diff mbox

[3/9,BZ,16892] ARM - Remove arm lowlevellock.h

Message ID EE2BD910-914B-4D8B-A398-416E6A4D2087@linaro.org
State New
Headers show

Commit Message

Bernie Ogden June 9, 2014, 8:25 p.m. UTC
Remove arm lowlevelock.h

Results in these changes:

Fixes BZ16892, as lll_timelock now checks value of futex before
changing it. There is a similar change in lll_cond_lock - as this
was unconditionally setting the futex to 2 rather than 1, this
should not have been causing any bugs, but the change is harmless.

Gain a few static always_inline functions - some didn't previously
exist for arm, others used to be macros.

lll_futex_timed_wait_requeue_pi now calls INTERNAL_SYSCALL_ERROR_P
on the return value. This function only has one caller, and that
caller just compares return value to 0, so the behaviour is
equivalent.

Passes regression tests.

Regards,

Bernie


2014-06-09  Bernard Ogden  <bernie.ogden@linaro.org>

	[BZ #16892]
	* sysdeps/unix/sysv/linux/arm/lowlevellock.h: Remove file.

Comments

Joseph Myers June 9, 2014, 8:51 p.m. UTC | #1
On Mon, 9 Jun 2014, Bernard Ogden wrote:

> Remove arm lowlevelock.h
> 
> Results in these changes:
> 
> Fixes BZ16892, as lll_timelock now checks value of futex before
> changing it. There is a similar change in lll_cond_lock - as this
> was unconditionally setting the futex to 2 rather than 1, this
> should not have been causing any bugs, but the change is harmless.
> 
> Gain a few static always_inline functions - some didn't previously
> exist for arm, others used to be macros.
> 
> lll_futex_timed_wait_requeue_pi now calls INTERNAL_SYSCALL_ERROR_P
> on the return value. This function only has one caller, and that
> caller just compares return value to 0, so the behaviour is
> equivalent.
> 
> Passes regression tests.

OK once the generic header is in.  This is not a review or approval of the 
generic header.
diff mbox

Patch

diff --git a/sysdeps/unix/sysv/linux/arm/lowlevellock.h b/sysdeps/unix/sysv/linux/arm/lowlevellock.h
deleted file mode 100644
index 5d19434..0000000
--- a/sysdeps/unix/sysv/linux/arm/lowlevellock.h
+++ /dev/null
@@ -1,321 +0,0 @@ 
-/* Copyright (C) 2005-2014 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
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _LOWLEVELLOCK_H
-#define _LOWLEVELLOCK_H	1
-
-#include <time.h>
-#include <sys/param.h>
-#include <bits/pthreadtypes.h>
-#include <atomic.h>
-#include <sysdep.h>
-#include <kernel-features.h>
-
-#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
-
-
-#if !defined NOT_IN_libc || defined IS_IN_rtld
-/* In libc.so or ld.so all futexes are private.  */
-# ifdef __ASSUME_PRIVATE_FUTEX
-#  define __lll_private_flag(fl, private) \
-  ((fl) | FUTEX_PRIVATE_FLAG)
-# else
-#  define __lll_private_flag(fl, private) \
-  ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
-# endif
-#else
-# ifdef __ASSUME_PRIVATE_FUTEX
-#  define __lll_private_flag(fl, private) \
-  (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
-# else
-#  define __lll_private_flag(fl, private) \
-  (__builtin_constant_p (private)					      \
-   ? ((private) == 0							      \
-      ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))	      \
-      : (fl))								      \
-   : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG)				      \
-	      & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
-# endif
-#endif
-
-
-#define lll_futex_wait(futexp, val, private) \
-  lll_futex_timed_wait(futexp, val, NULL, private)
-
-#define lll_futex_timed_wait(futexp, val, timespec, private) \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),		      \
-			      __lll_private_flag (FUTEX_WAIT, private),	      \
-			      (val), (timespec));			      \
-    __ret;								      \
-  })
-
-#define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
-  ({									\
-    INTERNAL_SYSCALL_DECL (__err);					\
-    long int __ret;							\
-    int __op = FUTEX_WAIT_BITSET | clockbit;				\
-    __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		\
-			      __lll_private_flag (__op, private),	\
-			      (val), (timespec), NULL /* Unused.  */,	\
-			      FUTEX_BITSET_MATCH_ANY);			\
-    __ret;								\
-  })
-
-#define lll_futex_wake(futexp, nr, private) \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),		      \
-			      __lll_private_flag (FUTEX_WAKE, private),	      \
-			      (nr), 0);					      \
-    __ret;								      \
-  })
-
-#define lll_robust_dead(futexv, private) \
-  do									      \
-    {									      \
-      int *__futexp = &(futexv);					      \
-      atomic_or (__futexp, FUTEX_OWNER_DIED);				      \
-      lll_futex_wake (__futexp, 1, private);				      \
-    }									      \
-  while (0)
-
-/* Returns non-zero if error happened, zero if success.  */
-#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		      \
-			      __lll_private_flag (FUTEX_CMP_REQUEUE, private),\
-			      (nr_wake), (nr_move), (mutex), (val));	      \
-    INTERNAL_SYSCALL_ERROR_P (__ret, __err);				      \
-  })
-
-
-/* Returns non-zero if error happened, zero if success.  */
-#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		      \
-			      __lll_private_flag (FUTEX_WAKE_OP, private),    \
-			      (nr_wake), (nr_wake2), (futexp2),		      \
-			      FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);		      \
-    INTERNAL_SYSCALL_ERROR_P (__ret, __err);				      \
-  })
-
-/* 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, timespec, clockbit,      \
-					mutex, private)			      \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    int __op = FUTEX_WAIT_REQUEUE_PI | clockbit;			      \
-									      \
-    INTERNAL_SYSCALL (futex, __err, 5, (futexp),			      \
-		      __lll_private_flag (__op, private),		      \
-		      (val), (timespec), mutex); 			      \
-  })
-
-#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv)  \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    long int __ret;							      \
-									      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		      \
-			      __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),\
-			      (nr_wake), (nr_move), (mutex), (val));	      \
-    INTERNAL_SYSCALL_ERROR_P (__ret, __err);				      \
-  })
-
-
-#define lll_trylock(lock)	\
-  atomic_compare_and_exchange_val_acq(&(lock), 1, 0)
-
-#define lll_cond_trylock(lock)	\
-  atomic_compare_and_exchange_val_acq(&(lock), 2, 0)
-
-#define __lll_robust_trylock(futex, id) \
-  (atomic_compare_and_exchange_val_acq (futex, id, 0) != 0)
-#define lll_robust_trylock(lock, id) \
-  __lll_robust_trylock (&(lock), id)
-
-extern void __lll_lock_wait_private (int *futex) attribute_hidden;
-extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
-extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;
-
-#define __lll_lock(futex, private)					      \
-  ((void) ({								      \
-    int *__futex = (futex);						      \
-    if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex,       \
-								1, 0), 0))    \
-      {									      \
-	if (__builtin_constant_p (private) && (private) == LLL_PRIVATE)	      \
-	  __lll_lock_wait_private (__futex);				      \
-	else								      \
-	  __lll_lock_wait (__futex, private);				      \
-      }									      \
-  }))
-#define lll_lock(futex, private) __lll_lock (&(futex), private)
-
-
-#define __lll_robust_lock(futex, id, private)				      \
-  ({									      \
-    int *__futex = (futex);						      \
-    int __val = 0;							      \
-									      \
-    if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
-								0), 0))	      \
-      __val = __lll_robust_lock_wait (__futex, private);		      \
-    __val;								      \
-  })
-#define lll_robust_lock(futex, id, private) \
-  __lll_robust_lock (&(futex), id, private)
-
-
-#define __lll_cond_lock(futex, private)					      \
-  ((void) ({								      \
-    int *__futex = (futex);						      \
-    if (__builtin_expect (atomic_exchange_acq (__futex, 2), 0))		      \
-      __lll_lock_wait (__futex, private);				      \
-  }))
-#define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)
-
-
-#define lll_robust_cond_lock(futex, id, private) \
-  __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private)
-
-
-extern int __lll_timedlock_wait (int *futex, const struct timespec *,
-				 int private) attribute_hidden;
-extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *,
-					int private) attribute_hidden;
-
-#define __lll_timedlock(futex, abstime, private)			      \
-  ({									      \
-     int *__futex = (futex);						      \
-     int __val = 0;							      \
-									      \
-     if (__builtin_expect (atomic_exchange_acq (__futex, 1), 0))	      \
-       __val = __lll_timedlock_wait (__futex, abstime, private);	      \
-     __val;								      \
-  })
-#define lll_timedlock(futex, abstime, private) \
-  __lll_timedlock (&(futex), abstime, private)
-
-
-#define __lll_robust_timedlock(futex, abstime, id, private)		      \
-  ({									      \
-    int *__futex = (futex);						      \
-    int __val = 0;							      \
-									      \
-    if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
-								0), 0))	      \
-      __val = __lll_robust_timedlock_wait (__futex, abstime, private);	      \
-    __val;								      \
-  })
-#define lll_robust_timedlock(futex, abstime, id, private) \
-  __lll_robust_timedlock (&(futex), abstime, id, private)
-
-
-#define __lll_unlock(futex, private) \
-  (void)							\
-    ({ int *__futex = (futex);					\
-       int __oldval = atomic_exchange_rel (__futex, 0);		\
-       if (__builtin_expect (__oldval > 1, 0))			\
-	 lll_futex_wake (__futex, 1, private);			\
-    })
-#define lll_unlock(futex, private) __lll_unlock(&(futex), private)
-
-
-#define __lll_robust_unlock(futex, private) \
-  (void)							\
-    ({ int *__futex = (futex);					\
-       int __oldval = atomic_exchange_rel (__futex, 0);		\
-       if (__builtin_expect (__oldval & FUTEX_WAITERS, 0))	\
-	 lll_futex_wake (__futex, 1, private);			\
-    })
-#define lll_robust_unlock(futex, private) \
-  __lll_robust_unlock(&(futex), private)
-
-
-#define lll_islocked(futex) \
-  (futex != 0)
-
-
-/* Our internal lock implementation is identical to the binary-compatible
-   mutex implementation. */
-
-/* Initializers for lock.  */
-#define LLL_LOCK_INITIALIZER		(0)
-#define LLL_LOCK_INITIALIZER_LOCKED	(1)
-
-/* The states of a lock are:
-    0  -  untaken
-    1  -  taken by one user
-   >1  -  taken by more users */
-
-/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
-   wakeup when the clone terminates.  The memory location contains the
-   thread ID while the clone is running and is reset to zero
-   afterwards.	*/
-#define lll_wait_tid(tid) \
-  do {					\
-    __typeof (tid) __tid;		\
-    while ((__tid = (tid)) != 0)	\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);\
-  } while (0)
-
-extern int __lll_timedwait_tid (int *, const struct timespec *)
-     attribute_hidden;
-
-#define lll_timedwait_tid(tid, abstime) \
-  ({							\
-    int __res = 0;					\
-    if ((tid) != 0)					\
-      __res = __lll_timedwait_tid (&(tid), (abstime));	\
-    __res;						\
-  })
-
-#endif	/* lowlevellock.h */