[2/5] Consolidate lowlevellock-futex.h

  NPTL is already Linux specific, there is no need to parametrize low
level lock futex operations and add a sysdep Linux specific
implementation.  This patch moves the relevant Linux code to nptl one.

Checked on x86_64-linux-gnu and i686-linux-gnu.
---
 sysdeps/nptl/lowlevellock-futex.h            | 165 ++++++++++++++----
 sysdeps/unix/sysv/linux/lowlevellock-futex.h | 168 -------------------
 2 files changed, 128 insertions(+), 205 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/lowlevellock-futex.h
  

On 10/30/19 4:00 PM, Adhemerval Zanella wrote:
> NPTL is already Linux specific, there is no need to parametrize low
> level lock futex operations and add a sysdep Linux specific
> implementation.  This patch moves the relevant Linux code to nptl one.
> 
> Checked on x86_64-linux-gnu and i686-linux-gnu.

OK for master.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  sysdeps/nptl/lowlevellock-futex.h            | 165 ++++++++++++++----
>  sysdeps/unix/sysv/linux/lowlevellock-futex.h | 168 -------------------
>  2 files changed, 128 insertions(+), 205 deletions(-)
>  delete mode 100644 sysdeps/unix/sysv/linux/lowlevellock-futex.h
> 
> diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h
> index 4cceade0db..392277e8a5 100644
> --- a/sysdeps/nptl/lowlevellock-futex.h
> +++ b/sysdeps/nptl/lowlevellock-futex.h
> @@ -19,14 +19,60 @@
>  #ifndef _LOWLEVELLOCK_FUTEX_H
>  #define _LOWLEVELLOCK_FUTEX_H   1
>  
> -#include <errno.h>
> -
> -
> -/* Values for 'private' parameter of locking macros.  Note pthreadP.h
> -   optimizes for these exact values, though they are not required.  */
> -#define LLL_PRIVATE     0
> -#define LLL_SHARED      128
> -
> +#ifndef __ASSEMBLER__
> +# include <sysdep.h>
> +# include <sysdep-cancel.h>
> +# include <kernel-features.h>
> +#endif
> +
> +#define FUTEX_WAIT		0
> +#define FUTEX_WAKE		1
> +#define FUTEX_REQUEUE		3
> +#define FUTEX_CMP_REQUEUE	4
> +#define FUTEX_WAKE_OP		5
> +#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE	((4 << 24) | 1)
> +#define FUTEX_LOCK_PI		6
> +#define FUTEX_UNLOCK_PI		7
> +#define FUTEX_TRYLOCK_PI	8
> +#define FUTEX_WAIT_BITSET	9
> +#define FUTEX_WAKE_BITSET	10
> +#define FUTEX_WAIT_REQUEUE_PI   11
> +#define FUTEX_CMP_REQUEUE_PI    12
> +#define FUTEX_PRIVATE_FLAG	128
> +#define FUTEX_CLOCK_REALTIME	256
> +
> +#define FUTEX_BITSET_MATCH_ANY	0xffffffff
> +
> +/* Values for 'private' parameter of locking macros.  Yes, the
> +   definition seems to be backwards.  But it is not.  The bit will be
> +   reversed before passing to the system call.  */
> +#define LLL_PRIVATE	0
> +#define LLL_SHARED	FUTEX_PRIVATE_FLAG
> +
> +#ifndef __ASSEMBLER__
> +
> +# if IS_IN (libc) || IS_IN (rtld)
> +/* In libc.so or ld.so all futexes are private.  */
> +#  define __lll_private_flag(fl, private)			\
> +  ({								\
> +    /* Prevent warnings in callers of this macro.  */		\
> +    int __lll_private_flag_priv __attribute__ ((unused));	\
> +    __lll_private_flag_priv = (private);			\
> +    ((fl) | FUTEX_PRIVATE_FLAG);				\
> +  })
> +# else
> +#  define __lll_private_flag(fl, private) \
> +  (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
> +# endif
> +
> +# define lll_futex_syscall(nargs, futexp, op, ...)                       \
> +  ({                                                                    \
> +    INTERNAL_SYSCALL_DECL (__err);                                      \
> +    long int __ret = INTERNAL_SYSCALL (futex, __err, nargs, futexp, op, \
> +				       __VA_ARGS__);                    \
> +    (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret, __err))         \
> +     ? -INTERNAL_SYSCALL_ERRNO (__ret, __err) : 0);                     \
> +  })
>  
>  /* For most of these macros, the return value is never really used.
>     Nevertheless, the protocol is that each one returns a negated errno
> @@ -36,62 +82,107 @@
>  
>  
>  /* Wait while *FUTEXP == VAL for an lll_futex_wake call on FUTEXP.  */
> -#define lll_futex_wait(futexp, val, private) \
> +# define lll_futex_wait(futexp, val, private) \
>    lll_futex_timed_wait (futexp, val, NULL, private)
>  
> -/* Wait until a lll_futex_wake call on FUTEXP, or TIMEOUT elapses.  */
> -#define lll_futex_timed_wait(futexp, val, timeout, private)             \
> -  -ENOSYS
> +# define lll_futex_timed_wait(futexp, val, timeout, private)     \
> +  lll_futex_syscall (4, futexp,                                 \
> +		     __lll_private_flag (FUTEX_WAIT, private),  \
> +		     val, timeout)
>  
>  /* Verify whether the supplied clockid is supported by
>     lll_futex_clock_wait_bitset.  */
> -#define lll_futex_supported_clockid(clockid)				\
> -  (0)
> -
> -/* Wait until a lll_futex_wake call on FUTEXP, or the absolute TIMEOUT
> -   measured against CLOCKID elapses. CLOCKID may be CLOCK_REALTIME or
> -   CLOCK_MONOTONIC.  */
> -#define lll_futex_clock_wait_bitset(futexp, val, clockid, timeout, private) \
> -  -ENOSYS
> +# define lll_futex_supported_clockid(clockid)			\
> +  ((clockid) == CLOCK_REALTIME || (clockid) == CLOCK_MONOTONIC)
> +
> +/* The kernel currently only supports CLOCK_MONOTONIC or
> +   CLOCK_REALTIME timeouts for FUTEX_WAIT_BITSET.  We could attempt to
> +   convert others here but currently do not.  */
> +# define lll_futex_clock_wait_bitset(futexp, val, clockid, timeout, private) \
> +  ({									\
> +    long int __ret;							\
> +    if (lll_futex_supported_clockid (clockid))                          \
> +      {                                                                 \
> +        const unsigned int clockbit =                                   \
> +          (clockid == CLOCK_REALTIME) ? FUTEX_CLOCK_REALTIME : 0;       \
> +        const int op =                                                  \
> +          __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private);   \
> +                                                                        \
> +        __ret = lll_futex_syscall (6, futexp, op, val,                  \
> +                                   timeout, NULL /* Unused.  */,	\
> +                                   FUTEX_BITSET_MATCH_ANY);		\
> +      }                                                                 \
> +    else                                                                \
> +      __ret = -EINVAL;							\
> +    __ret;								\
> +  })
>  
>  /* Wake up up to NR waiters on FUTEXP.  */
> -#define lll_futex_wake(futexp, nr, private)                             \
> -  -ENOSYS
> +# define lll_futex_wake(futexp, nr, private)                             \
> +  lll_futex_syscall (4, futexp,                                         \
> +		     __lll_private_flag (FUTEX_WAKE, private), nr, 0)
>  
>  /* Wake up up to NR_WAKE waiters on FUTEXP.  Move up to NR_MOVE of the
> -   rest from waiting on FUTEXP to waiting on MUTEX (a different futex).  */
> -#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
> -  -ENOSYS
> +   rest from waiting on FUTEXP to waiting on MUTEX (a different futex).
> +   Returns non-zero if error happened, zero if success.  */
> +# define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
> +  lll_futex_syscall (6, futexp,                                         \
> +		     __lll_private_flag (FUTEX_CMP_REQUEUE, private),   \
> +		     nr_wake, nr_move, mutex, val)
> +
> +/* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2.
> +   Returns non-zero if error happened, zero if success.  */
> +# define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
> +  lll_futex_syscall (6, futexp,                                         \
> +		     __lll_private_flag (FUTEX_WAKE_OP, private),       \
> +		     nr_wake, nr_wake2, futexp2,                        \
> +		     FUTEX_OP_CLEAR_WAKE_IF_GT_ONE)
>  
> -/* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2.  */
> -#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
> -  -ENOSYS
>  
> +/* Priority Inheritance support.  */
>  
>  /* Like lll_futex_wait (FUTEXP, VAL, PRIVATE) but with the expectation
>     that lll_futex_cmp_requeue_pi (FUTEXP, _, _, MUTEX, _, PRIVATE) will
>     be used to do the wakeup.  Confers priority-inheritance behavior on
>     the waiter.  */
> -#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
> +# define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
>    lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
>  
>  /* Like lll_futex_wait_requeue_pi, but with a timeout.  */
> -#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
> +# define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
>                                          mutex, private)                 \
> -  -ENOSYS
> +  lll_futex_syscall (5, futexp,                                         \
> +		     __lll_private_flag (FUTEX_WAIT_REQUEUE_PI          \
> +					 | (clockbit), private),        \
> +		     val, timeout, mutex)
>  
>  /* Like lll_futex_requeue, but pairs with lll_futex_wait_requeue_pi
>     and inherits priority from the waiter.  */
> -#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex,       \
> +# define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex,       \
>                                   val, private)                          \
> -  -ENOSYS
> +  lll_futex_syscall (6, futexp,                                         \
> +		     __lll_private_flag (FUTEX_CMP_REQUEUE_PI,          \
> +					 private),                      \
> +		     nr_wake, nr_move, mutex, val)
>  
>  /* Like lll_futex_wait, but acting as a cancellable entrypoint.  */
> -#define lll_futex_wait_cancel(futexp, val, private) \
> -  -ENOSYS
> +# define lll_futex_wait_cancel(futexp, val, private) \
> +  ({                                                                   \
> +    int __oldtype = CANCEL_ASYNC ();				       \
> +    long int __err = lll_futex_wait (futexp, val, LLL_SHARED);	       \
> +    CANCEL_RESET (__oldtype);					       \
> +    __err;							       \
> +  })
>  
>  /* Like lll_futex_timed_wait, but acting as a cancellable entrypoint.  */
> -#define lll_futex_timed_wait_cancel(futexp, val, timeout, private) \
> -  -ENOSYS
> +# define lll_futex_timed_wait_cancel(futexp, val, timeout, private) \
> +  ({									   \
> +    int __oldtype = CANCEL_ASYNC ();				       	   \
> +    long int __err = lll_futex_timed_wait (futexp, val, timeout, private); \
> +    CANCEL_RESET (__oldtype);						   \
> +    __err;								   \
> +  })
> +
> +#endif  /* !__ASSEMBLER__  */
>  
>  #endif  /* lowlevellock-futex.h */
> diff --git a/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
> deleted file mode 100644
> index b423673ed4..0000000000
> --- a/sysdeps/unix/sysv/linux/lowlevellock-futex.h
> +++ /dev/null
> @@ -1,168 +0,0 @@
> -/* Low-level locking access to futex facilities.  Linux version.
> -   Copyright (C) 2005-2019 Free Software Foundation, Inc.
> -   This file is part of the GNU C Library.
> -
> -   The GNU C Library is free software; you can redistribute it and/or
> -   modify it under the terms of the GNU Lesser General Public
> -   License as published by the Free Software Foundation; either
> -   version 2.1 of the License, or (at your option) any later version.
> -
> -   The GNU C Library is distributed in the hope that it will be useful,
> -   but WITHOUT ANY WARRANTY; without even the implied warranty of
> -   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
> -   Lesser General Public License for more details.
> -
> -   You should have received a copy of the GNU Lesser General Public
> -   License along with the GNU C Library.  If not, see
> -   <https://www.gnu.org/licenses/>.  */
> -
> -#ifndef _LOWLEVELLOCK_FUTEX_H
> -#define _LOWLEVELLOCK_FUTEX_H	1
> -
> -#ifndef __ASSEMBLER__
> -#include <sysdep.h>
> -#include <sysdep-cancel.h>
> -#include <kernel-features.h>
> -#endif
> -
> -#define FUTEX_WAIT		0
> -#define FUTEX_WAKE		1
> -#define FUTEX_REQUEUE		3
> -#define FUTEX_CMP_REQUEUE	4
> -#define FUTEX_WAKE_OP		5
> -#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE	((4 << 24) | 1)
> -#define FUTEX_LOCK_PI		6
> -#define FUTEX_UNLOCK_PI		7
> -#define FUTEX_TRYLOCK_PI	8
> -#define FUTEX_WAIT_BITSET	9
> -#define FUTEX_WAKE_BITSET	10
> -#define FUTEX_WAIT_REQUEUE_PI   11
> -#define FUTEX_CMP_REQUEUE_PI    12
> -#define FUTEX_PRIVATE_FLAG	128
> -#define FUTEX_CLOCK_REALTIME	256
> -
> -#define FUTEX_BITSET_MATCH_ANY	0xffffffff
> -
> -/* Values for 'private' parameter of locking macros.  Yes, the
> -   definition seems to be backwards.  But it is not.  The bit will be
> -   reversed before passing to the system call.  */
> -#define LLL_PRIVATE	0
> -#define LLL_SHARED	FUTEX_PRIVATE_FLAG
> -
> -#ifndef __ASSEMBLER__
> -
> -#if IS_IN (libc) || IS_IN (rtld)
> -/* In libc.so or ld.so all futexes are private.  */
> -# define __lll_private_flag(fl, private)			\
> -  ({								\
> -    /* Prevent warnings in callers of this macro.  */		\
> -    int __lll_private_flag_priv __attribute__ ((unused));	\
> -    __lll_private_flag_priv = (private);			\
> -    ((fl) | FUTEX_PRIVATE_FLAG);				\
> -  })
> -#else
> -# define __lll_private_flag(fl, private) \
> -  (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
> -#endif
> -
> -#define lll_futex_syscall(nargs, futexp, op, ...)                       \
> -  ({                                                                    \
> -    INTERNAL_SYSCALL_DECL (__err);                                      \
> -    long int __ret = INTERNAL_SYSCALL (futex, __err, nargs, futexp, op, \
> -				       __VA_ARGS__);                    \
> -    (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret, __err))         \
> -     ? -INTERNAL_SYSCALL_ERRNO (__ret, __err) : 0);                     \
> -  })
> -
> -#define lll_futex_wait(futexp, val, private) \
> -  lll_futex_timed_wait (futexp, val, NULL, private)
> -
> -#define lll_futex_timed_wait(futexp, val, timeout, private)     \
> -  lll_futex_syscall (4, futexp,                                 \
> -		     __lll_private_flag (FUTEX_WAIT, private),  \
> -		     val, timeout)
> -
> -/* Verify whether the supplied clockid is supported by
> -   lll_futex_clock_wait_bitset.  */
> -#define lll_futex_supported_clockid(clockid)			\
> -  ((clockid) == CLOCK_REALTIME || (clockid) == CLOCK_MONOTONIC)
> -
> -/* The kernel currently only supports CLOCK_MONOTONIC or
> -   CLOCK_REALTIME timeouts for FUTEX_WAIT_BITSET.  We could attempt to
> -   convert others here but currently do not.  */
> -#define lll_futex_clock_wait_bitset(futexp, val, clockid, timeout, private) \
> -  ({									\
> -    long int __ret;							\
> -    if (lll_futex_supported_clockid (clockid))                          \
> -      {                                                                 \
> -        const unsigned int clockbit =                                   \
> -          (clockid == CLOCK_REALTIME) ? FUTEX_CLOCK_REALTIME : 0;       \
> -        const int op =                                                  \
> -          __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private);   \
> -                                                                        \
> -        __ret = lll_futex_syscall (6, futexp, op, val,                  \
> -                                   timeout, NULL /* Unused.  */,	\
> -                                   FUTEX_BITSET_MATCH_ANY);		\
> -      }                                                                 \
> -    else                                                                \
> -      __ret = -EINVAL;							\
> -    __ret;								\
> -  })
> -
> -#define lll_futex_wake(futexp, nr, private)                             \
> -  lll_futex_syscall (4, futexp,                                         \
> -		     __lll_private_flag (FUTEX_WAKE, private), nr, 0)
> -
> -/* Returns non-zero if error happened, zero if success.  */
> -#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
> -  lll_futex_syscall (6, futexp,                                         \
> -		     __lll_private_flag (FUTEX_CMP_REQUEUE, private),   \
> -		     nr_wake, nr_move, mutex, val)
> -
> -/* Returns non-zero if error happened, zero if success.  */
> -#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
> -  lll_futex_syscall (6, futexp,                                         \
> -		     __lll_private_flag (FUTEX_WAKE_OP, private),       \
> -		     nr_wake, nr_wake2, futexp2,                        \
> -		     FUTEX_OP_CLEAR_WAKE_IF_GT_ONE)
> -
> -/* Priority Inheritance support.  */
> -#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
> -  lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
> -
> -#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
> -					mutex, private)                 \
> -  lll_futex_syscall (5, futexp,                                         \
> -		     __lll_private_flag (FUTEX_WAIT_REQUEUE_PI          \
> -					 | (clockbit), private),        \
> -		     val, timeout, mutex)
> -
> -
> -#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex,       \
> -				 val, private)                          \
> -  lll_futex_syscall (6, futexp,                                         \
> -		     __lll_private_flag (FUTEX_CMP_REQUEUE_PI,          \
> -					 private),                      \
> -		     nr_wake, nr_move, mutex, val)
> -
> -
> -/* Cancellable futex macros.  */
> -#define lll_futex_wait_cancel(futexp, val, private) \
> -  ({                                                                   \
> -    int __oldtype = CANCEL_ASYNC ();				       \
> -    long int __err = lll_futex_wait (futexp, val, LLL_SHARED);	       \
> -    CANCEL_RESET (__oldtype);					       \
> -    __err;							       \
> -  })
> -
> -#define lll_futex_timed_wait_cancel(futexp, val, timeout, private)	   \
> -  ({									   \
> -    int __oldtype = CANCEL_ASYNC ();				       	   \
> -    long int __err = lll_futex_timed_wait (futexp, val, timeout, private); \
> -    CANCEL_RESET (__oldtype);						   \
> -    __err;								   \
> -  })
> -
> -#endif  /* !__ASSEMBLER__  */
> -
> -#endif  /* lowlevellock-futex.h */
>