[PATCH v2] Add x86 32 bit vDSO time function support

[Roland McGrath]

> 	* sysdeps/unix/sysv/linux/i386/Makefile [sysdep_routines]: Add dl-vdso
> 	object.

	* sysdeps/unix/sysv/linux/i386/Makefile [$(subdir) = elf]
	(sysdep_routines): Add dl-vdso object.

> 	* sysdeps/unix/sysv/linux/i386/gettimeofday.c: New file: add support
> 	to vDSO.

"support to use vDSO"?

> --- a/sysdeps/unix/sysv/linux/i386/Makefile
> +++ b/sysdeps/unix/sysv/linux/i386/Makefile
> @@ -21,3 +21,7 @@ endif
>  ifeq ($(subdir),stdlib)
>  gen-as-const-headers += ucontext_i.sym
>  endif
> +
> +ifeq ($(subdir),elf)
> +sysdep_routines += dl-vdso
> +endif

Instead just move that from x86_64/Makefile to x86/Makefile so it's shared.

> +long int (*__vdso_clock_gettime) (clockid_t, struct timespec *)
> +  __attribute__ ((nocommon));
> +strong_alias (__vdso_clock_gettime, __GI___vdso_clock_gettime attribute_hidden)

Use libc_hidden_data_def.

> +static inline void
> +_libc_vdso_platform_setup (void)

Don't use a _libc_ prefix like that on a static symbol.
Just use a descriptive name.

> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/i386/time.c
> @@ -0,0 +1,33 @@
> +/* Copyright (C) 2014 Free Software Foundation, Inc.

First line is a descriptive comment.

> +# define TIME_FALLBACK  (void*)__time_syscall

# define TIME_FALLBACK	((void *) &__time_syscall)

> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86/bits/libc-vdso.h
[...]
> +extern long int (*__vdso_clock_gettime) (clockid_t, struct timespec *);

libc_hidden_proto here to go with libc_hidden_def.

Also, this header really should not be in bits/.
That only makes sense for installed headers.

> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86/clock_gettime.c
> @@ -0,0 +1,20 @@
> +#include "bits/libc-vdso.h"

Missing top comment and license header.

> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86/timespec_get.c
> @@ -0,0 +1,10 @@
> +#include "bits/libc-vdso.h"

Here too.