diff mbox series

[15/22] arch: vdso: consolidate gettime prototypes

Message ID 20231108125843.3806765-16-arnd@kernel.org (mailing list archive)
State Handled Elsewhere
Headers show
Series -Wmissing-prototype warning fixes | expand

Commit Message

Arnd Bergmann Nov. 8, 2023, 12:58 p.m. UTC
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.

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>
---
 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

Comments

Christophe Leroy Nov. 8, 2023, 6:31 p.m. UTC | #1
Hi Arnd,

Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :
> 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.
> 
> 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>
> ---
>   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

powerpc has functions doing more or less the same, they are called 
__c_kernel_clock_gettime() and alike with their prototypes siting in 
arch/powerpc/include/asm/vdso/gettimeofday.h

Should those prototypes be moved to include/vdso/gettime.h too and 
eventually renamed, or are they considered too powerpc specific ?

Christophe
Arnd Bergmann Nov. 8, 2023, 7:37 p.m. UTC | #2
On Wed, Nov 8, 2023, at 19:31, Christophe Leroy wrote:
> Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :

> powerpc has functions doing more or less the same, they are called 
> __c_kernel_clock_gettime() and alike with their prototypes siting in 
> arch/powerpc/include/asm/vdso/gettimeofday.h
>
> Should those prototypes be moved to include/vdso/gettime.h too and 
> eventually renamed, or are they considered too powerpc specific ?

I don't actually know, my initial interpretation was that
these function names are part of the user ABI for the vdso,
but I never looked closely enough at how vdso works to
be sure what the actual ABI is.

If __c_kernel_clock_gettime() etc are not part of the user-facing
ABI, I think renaming them for consistency with the other
architectures would be best.

     Arnd
Christophe Leroy Nov. 9, 2023, 7:50 a.m. UTC | #3
Le 08/11/2023 à 20:37, Arnd Bergmann a écrit :
> On Wed, Nov 8, 2023, at 19:31, Christophe Leroy wrote:
>> Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :
> 
>> powerpc has functions doing more or less the same, they are called
>> __c_kernel_clock_gettime() and alike with their prototypes siting in
>> arch/powerpc/include/asm/vdso/gettimeofday.h
>>
>> Should those prototypes be moved to include/vdso/gettime.h too and
>> eventually renamed, or are they considered too powerpc specific ?
> 
> I don't actually know, my initial interpretation was that
> these function names are part of the user ABI for the vdso,
> but I never looked closely enough at how vdso works to
> be sure what the actual ABI is.
> 
> If __c_kernel_clock_gettime() etc are not part of the user-facing
> ABI, I think renaming them for consistency with the other
> architectures would be best.
> 

User-facing ABI function is __kernel_clock_gettime(), defined in 
arch/powerpc/kernel/vdso/gettimeofday.S , see man vdso.
There is no prototype defined for it anywhere, obviously that's 
undetected because it is assembly. Should a prototype be added somewhere 
anyway ?

__kernel_clock_gettime() sets up a stack frame, retrieves the address of 
the datapage then calls __c_kernel_clock_gettime() which then calls 
__cvdso_clock_gettime_data() which is part of the generic CVDSO.

Maybe that's too different from what other architectures do ?

Christophe
Michael Ellerman Nov. 9, 2023, 10:18 a.m. UTC | #4
"Arnd Bergmann" <arnd@arndb.de> writes:
> On Wed, Nov 8, 2023, at 19:31, Christophe Leroy wrote:
>> Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :
>
>> powerpc has functions doing more or less the same, they are called 
>> __c_kernel_clock_gettime() and alike with their prototypes siting in 
>> arch/powerpc/include/asm/vdso/gettimeofday.h
>>
>> Should those prototypes be moved to include/vdso/gettime.h too and 
>> eventually renamed, or are they considered too powerpc specific ?
>
> I don't actually know, my initial interpretation was that
> these function names are part of the user ABI for the vdso,
> but I never looked closely enough at how vdso works to
> be sure what the actual ABI is.

AFAIK the ABI is just the symbols we export, as defined in the linker
script:

/*
 * This controls what symbols we export from the DSO.
 */
VERSION
{
	VDSO_VERSION_STRING {
	global:
		__kernel_get_syscall_map;
		__kernel_gettimeofday;
		__kernel_clock_gettime;
		__kernel_clock_getres;
		__kernel_get_tbfreq;
		__kernel_sync_dicache;
		__kernel_sigtramp_rt64;
		__kernel_getcpu;
		__kernel_time;

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/kernel/vdso/vdso64.lds.S?h=v6.6&#n117

> If __c_kernel_clock_gettime() etc are not part of the user-facing
> ABI, I think renaming them for consistency with the other
> architectures would be best.

The __c symbols are not part of the ABI, so we could rename them.

At the moment though they don't have the same prototype as the generic
versions, because we find the VDSO data in asm and pass it to the C
functions, eg:

int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
			    const struct vdso_data *vd);

I think we can rework that though, by implementing
__arch_get_vdso_data() and getting the vdso_data in C. Then we'd be able
to share the prototypes.

cheers
Christophe Leroy Nov. 9, 2023, 10:49 a.m. UTC | #5
Le 09/11/2023 à 11:18, Michael Ellerman a écrit :
> "Arnd Bergmann" <arnd@arndb.de> writes:
>> On Wed, Nov 8, 2023, at 19:31, Christophe Leroy wrote:
>>> Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :
>>
>>> powerpc has functions doing more or less the same, they are called
>>> __c_kernel_clock_gettime() and alike with their prototypes siting in
>>> arch/powerpc/include/asm/vdso/gettimeofday.h
>>>
>>> Should those prototypes be moved to include/vdso/gettime.h too and
>>> eventually renamed, or are they considered too powerpc specific ?
>>
>> I don't actually know, my initial interpretation was that
>> these function names are part of the user ABI for the vdso,
>> but I never looked closely enough at how vdso works to
>> be sure what the actual ABI is.
> 
> AFAIK the ABI is just the symbols we export, as defined in the linker
> script:
> 
> /*
>   * This controls what symbols we export from the DSO.
>   */
> VERSION
> {
> 	VDSO_VERSION_STRING {
> 	global:
> 		__kernel_get_syscall_map;
> 		__kernel_gettimeofday;
> 		__kernel_clock_gettime;
> 		__kernel_clock_getres;
> 		__kernel_get_tbfreq;
> 		__kernel_sync_dicache;
> 		__kernel_sigtramp_rt64;
> 		__kernel_getcpu;
> 		__kernel_time;
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/kernel/vdso/vdso64.lds.S?h=v6.6&#n117
> 
>> If __c_kernel_clock_gettime() etc are not part of the user-facing
>> ABI, I think renaming them for consistency with the other
>> architectures would be best.
> 
> The __c symbols are not part of the ABI, so we could rename them.
> 
> At the moment though they don't have the same prototype as the generic
> versions, because we find the VDSO data in asm and pass it to the C
> functions, eg:
> 
> int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
> 			    const struct vdso_data *vd);
> 
> I think we can rework that though, by implementing
> __arch_get_vdso_data() and getting the vdso_data in C. Then we'd be able
> to share the prototypes.

I think it would not a been good idea, it would be less performant, for 
explanation see commit 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e876f0b69dc993e86ca7795e63e98385aa9a7ef3

Christophe
Michael Ellerman Nov. 9, 2023, 12:23 p.m. UTC | #6
Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 09/11/2023 à 11:18, Michael Ellerman a écrit :
>> "Arnd Bergmann" <arnd@arndb.de> writes:
>>> On Wed, Nov 8, 2023, at 19:31, Christophe Leroy wrote:
>>>> Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :
>>>
>>>> powerpc has functions doing more or less the same, they are called
>>>> __c_kernel_clock_gettime() and alike with their prototypes siting in
>>>> arch/powerpc/include/asm/vdso/gettimeofday.h
>>>>
>>>> Should those prototypes be moved to include/vdso/gettime.h too and
>>>> eventually renamed, or are they considered too powerpc specific ?
>>>
>>> I don't actually know, my initial interpretation was that
>>> these function names are part of the user ABI for the vdso,
>>> but I never looked closely enough at how vdso works to
>>> be sure what the actual ABI is.
>> 
>> AFAIK the ABI is just the symbols we export, as defined in the linker
>> script:
>> 
>> /*
>>   * This controls what symbols we export from the DSO.
>>   */
>> VERSION
>> {
>> 	VDSO_VERSION_STRING {
>> 	global:
>> 		__kernel_get_syscall_map;
>> 		__kernel_gettimeofday;
>> 		__kernel_clock_gettime;
>> 		__kernel_clock_getres;
>> 		__kernel_get_tbfreq;
>> 		__kernel_sync_dicache;
>> 		__kernel_sigtramp_rt64;
>> 		__kernel_getcpu;
>> 		__kernel_time;
>> 
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/kernel/vdso/vdso64.lds.S?h=v6.6&#n117
>> 
>>> If __c_kernel_clock_gettime() etc are not part of the user-facing
>>> ABI, I think renaming them for consistency with the other
>>> architectures would be best.
>> 
>> The __c symbols are not part of the ABI, so we could rename them.
>> 
>> At the moment though they don't have the same prototype as the generic
>> versions, because we find the VDSO data in asm and pass it to the C
>> functions, eg:
>> 
>> int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
>> 			    const struct vdso_data *vd);
>> 
>> I think we can rework that though, by implementing
>> __arch_get_vdso_data() and getting the vdso_data in C. Then we'd be able
>> to share the prototypes.
>
> I think it would not a been good idea, it would be less performant, for 
> explanation see commit 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e876f0b69dc993e86ca7795e63e98385aa9a7ef3

Ah thanks. I was wondering why you had done it in asm.

It's a pity but you're right that's probably a measurable performance
hit for some of those calls.

cheers
Vincenzo Frascino Nov. 10, 2023, 10:16 a.m. UTC | #7
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
Mark Brown Nov. 24, 2023, 12:04 p.m. UTC | #8
On Wed, Nov 08, 2023 at 01:58:36PM +0100, 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.

This is in -next as commit 42874e4eb35bdfc54f8514685e50434098ba4f6c and
breaks an arm64 defconfig build, the 32 bit vDSO build is broken:

/build/stage/linux/arch/arm64/kernel/vdso32/vgettimeofday.c:10:5: error: conflic
ting types for ‘__vdso_clock_gettime’; have ‘int(clockid_t,  struct old_timespec
32 *)’ {aka ‘int(int,  struct old_timespec32 *)’}
   10 | int __vdso_clock_gettime(clockid_t clock,
      |     ^~~~~~~~~~~~~~~~~~~~
In file included from /build/stage/linux/arch/arm64/kernel/vdso32/vgettimeofday.
c:8:
/build/stage/linux/include/vdso/gettime.h:16:5: note: previous declaration of ‘__vdso_clock_gettime’ with type ‘int(clockid_t,  struct __kernel_timespec *)’ {aka ‘int(int,  struct __kernel_timespec *)’}
   16 | int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts);
      |     ^~~~~~~~~~~~~~~~~~~~
/build/stage/linux/arch/arm64/kernel/vdso32/vgettimeofday.c:28:5: error: conflicting types for ‘__vdso_clock_getres’; have ‘int(clockid_t,  struct old_timespec32 *)’ {aka ‘int(int,  struct old_timespec32 *)’}
   28 | int __vdso_clock_getres(clockid_t clock_id,
      |     ^~~~~~~~~~~~~~~~~~~
/build/stage/linux/include/vdso/gettime.h:15:5: note: previous declaration of ‘__vdso_clock_getres’ with type ‘int(clockid_t,  struct __kernel_timespec *)’ {aka ‘int(int,  struct __kernel_timespec *)’}
   15 | int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res);
      |     ^~~~~~~~~~~~~~~~~~~
diff mbox series

Patch

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