[v5] sysdeps/clock_nanosleep: Use clock_nanosleep_time64 if avaliable
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Message ID 20191107181142.1048-1-alistair.francis@wdc.com
State New
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Series
  • [v5] sysdeps/clock_nanosleep: Use clock_nanosleep_time64 if avaliable
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Commit Message

Alistair Francis Nov. 7, 2019, 6:11 p.m. UTC
The clock_nanosleep syscall is not supported on newer 32-bit platforms (such
as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
avaliable.
---
This was patch was runtime tested with RV32 and RV64
It was build tested using the ./scripts/build-many-glibcs.py script.

I also ran:
$ make ; make install ; make check
tests on native ARM (32-bit) with the following three confiugrations:
 - 4.19 Kernel and 4.19 Headers
 - 5.2 Kernel and 4.19 Headers
 - 5.2 Kernel and 5.2 Headers
and didn't see any regressions

v5:
 - Fix clock_nanosleep syscall
 - Rebase on master

v4:
 - Rebase on master
 - Use __clock_nanosleep to avoid duplicate implementations
 - Fix the error handling when a syscall fails
v2:
 - Explicitly include `#include <kernel-features.h>`

 include/time.h                            | 20 +++++++
 sysdeps/unix/sysv/linux/clock_nanosleep.c | 66 +++++++++++++++++++++--
 2 files changed, 81 insertions(+), 5 deletions(-)

Comments

Adhemerval Zanella Nov. 7, 2019, 7:15 p.m. UTC | #1
On 07/11/2019 15:11, Alistair Francis wrote:
> The clock_nanosleep syscall is not supported on newer 32-bit platforms (such
> as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
> avaliable.
> ---
> This was patch was runtime tested with RV32 and RV64
> It was build tested using the ./scripts/build-many-glibcs.py script.
> 
> I also ran:
> $ make ; make install ; make check
> tests on native ARM (32-bit) with the following three confiugrations:
>  - 4.19 Kernel and 4.19 Headers
>  - 5.2 Kernel and 4.19 Headers
>  - 5.2 Kernel and 5.2 Headers
> and didn't see any regressions
> 
> v5:
>  - Fix clock_nanosleep syscall
>  - Rebase on master
> 
> v4:
>  - Rebase on master
>  - Use __clock_nanosleep to avoid duplicate implementations
>  - Fix the error handling when a syscall fails
> v2:
>  - Explicitly include `#include <kernel-features.h>`
> 
>  include/time.h                            | 20 +++++++
>  sysdeps/unix/sysv/linux/clock_nanosleep.c | 66 +++++++++++++++++++++--
>  2 files changed, 81 insertions(+), 5 deletions(-)
> 
> diff --git a/include/time.h b/include/time.h
> index b3e635395db..03389bda290 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64)
>  
>  extern double __difftime (time_t time1, time_t time0);
>  
> +#if __TIMESIZE == 64
> +# define __thrd_sleep_time64 thrd_sleep

I think it should be on its own patch.

> +# define __clock_nanosleep_time64 __clock_nanosleep
> +# define __nanosleep_time64 __nanosleep

Same as before.

> +# define __nanosleep_nocancel_time64 __nanosleep_nocancel

There is no need to redirect this inexistent symbol.

> +#else
> +extern int __thrd_sleep_time64 (const struct __timespec64* time_point,
> +                                struct __timespec64* remaining);

As before.

> +libc_hidden_proto (__thrd_sleep_time64)
> +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> +                                     int flags, const struct __timespec64 *req,
> +                                     struct __timespec64 *rem);
> +libc_hidden_proto (__clock_nanosleep_time64)
> +extern int __nanosleep_time64 (const struct __timespec64 *requested_time,
> +                                struct __timespec64 *remaining);

As before.

> +libc_hidden_proto (__nanosleep_time64)
> +extern int __nanosleep_nocancel_time64 (const struct __timespec64 *requested_time,
> +                                        struct __timespec64 *remaining);
> +libc_hidden_proto (__nanosleep_nocancel_time64)

As before.

> +#endif
>  
>  /* Use in the clock_* functions.  Size of the field representing the
>     actual clock ID.  */
> diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> index f3c6fd2d5f7..7212dcf9c6d 100644
> --- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> +++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> @@ -16,6 +16,7 @@
>     <https://www.gnu.org/licenses/>.  */
>  
>  #include <time.h>
> +#include <kernel-features.h>
>  #include <errno.h>
>  
>  #include <sysdep-cancel.h>
> @@ -26,9 +27,11 @@
>  /* We can simply use the syscall.  The CPU clocks are not supported
>     with this function.  */
>  int
> -__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> -		   struct timespec *rem)
> +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const struct __timespec64 *req,
> +                          struct __timespec64 *rem)
>  {
> +  int r;
> +
>    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
>      return EINVAL;
>    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)

Ok.

> @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
>    /* If the call is interrupted by a signal handler or encounters an error,
>       it returns a positive value similar to errno.  */
>    INTERNAL_SYSCALL_DECL (err);
> -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> -				   req, rem);
> +
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_clock_nanosleep_time64
> +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> +# endif
> +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> +                               flags, req, rem);

Ok.

> +#else
> +# ifdef __NR_clock_nanosleep_time64
> +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> +                               flags, req, rem);
> +
> +  if (r == 0 || errno != ENOSYS)
> +    {
> +      return (INTERNAL_SYSCALL_ERROR_P (r, err)
> +              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> +    }

Ok.

> +# endif /* __NR_clock_nanosleep_time64 */
> +  struct timespec ts32, tr32;
> +
> +  if (! in_time_t_range (req->tv_sec))
> +    {
> +      __set_errno (EOVERFLOW);
> +      return -1;
> +    }
> +
> +  ts32 = valid_timespec64_to_timespec (*req);
> +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> +                                &ts32, &tr32);
> +
> +  if ((r == 0 || errno != ENOSYS) && rem)
> +    *rem = valid_timespec_to_timespec64 (tr32);

I think we can assume __NR_nanosleep here.

> +#endif /* __ASSUME_TIME64_SYSCALLS */
> +
>    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> -	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
>  }

This is just replacing a tab with spaces, I don't think it is really required.

> +
> +#if __TIMESIZE != 64
> +int
> +__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> +                   struct timespec *rem)
> +{
> +  int r;
> +  struct __timespec64 treq64, trem64;
> +
> +  treq64 = valid_timespec_to_timespec64 (*req);
> +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> +
> +  if (r == 0 || errno != ENOSYS)
> +    {
> +      if (rem)
> +        *rem = valid_timespec64_to_timespec (trem64);

Wouldn't we copy uninitialised data for EINVAL/ENOTSUPP/EFAULT?

> +    }
> +
> +  return r;
> +}
> +#endif
>  libc_hidden_def (__clock_nanosleep)
>  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
>  /* clock_nanosleep moved to libc in version 2.17;
> 

Ok
Alistair Francis Nov. 7, 2019, 7:23 p.m. UTC | #2
On Thu, Nov 7, 2019 at 11:15 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 07/11/2019 15:11, Alistair Francis wrote:
> > The clock_nanosleep syscall is not supported on newer 32-bit platforms (such
> > as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
> > avaliable.
> > ---
> > This was patch was runtime tested with RV32 and RV64
> > It was build tested using the ./scripts/build-many-glibcs.py script.
> >
> > I also ran:
> > $ make ; make install ; make check
> > tests on native ARM (32-bit) with the following three confiugrations:
> >  - 4.19 Kernel and 4.19 Headers
> >  - 5.2 Kernel and 4.19 Headers
> >  - 5.2 Kernel and 5.2 Headers
> > and didn't see any regressions
> >
> > v5:
> >  - Fix clock_nanosleep syscall
> >  - Rebase on master
> >
> > v4:
> >  - Rebase on master
> >  - Use __clock_nanosleep to avoid duplicate implementations
> >  - Fix the error handling when a syscall fails
> > v2:
> >  - Explicitly include `#include <kernel-features.h>`
> >
> >  include/time.h                            | 20 +++++++
> >  sysdeps/unix/sysv/linux/clock_nanosleep.c | 66 +++++++++++++++++++++--
> >  2 files changed, 81 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/time.h b/include/time.h
> > index b3e635395db..03389bda290 100644
> > --- a/include/time.h
> > +++ b/include/time.h
> > @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64)
> >
> >  extern double __difftime (time_t time1, time_t time0);
> >
> > +#if __TIMESIZE == 64
> > +# define __thrd_sleep_time64 thrd_sleep
>
> I think it should be on its own patch.

Ok, I'll split this out, as with the other comments.

>
> > +# define __clock_nanosleep_time64 __clock_nanosleep
> > +# define __nanosleep_time64 __nanosleep
>
> Same as before.
>
> > +# define __nanosleep_nocancel_time64 __nanosleep_nocancel
>
> There is no need to redirect this inexistent symbol.
>
> > +#else
> > +extern int __thrd_sleep_time64 (const struct __timespec64* time_point,
> > +                                struct __timespec64* remaining);
>
> As before.
>
> > +libc_hidden_proto (__thrd_sleep_time64)
> > +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> > +                                     int flags, const struct __timespec64 *req,
> > +                                     struct __timespec64 *rem);
> > +libc_hidden_proto (__clock_nanosleep_time64)
> > +extern int __nanosleep_time64 (const struct __timespec64 *requested_time,
> > +                                struct __timespec64 *remaining);
>
> As before.
>
> > +libc_hidden_proto (__nanosleep_time64)
> > +extern int __nanosleep_nocancel_time64 (const struct __timespec64 *requested_time,
> > +                                        struct __timespec64 *remaining);
> > +libc_hidden_proto (__nanosleep_nocancel_time64)
>
> As before.
>
> > +#endif
> >
> >  /* Use in the clock_* functions.  Size of the field representing the
> >     actual clock ID.  */
> > diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > index f3c6fd2d5f7..7212dcf9c6d 100644
> > --- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > +++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > @@ -16,6 +16,7 @@
> >     <https://www.gnu.org/licenses/>.  */
> >
> >  #include <time.h>
> > +#include <kernel-features.h>
> >  #include <errno.h>
> >
> >  #include <sysdep-cancel.h>
> > @@ -26,9 +27,11 @@
> >  /* We can simply use the syscall.  The CPU clocks are not supported
> >     with this function.  */
> >  int
> > -__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> > -                struct timespec *rem)
> > +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const struct __timespec64 *req,
> > +                          struct __timespec64 *rem)
> >  {
> > +  int r;
> > +
> >    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
> >      return EINVAL;
> >    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
>
> Ok.
>
> > @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> >    /* If the call is interrupted by a signal handler or encounters an error,
> >       it returns a positive value similar to errno.  */
> >    INTERNAL_SYSCALL_DECL (err);
> > -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> > -                                req, rem);
> > +
> > +#ifdef __ASSUME_TIME64_SYSCALLS
> > +# ifndef __NR_clock_nanosleep_time64
> > +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> > +# endif
> > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > +                               flags, req, rem);
>
> Ok.
>
> > +#else
> > +# ifdef __NR_clock_nanosleep_time64
> > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > +                               flags, req, rem);
> > +
> > +  if (r == 0 || errno != ENOSYS)
> > +    {
> > +      return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > +              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > +    }
>
> Ok.
>
> > +# endif /* __NR_clock_nanosleep_time64 */
> > +  struct timespec ts32, tr32;
> > +
> > +  if (! in_time_t_range (req->tv_sec))
> > +    {
> > +      __set_errno (EOVERFLOW);
> > +      return -1;
> > +    }
> > +
> > +  ts32 = valid_timespec64_to_timespec (*req);
> > +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> > +                                &ts32, &tr32);
> > +
> > +  if ((r == 0 || errno != ENOSYS) && rem)
> > +    *rem = valid_timespec_to_timespec64 (tr32);
>
> I think we can assume __NR_nanosleep here.

I'm not sure what you mean

>
> > +#endif /* __ASSUME_TIME64_SYSCALLS */
> > +
> >    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > -       ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> >  }
>
> This is just replacing a tab with spaces, I don't think it is really required.

It's the only tab in the file. I was cleaning up the indentation while
touching everything else. I can drop it though.

>
> > +
> > +#if __TIMESIZE != 64
> > +int
> > +__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> > +                   struct timespec *rem)
> > +{
> > +  int r;
> > +  struct __timespec64 treq64, trem64;
> > +
> > +  treq64 = valid_timespec_to_timespec64 (*req);
> > +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> > +
> > +  if (r == 0 || errno != ENOSYS)
> > +    {
> > +      if (rem)
> > +        *rem = valid_timespec64_to_timespec (trem64);
>
> Wouldn't we copy uninitialised data for EINVAL/ENOTSUPP/EFAULT?

This I'm not sure about. Should we only set it if we don't fail?

Alistair

>
> > +    }
> > +
> > +  return r;
> > +}
> > +#endif
> >  libc_hidden_def (__clock_nanosleep)
> >  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
> >  /* clock_nanosleep moved to libc in version 2.17;
> >
>
> Ok
Alistair Francis Nov. 7, 2019, 7:37 p.m. UTC | #3
On Thu, Nov 7, 2019 at 11:23 AM Alistair Francis <alistair23@gmail.com> wrote:
>
> On Thu, Nov 7, 2019 at 11:15 AM Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
> >
> >
> >
> > On 07/11/2019 15:11, Alistair Francis wrote:
> > > The clock_nanosleep syscall is not supported on newer 32-bit platforms (such
> > > as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
> > > avaliable.
> > > ---
> > > This was patch was runtime tested with RV32 and RV64
> > > It was build tested using the ./scripts/build-many-glibcs.py script.
> > >
> > > I also ran:
> > > $ make ; make install ; make check
> > > tests on native ARM (32-bit) with the following three confiugrations:
> > >  - 4.19 Kernel and 4.19 Headers
> > >  - 5.2 Kernel and 4.19 Headers
> > >  - 5.2 Kernel and 5.2 Headers
> > > and didn't see any regressions
> > >
> > > v5:
> > >  - Fix clock_nanosleep syscall
> > >  - Rebase on master
> > >
> > > v4:
> > >  - Rebase on master
> > >  - Use __clock_nanosleep to avoid duplicate implementations
> > >  - Fix the error handling when a syscall fails
> > > v2:
> > >  - Explicitly include `#include <kernel-features.h>`
> > >
> > >  include/time.h                            | 20 +++++++
> > >  sysdeps/unix/sysv/linux/clock_nanosleep.c | 66 +++++++++++++++++++++--
> > >  2 files changed, 81 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/include/time.h b/include/time.h
> > > index b3e635395db..03389bda290 100644
> > > --- a/include/time.h
> > > +++ b/include/time.h
> > > @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64)
> > >
> > >  extern double __difftime (time_t time1, time_t time0);
> > >
> > > +#if __TIMESIZE == 64
> > > +# define __thrd_sleep_time64 thrd_sleep
> >
> > I think it should be on its own patch.
>
> Ok, I'll split this out, as with the other comments.
>
> >
> > > +# define __clock_nanosleep_time64 __clock_nanosleep
> > > +# define __nanosleep_time64 __nanosleep
> >
> > Same as before.
> >
> > > +# define __nanosleep_nocancel_time64 __nanosleep_nocancel
> >
> > There is no need to redirect this inexistent symbol.
> >
> > > +#else
> > > +extern int __thrd_sleep_time64 (const struct __timespec64* time_point,
> > > +                                struct __timespec64* remaining);
> >
> > As before.
> >
> > > +libc_hidden_proto (__thrd_sleep_time64)
> > > +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> > > +                                     int flags, const struct __timespec64 *req,
> > > +                                     struct __timespec64 *rem);
> > > +libc_hidden_proto (__clock_nanosleep_time64)
> > > +extern int __nanosleep_time64 (const struct __timespec64 *requested_time,
> > > +                                struct __timespec64 *remaining);
> >
> > As before.
> >
> > > +libc_hidden_proto (__nanosleep_time64)
> > > +extern int __nanosleep_nocancel_time64 (const struct __timespec64 *requested_time,
> > > +                                        struct __timespec64 *remaining);
> > > +libc_hidden_proto (__nanosleep_nocancel_time64)
> >
> > As before.
> >
> > > +#endif
> > >
> > >  /* Use in the clock_* functions.  Size of the field representing the
> > >     actual clock ID.  */
> > > diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > > index f3c6fd2d5f7..7212dcf9c6d 100644
> > > --- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > > +++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > > @@ -16,6 +16,7 @@
> > >     <https://www.gnu.org/licenses/>.  */
> > >
> > >  #include <time.h>
> > > +#include <kernel-features.h>
> > >  #include <errno.h>
> > >
> > >  #include <sysdep-cancel.h>
> > > @@ -26,9 +27,11 @@
> > >  /* We can simply use the syscall.  The CPU clocks are not supported
> > >     with this function.  */
> > >  int
> > > -__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> > > -                struct timespec *rem)
> > > +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const struct __timespec64 *req,
> > > +                          struct __timespec64 *rem)
> > >  {
> > > +  int r;
> > > +
> > >    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
> > >      return EINVAL;
> > >    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
> >
> > Ok.
> >
> > > @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> > >    /* If the call is interrupted by a signal handler or encounters an error,
> > >       it returns a positive value similar to errno.  */
> > >    INTERNAL_SYSCALL_DECL (err);
> > > -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> > > -                                req, rem);
> > > +
> > > +#ifdef __ASSUME_TIME64_SYSCALLS
> > > +# ifndef __NR_clock_nanosleep_time64
> > > +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> > > +# endif
> > > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > > +                               flags, req, rem);
> >
> > Ok.
> >
> > > +#else
> > > +# ifdef __NR_clock_nanosleep_time64
> > > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > > +                               flags, req, rem);
> > > +
> > > +  if (r == 0 || errno != ENOSYS)
> > > +    {
> > > +      return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > > +              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > > +    }
> >
> > Ok.
> >
> > > +# endif /* __NR_clock_nanosleep_time64 */
> > > +  struct timespec ts32, tr32;
> > > +
> > > +  if (! in_time_t_range (req->tv_sec))
> > > +    {
> > > +      __set_errno (EOVERFLOW);
> > > +      return -1;
> > > +    }
> > > +
> > > +  ts32 = valid_timespec64_to_timespec (*req);
> > > +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> > > +                                &ts32, &tr32);
> > > +
> > > +  if ((r == 0 || errno != ENOSYS) && rem)
> > > +    *rem = valid_timespec_to_timespec64 (tr32);
> >
> > I think we can assume __NR_nanosleep here.
>
> I'm not sure what you mean
>
> >
> > > +#endif /* __ASSUME_TIME64_SYSCALLS */
> > > +
> > >    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > > -       ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > > +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > >  }
> >
> > This is just replacing a tab with spaces, I don't think it is really required.
>
> It's the only tab in the file. I was cleaning up the indentation while
> touching everything else. I can drop it though.
>
> >
> > > +
> > > +#if __TIMESIZE != 64
> > > +int
> > > +__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
> > > +                   struct timespec *rem)
> > > +{
> > > +  int r;
> > > +  struct __timespec64 treq64, trem64;
> > > +
> > > +  treq64 = valid_timespec_to_timespec64 (*req);
> > > +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> > > +
> > > +  if (r == 0 || errno != ENOSYS)
> > > +    {
> > > +      if (rem)
> > > +        *rem = valid_timespec64_to_timespec (trem64);
> >
> > Wouldn't we copy uninitialised data for EINVAL/ENOTSUPP/EFAULT?
>
> This I'm not sure about. Should we only set it if we don't fail?

Yeah, it will have invalid data for EFAULT [1].

Should it only be set on success or is there some combination of
errors where we set it as well?

1: https://elixir.bootlin.com/linux/v5.4-rc5/source/kernel/time/hrtimer.c#L1854

>
> Alistair
>
> >
> > > +    }
> > > +
> > > +  return r;
> > > +}
> > > +#endif
> > >  libc_hidden_def (__clock_nanosleep)
> > >  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
> > >  /* clock_nanosleep moved to libc in version 2.17;
> > >
> >
> > Ok
Lukasz Majewski Nov. 8, 2019, 12:54 p.m. UTC | #4
Hi Alistair,

Please find my comments regarding checking of NULL pointers.

> The clock_nanosleep syscall is not supported on newer 32-bit
> platforms (such as RV32). To fix this issue let's use
> clock_nanosleep_time64 if it is avaliable.
> ---
> This was patch was runtime tested with RV32 and RV64
> It was build tested using the ./scripts/build-many-glibcs.py script.
> 
> I also ran:
> $ make ; make install ; make check
> tests on native ARM (32-bit) with the following three confiugrations:
>  - 4.19 Kernel and 4.19 Headers
>  - 5.2 Kernel and 4.19 Headers
>  - 5.2 Kernel and 5.2 Headers
> and didn't see any regressions
> 
> v5:
>  - Fix clock_nanosleep syscall
>  - Rebase on master
> 
> v4:
>  - Rebase on master
>  - Use __clock_nanosleep to avoid duplicate implementations
>  - Fix the error handling when a syscall fails
> v2:
>  - Explicitly include `#include <kernel-features.h>`
> 
>  include/time.h                            | 20 +++++++
>  sysdeps/unix/sysv/linux/clock_nanosleep.c | 66
> +++++++++++++++++++++-- 2 files changed, 81 insertions(+), 5
> deletions(-)
> 
> diff --git a/include/time.h b/include/time.h
> index b3e635395db..03389bda290 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64)
>  
>  extern double __difftime (time_t time1, time_t time0);
>  
> +#if __TIMESIZE == 64
> +# define __thrd_sleep_time64 thrd_sleep
> +# define __clock_nanosleep_time64 __clock_nanosleep
> +# define __nanosleep_time64 __nanosleep
> +# define __nanosleep_nocancel_time64 __nanosleep_nocancel
> +#else
> +extern int __thrd_sleep_time64 (const struct __timespec64*
> time_point,
> +                                struct __timespec64* remaining);
> +libc_hidden_proto (__thrd_sleep_time64)
> +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> +                                     int flags, const struct
> __timespec64 *req,
> +                                     struct __timespec64 *rem);
> +libc_hidden_proto (__clock_nanosleep_time64)
> +extern int __nanosleep_time64 (const struct __timespec64
> *requested_time,
> +                                struct __timespec64 *remaining);
> +libc_hidden_proto (__nanosleep_time64)
> +extern int __nanosleep_nocancel_time64 (const struct __timespec64
> *requested_time,
> +                                        struct __timespec64
> *remaining); +libc_hidden_proto (__nanosleep_nocancel_time64)
> +#endif
>  
>  /* Use in the clock_* functions.  Size of the field representing the
>     actual clock ID.  */
> diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> b/sysdeps/unix/sysv/linux/clock_nanosleep.c index
> f3c6fd2d5f7..7212dcf9c6d 100644 ---
> a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++
> b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -16,6 +16,7 @@
>     <https://www.gnu.org/licenses/>.  */
>  
>  #include <time.h>
> +#include <kernel-features.h>
>  #include <errno.h>
>  
>  #include <sysdep-cancel.h>
> @@ -26,9 +27,11 @@
>  /* We can simply use the syscall.  The CPU clocks are not supported
>     with this function.  */
>  int
> -__clock_nanosleep (clockid_t clock_id, int flags, const struct
> timespec *req,
> -		   struct timespec *rem)
> +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const
> struct __timespec64 *req,
> +                          struct __timespec64 *rem)
>  {
> +  int r;
> +
>    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
>      return EINVAL;
>    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
> @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags,
> const struct timespec *req, /* If the call is interrupted by a signal
> handler or encounters an error, it returns a positive value similar
> to errno.  */ INTERNAL_SYSCALL_DECL (err);
> -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> flags,
> -				   req, rem);
> +
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_clock_nanosleep_time64
> +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> +# endif
> +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> +                               flags, req, rem);
> +#else
> +# ifdef __NR_clock_nanosleep_time64
> +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> +                               flags, req, rem);
> +
> +  if (r == 0 || errno != ENOSYS)
> +    {
> +      return (INTERNAL_SYSCALL_ERROR_P (r, err)
> +              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> +    }
> +# endif /* __NR_clock_nanosleep_time64 */
> +  struct timespec ts32, tr32;
> +
> +  if (! in_time_t_range (req->tv_sec))
> +    {
> +      __set_errno (EOVERFLOW);
> +      return -1;
> +    }
> +
> +  ts32 = valid_timespec64_to_timespec (*req);

Here we don't need to check req == NULL, as we will go into this piece
of code only for 32 bit systems (and kernel < 5.1) with glibc's local
copy of struct __timespec64.

> +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> flags,
> +                                &ts32, &tr32);
> +
> +  if ((r == 0 || errno != ENOSYS) && rem)
> +    *rem = valid_timespec_to_timespec64 (tr32);
> +#endif /* __ASSUME_TIME64_SYSCALLS */
> +
>    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> -	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
>  }
> +
> +#if __TIMESIZE != 64
> +int
> +__clock_nanosleep (clockid_t clock_id, int flags, const struct
> timespec *req,
> +                   struct timespec *rem)
> +{
> +  int r;
> +  struct __timespec64 treq64, trem64;
> +

^^^^^^^^^^^^ - [*]

> +  treq64 = valid_timespec_to_timespec64 (*req);

The above line would cause regression. Please find below explanation:

The check on *rqtp (in Linux kernel's clock_nanosleep syscall handling):
https://elixir.bootlin.com/linux/v5.4-rc5/source/kernel/time/posix-timers.c#L1220

When compiling test program with clock_nanosleep() passing *request [1]
as NULL [3] - the clock_nanosleep returns 14, which corresponds to 
#define EFAULT 14 [2] (which matches [1]).

Hence we should have following code in [*]:

if (req == NULL)
  {
    __set_errno(EFAULT)
    returm 1;
  }


Otherwise we will break in glibc before we enter the clock_nanosleep
syscall (which would then return with proper error code).


Links:
[1] - http://man7.org/linux/man-pages/man2/clock_nanosleep.2.html
[2] - cpp -dM /usr/include/errno.h | grep 'define E' | sort -n -k 3
[3] - test program:

int main(int argc, char **argv)
{
  int result;

  result = clock_nanosleep(CLOCK_REALTIME, 0 /* relative */,
    NULL, NULL);

  if (result)
    printf("clock_nanosleep: %d\n", result);

  return 0;
}

> +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> +
> +  if (r == 0 || errno != ENOSYS)
> +    {
> +      if (rem)
> +        *rem = valid_timespec64_to_timespec (trem64);
> +    }
> +
> +  return r;
> +}
> +#endif
>  libc_hidden_def (__clock_nanosleep)
>  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep,
> GLIBC_2_17); /* clock_nanosleep moved to libc in version 2.17;




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
Adhemerval Zanella Nov. 8, 2019, 1:49 p.m. UTC | #5
On 07/11/2019 16:23, Alistair Francis wrote:
> On Thu, Nov 7, 2019 at 11:15 AM Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>>
>>
>>
>> On 07/11/2019 15:11, Alistair Francis wrote:

>>> +# endif /* __NR_clock_nanosleep_time64 */
>>> +  struct timespec ts32, tr32;
>>> +
>>> +  if (! in_time_t_range (req->tv_sec))
>>> +    {
>>> +      __set_errno (EOVERFLOW);
>>> +      return -1;
>>> +    }
>>> +
>>> +  ts32 = valid_timespec64_to_timespec (*req);
>>> +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
>>> +                                &ts32, &tr32);
>>> +
>>> +  if ((r == 0 || errno != ENOSYS) && rem)
>>> +    *rem = valid_timespec_to_timespec64 (tr32);
>>
>> I think we can assume __NR_nanosleep here.
> 
> I'm not sure what you mean

I mean that it does not require to check for ENOSYS.

> 
>>
>>> +#endif /* __ASSUME_TIME64_SYSCALLS */
>>> +
>>>    return (INTERNAL_SYSCALL_ERROR_P (r, err)
>>> -       ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
>>> +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
>>>  }
>>
>> This is just replacing a tab with spaces, I don't think it is really required.
> 
> It's the only tab in the file. I was cleaning up the indentation while
> touching everything else. I can drop it though.

Afaik glibc code conventions uses tabs for C file indentation (except for some 
imported files).
Alistair Francis Nov. 8, 2019, 4:56 p.m. UTC | #6
On Fri, Nov 8, 2019 at 4:54 AM Lukasz Majewski <lukma@denx.de> wrote:
>
> Hi Alistair,
>
> Please find my comments regarding checking of NULL pointers.
>
> > The clock_nanosleep syscall is not supported on newer 32-bit
> > platforms (such as RV32). To fix this issue let's use
> > clock_nanosleep_time64 if it is avaliable.
> > ---
> > This was patch was runtime tested with RV32 and RV64
> > It was build tested using the ./scripts/build-many-glibcs.py script.
> >
> > I also ran:
> > $ make ; make install ; make check
> > tests on native ARM (32-bit) with the following three confiugrations:
> >  - 4.19 Kernel and 4.19 Headers
> >  - 5.2 Kernel and 4.19 Headers
> >  - 5.2 Kernel and 5.2 Headers
> > and didn't see any regressions
> >
> > v5:
> >  - Fix clock_nanosleep syscall
> >  - Rebase on master
> >
> > v4:
> >  - Rebase on master
> >  - Use __clock_nanosleep to avoid duplicate implementations
> >  - Fix the error handling when a syscall fails
> > v2:
> >  - Explicitly include `#include <kernel-features.h>`
> >
> >  include/time.h                            | 20 +++++++
> >  sysdeps/unix/sysv/linux/clock_nanosleep.c | 66
> > +++++++++++++++++++++-- 2 files changed, 81 insertions(+), 5
> > deletions(-)
> >
> > diff --git a/include/time.h b/include/time.h
> > index b3e635395db..03389bda290 100644
> > --- a/include/time.h
> > +++ b/include/time.h
> > @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64)
> >
> >  extern double __difftime (time_t time1, time_t time0);
> >
> > +#if __TIMESIZE == 64
> > +# define __thrd_sleep_time64 thrd_sleep
> > +# define __clock_nanosleep_time64 __clock_nanosleep
> > +# define __nanosleep_time64 __nanosleep
> > +# define __nanosleep_nocancel_time64 __nanosleep_nocancel
> > +#else
> > +extern int __thrd_sleep_time64 (const struct __timespec64*
> > time_point,
> > +                                struct __timespec64* remaining);
> > +libc_hidden_proto (__thrd_sleep_time64)
> > +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> > +                                     int flags, const struct
> > __timespec64 *req,
> > +                                     struct __timespec64 *rem);
> > +libc_hidden_proto (__clock_nanosleep_time64)
> > +extern int __nanosleep_time64 (const struct __timespec64
> > *requested_time,
> > +                                struct __timespec64 *remaining);
> > +libc_hidden_proto (__nanosleep_time64)
> > +extern int __nanosleep_nocancel_time64 (const struct __timespec64
> > *requested_time,
> > +                                        struct __timespec64
> > *remaining); +libc_hidden_proto (__nanosleep_nocancel_time64)
> > +#endif
> >
> >  /* Use in the clock_* functions.  Size of the field representing the
> >     actual clock ID.  */
> > diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > b/sysdeps/unix/sysv/linux/clock_nanosleep.c index
> > f3c6fd2d5f7..7212dcf9c6d 100644 ---
> > a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++
> > b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -16,6 +16,7 @@
> >     <https://www.gnu.org/licenses/>.  */
> >
> >  #include <time.h>
> > +#include <kernel-features.h>
> >  #include <errno.h>
> >
> >  #include <sysdep-cancel.h>
> > @@ -26,9 +27,11 @@
> >  /* We can simply use the syscall.  The CPU clocks are not supported
> >     with this function.  */
> >  int
> > -__clock_nanosleep (clockid_t clock_id, int flags, const struct
> > timespec *req,
> > -                struct timespec *rem)
> > +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const
> > struct __timespec64 *req,
> > +                          struct __timespec64 *rem)
> >  {
> > +  int r;
> > +
> >    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
> >      return EINVAL;
> >    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
> > @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags,
> > const struct timespec *req, /* If the call is interrupted by a signal
> > handler or encounters an error, it returns a positive value similar
> > to errno.  */ INTERNAL_SYSCALL_DECL (err);
> > -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> > flags,
> > -                                req, rem);
> > +
> > +#ifdef __ASSUME_TIME64_SYSCALLS
> > +# ifndef __NR_clock_nanosleep_time64
> > +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> > +# endif
> > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > +                               flags, req, rem);
> > +#else
> > +# ifdef __NR_clock_nanosleep_time64
> > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > +                               flags, req, rem);
> > +
> > +  if (r == 0 || errno != ENOSYS)
> > +    {
> > +      return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > +              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > +    }
> > +# endif /* __NR_clock_nanosleep_time64 */
> > +  struct timespec ts32, tr32;
> > +
> > +  if (! in_time_t_range (req->tv_sec))
> > +    {
> > +      __set_errno (EOVERFLOW);
> > +      return -1;
> > +    }
> > +
> > +  ts32 = valid_timespec64_to_timespec (*req);
>
> Here we don't need to check req == NULL, as we will go into this piece
> of code only for 32 bit systems (and kernel < 5.1) with glibc's local
> copy of struct __timespec64.
>
> > +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> > flags,
> > +                                &ts32, &tr32);
> > +
> > +  if ((r == 0 || errno != ENOSYS) && rem)
> > +    *rem = valid_timespec_to_timespec64 (tr32);
> > +#endif /* __ASSUME_TIME64_SYSCALLS */
> > +
> >    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > -       ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> >  }
> > +
> > +#if __TIMESIZE != 64
> > +int
> > +__clock_nanosleep (clockid_t clock_id, int flags, const struct
> > timespec *req,
> > +                   struct timespec *rem)
> > +{
> > +  int r;
> > +  struct __timespec64 treq64, trem64;
> > +
>
> ^^^^^^^^^^^^ - [*]
>
> > +  treq64 = valid_timespec_to_timespec64 (*req);
>
> The above line would cause regression. Please find below explanation:
>
> The check on *rqtp (in Linux kernel's clock_nanosleep syscall handling):
> https://elixir.bootlin.com/linux/v5.4-rc5/source/kernel/time/posix-timers.c#L1220
>
> When compiling test program with clock_nanosleep() passing *request [1]
> as NULL [3] - the clock_nanosleep returns 14, which corresponds to
> #define EFAULT 14 [2] (which matches [1]).
>
> Hence we should have following code in [*]:
>
> if (req == NULL)
>   {
>     __set_errno(EFAULT)
>     returm 1;
>   }
>
>
> Otherwise we will break in glibc before we enter the clock_nanosleep
> syscall (which would then return with proper error code).

I think you are right. I have updated the patch.

Alistair

>
>
> Links:
> [1] - http://man7.org/linux/man-pages/man2/clock_nanosleep.2.html
> [2] - cpp -dM /usr/include/errno.h | grep 'define E' | sort -n -k 3
> [3] - test program:
>
> int main(int argc, char **argv)
> {
>   int result;
>
>   result = clock_nanosleep(CLOCK_REALTIME, 0 /* relative */,
>     NULL, NULL);
>
>   if (result)
>     printf("clock_nanosleep: %d\n", result);
>
>   return 0;
> }
>
> > +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> > +
> > +  if (r == 0 || errno != ENOSYS)
> > +    {
> > +      if (rem)
> > +        *rem = valid_timespec64_to_timespec (trem64);
> > +    }
> > +
> > +  return r;
> > +}
> > +#endif
> >  libc_hidden_def (__clock_nanosleep)
> >  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep,
> > GLIBC_2_17); /* clock_nanosleep moved to libc in version 2.17;
>
>
>
>
> Best regards,
>
> Lukasz Majewski
>
> --
>
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
Alistair Francis Nov. 8, 2019, 5:07 p.m. UTC | #7
On Fri, Nov 8, 2019 at 8:56 AM Alistair Francis <alistair23@gmail.com> wrote:
>
> On Fri, Nov 8, 2019 at 4:54 AM Lukasz Majewski <lukma@denx.de> wrote:
> >
> > Hi Alistair,
> >
> > Please find my comments regarding checking of NULL pointers.
> >
> > > The clock_nanosleep syscall is not supported on newer 32-bit
> > > platforms (such as RV32). To fix this issue let's use
> > > clock_nanosleep_time64 if it is avaliable.
> > > ---
> > > This was patch was runtime tested with RV32 and RV64
> > > It was build tested using the ./scripts/build-many-glibcs.py script.
> > >
> > > I also ran:
> > > $ make ; make install ; make check
> > > tests on native ARM (32-bit) with the following three confiugrations:
> > >  - 4.19 Kernel and 4.19 Headers
> > >  - 5.2 Kernel and 4.19 Headers
> > >  - 5.2 Kernel and 5.2 Headers
> > > and didn't see any regressions
> > >
> > > v5:
> > >  - Fix clock_nanosleep syscall
> > >  - Rebase on master
> > >
> > > v4:
> > >  - Rebase on master
> > >  - Use __clock_nanosleep to avoid duplicate implementations
> > >  - Fix the error handling when a syscall fails
> > > v2:
> > >  - Explicitly include `#include <kernel-features.h>`
> > >
> > >  include/time.h                            | 20 +++++++
> > >  sysdeps/unix/sysv/linux/clock_nanosleep.c | 66
> > > +++++++++++++++++++++-- 2 files changed, 81 insertions(+), 5
> > > deletions(-)
> > >
> > > diff --git a/include/time.h b/include/time.h
> > > index b3e635395db..03389bda290 100644
> > > --- a/include/time.h
> > > +++ b/include/time.h
> > > @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64)
> > >
> > >  extern double __difftime (time_t time1, time_t time0);
> > >
> > > +#if __TIMESIZE == 64
> > > +# define __thrd_sleep_time64 thrd_sleep
> > > +# define __clock_nanosleep_time64 __clock_nanosleep
> > > +# define __nanosleep_time64 __nanosleep
> > > +# define __nanosleep_nocancel_time64 __nanosleep_nocancel
> > > +#else
> > > +extern int __thrd_sleep_time64 (const struct __timespec64*
> > > time_point,
> > > +                                struct __timespec64* remaining);
> > > +libc_hidden_proto (__thrd_sleep_time64)
> > > +extern int __clock_nanosleep_time64 (clockid_t clock_id,
> > > +                                     int flags, const struct
> > > __timespec64 *req,
> > > +                                     struct __timespec64 *rem);
> > > +libc_hidden_proto (__clock_nanosleep_time64)
> > > +extern int __nanosleep_time64 (const struct __timespec64
> > > *requested_time,
> > > +                                struct __timespec64 *remaining);
> > > +libc_hidden_proto (__nanosleep_time64)
> > > +extern int __nanosleep_nocancel_time64 (const struct __timespec64
> > > *requested_time,
> > > +                                        struct __timespec64
> > > *remaining); +libc_hidden_proto (__nanosleep_nocancel_time64)
> > > +#endif
> > >
> > >  /* Use in the clock_* functions.  Size of the field representing the
> > >     actual clock ID.  */
> > > diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c
> > > b/sysdeps/unix/sysv/linux/clock_nanosleep.c index
> > > f3c6fd2d5f7..7212dcf9c6d 100644 ---
> > > a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++
> > > b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -16,6 +16,7 @@
> > >     <https://www.gnu.org/licenses/>.  */
> > >
> > >  #include <time.h>
> > > +#include <kernel-features.h>
> > >  #include <errno.h>
> > >
> > >  #include <sysdep-cancel.h>
> > > @@ -26,9 +27,11 @@
> > >  /* We can simply use the syscall.  The CPU clocks are not supported
> > >     with this function.  */
> > >  int
> > > -__clock_nanosleep (clockid_t clock_id, int flags, const struct
> > > timespec *req,
> > > -                struct timespec *rem)
> > > +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const
> > > struct __timespec64 *req,
> > > +                          struct __timespec64 *rem)
> > >  {
> > > +  int r;
> > > +
> > >    if (clock_id == CLOCK_THREAD_CPUTIME_ID)
> > >      return EINVAL;
> > >    if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
> > > @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags,
> > > const struct timespec *req, /* If the call is interrupted by a signal
> > > handler or encounters an error, it returns a positive value similar
> > > to errno.  */ INTERNAL_SYSCALL_DECL (err);
> > > -  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> > > flags,
> > > -                                req, rem);
> > > +
> > > +#ifdef __ASSUME_TIME64_SYSCALLS
> > > +# ifndef __NR_clock_nanosleep_time64
> > > +#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
> > > +# endif
> > > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > > +                               flags, req, rem);
> > > +#else
> > > +# ifdef __NR_clock_nanosleep_time64
> > > +  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
> > > +                               flags, req, rem);
> > > +
> > > +  if (r == 0 || errno != ENOSYS)
> > > +    {
> > > +      return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > > +              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > > +    }
> > > +# endif /* __NR_clock_nanosleep_time64 */
> > > +  struct timespec ts32, tr32;
> > > +
> > > +  if (! in_time_t_range (req->tv_sec))
> > > +    {
> > > +      __set_errno (EOVERFLOW);
> > > +      return -1;
> > > +    }
> > > +
> > > +  ts32 = valid_timespec64_to_timespec (*req);
> >
> > Here we don't need to check req == NULL, as we will go into this piece
> > of code only for 32 bit systems (and kernel < 5.1) with glibc's local
> > copy of struct __timespec64.
> >
> > > +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id,
> > > flags,
> > > +                                &ts32, &tr32);
> > > +
> > > +  if ((r == 0 || errno != ENOSYS) && rem)
> > > +    *rem = valid_timespec_to_timespec64 (tr32);
> > > +#endif /* __ASSUME_TIME64_SYSCALLS */
> > > +
> > >    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> > > -       ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > > +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> > >  }
> > > +
> > > +#if __TIMESIZE != 64
> > > +int
> > > +__clock_nanosleep (clockid_t clock_id, int flags, const struct
> > > timespec *req,
> > > +                   struct timespec *rem)
> > > +{
> > > +  int r;
> > > +  struct __timespec64 treq64, trem64;
> > > +
> >
> > ^^^^^^^^^^^^ - [*]
> >
> > > +  treq64 = valid_timespec_to_timespec64 (*req);
> >
> > The above line would cause regression. Please find below explanation:
> >
> > The check on *rqtp (in Linux kernel's clock_nanosleep syscall handling):
> > https://elixir.bootlin.com/linux/v5.4-rc5/source/kernel/time/posix-timers.c#L1220
> >
> > When compiling test program with clock_nanosleep() passing *request [1]
> > as NULL [3] - the clock_nanosleep returns 14, which corresponds to
> > #define EFAULT 14 [2] (which matches [1]).
> >
> > Hence we should have following code in [*]:
> >
> > if (req == NULL)
> >   {
> >     __set_errno(EFAULT)
> >     returm 1;
> >   }
> >
> >
> > Otherwise we will break in glibc before we enter the clock_nanosleep
> > syscall (which would then return with proper error code).
>
> I think you are right. I have updated the patch.

As Joseph mentioned in another thread, glibc doesn't check for NULL
pointers, so I have removed this.

Alistair

>
> Alistair
>
> >
> >
> > Links:
> > [1] - http://man7.org/linux/man-pages/man2/clock_nanosleep.2.html
> > [2] - cpp -dM /usr/include/errno.h | grep 'define E' | sort -n -k 3
> > [3] - test program:
> >
> > int main(int argc, char **argv)
> > {
> >   int result;
> >
> >   result = clock_nanosleep(CLOCK_REALTIME, 0 /* relative */,
> >     NULL, NULL);
> >
> >   if (result)
> >     printf("clock_nanosleep: %d\n", result);
> >
> >   return 0;
> > }
> >
> > > +  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
> > > +
> > > +  if (r == 0 || errno != ENOSYS)
> > > +    {
> > > +      if (rem)
> > > +        *rem = valid_timespec64_to_timespec (trem64);
> > > +    }
> > > +
> > > +  return r;
> > > +}
> > > +#endif
> > >  libc_hidden_def (__clock_nanosleep)
> > >  versioned_symbol (libc, __clock_nanosleep, clock_nanosleep,
> > > GLIBC_2_17); /* clock_nanosleep moved to libc in version 2.17;
> >
> >
> >
> >
> > Best regards,
> >
> > Lukasz Majewski
> >
> > --
> >
> > DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> > Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
Alistair Francis Nov. 8, 2019, 5:08 p.m. UTC | #8
On Fri, Nov 8, 2019 at 5:49 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 07/11/2019 16:23, Alistair Francis wrote:
> > On Thu, Nov 7, 2019 at 11:15 AM Adhemerval Zanella
> > <adhemerval.zanella@linaro.org> wrote:
> >>
> >>
> >>
> >> On 07/11/2019 15:11, Alistair Francis wrote:
>
> >>> +# endif /* __NR_clock_nanosleep_time64 */
> >>> +  struct timespec ts32, tr32;
> >>> +
> >>> +  if (! in_time_t_range (req->tv_sec))
> >>> +    {
> >>> +      __set_errno (EOVERFLOW);
> >>> +      return -1;
> >>> +    }
> >>> +
> >>> +  ts32 = valid_timespec64_to_timespec (*req);
> >>> +  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
> >>> +                                &ts32, &tr32);
> >>> +
> >>> +  if ((r == 0 || errno != ENOSYS) && rem)
> >>> +    *rem = valid_timespec_to_timespec64 (tr32);
> >>
> >> I think we can assume __NR_nanosleep here.
> >
> > I'm not sure what you mean
>
> I mean that it does not require to check for ENOSYS.
>
> >
> >>
> >>> +#endif /* __ASSUME_TIME64_SYSCALLS */
> >>> +
> >>>    return (INTERNAL_SYSCALL_ERROR_P (r, err)
> >>> -       ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> >>> +          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
> >>>  }
> >>
> >> This is just replacing a tab with spaces, I don't think it is really required.
> >
> > It's the only tab in the file. I was cleaning up the indentation while
> > touching everything else. I can drop it though.
>
> Afaik glibc code conventions uses tabs for C file indentation (except for some
> imported files).

Ok, I have addressed all of your comments in v6.

Alistair

Patch
diff mbox series

diff --git a/include/time.h b/include/time.h
index b3e635395db..03389bda290 100644
--- a/include/time.h
+++ b/include/time.h
@@ -209,6 +209,26 @@  libc_hidden_proto (__difftime64)
 
 extern double __difftime (time_t time1, time_t time0);
 
+#if __TIMESIZE == 64
+# define __thrd_sleep_time64 thrd_sleep
+# define __clock_nanosleep_time64 __clock_nanosleep
+# define __nanosleep_time64 __nanosleep
+# define __nanosleep_nocancel_time64 __nanosleep_nocancel
+#else
+extern int __thrd_sleep_time64 (const struct __timespec64* time_point,
+                                struct __timespec64* remaining);
+libc_hidden_proto (__thrd_sleep_time64)
+extern int __clock_nanosleep_time64 (clockid_t clock_id,
+                                     int flags, const struct __timespec64 *req,
+                                     struct __timespec64 *rem);
+libc_hidden_proto (__clock_nanosleep_time64)
+extern int __nanosleep_time64 (const struct __timespec64 *requested_time,
+                                struct __timespec64 *remaining);
+libc_hidden_proto (__nanosleep_time64)
+extern int __nanosleep_nocancel_time64 (const struct __timespec64 *requested_time,
+                                        struct __timespec64 *remaining);
+libc_hidden_proto (__nanosleep_nocancel_time64)
+#endif
 
 /* Use in the clock_* functions.  Size of the field representing the
    actual clock ID.  */
diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
index f3c6fd2d5f7..7212dcf9c6d 100644
--- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
+++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
@@ -16,6 +16,7 @@ 
    <https://www.gnu.org/licenses/>.  */
 
 #include <time.h>
+#include <kernel-features.h>
 #include <errno.h>
 
 #include <sysdep-cancel.h>
@@ -26,9 +27,11 @@ 
 /* We can simply use the syscall.  The CPU clocks are not supported
    with this function.  */
 int
-__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
-		   struct timespec *rem)
+__clock_nanosleep_time64 (clockid_t clock_id, int flags, const struct __timespec64 *req,
+                          struct __timespec64 *rem)
 {
+  int r;
+
   if (clock_id == CLOCK_THREAD_CPUTIME_ID)
     return EINVAL;
   if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
@@ -37,11 +40,64 @@  __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
   /* If the call is interrupted by a signal handler or encounters an error,
      it returns a positive value similar to errno.  */
   INTERNAL_SYSCALL_DECL (err);
-  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
-				   req, rem);
+
+#ifdef __ASSUME_TIME64_SYSCALLS
+# ifndef __NR_clock_nanosleep_time64
+#  define __NR_clock_nanosleep_time64 __NR_clock_nanosleep
+# endif
+  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
+                               flags, req, rem);
+#else
+# ifdef __NR_clock_nanosleep_time64
+  r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id,
+                               flags, req, rem);
+
+  if (r == 0 || errno != ENOSYS)
+    {
+      return (INTERNAL_SYSCALL_ERROR_P (r, err)
+              ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
+    }
+# endif /* __NR_clock_nanosleep_time64 */
+  struct timespec ts32, tr32;
+
+  if (! in_time_t_range (req->tv_sec))
+    {
+      __set_errno (EOVERFLOW);
+      return -1;
+    }
+
+  ts32 = valid_timespec64_to_timespec (*req);
+  r =  INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
+                                &ts32, &tr32);
+
+  if ((r == 0 || errno != ENOSYS) && rem)
+    *rem = valid_timespec_to_timespec64 (tr32);
+#endif /* __ASSUME_TIME64_SYSCALLS */
+
   return (INTERNAL_SYSCALL_ERROR_P (r, err)
-	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
+          ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
 }
+
+#if __TIMESIZE != 64
+int
+__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
+                   struct timespec *rem)
+{
+  int r;
+  struct __timespec64 treq64, trem64;
+
+  treq64 = valid_timespec_to_timespec64 (*req);
+  r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64);
+
+  if (r == 0 || errno != ENOSYS)
+    {
+      if (rem)
+        *rem = valid_timespec64_to_timespec (trem64);
+    }
+
+  return r;
+}
+#endif
 libc_hidden_def (__clock_nanosleep)
 versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
 /* clock_nanosleep moved to libc in version 2.17;