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b433334065
In the i386 case, it appears that the sole remaining LIBC_PROBE was removed in commita9fe4c5aa8("Support six-argument syscalls from C for 32-bit x86, use generic lowlevellock-futex.h (bug 18138)."), when sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h was replaced with the generic version. For x86_64, the relevant change is commit76f71081cd("Use generic lowlevellock-futex.h in x86_64 lowlevellock.h."), again by using the generic version of <lowlevellock-futex.h>. Tested on i386 and x86_64, with and without --enable-systemtap.
269 lines
9.6 KiB
C
269 lines
9.6 KiB
C
/* Copyright (C) 2002-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _LOWLEVELLOCK_H
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#define _LOWLEVELLOCK_H 1
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#ifndef __ASSEMBLER__
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# include <time.h>
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# include <sys/param.h>
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# include <bits/pthreadtypes.h>
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# include <kernel-features.h>
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# ifndef LOCK_INSTR
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# ifdef UP
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# define LOCK_INSTR /* nothing */
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# else
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# define LOCK_INSTR "lock;"
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# endif
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# endif
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#else
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# ifndef LOCK
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# ifdef UP
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# define LOCK
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# else
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# define LOCK lock
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# endif
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# endif
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#endif
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#include <lowlevellock-futex.h>
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/* XXX Remove when no assembler code uses futexes anymore. */
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#define SYS_futex __NR_futex
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#ifndef __ASSEMBLER__
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/* Initializer for lock. */
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#define LLL_LOCK_INITIALIZER (0)
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#define LLL_LOCK_INITIALIZER_LOCKED (1)
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#define LLL_LOCK_INITIALIZER_WAITERS (2)
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/* NB: in the lll_trylock macro we simply return the value in %eax
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after the cmpxchg instruction. In case the operation succeded this
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value is zero. In case the operation failed, the cmpxchg instruction
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has loaded the current value of the memory work which is guaranteed
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to be nonzero. */
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#if !IS_IN (libc) || defined UP
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# define __lll_trylock_asm LOCK_INSTR "cmpxchgl %2, %1"
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#else
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# define __lll_trylock_asm "cmpl $0, __libc_multiple_threads(%%rip)\n\t" \
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"je 0f\n\t" \
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"lock; cmpxchgl %2, %1\n\t" \
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"jmp 1f\n\t" \
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"0:\tcmpxchgl %2, %1\n\t" \
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"1:"
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#endif
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#define lll_trylock(futex) \
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({ int ret; \
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__asm __volatile (__lll_trylock_asm \
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: "=a" (ret), "=m" (futex) \
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: "r" (LLL_LOCK_INITIALIZER_LOCKED), "m" (futex), \
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"0" (LLL_LOCK_INITIALIZER) \
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: "memory"); \
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ret; })
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#define lll_cond_trylock(futex) \
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({ int ret; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %2, %1" \
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: "=a" (ret), "=m" (futex) \
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: "r" (LLL_LOCK_INITIALIZER_WAITERS), \
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"m" (futex), "0" (LLL_LOCK_INITIALIZER) \
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: "memory"); \
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ret; })
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#if !IS_IN (libc) || defined UP
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# define __lll_lock_asm_start LOCK_INSTR "cmpxchgl %4, %2\n\t" \
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"jz 24f\n\t"
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#else
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# define __lll_lock_asm_start "cmpl $0, __libc_multiple_threads(%%rip)\n\t" \
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"je 0f\n\t" \
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"lock; cmpxchgl %4, %2\n\t" \
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"jnz 1f\n\t" \
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"jmp 24f\n" \
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"0:\tcmpxchgl %4, %2\n\t" \
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"jz 24f\n\t"
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#endif
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#define lll_lock(futex, private) \
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(void) \
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({ int ignore1, ignore2, ignore3; \
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if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
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__asm __volatile (__lll_lock_asm_start \
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"1:\tlea %2, %%" RDI_LP "\n" \
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"2:\tsub $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset 128\n" \
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"3:\tcallq __lll_lock_wait_private\n" \
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"4:\tadd $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset -128\n" \
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"24:" \
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: "=S" (ignore1), "=&D" (ignore2), "=m" (futex), \
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"=a" (ignore3) \
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: "0" (1), "m" (futex), "3" (0) \
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: "cx", "r11", "cc", "memory"); \
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else \
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__asm __volatile (__lll_lock_asm_start \
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"1:\tlea %2, %%" RDI_LP "\n" \
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"2:\tsub $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset 128\n" \
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"3:\tcallq __lll_lock_wait\n" \
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"4:\tadd $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset -128\n" \
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"24:" \
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: "=S" (ignore1), "=D" (ignore2), "=m" (futex), \
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"=a" (ignore3) \
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: "1" (1), "m" (futex), "3" (0), "0" (private) \
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: "cx", "r11", "cc", "memory"); \
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}) \
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#define lll_cond_lock(futex, private) \
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(void) \
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({ int ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %4, %2\n\t" \
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"jz 24f\n" \
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"1:\tlea %2, %%" RDI_LP "\n" \
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"2:\tsub $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset 128\n" \
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"3:\tcallq __lll_lock_wait\n" \
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"4:\tadd $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset -128\n" \
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"24:" \
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: "=S" (ignore1), "=D" (ignore2), "=m" (futex), \
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"=a" (ignore3) \
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: "1" (2), "m" (futex), "3" (0), "0" (private) \
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: "cx", "r11", "cc", "memory"); \
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})
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#define lll_timedlock(futex, timeout, private) \
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({ int result, ignore1, ignore2, ignore3; \
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__asm __volatile (LOCK_INSTR "cmpxchgl %1, %4\n\t" \
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"jz 24f\n" \
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"1:\tlea %4, %%" RDI_LP "\n" \
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"0:\tmov %8, %%" RDX_LP "\n" \
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"2:\tsub $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset 128\n" \
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"3:\tcallq __lll_timedlock_wait\n" \
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"4:\tadd $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset -128\n" \
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"24:" \
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: "=a" (result), "=D" (ignore1), "=S" (ignore2), \
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"=&d" (ignore3), "=m" (futex) \
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: "0" (0), "1" (1), "m" (futex), "m" (timeout), \
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"2" (private) \
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: "memory", "cx", "cc", "r10", "r11"); \
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result; })
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extern int __lll_timedlock_elision (int *futex, short *adapt_count,
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const struct timespec *timeout,
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int private) attribute_hidden;
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#define lll_timedlock_elision(futex, adapt_count, timeout, private) \
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__lll_timedlock_elision(&(futex), &(adapt_count), timeout, private)
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#if !IS_IN (libc) || defined UP
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# define __lll_unlock_asm_start LOCK_INSTR "decl %0\n\t" \
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"je 24f\n\t"
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#else
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# define __lll_unlock_asm_start "cmpl $0, __libc_multiple_threads(%%rip)\n\t" \
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"je 0f\n\t" \
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"lock; decl %0\n\t" \
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"jne 1f\n\t" \
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"jmp 24f\n\t" \
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"0:\tdecl %0\n\t" \
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"je 24f\n\t"
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#endif
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#define lll_unlock(futex, private) \
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(void) \
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({ int ignore; \
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if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
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__asm __volatile (__lll_unlock_asm_start \
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"1:\tlea %0, %%" RDI_LP "\n" \
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"2:\tsub $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset 128\n" \
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"3:\tcallq __lll_unlock_wake_private\n" \
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"4:\tadd $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset -128\n" \
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"24:" \
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: "=m" (futex), "=&D" (ignore) \
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: "m" (futex) \
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: "ax", "cx", "r11", "cc", "memory"); \
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else \
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__asm __volatile (__lll_unlock_asm_start \
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"1:\tlea %0, %%" RDI_LP "\n" \
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"2:\tsub $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset 128\n" \
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"3:\tcallq __lll_unlock_wake\n" \
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"4:\tadd $128, %%" RSP_LP "\n" \
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".cfi_adjust_cfa_offset -128\n" \
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"24:" \
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: "=m" (futex), "=&D" (ignore) \
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: "m" (futex), "S" (private) \
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: "ax", "cx", "r11", "cc", "memory"); \
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})
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#define lll_islocked(futex) \
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(futex != LLL_LOCK_INITIALIZER)
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extern int __lll_timedwait_tid (int *, const struct timespec *)
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attribute_hidden;
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/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
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wake-up when the clone terminates. The memory location contains the
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thread ID while the clone is running and is reset to zero by the kernel
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afterwards. The kernel up to version 3.16.3 does not use the private futex
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operations for futex wake-up when the clone terminates.
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If ABSTIME is not NULL, is used a timeout for futex call. If the timeout
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occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
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The futex operation are issues with cancellable versions. */
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#define lll_wait_tid(tid, abstime) \
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({ \
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int __res = 0; \
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__typeof (tid) __tid; \
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if (abstime != NULL) \
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__res = __lll_timedwait_tid (&(tid), (abstime)); \
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else \
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/* We need acquire MO here so that we synchronize with the \
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kernel's store to 0 when the clone terminates. (see above) */ \
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while ((__tid = atomic_load_acquire (&(tid))) != 0) \
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lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED); \
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__res; \
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})
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extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
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attribute_hidden;
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extern int __lll_unlock_elision (int *lock, int private)
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attribute_hidden;
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extern int __lll_trylock_elision (int *lock, short *adapt_count)
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attribute_hidden;
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#define lll_lock_elision(futex, adapt_count, private) \
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__lll_lock_elision (&(futex), &(adapt_count), private)
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#define lll_unlock_elision(futex, adapt_count, private) \
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__lll_unlock_elision (&(futex), private)
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#define lll_trylock_elision(futex, adapt_count) \
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__lll_trylock_elision (&(futex), &(adapt_count))
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#endif /* !__ASSEMBLER__ */
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#endif /* lowlevellock.h */
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