From a4a43a907c1e7b610715848f5a69e937a9f22903 Mon Sep 17 00:00:00 2001 From: Torvald Riegel Date: Wed, 17 Dec 2014 19:09:04 +0100 Subject: [PATCH] i386: Move futex functions from lowlevellock.h to lowlevellock-futex.h. --- ChangeLog | 10 ++ sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h | 137 ++++++++++++++++++++++ sysdeps/unix/sysv/linux/i386/lowlevellock.h | 130 ++++---------------- 3 files changed, 167 insertions(+), 110 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h diff --git a/ChangeLog b/ChangeLog index 76f5a3c..7d6d2de 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,15 @@ 2014-12-19 Torvald Riegel + * sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h: New file. + Contains futex constants and functions moved over from ... + * sysdeps/unix/sysv/linux/i386/lowlevellock.h: ... here. Include + . + (lll_wait_tid): Use lll_futex_wait instead of assembly code. + (lll_timedwait_tid): Add comments and parentheses around macro + arguments. + +2014-12-19 Torvald Riegel + * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Include . Remove FUTEX_* constants defined there. (__lll_private_flag): Remove. diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h new file mode 100644 index 0000000..d7f8728 --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h @@ -0,0 +1,137 @@ +/* Low-level locking access to futex facilities. Linux/i386 version. + Copyright (C) 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 + . */ + +#ifndef _LOWLEVELLOCK_FUTEX_H +#define _LOWLEVELLOCK_FUTEX_H 1 + +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 +#define FUTEX_CMP_REQUEUE 4 +#define FUTEX_WAKE_OP 5 +#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 + +#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) + +/* 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 IS_IN (libc) || 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)) \ + : ({ unsigned int __fl = ((private) ^ FUTEX_PRIVATE_FLAG); \ + asm ("andl %%gs:%P1, %0" : "+r" (__fl) \ + : "i" (offsetof (struct pthread, header.private_futex))); \ + __fl | (fl); })) +# endif +#endif + + +#ifndef __ASSEMBLER__ + +/* To avoid naming conflicts with lowlevellock.h, use a different prefix + here. */ +#ifdef PIC +# define LLLF_EBX_LOAD "xchgl %2, %%ebx\n" +# define LLLF_EBX_REG "D" +#else +# define LLLF_EBX_LOAD +# define LLLF_EBX_REG "b" +#endif + +#ifdef I386_USE_SYSENTER +# ifdef SHARED +# define LLLF_ENTER_KERNEL "call *%%gs:%P6\n\t" +# else +# define LLLF_ENTER_KERNEL "call *_dl_sysinfo\n\t" +# endif +#else +# define LLLF_ENTER_KERNEL "int $0x80\n\t" +#endif + + +#define lll_futex_wait(futex, val, private) \ + lll_futex_timed_wait (futex, val, NULL, private) + + +#define lll_futex_timed_wait(futex, val, timeout, private) \ + ({ \ + int __status; \ + register __typeof (val) _val asm ("edx") = (val); \ + __asm __volatile (LLLF_EBX_LOAD \ + LLLF_ENTER_KERNEL \ + LLLF_EBX_LOAD \ + : "=a" (__status) \ + : "0" (SYS_futex), LLLF_EBX_REG (futex), "S" (timeout), \ + "c" (__lll_private_flag (FUTEX_WAIT, private)), \ + "d" (_val), "i" (offsetof (tcbhead_t, sysinfo)) \ + : "memory"); \ + __status; \ + }) + + +#define lll_futex_wake(futex, nr, private) \ + ({ \ + int __status; \ + register __typeof (nr) _nr asm ("edx") = (nr); \ + LIBC_PROBE (lll_futex_wake, 3, futex, nr, private); \ + __asm __volatile (LLLF_EBX_LOAD \ + LLLF_ENTER_KERNEL \ + LLLF_EBX_LOAD \ + : "=a" (__status) \ + : "0" (SYS_futex), LLLF_EBX_REG (futex), \ + "c" (__lll_private_flag (FUTEX_WAKE, private)), \ + "d" (_nr), \ + "i" (0) /* phony, to align next arg's number */, \ + "i" (offsetof (tcbhead_t, sysinfo))); \ + __status; \ + }) + + +#endif /* !__ASSEMBLER__ */ + +#endif /* lowlevellock-futex.h */ diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/sysdeps/unix/sysv/linux/i386/lowlevellock.h index 1032f4b..c3528a8 100644 --- a/sysdeps/unix/sysv/linux/i386/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -45,57 +45,10 @@ # endif #endif +#include + +/* XXX Remove when no assembler code uses futexes anymore. */ #define SYS_futex 240 -#define FUTEX_WAIT 0 -#define FUTEX_WAKE 1 -#define FUTEX_CMP_REQUEUE 4 -#define FUTEX_WAKE_OP 5 -#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 - -#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) - -/* 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 IS_IN (libc) || 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)) \ - : ({ unsigned int __fl = ((private) ^ FUTEX_PRIVATE_FLAG); \ - asm ("andl %%gs:%P1, %0" : "+r" (__fl) \ - : "i" (offsetof (struct pthread, header.private_futex))); \ - __fl | (fl); })) -# endif -#endif #ifndef __ASSEMBLER__ @@ -126,43 +79,6 @@ /* Delay in spinlock loop. */ #define BUSY_WAIT_NOP asm ("rep; nop") -#define lll_futex_wait(futex, val, private) \ - lll_futex_timed_wait (futex, val, NULL, private) - - -#define lll_futex_timed_wait(futex, val, timeout, private) \ - ({ \ - int __status; \ - register __typeof (val) _val asm ("edx") = (val); \ - __asm __volatile (LLL_EBX_LOAD \ - LLL_ENTER_KERNEL \ - LLL_EBX_LOAD \ - : "=a" (__status) \ - : "0" (SYS_futex), LLL_EBX_REG (futex), "S" (timeout), \ - "c" (__lll_private_flag (FUTEX_WAIT, private)), \ - "d" (_val), "i" (offsetof (tcbhead_t, sysinfo)) \ - : "memory"); \ - __status; \ - }) - - -#define lll_futex_wake(futex, nr, private) \ - ({ \ - int __status; \ - register __typeof (nr) _nr asm ("edx") = (nr); \ - LIBC_PROBE (lll_futex_wake, 3, futex, nr, private); \ - __asm __volatile (LLL_EBX_LOAD \ - LLL_ENTER_KERNEL \ - LLL_EBX_LOAD \ - : "=a" (__status) \ - : "0" (SYS_futex), LLL_EBX_REG (futex), \ - "c" (__lll_private_flag (FUTEX_WAKE, private)), \ - "d" (_nr), \ - "i" (0) /* phony, to align next arg's number */, \ - "i" (offsetof (tcbhead_t, sysinfo))); \ - __status; \ - }) - /* NB: in the lll_trylock macro we simply return the value in %eax after the cmpxchg instruction. In case the operation succeded this @@ -381,43 +297,37 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count, (futex != LLL_LOCK_INITIALIZER) /* 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. - - The macro parameter must not have any side effect. */ + wake-up when the clone terminates. The memory location contains the + thread ID while the clone is running and is reset to zero by the kernel + afterwards. The kernel up to version 3.16.3 does not use the private futex + operations for futex wake-up when the clone terminates. */ #define lll_wait_tid(tid) \ - do { \ - int __ignore; \ - register __typeof (tid) _tid asm ("edx") = (tid); \ - if (_tid != 0) \ - __asm __volatile (LLL_EBX_LOAD \ - "1:\tmovl %1, %%eax\n\t" \ - LLL_ENTER_KERNEL \ - "cmpl $0, (%%ebx)\n\t" \ - "jne 1b\n\t" \ - LLL_EBX_LOAD \ - : "=&a" (__ignore) \ - : "i" (SYS_futex), LLL_EBX_REG (&tid), "S" (0), \ - "c" (FUTEX_WAIT), "d" (_tid), \ - "i" (offsetof (tcbhead_t, sysinfo)) \ - : "memory"); \ + do { \ + __typeof (tid) __tid; \ + while ((__tid = (tid)) != 0) \ + lll_futex_wait (&(tid), __tid, LLL_SHARED);\ } while (0) extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime) __attribute__ ((regparm (2))) attribute_hidden; + +/* As lll_wait_tid, but with a timeout. If the timeout occurs then return + ETIMEDOUT. If ABSTIME is invalid, return EINVAL. + XXX Note that this differs from the generic version in that we do the + error checking here and not in __lll_timedwait_tid. */ #define lll_timedwait_tid(tid, abstime) \ ({ \ int __result = 0; \ - if (tid != 0) \ + if ((tid) != 0) \ { \ - if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) \ + if ((abstime)->tv_nsec < 0 || (abstime)->tv_nsec >= 1000000000) \ __result = EINVAL; \ else \ - __result = __lll_timedwait_tid (&tid, abstime); \ + __result = __lll_timedwait_tid (&(tid), (abstime)); \ } \ __result; }) + extern int __lll_lock_elision (int *futex, short *adapt_count, int private) attribute_hidden; -- 2.7.4