Add missing VDSO_{NAME,HASH}_* macros and use them for PREPARE_VERSION_KNOWN

Message ID 20190516115924.29027-1-tklauser@distanz.ch
State Superseded
Headers

Commit Message

Tobias Klauser May 16, 2019, 11:59 a.m. UTC
  Define all currently used Linux versions used for
PREPARE_VERSION{,_KNOWN} in sysdeps/unix/sysv/linux/dl-vdso.h and use
them instead of duplicating the versions and precomputed hashes across
architecture specific files.

2019-05-16  Tobias Klauser  <tklauser@distanz.ch>

	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c (INIT_ARCH): Use
	PREPARE_VERSION_KNOWN.
	* sysdeps/unix/sysv/linux/aarch64/init-first.c: Likewise.
	* sysdeps/unix/sysv/linux/dl-vdso.h (VDSO_NAME_LINUX_2_6_39): New
	define.
	(VDSO_HASH_LINUX_2_6_39): Likewise.
	(VDSO_NAME_LINUX_4_9): Likewise.
	(VDSO_HASH_LINUX_4_9): Likewise.
	* sysdeps/unix/sysv/linux/m68k/init-first.c (_libc_vdso_platform_setup):
	Use PREPARE_VERSION_KNOWN.
	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (INIT_ARCH): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/init-first.c
	(_libc_vdso_platform_setup): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/time.c (INIT_ARCH): Likewise.
	* sysdeps/unix/sysv/linux/s390/init-first.c (_libc_vdso_platform_setup):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/init-first.c (__vdso_platform_setup):
	Likewise.
---
 sysdeps/unix/sysv/linux/aarch64/gettimeofday.c | 4 ++--
 sysdeps/unix/sysv/linux/aarch64/init-first.c   | 4 ++--
 sysdeps/unix/sysv/linux/dl-vdso.h              | 4 ++++
 sysdeps/unix/sysv/linux/m68k/init-first.c      | 2 +-
 sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 4 ++--
 sysdeps/unix/sysv/linux/powerpc/init-first.c   | 2 +-
 sysdeps/unix/sysv/linux/powerpc/time.c         | 4 ++--
 sysdeps/unix/sysv/linux/s390/init-first.c      | 2 +-
 sysdeps/unix/sysv/linux/x86_64/init-first.c    | 2 +-
 9 files changed, 16 insertions(+), 12 deletions(-)
  

Comments

Adhemerval Zanella May 23, 2019, 7:36 p.m. UTC | #1
On 16/05/2019 08:59, Tobias Klauser wrote:
> Define all currently used Linux versions used for
> PREPARE_VERSION{,_KNOWN} in sysdeps/unix/sysv/linux/dl-vdso.h and use
> them instead of duplicating the versions and precomputed hashes across
> architecture specific files.
> 
> 2019-05-16  Tobias Klauser  <tklauser@distanz.ch>
> 
> 	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c (INIT_ARCH): Use
> 	PREPARE_VERSION_KNOWN.
> 	* sysdeps/unix/sysv/linux/aarch64/init-first.c: Likewise.
> 	* sysdeps/unix/sysv/linux/dl-vdso.h (VDSO_NAME_LINUX_2_6_39): New
> 	define.
> 	(VDSO_HASH_LINUX_2_6_39): Likewise.
> 	(VDSO_NAME_LINUX_4_9): Likewise.
> 	(VDSO_HASH_LINUX_4_9): Likewise.
> 	* sysdeps/unix/sysv/linux/m68k/init-first.c (_libc_vdso_platform_setup):
> 	Use PREPARE_VERSION_KNOWN.
> 	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (INIT_ARCH): Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/init-first.c
> 	(_libc_vdso_platform_setup): Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/time.c (INIT_ARCH): Likewise.
> 	* sysdeps/unix/sysv/linux/s390/init-first.c (_libc_vdso_platform_setup):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/init-first.c (__vdso_platform_setup):
> 	Likewise.


LGTM, I assume you checked a build against affected architectures.  As a side
note I think also should just remove PREPARE_VERSION macro and replace it with
a more sane interface:

--
static inline struct r_found_version
prepare_version_base (const char *name, ElfW(Word) hash)
{
  assert (hash == _dl_elf_hash (name));
  return (struct r_found_version) { name, hash, 1, NULL };
}
#define prepare_version(vname) \
  prepare_version_base (VDSO_NAME_##vname, VDSO_HASH_##vname)
--

> ---
>  sysdeps/unix/sysv/linux/aarch64/gettimeofday.c | 4 ++--
>  sysdeps/unix/sysv/linux/aarch64/init-first.c   | 4 ++--
>  sysdeps/unix/sysv/linux/dl-vdso.h              | 4 ++++
>  sysdeps/unix/sysv/linux/m68k/init-first.c      | 2 +-
>  sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 4 ++--
>  sysdeps/unix/sysv/linux/powerpc/init-first.c   | 2 +-
>  sysdeps/unix/sysv/linux/powerpc/time.c         | 4 ++--
>  sysdeps/unix/sysv/linux/s390/init-first.c      | 2 +-
>  sysdeps/unix/sysv/linux/x86_64/init-first.c    | 2 +-
>  9 files changed, 16 insertions(+), 12 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> index 6c008ed9357f..9180b50bf7c3 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> +++ b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> @@ -38,13 +38,13 @@ __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
>    return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
>  }
>  
> -/* PREPARE_VERSION will need an __LP64__ ifdef when ILP32 support
> +/* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
>     goes in.  See _libc_vdso_platform_setup in
>     sysdeps/unix/sysv/linux/aarch64/init-first.c.  */
>  
>  # undef INIT_ARCH
>  # define INIT_ARCH() \
> -	   PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537); \
> +	   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39); \
>  	   void *vdso_gettimeofday = \
>  	     _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);

Also a side note, this vsdo setup is not required. The init-first.c
already setups the VDSO_SYMBOL(gettimeofday). So a possible followup
cleanup would be:

--
# undef INIT_ARCH
# define INIT_ARCH()

static inline void *
gettimeofday_vdso (void)
{ 
  __typeof (VDSO_SYMBOL(gettimeofday)) vdsop = VDSO_SYMBOL(gettimeofday);
  PTR_DEMANGLE (vdsop);
  return vdsop != NULL ? vdsop : (void *) __gettimeofday_vsyscall;
}

libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
                   gettimeofday_vdso ())
--

>  
> diff --git a/sysdeps/unix/sysv/linux/aarch64/init-first.c b/sysdeps/unix/sysv/linux/aarch64/init-first.c
> index ce7319f3c95b..80f7ed91ef0a 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/init-first.c
> +++ b/sysdeps/unix/sysv/linux/aarch64/init-first.c
> @@ -27,9 +27,9 @@ static inline void
>  _libc_vdso_platform_setup (void)
>  {
>  #ifdef __LP64__
> -  PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537);
> +  PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39);
>  #else
> -  PREPARE_VERSION (linux_version, "LINUX_4.9", 61765625);
> +  PREPARE_VERSION_KNOWN (linux_version, LINUX_4_9);
>  #endif
>  
>    void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);

Ok.

> diff --git a/sysdeps/unix/sysv/linux/dl-vdso.h b/sysdeps/unix/sysv/linux/dl-vdso.h
> index 50ee29067d0b..9e61ca742363 100644
> --- a/sysdeps/unix/sysv/linux/dl-vdso.h
> +++ b/sysdeps/unix/sysv/linux/dl-vdso.h
> @@ -44,6 +44,10 @@
>  #define VDSO_HASH_LINUX_2_6_15	123718565
>  #define VDSO_NAME_LINUX_2_6_29	"LINUX_2.6.29"
>  #define VDSO_HASH_LINUX_2_6_29	123718585
> +#define VDSO_NAME_LINUX_2_6_39	"LINUX_2.6.39"
> +#define VDSO_HASH_LINUX_2_6_39	123718537
> +#define VDSO_NAME_LINUX_4_9	"LINUX_4.9"
> +#define VDSO_HASH_LINUX_4_9	61765625
>  #define VDSO_NAME_LINUX_4_15	"LINUX_4.15"
>  #define VDSO_HASH_LINUX_4_15	182943605
>  

Ok.

> diff --git a/sysdeps/unix/sysv/linux/m68k/init-first.c b/sysdeps/unix/sysv/linux/m68k/init-first.c
> index f8f09108393d..53caba218cfa 100644
> --- a/sysdeps/unix/sysv/linux/m68k/init-first.c
> +++ b/sysdeps/unix/sysv/linux/m68k/init-first.c
> @@ -29,7 +29,7 @@ _libc_vdso_platform_setup (void)
>  {
>    void *p;
>  
> -  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
> +  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
>  
>    /* It may happen that rtld didn't initialize the vDSO, so fallback
>       to the syscall implementations if _dl_vdso_vsym returns NULL.

Ok.

> diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
> index c8d7790d8adc..463b678ad935 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
> +++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
> @@ -57,8 +57,8 @@ __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
>    return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
>  }
>  
> -# define INIT_ARCH()							\
> -  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);		\
> +# define INIT_ARCH()						\
> +  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);		\
>    void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
>  
>  /* If the vDSO is not available we fall back syscall.  */

Ok.

> diff --git a/sysdeps/unix/sysv/linux/powerpc/init-first.c b/sysdeps/unix/sysv/linux/powerpc/init-first.c
> index 237b5abbf9b0..831f910788b3 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/init-first.c
> +++ b/sysdeps/unix/sysv/linux/powerpc/init-first.c
> @@ -37,7 +37,7 @@ void *VDSO_SYMBOL(sigtramp_rt32);
>  static inline void
>  _libc_vdso_platform_setup (void)
>  {
> -  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);
> +  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);
>  
>    void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
>    PTR_MANGLE (p);

Ok.

> diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c
> index c2f171b6228c..cb3e8b9a73a5 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/time.c
> +++ b/sysdeps/unix/sysv/linux/powerpc/time.c
> @@ -66,8 +66,8 @@ time_syscall (time_t *t)
>    return result;
>  }
>  
> -# define INIT_ARCH()							\
> -  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);		\
> +# define INIT_ARCH()						\
> +  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);		\
>    void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615);
>  
>  /* If the vDSO is not available we fall back to the syscall.  */

Ok.

> diff --git a/sysdeps/unix/sysv/linux/s390/init-first.c b/sysdeps/unix/sysv/linux/s390/init-first.c
> index 71dd43f738bf..1f46e8052a37 100644
> --- a/sysdeps/unix/sysv/linux/s390/init-first.c
> +++ b/sysdeps/unix/sysv/linux/s390/init-first.c
> @@ -35,7 +35,7 @@ long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
>  static inline void
>  _libc_vdso_platform_setup (void)
>  {
> -  PREPARE_VERSION (linux2629, "LINUX_2.6.29", 123718585);
> +  PREPARE_VERSION_KNOWN (linux2629, LINUX_2_6_29);
>  
>    void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2629);
>    PTR_MANGLE (p);

Ok.

> diff --git a/sysdeps/unix/sysv/linux/x86_64/init-first.c b/sysdeps/unix/sysv/linux/x86_64/init-first.c
> index 6a347becbe0d..85333e5ff309 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/init-first.c
> +++ b/sysdeps/unix/sysv/linux/x86_64/init-first.c
> @@ -32,7 +32,7 @@ extern __typeof (clock_gettime) __syscall_clock_gettime attribute_hidden;
>  static inline void
>  __vdso_platform_setup (void)
>  {
> -  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
> +  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
>  
>    void *p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
>    if (p == NULL)
> 

Ok.
  
Tobias Klauser May 24, 2019, 7:23 a.m. UTC | #2
Thank you for the review.

On 2019-05-23 at 21:36:01 +0200, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
> On 16/05/2019 08:59, Tobias Klauser wrote:
> > Define all currently used Linux versions used for
> > PREPARE_VERSION{,_KNOWN} in sysdeps/unix/sysv/linux/dl-vdso.h and use
> > them instead of duplicating the versions and precomputed hashes across
> > architecture specific files.
> > 
> > 2019-05-16  Tobias Klauser  <tklauser@distanz.ch>
> > 
> > 	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c (INIT_ARCH): Use
> > 	PREPARE_VERSION_KNOWN.
> > 	* sysdeps/unix/sysv/linux/aarch64/init-first.c: Likewise.
> > 	* sysdeps/unix/sysv/linux/dl-vdso.h (VDSO_NAME_LINUX_2_6_39): New
> > 	define.
> > 	(VDSO_HASH_LINUX_2_6_39): Likewise.
> > 	(VDSO_NAME_LINUX_4_9): Likewise.
> > 	(VDSO_HASH_LINUX_4_9): Likewise.
> > 	* sysdeps/unix/sysv/linux/m68k/init-first.c (_libc_vdso_platform_setup):
> > 	Use PREPARE_VERSION_KNOWN.
> > 	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (INIT_ARCH): Likewise.
> > 	* sysdeps/unix/sysv/linux/powerpc/init-first.c
> > 	(_libc_vdso_platform_setup): Likewise.
> > 	* sysdeps/unix/sysv/linux/powerpc/time.c (INIT_ARCH): Likewise.
> > 	* sysdeps/unix/sysv/linux/s390/init-first.c (_libc_vdso_platform_setup):
> > 	Likewise.
> > 	* sysdeps/unix/sysv/linux/x86_64/init-first.c (__vdso_platform_setup):
> > 	Likewise.
> 
> 
> LGTM, I assume you checked a build against affected architectures.  As a side
> note I think also should just remove PREPARE_VERSION macro and replace it with
> a more sane interface:

I (cross-)compile tested on all architectures and ran the test suite on
x86_64.

> --
> static inline struct r_found_version
> prepare_version_base (const char *name, ElfW(Word) hash)
> {
>   assert (hash == _dl_elf_hash (name));
>   return (struct r_found_version) { name, hash, 1, NULL };
> }
> #define prepare_version(vname) \
>   prepare_version_base (VDSO_NAME_##vname, VDSO_HASH_##vname)
> --

Should I add this to a v2 of this patch? Or should I send a follow-up
patch with the change?

> > ---
> >  sysdeps/unix/sysv/linux/aarch64/gettimeofday.c | 4 ++--
> >  sysdeps/unix/sysv/linux/aarch64/init-first.c   | 4 ++--
> >  sysdeps/unix/sysv/linux/dl-vdso.h              | 4 ++++
> >  sysdeps/unix/sysv/linux/m68k/init-first.c      | 2 +-
> >  sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 4 ++--
> >  sysdeps/unix/sysv/linux/powerpc/init-first.c   | 2 +-
> >  sysdeps/unix/sysv/linux/powerpc/time.c         | 4 ++--
> >  sysdeps/unix/sysv/linux/s390/init-first.c      | 2 +-
> >  sysdeps/unix/sysv/linux/x86_64/init-first.c    | 2 +-
> >  9 files changed, 16 insertions(+), 12 deletions(-)
> > 
> > diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> > index 6c008ed9357f..9180b50bf7c3 100644
> > --- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> > +++ b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> > @@ -38,13 +38,13 @@ __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
> >    return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
> >  }
> >  
> > -/* PREPARE_VERSION will need an __LP64__ ifdef when ILP32 support
> > +/* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
> >     goes in.  See _libc_vdso_platform_setup in
> >     sysdeps/unix/sysv/linux/aarch64/init-first.c.  */
> >  
> >  # undef INIT_ARCH
> >  # define INIT_ARCH() \
> > -	   PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537); \
> > +	   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39); \
> >  	   void *vdso_gettimeofday = \
> >  	     _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
> 
> Also a side note, this vsdo setup is not required. The init-first.c
> already setups the VDSO_SYMBOL(gettimeofday). So a possible followup
> cleanup would be:
> 
> --
> # undef INIT_ARCH
> # define INIT_ARCH()
> 
> static inline void *
> gettimeofday_vdso (void)
> { 
>   __typeof (VDSO_SYMBOL(gettimeofday)) vdsop = VDSO_SYMBOL(gettimeofday);
>   PTR_DEMANGLE (vdsop);
>   return vdsop != NULL ? vdsop : (void *) __gettimeofday_vsyscall;
> }
> 
> libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
>                    gettimeofday_vdso ())
> --

Thanks, will send a follow-up patch.
  
Adhemerval Zanella May 24, 2019, 2:42 p.m. UTC | #3
On 24/05/2019 04:23, Tobias Klauser wrote:
> Thank you for the review.
> 
> On 2019-05-23 at 21:36:01 +0200, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
>> On 16/05/2019 08:59, Tobias Klauser wrote:
>>> Define all currently used Linux versions used for
>>> PREPARE_VERSION{,_KNOWN} in sysdeps/unix/sysv/linux/dl-vdso.h and use
>>> them instead of duplicating the versions and precomputed hashes across
>>> architecture specific files.
>>>
>>> 2019-05-16  Tobias Klauser  <tklauser@distanz.ch>
>>>
>>> 	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c (INIT_ARCH): Use
>>> 	PREPARE_VERSION_KNOWN.
>>> 	* sysdeps/unix/sysv/linux/aarch64/init-first.c: Likewise.
>>> 	* sysdeps/unix/sysv/linux/dl-vdso.h (VDSO_NAME_LINUX_2_6_39): New
>>> 	define.
>>> 	(VDSO_HASH_LINUX_2_6_39): Likewise.
>>> 	(VDSO_NAME_LINUX_4_9): Likewise.
>>> 	(VDSO_HASH_LINUX_4_9): Likewise.
>>> 	* sysdeps/unix/sysv/linux/m68k/init-first.c (_libc_vdso_platform_setup):
>>> 	Use PREPARE_VERSION_KNOWN.
>>> 	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (INIT_ARCH): Likewise.
>>> 	* sysdeps/unix/sysv/linux/powerpc/init-first.c
>>> 	(_libc_vdso_platform_setup): Likewise.
>>> 	* sysdeps/unix/sysv/linux/powerpc/time.c (INIT_ARCH): Likewise.
>>> 	* sysdeps/unix/sysv/linux/s390/init-first.c (_libc_vdso_platform_setup):
>>> 	Likewise.
>>> 	* sysdeps/unix/sysv/linux/x86_64/init-first.c (__vdso_platform_setup):
>>> 	Likewise.
>>
>>
>> LGTM, I assume you checked a build against affected architectures.  As a side
>> note I think also should just remove PREPARE_VERSION macro and replace it with
>> a more sane interface:
> 
> I (cross-)compile tested on all architectures and ran the test suite on
> x86_64.
> 
>> --
>> static inline struct r_found_version
>> prepare_version_base (const char *name, ElfW(Word) hash)
>> {
>>   assert (hash == _dl_elf_hash (name));
>>   return (struct r_found_version) { name, hash, 1, NULL };
>> }
>> #define prepare_version(vname) \
>>   prepare_version_base (VDSO_NAME_##vname, VDSO_HASH_##vname)
>> --
> 
> Should I add this to a v2 of this patch? Or should I send a follow-up
> patch with the change?

I don't have a preference here. Refactor the vDSO code is something
I have in mind for some time.

> 
>>> ---
>>>  sysdeps/unix/sysv/linux/aarch64/gettimeofday.c | 4 ++--
>>>  sysdeps/unix/sysv/linux/aarch64/init-first.c   | 4 ++--
>>>  sysdeps/unix/sysv/linux/dl-vdso.h              | 4 ++++
>>>  sysdeps/unix/sysv/linux/m68k/init-first.c      | 2 +-
>>>  sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 4 ++--
>>>  sysdeps/unix/sysv/linux/powerpc/init-first.c   | 2 +-
>>>  sysdeps/unix/sysv/linux/powerpc/time.c         | 4 ++--
>>>  sysdeps/unix/sysv/linux/s390/init-first.c      | 2 +-
>>>  sysdeps/unix/sysv/linux/x86_64/init-first.c    | 2 +-
>>>  9 files changed, 16 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
>>> index 6c008ed9357f..9180b50bf7c3 100644
>>> --- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
>>> +++ b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
>>> @@ -38,13 +38,13 @@ __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
>>>    return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
>>>  }
>>>  
>>> -/* PREPARE_VERSION will need an __LP64__ ifdef when ILP32 support
>>> +/* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
>>>     goes in.  See _libc_vdso_platform_setup in
>>>     sysdeps/unix/sysv/linux/aarch64/init-first.c.  */
>>>  
>>>  # undef INIT_ARCH
>>>  # define INIT_ARCH() \
>>> -	   PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537); \
>>> +	   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39); \
>>>  	   void *vdso_gettimeofday = \
>>>  	     _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
>>
>> Also a side note, this vsdo setup is not required. The init-first.c
>> already setups the VDSO_SYMBOL(gettimeofday). So a possible followup
>> cleanup would be:
>>
>> --
>> # undef INIT_ARCH
>> # define INIT_ARCH()
>>
>> static inline void *
>> gettimeofday_vdso (void)
>> { 
>>   __typeof (VDSO_SYMBOL(gettimeofday)) vdsop = VDSO_SYMBOL(gettimeofday);
>>   PTR_DEMANGLE (vdsop);
>>   return vdsop != NULL ? vdsop : (void *) __gettimeofday_vsyscall;
>> }
>>
>> libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
>>                    gettimeofday_vdso ())
>> --
> 
> Thanks, will send a follow-up patch.
>
  
Tobias Klauser May 24, 2019, 3:41 p.m. UTC | #4
On 2019-05-24 at 16:42:32 +0200, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
> 
> 
> On 24/05/2019 04:23, Tobias Klauser wrote:
> > Thank you for the review.
> > 
> > On 2019-05-23 at 21:36:01 +0200, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
> >> On 16/05/2019 08:59, Tobias Klauser wrote:
> >>> Define all currently used Linux versions used for
> >>> PREPARE_VERSION{,_KNOWN} in sysdeps/unix/sysv/linux/dl-vdso.h and use
> >>> them instead of duplicating the versions and precomputed hashes across
> >>> architecture specific files.
> >>>
> >>> 2019-05-16  Tobias Klauser  <tklauser@distanz.ch>
> >>>
> >>> 	* sysdeps/unix/sysv/linux/aarch64/gettimeofday.c (INIT_ARCH): Use
> >>> 	PREPARE_VERSION_KNOWN.
> >>> 	* sysdeps/unix/sysv/linux/aarch64/init-first.c: Likewise.
> >>> 	* sysdeps/unix/sysv/linux/dl-vdso.h (VDSO_NAME_LINUX_2_6_39): New
> >>> 	define.
> >>> 	(VDSO_HASH_LINUX_2_6_39): Likewise.
> >>> 	(VDSO_NAME_LINUX_4_9): Likewise.
> >>> 	(VDSO_HASH_LINUX_4_9): Likewise.
> >>> 	* sysdeps/unix/sysv/linux/m68k/init-first.c (_libc_vdso_platform_setup):
> >>> 	Use PREPARE_VERSION_KNOWN.
> >>> 	* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (INIT_ARCH): Likewise.
> >>> 	* sysdeps/unix/sysv/linux/powerpc/init-first.c
> >>> 	(_libc_vdso_platform_setup): Likewise.
> >>> 	* sysdeps/unix/sysv/linux/powerpc/time.c (INIT_ARCH): Likewise.
> >>> 	* sysdeps/unix/sysv/linux/s390/init-first.c (_libc_vdso_platform_setup):
> >>> 	Likewise.
> >>> 	* sysdeps/unix/sysv/linux/x86_64/init-first.c (__vdso_platform_setup):
> >>> 	Likewise.
> >>
> >>
> >> LGTM, I assume you checked a build against affected architectures.  As a side
> >> note I think also should just remove PREPARE_VERSION macro and replace it with
> >> a more sane interface:
> > 
> > I (cross-)compile tested on all architectures and ran the test suite on
> > x86_64.
> > 
> >> --
> >> static inline struct r_found_version
> >> prepare_version_base (const char *name, ElfW(Word) hash)
> >> {
> >>   assert (hash == _dl_elf_hash (name));
> >>   return (struct r_found_version) { name, hash, 1, NULL };
> >> }
> >> #define prepare_version(vname) \
> >>   prepare_version_base (VDSO_NAME_##vname, VDSO_HASH_##vname)
> >> --
> > 
> > Should I add this to a v2 of this patch? Or should I send a follow-up
> > patch with the change?
> 
> I don't have a preference here. Refactor the vDSO code is something
> I have in mind for some time.

Sent it as a follow-up patch with Message-Id:
<20190524153941.10128-1-tklauser@distanz.ch>

And will send another follow-up for
sysdeps/unix/sysv/linux/aarch64/gettimeofday.c

> 
> > 
> >>> ---
> >>>  sysdeps/unix/sysv/linux/aarch64/gettimeofday.c | 4 ++--
> >>>  sysdeps/unix/sysv/linux/aarch64/init-first.c   | 4 ++--
> >>>  sysdeps/unix/sysv/linux/dl-vdso.h              | 4 ++++
> >>>  sysdeps/unix/sysv/linux/m68k/init-first.c      | 2 +-
> >>>  sysdeps/unix/sysv/linux/powerpc/gettimeofday.c | 4 ++--
> >>>  sysdeps/unix/sysv/linux/powerpc/init-first.c   | 2 +-
> >>>  sysdeps/unix/sysv/linux/powerpc/time.c         | 4 ++--
> >>>  sysdeps/unix/sysv/linux/s390/init-first.c      | 2 +-
> >>>  sysdeps/unix/sysv/linux/x86_64/init-first.c    | 2 +-
> >>>  9 files changed, 16 insertions(+), 12 deletions(-)
> >>>
> >>> diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> >>> index 6c008ed9357f..9180b50bf7c3 100644
> >>> --- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> >>> +++ b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> >>> @@ -38,13 +38,13 @@ __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
> >>>    return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
> >>>  }
> >>>  
> >>> -/* PREPARE_VERSION will need an __LP64__ ifdef when ILP32 support
> >>> +/* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
> >>>     goes in.  See _libc_vdso_platform_setup in
> >>>     sysdeps/unix/sysv/linux/aarch64/init-first.c.  */
> >>>  
> >>>  # undef INIT_ARCH
> >>>  # define INIT_ARCH() \
> >>> -	   PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537); \
> >>> +	   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39); \
> >>>  	   void *vdso_gettimeofday = \
> >>>  	     _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
> >>
> >> Also a side note, this vsdo setup is not required. The init-first.c
> >> already setups the VDSO_SYMBOL(gettimeofday). So a possible followup
> >> cleanup would be:
> >>
> >> --
> >> # undef INIT_ARCH
> >> # define INIT_ARCH()
> >>
> >> static inline void *
> >> gettimeofday_vdso (void)
> >> { 
> >>   __typeof (VDSO_SYMBOL(gettimeofday)) vdsop = VDSO_SYMBOL(gettimeofday);
> >>   PTR_DEMANGLE (vdsop);
> >>   return vdsop != NULL ? vdsop : (void *) __gettimeofday_vsyscall;
> >> }
> >>
> >> libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
> >>                    gettimeofday_vdso ())
> >> --
> > 
> > Thanks, will send a follow-up patch.
> > 
>
  

Patch

diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
index 6c008ed9357f..9180b50bf7c3 100644
--- a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
@@ -38,13 +38,13 @@  __gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
   return INLINE_VSYSCALL (gettimeofday, 2, tv, tz);
 }
 
-/* PREPARE_VERSION will need an __LP64__ ifdef when ILP32 support
+/* PREPARE_VERSION_KNOWN will need an __LP64__ ifdef when ILP32 support
    goes in.  See _libc_vdso_platform_setup in
    sysdeps/unix/sysv/linux/aarch64/init-first.c.  */
 
 # undef INIT_ARCH
 # define INIT_ARCH() \
-	   PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537); \
+	   PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39); \
 	   void *vdso_gettimeofday = \
 	     _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
 
diff --git a/sysdeps/unix/sysv/linux/aarch64/init-first.c b/sysdeps/unix/sysv/linux/aarch64/init-first.c
index ce7319f3c95b..80f7ed91ef0a 100644
--- a/sysdeps/unix/sysv/linux/aarch64/init-first.c
+++ b/sysdeps/unix/sysv/linux/aarch64/init-first.c
@@ -27,9 +27,9 @@  static inline void
 _libc_vdso_platform_setup (void)
 {
 #ifdef __LP64__
-  PREPARE_VERSION (linux_version, "LINUX_2.6.39", 123718537);
+  PREPARE_VERSION_KNOWN (linux_version, LINUX_2_6_39);
 #else
-  PREPARE_VERSION (linux_version, "LINUX_4.9", 61765625);
+  PREPARE_VERSION_KNOWN (linux_version, LINUX_4_9);
 #endif
 
   void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux_version);
diff --git a/sysdeps/unix/sysv/linux/dl-vdso.h b/sysdeps/unix/sysv/linux/dl-vdso.h
index 50ee29067d0b..9e61ca742363 100644
--- a/sysdeps/unix/sysv/linux/dl-vdso.h
+++ b/sysdeps/unix/sysv/linux/dl-vdso.h
@@ -44,6 +44,10 @@ 
 #define VDSO_HASH_LINUX_2_6_15	123718565
 #define VDSO_NAME_LINUX_2_6_29	"LINUX_2.6.29"
 #define VDSO_HASH_LINUX_2_6_29	123718585
+#define VDSO_NAME_LINUX_2_6_39	"LINUX_2.6.39"
+#define VDSO_HASH_LINUX_2_6_39	123718537
+#define VDSO_NAME_LINUX_4_9	"LINUX_4.9"
+#define VDSO_HASH_LINUX_4_9	61765625
 #define VDSO_NAME_LINUX_4_15	"LINUX_4.15"
 #define VDSO_HASH_LINUX_4_15	182943605
 
diff --git a/sysdeps/unix/sysv/linux/m68k/init-first.c b/sysdeps/unix/sysv/linux/m68k/init-first.c
index f8f09108393d..53caba218cfa 100644
--- a/sysdeps/unix/sysv/linux/m68k/init-first.c
+++ b/sysdeps/unix/sysv/linux/m68k/init-first.c
@@ -29,7 +29,7 @@  _libc_vdso_platform_setup (void)
 {
   void *p;
 
-  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
 
   /* It may happen that rtld didn't initialize the vDSO, so fallback
      to the syscall implementations if _dl_vdso_vsym returns NULL.
diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
index c8d7790d8adc..463b678ad935 100644
--- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
@@ -57,8 +57,8 @@  __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
   return INLINE_SYSCALL (gettimeofday, 2, tv, tz);
 }
 
-# define INIT_ARCH()							\
-  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);		\
+# define INIT_ARCH()						\
+  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);		\
   void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
 
 /* If the vDSO is not available we fall back syscall.  */
diff --git a/sysdeps/unix/sysv/linux/powerpc/init-first.c b/sysdeps/unix/sysv/linux/powerpc/init-first.c
index 237b5abbf9b0..831f910788b3 100644
--- a/sysdeps/unix/sysv/linux/powerpc/init-first.c
+++ b/sysdeps/unix/sysv/linux/powerpc/init-first.c
@@ -37,7 +37,7 @@  void *VDSO_SYMBOL(sigtramp_rt32);
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);
+  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);
 
   void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c
index c2f171b6228c..cb3e8b9a73a5 100644
--- a/sysdeps/unix/sysv/linux/powerpc/time.c
+++ b/sysdeps/unix/sysv/linux/powerpc/time.c
@@ -66,8 +66,8 @@  time_syscall (time_t *t)
   return result;
 }
 
-# define INIT_ARCH()							\
-  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);		\
+# define INIT_ARCH()						\
+  PREPARE_VERSION_KNOWN (linux2615, LINUX_2_6_15);		\
   void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615);
 
 /* If the vDSO is not available we fall back to the syscall.  */
diff --git a/sysdeps/unix/sysv/linux/s390/init-first.c b/sysdeps/unix/sysv/linux/s390/init-first.c
index 71dd43f738bf..1f46e8052a37 100644
--- a/sysdeps/unix/sysv/linux/s390/init-first.c
+++ b/sysdeps/unix/sysv/linux/s390/init-first.c
@@ -35,7 +35,7 @@  long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
 static inline void
 _libc_vdso_platform_setup (void)
 {
-  PREPARE_VERSION (linux2629, "LINUX_2.6.29", 123718585);
+  PREPARE_VERSION_KNOWN (linux2629, LINUX_2_6_29);
 
   void *p = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2629);
   PTR_MANGLE (p);
diff --git a/sysdeps/unix/sysv/linux/x86_64/init-first.c b/sysdeps/unix/sysv/linux/x86_64/init-first.c
index 6a347becbe0d..85333e5ff309 100644
--- a/sysdeps/unix/sysv/linux/x86_64/init-first.c
+++ b/sysdeps/unix/sysv/linux/x86_64/init-first.c
@@ -32,7 +32,7 @@  extern __typeof (clock_gettime) __syscall_clock_gettime attribute_hidden;
 static inline void
 __vdso_platform_setup (void)
 {
-  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
+  PREPARE_VERSION_KNOWN (linux26, LINUX_2_6);
 
   void *p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
   if (p == NULL)