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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build race
package runtime
import (
"unsafe"
)
// Public race detection API, present iff build with -race.
func RaceRead(addr unsafe.Pointer)
func RaceWrite(addr unsafe.Pointer)
func RaceReadRange(addr unsafe.Pointer, len int)
func RaceWriteRange(addr unsafe.Pointer, len int)
func RaceErrors() int {
var n uint64
racecall(&__tsan_report_count, uintptr(unsafe.Pointer(&n)), 0, 0, 0)
return int(n)
}
//go:nosplit
// RaceAcquire/RaceRelease/RaceReleaseMerge establish happens-before relations
// between goroutines. These inform the race detector about actual synchronization
// that it can't see for some reason (e.g. synchronization within RaceDisable/RaceEnable
// sections of code).
// RaceAcquire establishes a happens-before relation with the preceding
// RaceReleaseMerge on addr up to and including the last RaceRelease on addr.
// In terms of the C memory model (C11 §5.1.2.4, §7.17.3),
// RaceAcquire is equivalent to atomic_load(memory_order_acquire).
func RaceAcquire(addr unsafe.Pointer) {
raceacquire(addr)
}
//go:nosplit
// RaceRelease performs a release operation on addr that
// can synchronize with a later RaceAcquire on addr.
//
// In terms of the C memory model, RaceRelease is equivalent to
// atomic_store(memory_order_release).
func RaceRelease(addr unsafe.Pointer) {
racerelease(addr)
}
//go:nosplit
// RaceReleaseMerge is like RaceRelease, but also establishes a happens-before
// relation with the preceding RaceRelease or RaceReleaseMerge on addr.
//
// In terms of the C memory model, RaceReleaseMerge is equivalent to
// atomic_exchange(memory_order_release).
func RaceReleaseMerge(addr unsafe.Pointer) {
racereleasemerge(addr)
}
//go:nosplit
// RaceDisable disables handling of race synchronization events in the current goroutine.
// Handling is re-enabled with RaceEnable. RaceDisable/RaceEnable can be nested.
// Non-synchronization events (memory accesses, function entry/exit) still affect
// the race detector.
func RaceDisable() {
_g_ := getg()
if _g_.raceignore == 0 {
racecall(&__tsan_go_ignore_sync_begin, _g_.racectx, 0, 0, 0)
}
_g_.raceignore++
}
//go:nosplit
// RaceEnable re-enables handling of race events in the current goroutine.
func RaceEnable() {
_g_ := getg()
_g_.raceignore--
if _g_.raceignore == 0 {
racecall(&__tsan_go_ignore_sync_end, _g_.racectx, 0, 0, 0)
}
}
// Private interface for the runtime.
const raceenabled = true
// For all functions accepting callerpc and pc,
// callerpc is a return PC of the function that calls this function,
// pc is start PC of the function that calls this function.
func raceReadObjectPC(t *_type, addr unsafe.Pointer, callerpc, pc uintptr) {
kind := t.kind & kindMask
if kind == kindArray || kind == kindStruct {
// for composite objects we have to read every address
// because a write might happen to any subobject.
racereadrangepc(addr, t.size, callerpc, pc)
} else {
// for non-composite objects we can read just the start
// address, as any write must write the first byte.
racereadpc(addr, callerpc, pc)
}
}
func raceWriteObjectPC(t *_type, addr unsafe.Pointer, callerpc, pc uintptr) {
kind := t.kind & kindMask
if kind == kindArray || kind == kindStruct {
// for composite objects we have to write every address
// because a write might happen to any subobject.
racewriterangepc(addr, t.size, callerpc, pc)
} else {
// for non-composite objects we can write just the start
// address, as any write must write the first byte.
racewritepc(addr, callerpc, pc)
}
}
//go:noescape
func racereadpc(addr unsafe.Pointer, callpc, pc uintptr)
//go:noescape
func racewritepc(addr unsafe.Pointer, callpc, pc uintptr)
type symbolizeCodeContext struct {
pc uintptr
fn *byte
file *byte
line uintptr
off uintptr
res uintptr
}
var qq = [...]byte{'?', '?', 0}
var dash = [...]byte{'-', 0}
const (
raceGetProcCmd = iota
raceSymbolizeCodeCmd
raceSymbolizeDataCmd
)
// Callback from C into Go, runs on g0.
func racecallback(cmd uintptr, ctx unsafe.Pointer) {
switch cmd {
case raceGetProcCmd:
throw("should have been handled by racecallbackthunk")
case raceSymbolizeCodeCmd:
raceSymbolizeCode((*symbolizeCodeContext)(ctx))
case raceSymbolizeDataCmd:
raceSymbolizeData((*symbolizeDataContext)(ctx))
default:
throw("unknown command")
}
}
func raceSymbolizeCode(ctx *symbolizeCodeContext) {
f := FuncForPC(ctx.pc)
if f != nil {
file, line := f.FileLine(ctx.pc)
if line != 0 {
ctx.fn = cfuncname(f.funcInfo())
ctx.line = uintptr(line)
ctx.file = &bytes(file)[0] // assume NUL-terminated
ctx.off = ctx.pc - f.Entry()
ctx.res = 1
return
}
}
ctx.fn = &qq[0]
ctx.file = &dash[0]
ctx.line = 0
ctx.off = ctx.pc
ctx.res = 1
}
type symbolizeDataContext struct {
addr uintptr
heap uintptr
start uintptr
size uintptr
name *byte
file *byte
line uintptr
res uintptr
}
func raceSymbolizeData(ctx *symbolizeDataContext) {
if base, span, _ := findObject(ctx.addr, 0, 0); base != 0 {
ctx.heap = 1
ctx.start = base
ctx.size = span.elemsize
ctx.res = 1
}
}
// Race runtime functions called via runtime·racecall.
//go:linkname __tsan_init __tsan_init
var __tsan_init byte
//go:linkname __tsan_fini __tsan_fini
var __tsan_fini byte
//go:linkname __tsan_proc_create __tsan_proc_create
var __tsan_proc_create byte
//go:linkname __tsan_proc_destroy __tsan_proc_destroy
var __tsan_proc_destroy byte
//go:linkname __tsan_map_shadow __tsan_map_shadow
var __tsan_map_shadow byte
//go:linkname __tsan_finalizer_goroutine __tsan_finalizer_goroutine
var __tsan_finalizer_goroutine byte
//go:linkname __tsan_go_start __tsan_go_start
var __tsan_go_start byte
//go:linkname __tsan_go_end __tsan_go_end
var __tsan_go_end byte
//go:linkname __tsan_malloc __tsan_malloc
var __tsan_malloc byte
//go:linkname __tsan_free __tsan_free
var __tsan_free byte
//go:linkname __tsan_acquire __tsan_acquire
var __tsan_acquire byte
//go:linkname __tsan_release __tsan_release
var __tsan_release byte
//go:linkname __tsan_release_merge __tsan_release_merge
var __tsan_release_merge byte
//go:linkname __tsan_go_ignore_sync_begin __tsan_go_ignore_sync_begin
var __tsan_go_ignore_sync_begin byte
//go:linkname __tsan_go_ignore_sync_end __tsan_go_ignore_sync_end
var __tsan_go_ignore_sync_end byte
//go:linkname __tsan_report_count __tsan_report_count
var __tsan_report_count byte
// Mimic what cmd/cgo would do.
//go:cgo_import_static __tsan_init
//go:cgo_import_static __tsan_fini
//go:cgo_import_static __tsan_proc_create
//go:cgo_import_static __tsan_proc_destroy
//go:cgo_import_static __tsan_map_shadow
//go:cgo_import_static __tsan_finalizer_goroutine
//go:cgo_import_static __tsan_go_start
//go:cgo_import_static __tsan_go_end
//go:cgo_import_static __tsan_malloc
//go:cgo_import_static __tsan_free
//go:cgo_import_static __tsan_acquire
//go:cgo_import_static __tsan_release
//go:cgo_import_static __tsan_release_merge
//go:cgo_import_static __tsan_go_ignore_sync_begin
//go:cgo_import_static __tsan_go_ignore_sync_end
//go:cgo_import_static __tsan_report_count
// These are called from race_amd64.s.
//go:cgo_import_static __tsan_read
//go:cgo_import_static __tsan_read_pc
//go:cgo_import_static __tsan_read_range
//go:cgo_import_static __tsan_write
//go:cgo_import_static __tsan_write_pc
//go:cgo_import_static __tsan_write_range
//go:cgo_import_static __tsan_func_enter
//go:cgo_import_static __tsan_func_exit
//go:cgo_import_static __tsan_go_atomic32_load
//go:cgo_import_static __tsan_go_atomic64_load
//go:cgo_import_static __tsan_go_atomic32_store
//go:cgo_import_static __tsan_go_atomic64_store
//go:cgo_import_static __tsan_go_atomic32_exchange
//go:cgo_import_static __tsan_go_atomic64_exchange
//go:cgo_import_static __tsan_go_atomic32_fetch_add
//go:cgo_import_static __tsan_go_atomic64_fetch_add
//go:cgo_import_static __tsan_go_atomic32_compare_exchange
//go:cgo_import_static __tsan_go_atomic64_compare_exchange
// start/end of global data (data+bss).
var racedatastart uintptr
var racedataend uintptr
// start/end of heap for race_amd64.s
var racearenastart uintptr
var racearenaend uintptr
func racefuncenter(uintptr)
func racefuncenterfp()
func racefuncexit()
func racereadrangepc1(uintptr, uintptr, uintptr)
func racewriterangepc1(uintptr, uintptr, uintptr)
func racecallbackthunk(uintptr)
// racecall allows calling an arbitrary function f from C race runtime
// with up to 4 uintptr arguments.
func racecall(*byte, uintptr, uintptr, uintptr, uintptr)
// checks if the address has shadow (i.e. heap or data/bss)
//go:nosplit
func isvalidaddr(addr unsafe.Pointer) bool {
return racearenastart <= uintptr(addr) && uintptr(addr) < racearenaend ||
racedatastart <= uintptr(addr) && uintptr(addr) < racedataend
}
//go:nosplit
func raceinit() (gctx, pctx uintptr) {
// cgo is required to initialize libc, which is used by race runtime
if !iscgo {
throw("raceinit: race build must use cgo")
}
racecall(&__tsan_init, uintptr(unsafe.Pointer(&gctx)), uintptr(unsafe.Pointer(&pctx)), funcPC(racecallbackthunk), 0)
// Round data segment to page boundaries, because it's used in mmap().
start := ^uintptr(0)
end := uintptr(0)
if start > firstmoduledata.noptrdata {
start = firstmoduledata.noptrdata
}
if start > firstmoduledata.data {
start = firstmoduledata.data
}
if start > firstmoduledata.noptrbss {
start = firstmoduledata.noptrbss
}
if start > firstmoduledata.bss {
start = firstmoduledata.bss
}
if end < firstmoduledata.enoptrdata {
end = firstmoduledata.enoptrdata
}
if end < firstmoduledata.edata {
end = firstmoduledata.edata
}
if end < firstmoduledata.enoptrbss {
end = firstmoduledata.enoptrbss
}
if end < firstmoduledata.ebss {
end = firstmoduledata.ebss
}
size := round(end-start, _PageSize)
racecall(&__tsan_map_shadow, start, size, 0, 0)
racedatastart = start
racedataend = start + size
return
}
var raceFiniLock mutex
//go:nosplit
func racefini() {
// racefini() can only be called once to avoid races.
// This eventually (via __tsan_fini) calls C.exit which has
// undefined behavior if called more than once. If the lock is
// already held it's assumed that the first caller exits the program
// so other calls can hang forever without an issue.
lock(&raceFiniLock)
racecall(&__tsan_fini, 0, 0, 0, 0)
}
//go:nosplit
func raceproccreate() uintptr {
var ctx uintptr
racecall(&__tsan_proc_create, uintptr(unsafe.Pointer(&ctx)), 0, 0, 0)
return ctx
}
//go:nosplit
func raceprocdestroy(ctx uintptr) {
racecall(&__tsan_proc_destroy, ctx, 0, 0, 0)
}
//go:nosplit
func racemapshadow(addr unsafe.Pointer, size uintptr) {
if racearenastart == 0 {
racearenastart = uintptr(addr)
}
if racearenaend < uintptr(addr)+size {
racearenaend = uintptr(addr) + size
}
racecall(&__tsan_map_shadow, uintptr(addr), size, 0, 0)
}
//go:nosplit
func racemalloc(p unsafe.Pointer, sz uintptr) {
racecall(&__tsan_malloc, 0, 0, uintptr(p), sz)
}
//go:nosplit
func racefree(p unsafe.Pointer, sz uintptr) {
racecall(&__tsan_free, uintptr(p), sz, 0, 0)
}
//go:nosplit
func racegostart(pc uintptr) uintptr {
_g_ := getg()
var spawng *g
if _g_.m.curg != nil {
spawng = _g_.m.curg
} else {
spawng = _g_
}
var racectx uintptr
racecall(&__tsan_go_start, spawng.racectx, uintptr(unsafe.Pointer(&racectx)), pc, 0)
return racectx
}
//go:nosplit
func racegoend() {
racecall(&__tsan_go_end, getg().racectx, 0, 0, 0)
}
//go:nosplit
func racewriterangepc(addr unsafe.Pointer, sz, callpc, pc uintptr) {
_g_ := getg()
if _g_ != _g_.m.curg {
// The call is coming from manual instrumentation of Go code running on g0/gsignal.
// Not interesting.
return
}
if callpc != 0 {
racefuncenter(callpc)
}
racewriterangepc1(uintptr(addr), sz, pc)
if callpc != 0 {
racefuncexit()
}
}
//go:nosplit
func racereadrangepc(addr unsafe.Pointer, sz, callpc, pc uintptr) {
_g_ := getg()
if _g_ != _g_.m.curg {
// The call is coming from manual instrumentation of Go code running on g0/gsignal.
// Not interesting.
return
}
if callpc != 0 {
racefuncenter(callpc)
}
racereadrangepc1(uintptr(addr), sz, pc)
if callpc != 0 {
racefuncexit()
}
}
//go:nosplit
func raceacquire(addr unsafe.Pointer) {
raceacquireg(getg(), addr)
}
//go:nosplit
func raceacquireg(gp *g, addr unsafe.Pointer) {
if getg().raceignore != 0 || !isvalidaddr(addr) {
return
}
racecall(&__tsan_acquire, gp.racectx, uintptr(addr), 0, 0)
}
//go:nosplit
func racerelease(addr unsafe.Pointer) {
racereleaseg(getg(), addr)
}
//go:nosplit
func racereleaseg(gp *g, addr unsafe.Pointer) {
if getg().raceignore != 0 || !isvalidaddr(addr) {
return
}
racecall(&__tsan_release, gp.racectx, uintptr(addr), 0, 0)
}
//go:nosplit
func racereleasemerge(addr unsafe.Pointer) {
racereleasemergeg(getg(), addr)
}
//go:nosplit
func racereleasemergeg(gp *g, addr unsafe.Pointer) {
if getg().raceignore != 0 || !isvalidaddr(addr) {
return
}
racecall(&__tsan_release_merge, gp.racectx, uintptr(addr), 0, 0)
}
//go:nosplit
func racefingo() {
racecall(&__tsan_finalizer_goroutine, getg().racectx, 0, 0, 0)
}