Netdev List

* Re: [PATCH 15/22] arch: vdso: consolidate gettime prototypes
From: Vincenzo Frascino @ 2023-11-10 10:16 UTC (permalink / raw)
  To: Arnd Bergmann, Andrew Morton, linux-kernel, Masahiro Yamada,
	linux-kbuild
  Cc: Arnd Bergmann, Matt Turner, Vineet Gupta, Russell King,
	Catalin Marinas, Will Deacon, Steven Rostedt, Masami Hiramatsu,
	Mark Rutland, Guo Ren, Peter Zijlstra, Ard Biesheuvel,
	Huacai Chen, Greg Ungerer, Michal Simek, Thomas Bogendoerfer,
	Dinh Nguyen, Michael Ellerman, Nicholas Piggin, Christophe Leroy,
	Geoff Levand, Palmer Dabbelt, Heiko Carstens,
	John Paul Adrian Glaubitz, David S. Miller, Andy Lutomirski,
	Thomas Gleixner, Ingo Molnar, x86, Helge Deller, Sudip Mukherjee,
	Greg Kroah-Hartman, Timur Tabi, Kent Overstreet, David Woodhouse,
	Naveen N. Rao, Anil S Keshavamurthy, Kees Cook, Juri Lelli,
	Vincent Guittot, Nathan Chancellor, Nick Desaulniers,
	Nicolas Schier, Al Viro, Uwe Kleine-König, linux-alpha,
	linux-snps-arc, linux-arm-kernel, linux-trace-kernel, linux-csky,
	loongarch, linux-m68k, linux-mips, linuxppc-dev, linux-riscv,
	linux-s390, linux-sh, sparclinux, netdev, linux-parisc, linux-usb,
	linux-fbdev, dri-devel, linux-bcachefs, linux-mtd
In-Reply-To: <20231108125843.3806765-16-arnd@kernel.org>

Hi Arnd,

On 11/8/23 12:58, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The VDSO functions are defined as globals in the kernel sources but intended
> to be called from userspace, so there is no need to declare them in a kernel
> side header.
> 
> Without a prototype, this now causes warnings such as
> 
> arch/mips/vdso/vgettimeofday.c:14:5: error: no previous prototype for '__vdso_clock_gettime' [-Werror=missing-prototypes]
> arch/mips/vdso/vgettimeofday.c:28:5: error: no previous prototype for '__vdso_gettimeofday' [-Werror=missing-prototypes]
> arch/mips/vdso/vgettimeofday.c:36:5: error: no previous prototype for '__vdso_clock_getres' [-Werror=missing-prototypes]
> arch/mips/vdso/vgettimeofday.c:42:5: error: no previous prototype for '__vdso_clock_gettime64' [-Werror=missing-prototypes]
> arch/sparc/vdso/vclock_gettime.c:254:1: error: no previous prototype for '__vdso_clock_gettime' [-Werror=missing-prototypes]
> arch/sparc/vdso/vclock_gettime.c:282:1: error: no previous prototype for '__vdso_clock_gettime_stick' [-Werror=missing-prototypes]
> arch/sparc/vdso/vclock_gettime.c:307:1: error: no previous prototype for '__vdso_gettimeofday' [-Werror=missing-prototypes]
> arch/sparc/vdso/vclock_gettime.c:343:1: error: no previous prototype for '__vdso_gettimeofday_stick' [-Werror=missing-prototypes]
> 
> Most architectures have already added workarounds for these by adding
> declarations somewhere, but since these are all compatible, we should
> really just have one copy, with an #ifdef check for the 32-bit vs
> 64-bit variant and use that everywhere.
> 

I agree, it is a good idea to have a single header for this purpose.

> Unfortunately, the sparc version is currently incompatible since
> that never added support for __vdso_clock_gettime64() in 32-bit
> userland. For the moment, I'm leaving this one out, as I can't
> easily test it and it requires a larger rework.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  arch/arm/include/asm/vdso.h              |  5 -----
>  arch/arm/vdso/vgettimeofday.c            |  1 +
>  arch/arm64/kernel/vdso32/vgettimeofday.c |  1 +
>  arch/csky/kernel/vdso/vgettimeofday.c    | 11 +----------
>  arch/loongarch/vdso/vgettimeofday.c      |  7 +------
>  arch/mips/vdso/vgettimeofday.c           |  1 +
>  arch/riscv/kernel/vdso/vgettimeofday.c   |  7 +------
>  arch/x86/entry/vdso/vclock_gettime.c     | 10 +---------
>  arch/x86/include/asm/vdso/gettimeofday.h |  2 --
>  arch/x86/um/vdso/um_vdso.c               |  1 +
>  include/vdso/gettime.h                   | 23 +++++++++++++++++++++++
>  11 files changed, 31 insertions(+), 38 deletions(-)
>  create mode 100644 include/vdso/gettime.h
> 
> diff --git a/arch/arm/include/asm/vdso.h b/arch/arm/include/asm/vdso.h
> index 422c3afa806a..5b85889f82ee 100644
> --- a/arch/arm/include/asm/vdso.h
> +++ b/arch/arm/include/asm/vdso.h
> @@ -24,11 +24,6 @@ static inline void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
>  
>  #endif /* CONFIG_VDSO */
>  
> -int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts);
> -int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts);
> -int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
> -int __vdso_clock_getres(clockid_t clock_id, struct old_timespec32 *res);
> -
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* __KERNEL__ */
> diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
> index a003beacac76..3554aa35f1ba 100644
> --- a/arch/arm/vdso/vgettimeofday.c
> +++ b/arch/arm/vdso/vgettimeofday.c
> @@ -8,6 +8,7 @@
>  #include <linux/types.h>
>  #include <asm/vdso.h>
>  #include <asm/unwind.h>
> +#include <vdso/gettime.h>
>  
>  int __vdso_clock_gettime(clockid_t clock,
>  			 struct old_timespec32 *ts)
> diff --git a/arch/arm64/kernel/vdso32/vgettimeofday.c b/arch/arm64/kernel/vdso32/vgettimeofday.c
> index 5acff29c5991..e23c7f4ef26b 100644
> --- a/arch/arm64/kernel/vdso32/vgettimeofday.c
> +++ b/arch/arm64/kernel/vdso32/vgettimeofday.c
> @@ -5,6 +5,7 @@
>   * Copyright (C) 2018 ARM Limited
>   *
>   */
> +#include <vdso/gettime.h>
>  
>  int __vdso_clock_gettime(clockid_t clock,
>  			 struct old_timespec32 *ts)
> diff --git a/arch/csky/kernel/vdso/vgettimeofday.c b/arch/csky/kernel/vdso/vgettimeofday.c
> index c4831145eed5..55af30e83752 100644
> --- a/arch/csky/kernel/vdso/vgettimeofday.c
> +++ b/arch/csky/kernel/vdso/vgettimeofday.c
> @@ -2,36 +2,27 @@
>  
>  #include <linux/time.h>
>  #include <linux/types.h>
> +#include <vdso/gettime.h>
>  
>  extern
> -int __vdso_clock_gettime(clockid_t clock,
> -			 struct old_timespec32 *ts);
>  int __vdso_clock_gettime(clockid_t clock,
>  			 struct old_timespec32 *ts)
>  {
>  	return __cvdso_clock_gettime32(clock, ts);
>  }
>  
> -int __vdso_clock_gettime64(clockid_t clock,
> -			   struct __kernel_timespec *ts);
>  int __vdso_clock_gettime64(clockid_t clock,
>  			   struct __kernel_timespec *ts)
>  {
>  	return __cvdso_clock_gettime(clock, ts);
>  }
>  
> -extern
> -int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
> -			struct timezone *tz);
>  int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
>  			struct timezone *tz)
>  {
>  	return __cvdso_gettimeofday(tv, tz);
>  }
>  
> -extern
> -int __vdso_clock_getres(clockid_t clock_id,
> -			struct old_timespec32 *res);
>  int __vdso_clock_getres(clockid_t clock_id,
>  			struct old_timespec32 *res)
>  {
> diff --git a/arch/loongarch/vdso/vgettimeofday.c b/arch/loongarch/vdso/vgettimeofday.c
> index 8f22863bd7ea..0885c1f3a89d 100644
> --- a/arch/loongarch/vdso/vgettimeofday.c
> +++ b/arch/loongarch/vdso/vgettimeofday.c
> @@ -5,23 +5,18 @@
>   * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
>   */
>  #include <linux/types.h>
> +#include <vdso/gettime.h>
>  
> -extern
> -int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts);
>  int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
>  {
>  	return __cvdso_clock_gettime(clock, ts);
>  }
>  
> -extern
> -int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
>  int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
>  {
>  	return __cvdso_gettimeofday(tv, tz);
>  }
>  
> -extern
> -int __vdso_clock_getres(clockid_t clock_id, struct __kernel_timespec *res);
>  int __vdso_clock_getres(clockid_t clock_id, struct __kernel_timespec *res)
>  {
>  	return __cvdso_clock_getres(clock_id, res);
> diff --git a/arch/mips/vdso/vgettimeofday.c b/arch/mips/vdso/vgettimeofday.c
> index 6b83b6376a4b..604afea3f336 100644
> --- a/arch/mips/vdso/vgettimeofday.c
> +++ b/arch/mips/vdso/vgettimeofday.c
> @@ -9,6 +9,7 @@
>   */
>  #include <linux/time.h>
>  #include <linux/types.h>
> +#include <vdso/gettime.h>
>  
>  #if _MIPS_SIM != _MIPS_SIM_ABI64
>  int __vdso_clock_gettime(clockid_t clock,
> diff --git a/arch/riscv/kernel/vdso/vgettimeofday.c b/arch/riscv/kernel/vdso/vgettimeofday.c
> index cc0d80699c31..b35057802584 100644
> --- a/arch/riscv/kernel/vdso/vgettimeofday.c
> +++ b/arch/riscv/kernel/vdso/vgettimeofday.c
> @@ -8,23 +8,18 @@
>  
>  #include <linux/time.h>
>  #include <linux/types.h>
> +#include <vdso/gettime.h>
>  
> -extern
> -int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts);
>  int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
>  {
>  	return __cvdso_clock_gettime(clock, ts);
>  }
>  
> -extern
> -int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
>  int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
>  {
>  	return __cvdso_gettimeofday(tv, tz);
>  }
>  
> -extern
> -int __vdso_clock_getres(clockid_t clock_id, struct __kernel_timespec *res);
>  int __vdso_clock_getres(clockid_t clock_id, struct __kernel_timespec *res)
>  {
>  	return __cvdso_clock_getres(clock_id, res);
> diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
> index 7d70935b6758..0debc194bd78 100644
> --- a/arch/x86/entry/vdso/vclock_gettime.c
> +++ b/arch/x86/entry/vdso/vclock_gettime.c
> @@ -11,12 +11,10 @@
>  #include <linux/time.h>
>  #include <linux/kernel.h>
>  #include <linux/types.h>
> +#include <vdso/gettime.h>
>  
>  #include "../../../../lib/vdso/gettimeofday.c"
>  
> -extern int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
> -extern __kernel_old_time_t __vdso_time(__kernel_old_time_t *t);
> -
>  int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
>  {
>  	return __cvdso_gettimeofday(tv, tz);
> @@ -35,9 +33,6 @@ __kernel_old_time_t time(__kernel_old_time_t *t)	__attribute__((weak, alias("__v
>  
>  #if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64)
>  /* both 64-bit and x32 use these */
> -extern int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts);
> -extern int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res);
> -
>  int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
>  {
>  	return __cvdso_clock_gettime(clock, ts);
> @@ -56,9 +51,6 @@ int clock_getres(clockid_t, struct __kernel_timespec *)
>  
>  #else
>  /* i386 only */
> -extern int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts);
> -extern int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res);
> -
>  int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts)
>  {
>  	return __cvdso_clock_gettime32(clock, ts);
> diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
> index c81858d903dc..a46edb0e0cf7 100644
> --- a/arch/x86/include/asm/vdso/gettimeofday.h
> +++ b/arch/x86/include/asm/vdso/gettimeofday.h
> @@ -337,8 +337,6 @@ u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
>  }
>  #define vdso_calc_delta vdso_calc_delta
>  
> -int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts);
> -
>  #endif /* !__ASSEMBLY__ */
>  
>  #endif /* __ASM_VDSO_GETTIMEOFDAY_H */
> diff --git a/arch/x86/um/vdso/um_vdso.c b/arch/x86/um/vdso/um_vdso.c
> index ff0f3b4b6c45..63768dd347ce 100644
> --- a/arch/x86/um/vdso/um_vdso.c
> +++ b/arch/x86/um/vdso/um_vdso.c
> @@ -12,6 +12,7 @@
>  #include <linux/time.h>
>  #include <linux/getcpu.h>
>  #include <asm/unistd.h>
> +#include <vdso/gettime.h>
>  
>  int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
>  {
> diff --git a/include/vdso/gettime.h b/include/vdso/gettime.h
> new file mode 100644
> index 000000000000..c50d152e7b3e
> --- /dev/null
> +++ b/include/vdso/gettime.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _VDSO_GETTIME_H
> +#define _VDSO_GETTIME_H
> +
> +#include <linux/types.h>
> +
> +struct __kernel_timespec;
> +struct timezone;
> +
> +#if !defined(CONFIG_64BIT) || defined(BUILD_VDSO32_64)
> +struct old_timespec32;
> +int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res);
> +int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts);
> +#else
> +int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res);
> +int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts);
> +#endif
> +
> +__kernel_old_time_t __vdso_time(__kernel_old_time_t *t);
> +int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
> +int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts);
> +
> +#endif

-- 
Regards,
Vincenzo

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