the ELF headers in the vsyscall page.  */
>  const ElfW(Ehdr) *_dl_sysinfo_dso;
> +
> +struct link_map *_dl_sysinfo_map;
> +
> +# include "get-dynamic-info.h"
> +# include "setup-vdso.h"
>  #endif
>  
>  /* During the program run we must not modify the global data of
> @@ -266,6 +271,10 @@ _dl_non_dynamic_init (void)
>  
>    _dl_verbose = *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1;
>  
> +  /* Set up the data structures for the system-supplied DSO early,
> +     so they can influence _dl_init_paths.  */
> +  setup_vdso (NULL, NULL);

For Â!(defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO)Â (as it is
on GNU Hurd), this causes:

    dl-support.c: In function '_dl_non_dynamic_init':
    dl-support.c:277:3: warning: implicit declaration of function 'setup_vdso' [-Wimplicit-function-declaration]
       setup_vdso (NULL, NULL);
       ^
    [...]
    [...]/libc.a(dl-support.o): In function `_dl_non_dynamic_init':
    [...]/elf/dl-support.c:277: undefined reference to `setup_vdso'
    collect2: error: ld returned 1 exit status
    make[2]: *** [[...]/elf/sln] Error 1

Is the following a suitable minimal fix, given that setup_vdso itself
only gets active for Âdefined NEED_DL_SYSINFO || defined
NEED_DL_SYSINFO_DSOÂ?

diff --git elf/dl-support.c elf/dl-support.c
index 722b1b9..5688ecd 100644
--- elf/dl-support.c
+++ elf/dl-support.c
@@ -166,8 +166,8 @@ const ElfW(Ehdr) *_dl_sysinfo_dso;
 struct link_map *_dl_sysinfo_map;
 
 # include "get-dynamic-info.h"
-# include "setup-vdso.h"
 #endif
+#include "setup-vdso.h"
 
 /* During the program run we must not modify the global data of
    loaded shared object simultanously in two threads.  Therefore we


Also, I generally don't understand the "#include discipline" of the new
files elf/get-dynamic-info.h and elf/setup-vdso.h -- there are no
#includes in these.  But it seems that other files in elf/ also don't
always #include what they use, so rely on what they implicitly get.


GrÃÃe,
 Thomas

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