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Re: [PATCH v2 1/2] sysdeps: Add clock_gettime64 vDSO
- From: Alistair Francis <alistair23 at gmail dot com>
- To: Alistair Francis <alistair dot francis at wdc dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Mon, 18 Nov 2019 13:40:51 -0800
- Subject: Re: [PATCH v2 1/2] sysdeps: Add clock_gettime64 vDSO
- References: <20191110025658.3149-1-alistair.francis@wdc.com>
On Sat, Nov 9, 2019 at 7:02 PM Alistair Francis
<alistair.francis@wdc.com> wrote:
>
> Add support for the clock_gettim64 vDSO calls. These are protected by
> the HAVE_CLOCK_GETTIME64_VSYSCALL define.
>
> HAVE_CLOCK_GETTIME64_VSYSCALL should be defined for 32-bit platforms
> (WORDSIZE == 32) that only run on the 5.1 kernel or later. WORDSIZE ==
> 64 platforms can use #define __vdso_clock_gettime64 __vdso_clock_gettime
> and use the __vdso_clock_gettime syscall as they don't have a
> __vdso_clock_gettime64 call.
>
> * sysdeps/unix/sysv/linux/init-first.c: Add clock_gettime64
> vDSO.
> * sysdeps/unix/sysv/linux/libc-vdso.h: Likewise.
Ping!
Alistair
> ---
> sysdeps/unix/sysv/linux/init-first.c | 10 ++++++++++
> sysdeps/unix/sysv/linux/libc-vdso.h | 4 ++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/sysdeps/unix/sysv/linux/init-first.c b/sysdeps/unix/sysv/linux/init-first.c
> index d90ca820be0..d005d133220 100644
> --- a/sysdeps/unix/sysv/linux/init-first.c
> +++ b/sysdeps/unix/sysv/linux/init-first.c
> @@ -24,6 +24,11 @@
> int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
> attribute_hidden;
> #endif
> +/* vDSO symbol used on clock_gettime64 implementation. */
> +#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
> +int (*VDSO_SYMBOL(clock_gettime64)) (clockid_t, struct __timespec64 *)
> + attribute_hidden;
> +#endif
> /* vDSO symbol used on clock_getres implementation. */
> #ifdef HAVE_CLOCK_GETRES_VSYSCALL
> int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
> @@ -52,6 +57,11 @@ __libc_vdso_platform_setup (void)
> = get_vdso_mangle_symbol (HAVE_CLOCK_GETTIME_VSYSCALL);
> #endif
>
> +#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
> + VDSO_SYMBOL(clock_gettime64)
> + = get_vdso_mangle_symbol (HAVE_CLOCK_GETTIME64_VSYSCALL);
> +#endif
> +
> #ifdef HAVE_CLOCK_GETRES_VSYSCALL
> VDSO_SYMBOL(clock_getres)
> = get_vdso_mangle_symbol (HAVE_CLOCK_GETRES_VSYSCALL);
> diff --git a/sysdeps/unix/sysv/linux/libc-vdso.h b/sysdeps/unix/sysv/linux/libc-vdso.h
> index 792ac39d85a..c6d505bab39 100644
> --- a/sysdeps/unix/sysv/linux/libc-vdso.h
> +++ b/sysdeps/unix/sysv/linux/libc-vdso.h
> @@ -32,6 +32,10 @@
> extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
> attribute_hidden;
> #endif
> +#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
> +extern int (*VDSO_SYMBOL(clock_gettime64)) (clockid_t, struct __timespec64 *)
> + attribute_hidden;
> +#endif
> #ifdef HAVE_CLOCK_GETRES_VSYSCALL
> extern int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
> attribute_hidden;
> --
> 2.23.0
>