2018-10-19 23:34:09 +00:00
|
|
|
// Copyright 2018 Google LLC
|
2018-04-27 17:37:02 +00:00
|
|
|
//
|
|
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
|
|
// you may not use this file except in compliance with the License.
|
|
|
|
// You may obtain a copy of the License at
|
|
|
|
//
|
|
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
//
|
|
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
|
|
// See the License for the specific language governing permissions and
|
|
|
|
// limitations under the License.
|
|
|
|
|
|
|
|
#include "textflag.h"
|
|
|
|
|
|
|
|
// handleSwapUint32Fault returns the value stored in DI. Control is transferred
|
|
|
|
// to it when swapUint32 below receives SIGSEGV or SIGBUS, with the signal
|
|
|
|
// number stored in DI.
|
|
|
|
//
|
|
|
|
// It must have the same frame configuration as swapUint32 so that it can undo
|
|
|
|
// any potential call frame set up by the assembler.
|
|
|
|
TEXT handleSwapUint32Fault(SB), NOSPLIT, $0-24
|
|
|
|
MOVL DI, sig+20(FP)
|
|
|
|
RET
|
|
|
|
|
|
|
|
// swapUint32 atomically stores new into *addr and returns (the previous *addr
|
|
|
|
// value, 0). If a SIGSEGV or SIGBUS signal is received during the swap, the
|
|
|
|
// value of old is unspecified, and sig is the number of the signal that was
|
|
|
|
// received.
|
|
|
|
//
|
|
|
|
// Preconditions: addr must be aligned to a 4-byte boundary.
|
|
|
|
//
|
|
|
|
//func swapUint32(ptr unsafe.Pointer, new uint32) (old uint32, sig int32)
|
|
|
|
TEXT ·swapUint32(SB), NOSPLIT, $0-24
|
|
|
|
// Store 0 as the returned signal number. If we run to completion,
|
|
|
|
// this is the value the caller will see; if a signal is received,
|
|
|
|
// handleSwapUint32Fault will store a different value in this address.
|
|
|
|
MOVL $0, sig+20(FP)
|
|
|
|
|
|
|
|
MOVQ addr+0(FP), DI
|
|
|
|
MOVL new+8(FP), AX
|
|
|
|
XCHGL AX, 0(DI)
|
|
|
|
MOVL AX, old+16(FP)
|
|
|
|
RET
|
|
|
|
|
|
|
|
// handleSwapUint64Fault returns the value stored in DI. Control is transferred
|
|
|
|
// to it when swapUint64 below receives SIGSEGV or SIGBUS, with the signal
|
|
|
|
// number stored in DI.
|
|
|
|
//
|
|
|
|
// It must have the same frame configuration as swapUint64 so that it can undo
|
|
|
|
// any potential call frame set up by the assembler.
|
|
|
|
TEXT handleSwapUint64Fault(SB), NOSPLIT, $0-28
|
|
|
|
MOVL DI, sig+24(FP)
|
|
|
|
RET
|
|
|
|
|
|
|
|
// swapUint64 atomically stores new into *addr and returns (the previous *addr
|
|
|
|
// value, 0). If a SIGSEGV or SIGBUS signal is received during the swap, the
|
|
|
|
// value of old is unspecified, and sig is the number of the signal that was
|
|
|
|
// received.
|
|
|
|
//
|
|
|
|
// Preconditions: addr must be aligned to a 8-byte boundary.
|
|
|
|
//
|
|
|
|
//func swapUint64(ptr unsafe.Pointer, new uint64) (old uint64, sig int32)
|
|
|
|
TEXT ·swapUint64(SB), NOSPLIT, $0-28
|
|
|
|
// Store 0 as the returned signal number. If we run to completion,
|
|
|
|
// this is the value the caller will see; if a signal is received,
|
|
|
|
// handleSwapUint64Fault will store a different value in this address.
|
|
|
|
MOVL $0, sig+24(FP)
|
|
|
|
|
|
|
|
MOVQ addr+0(FP), DI
|
|
|
|
MOVQ new+8(FP), AX
|
|
|
|
XCHGQ AX, 0(DI)
|
|
|
|
MOVQ AX, old+16(FP)
|
|
|
|
RET
|
|
|
|
|
|
|
|
// handleCompareAndSwapUint32Fault returns the value stored in DI. Control is
|
|
|
|
// transferred to it when swapUint64 below receives SIGSEGV or SIGBUS, with the
|
|
|
|
// signal number stored in DI.
|
|
|
|
//
|
|
|
|
// It must have the same frame configuration as compareAndSwapUint32 so that it
|
|
|
|
// can undo any potential call frame set up by the assembler.
|
|
|
|
TEXT handleCompareAndSwapUint32Fault(SB), NOSPLIT, $0-24
|
|
|
|
MOVL DI, sig+20(FP)
|
|
|
|
RET
|
|
|
|
|
|
|
|
// compareAndSwapUint32 is like sync/atomic.CompareAndSwapUint32, but returns
|
|
|
|
// (the value previously stored at addr, 0). If a SIGSEGV or SIGBUS signal is
|
|
|
|
// received during the operation, the value of prev is unspecified, and sig is
|
|
|
|
// the number of the signal that was received.
|
|
|
|
//
|
|
|
|
// Preconditions: addr must be aligned to a 4-byte boundary.
|
|
|
|
//
|
|
|
|
//func compareAndSwapUint32(ptr unsafe.Pointer, old, new uint32) (prev uint32, sig int32)
|
|
|
|
TEXT ·compareAndSwapUint32(SB), NOSPLIT, $0-24
|
|
|
|
// Store 0 as the returned signal number. If we run to completion, this is
|
|
|
|
// the value the caller will see; if a signal is received,
|
|
|
|
// handleCompareAndSwapUint32Fault will store a different value in this
|
|
|
|
// address.
|
|
|
|
MOVL $0, sig+20(FP)
|
|
|
|
|
|
|
|
MOVQ addr+0(FP), DI
|
|
|
|
MOVL old+8(FP), AX
|
|
|
|
MOVL new+12(FP), DX
|
|
|
|
LOCK
|
|
|
|
CMPXCHGL DX, 0(DI)
|
|
|
|
MOVL AX, prev+16(FP)
|
|
|
|
RET
|
2019-03-06 07:39:14 +00:00
|
|
|
|
|
|
|
// handleLoadUint32Fault returns the value stored in DI. Control is transferred
|
|
|
|
// to it when LoadUint32 below receives SIGSEGV or SIGBUS, with the signal
|
|
|
|
// number stored in DI.
|
|
|
|
//
|
|
|
|
// It must have the same frame configuration as loadUint32 so that it can undo
|
|
|
|
// any potential call frame set up by the assembler.
|
|
|
|
TEXT handleLoadUint32Fault(SB), NOSPLIT, $0-16
|
|
|
|
MOVL DI, sig+12(FP)
|
|
|
|
RET
|
|
|
|
|
|
|
|
// loadUint32 atomically loads *addr and returns it. If a SIGSEGV or SIGBUS
|
|
|
|
// signal is received, the value returned is unspecified, and sig is the number
|
|
|
|
// of the signal that was received.
|
|
|
|
//
|
|
|
|
// Preconditions: addr must be aligned to a 4-byte boundary.
|
|
|
|
//
|
|
|
|
//func loadUint32(ptr unsafe.Pointer) (val uint32, sig int32)
|
|
|
|
TEXT ·loadUint32(SB), NOSPLIT, $0-16
|
|
|
|
// Store 0 as the returned signal number. If we run to completion,
|
|
|
|
// this is the value the caller will see; if a signal is received,
|
|
|
|
// handleLoadUint32Fault will store a different value in this address.
|
|
|
|
MOVL $0, sig+12(FP)
|
|
|
|
|
|
|
|
MOVQ addr+0(FP), AX
|
|
|
|
MOVL (AX), BX
|
|
|
|
MOVL BX, val+8(FP)
|
|
|
|
RET
|