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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
commit | 73df946d56c74384511a194dd01dbe099584fd1a (patch) | |
tree | fd0bcea490dd81327ddfbb31e215439672c9a068 /src/runtime/runtime1.go | |
parent | Initial commit. (diff) | |
download | golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip |
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/runtime/runtime1.go')
-rw-r--r-- | src/runtime/runtime1.go | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/src/runtime/runtime1.go b/src/runtime/runtime1.go new file mode 100644 index 0000000..30b7044 --- /dev/null +++ b/src/runtime/runtime1.go @@ -0,0 +1,544 @@ +// Copyright 2009 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. + +package runtime + +import ( + "internal/bytealg" + "runtime/internal/atomic" + "runtime/internal/sys" + "unsafe" +) + +// Keep a cached value to make gotraceback fast, +// since we call it on every call to gentraceback. +// The cached value is a uint32 in which the low bits +// are the "crash" and "all" settings and the remaining +// bits are the traceback value (0 off, 1 on, 2 include system). +const ( + tracebackCrash = 1 << iota + tracebackAll + tracebackShift = iota +) + +var traceback_cache uint32 = 2 << tracebackShift +var traceback_env uint32 + +// gotraceback returns the current traceback settings. +// +// If level is 0, suppress all tracebacks. +// If level is 1, show tracebacks, but exclude runtime frames. +// If level is 2, show tracebacks including runtime frames. +// If all is set, print all goroutine stacks. Otherwise, print just the current goroutine. +// If crash is set, crash (core dump, etc) after tracebacking. +// +//go:nosplit +func gotraceback() (level int32, all, crash bool) { + _g_ := getg() + t := atomic.Load(&traceback_cache) + crash = t&tracebackCrash != 0 + all = _g_.m.throwing > 0 || t&tracebackAll != 0 + if _g_.m.traceback != 0 { + level = int32(_g_.m.traceback) + } else { + level = int32(t >> tracebackShift) + } + return +} + +var ( + argc int32 + argv **byte +) + +// nosplit for use in linux startup sysargs +//go:nosplit +func argv_index(argv **byte, i int32) *byte { + return *(**byte)(add(unsafe.Pointer(argv), uintptr(i)*sys.PtrSize)) +} + +func args(c int32, v **byte) { + argc = c + argv = v + sysargs(c, v) +} + +func goargs() { + if GOOS == "windows" { + return + } + argslice = make([]string, argc) + for i := int32(0); i < argc; i++ { + argslice[i] = gostringnocopy(argv_index(argv, i)) + } +} + +func goenvs_unix() { + // TODO(austin): ppc64 in dynamic linking mode doesn't + // guarantee env[] will immediately follow argv. Might cause + // problems. + n := int32(0) + for argv_index(argv, argc+1+n) != nil { + n++ + } + + envs = make([]string, n) + for i := int32(0); i < n; i++ { + envs[i] = gostring(argv_index(argv, argc+1+i)) + } +} + +func environ() []string { + return envs +} + +// TODO: These should be locals in testAtomic64, but we don't 8-byte +// align stack variables on 386. +var test_z64, test_x64 uint64 + +func testAtomic64() { + test_z64 = 42 + test_x64 = 0 + if atomic.Cas64(&test_z64, test_x64, 1) { + throw("cas64 failed") + } + if test_x64 != 0 { + throw("cas64 failed") + } + test_x64 = 42 + if !atomic.Cas64(&test_z64, test_x64, 1) { + throw("cas64 failed") + } + if test_x64 != 42 || test_z64 != 1 { + throw("cas64 failed") + } + if atomic.Load64(&test_z64) != 1 { + throw("load64 failed") + } + atomic.Store64(&test_z64, (1<<40)+1) + if atomic.Load64(&test_z64) != (1<<40)+1 { + throw("store64 failed") + } + if atomic.Xadd64(&test_z64, (1<<40)+1) != (2<<40)+2 { + throw("xadd64 failed") + } + if atomic.Load64(&test_z64) != (2<<40)+2 { + throw("xadd64 failed") + } + if atomic.Xchg64(&test_z64, (3<<40)+3) != (2<<40)+2 { + throw("xchg64 failed") + } + if atomic.Load64(&test_z64) != (3<<40)+3 { + throw("xchg64 failed") + } +} + +func check() { + var ( + a int8 + b uint8 + c int16 + d uint16 + e int32 + f uint32 + g int64 + h uint64 + i, i1 float32 + j, j1 float64 + k unsafe.Pointer + l *uint16 + m [4]byte + ) + type x1t struct { + x uint8 + } + type y1t struct { + x1 x1t + y uint8 + } + var x1 x1t + var y1 y1t + + if unsafe.Sizeof(a) != 1 { + throw("bad a") + } + if unsafe.Sizeof(b) != 1 { + throw("bad b") + } + if unsafe.Sizeof(c) != 2 { + throw("bad c") + } + if unsafe.Sizeof(d) != 2 { + throw("bad d") + } + if unsafe.Sizeof(e) != 4 { + throw("bad e") + } + if unsafe.Sizeof(f) != 4 { + throw("bad f") + } + if unsafe.Sizeof(g) != 8 { + throw("bad g") + } + if unsafe.Sizeof(h) != 8 { + throw("bad h") + } + if unsafe.Sizeof(i) != 4 { + throw("bad i") + } + if unsafe.Sizeof(j) != 8 { + throw("bad j") + } + if unsafe.Sizeof(k) != sys.PtrSize { + throw("bad k") + } + if unsafe.Sizeof(l) != sys.PtrSize { + throw("bad l") + } + if unsafe.Sizeof(x1) != 1 { + throw("bad unsafe.Sizeof x1") + } + if unsafe.Offsetof(y1.y) != 1 { + throw("bad offsetof y1.y") + } + if unsafe.Sizeof(y1) != 2 { + throw("bad unsafe.Sizeof y1") + } + + if timediv(12345*1000000000+54321, 1000000000, &e) != 12345 || e != 54321 { + throw("bad timediv") + } + + var z uint32 + z = 1 + if !atomic.Cas(&z, 1, 2) { + throw("cas1") + } + if z != 2 { + throw("cas2") + } + + z = 4 + if atomic.Cas(&z, 5, 6) { + throw("cas3") + } + if z != 4 { + throw("cas4") + } + + z = 0xffffffff + if !atomic.Cas(&z, 0xffffffff, 0xfffffffe) { + throw("cas5") + } + if z != 0xfffffffe { + throw("cas6") + } + + m = [4]byte{1, 1, 1, 1} + atomic.Or8(&m[1], 0xf0) + if m[0] != 1 || m[1] != 0xf1 || m[2] != 1 || m[3] != 1 { + throw("atomicor8") + } + + m = [4]byte{0xff, 0xff, 0xff, 0xff} + atomic.And8(&m[1], 0x1) + if m[0] != 0xff || m[1] != 0x1 || m[2] != 0xff || m[3] != 0xff { + throw("atomicand8") + } + + *(*uint64)(unsafe.Pointer(&j)) = ^uint64(0) + if j == j { + throw("float64nan") + } + if !(j != j) { + throw("float64nan1") + } + + *(*uint64)(unsafe.Pointer(&j1)) = ^uint64(1) + if j == j1 { + throw("float64nan2") + } + if !(j != j1) { + throw("float64nan3") + } + + *(*uint32)(unsafe.Pointer(&i)) = ^uint32(0) + if i == i { + throw("float32nan") + } + if i == i { + throw("float32nan1") + } + + *(*uint32)(unsafe.Pointer(&i1)) = ^uint32(1) + if i == i1 { + throw("float32nan2") + } + if i == i1 { + throw("float32nan3") + } + + testAtomic64() + + if _FixedStack != round2(_FixedStack) { + throw("FixedStack is not power-of-2") + } + + if !checkASM() { + throw("assembly checks failed") + } +} + +type dbgVar struct { + name string + value *int32 +} + +// Holds variables parsed from GODEBUG env var, +// except for "memprofilerate" since there is an +// existing int var for that value, which may +// already have an initial value. +var debug struct { + cgocheck int32 + clobberfree int32 + efence int32 + gccheckmark int32 + gcpacertrace int32 + gcshrinkstackoff int32 + gcstoptheworld int32 + gctrace int32 + invalidptr int32 + madvdontneed int32 // for Linux; issue 28466 + scavenge int32 + scavtrace int32 + scheddetail int32 + schedtrace int32 + tracebackancestors int32 + asyncpreemptoff int32 + + // debug.malloc is used as a combined debug check + // in the malloc function and should be set + // if any of the below debug options is != 0. + malloc bool + allocfreetrace int32 + inittrace int32 + sbrk int32 +} + +var dbgvars = []dbgVar{ + {"allocfreetrace", &debug.allocfreetrace}, + {"clobberfree", &debug.clobberfree}, + {"cgocheck", &debug.cgocheck}, + {"efence", &debug.efence}, + {"gccheckmark", &debug.gccheckmark}, + {"gcpacertrace", &debug.gcpacertrace}, + {"gcshrinkstackoff", &debug.gcshrinkstackoff}, + {"gcstoptheworld", &debug.gcstoptheworld}, + {"gctrace", &debug.gctrace}, + {"invalidptr", &debug.invalidptr}, + {"madvdontneed", &debug.madvdontneed}, + {"sbrk", &debug.sbrk}, + {"scavenge", &debug.scavenge}, + {"scavtrace", &debug.scavtrace}, + {"scheddetail", &debug.scheddetail}, + {"schedtrace", &debug.schedtrace}, + {"tracebackancestors", &debug.tracebackancestors}, + {"asyncpreemptoff", &debug.asyncpreemptoff}, + {"inittrace", &debug.inittrace}, +} + +func parsedebugvars() { + // defaults + debug.cgocheck = 1 + debug.invalidptr = 1 + if GOOS == "linux" { + // On Linux, MADV_FREE is faster than MADV_DONTNEED, + // but doesn't affect many of the statistics that + // MADV_DONTNEED does until the memory is actually + // reclaimed. This generally leads to poor user + // experience, like confusing stats in top and other + // monitoring tools; and bad integration with + // management systems that respond to memory usage. + // Hence, default to MADV_DONTNEED. + debug.madvdontneed = 1 + } + + for p := gogetenv("GODEBUG"); p != ""; { + field := "" + i := bytealg.IndexByteString(p, ',') + if i < 0 { + field, p = p, "" + } else { + field, p = p[:i], p[i+1:] + } + i = bytealg.IndexByteString(field, '=') + if i < 0 { + continue + } + key, value := field[:i], field[i+1:] + + // Update MemProfileRate directly here since it + // is int, not int32, and should only be updated + // if specified in GODEBUG. + if key == "memprofilerate" { + if n, ok := atoi(value); ok { + MemProfileRate = n + } + } else { + for _, v := range dbgvars { + if v.name == key { + if n, ok := atoi32(value); ok { + *v.value = n + } + } + } + } + } + + debug.malloc = (debug.allocfreetrace | debug.inittrace | debug.sbrk) != 0 + + setTraceback(gogetenv("GOTRACEBACK")) + traceback_env = traceback_cache +} + +//go:linkname setTraceback runtime/debug.SetTraceback +func setTraceback(level string) { + var t uint32 + switch level { + case "none": + t = 0 + case "single", "": + t = 1 << tracebackShift + case "all": + t = 1<<tracebackShift | tracebackAll + case "system": + t = 2<<tracebackShift | tracebackAll + case "crash": + t = 2<<tracebackShift | tracebackAll | tracebackCrash + default: + t = tracebackAll + if n, ok := atoi(level); ok && n == int(uint32(n)) { + t |= uint32(n) << tracebackShift + } + } + // when C owns the process, simply exit'ing the process on fatal errors + // and panics is surprising. Be louder and abort instead. + if islibrary || isarchive { + t |= tracebackCrash + } + + t |= traceback_env + + atomic.Store(&traceback_cache, t) +} + +// Poor mans 64-bit division. +// This is a very special function, do not use it if you are not sure what you are doing. +// int64 division is lowered into _divv() call on 386, which does not fit into nosplit functions. +// Handles overflow in a time-specific manner. +// This keeps us within no-split stack limits on 32-bit processors. +//go:nosplit +func timediv(v int64, div int32, rem *int32) int32 { + res := int32(0) + for bit := 30; bit >= 0; bit-- { + if v >= int64(div)<<uint(bit) { + v = v - (int64(div) << uint(bit)) + // Before this for loop, res was 0, thus all these + // power of 2 increments are now just bitsets. + res |= 1 << uint(bit) + } + } + if v >= int64(div) { + if rem != nil { + *rem = 0 + } + return 0x7fffffff + } + if rem != nil { + *rem = int32(v) + } + return res +} + +// Helpers for Go. Must be NOSPLIT, must only call NOSPLIT functions, and must not block. + +//go:nosplit +func acquirem() *m { + _g_ := getg() + _g_.m.locks++ + return _g_.m +} + +//go:nosplit +func releasem(mp *m) { + _g_ := getg() + mp.locks-- + if mp.locks == 0 && _g_.preempt { + // restore the preemption request in case we've cleared it in newstack + _g_.stackguard0 = stackPreempt + } +} + +//go:linkname reflect_typelinks reflect.typelinks +func reflect_typelinks() ([]unsafe.Pointer, [][]int32) { + modules := activeModules() + sections := []unsafe.Pointer{unsafe.Pointer(modules[0].types)} + ret := [][]int32{modules[0].typelinks} + for _, md := range modules[1:] { + sections = append(sections, unsafe.Pointer(md.types)) + ret = append(ret, md.typelinks) + } + return sections, ret +} + +// reflect_resolveNameOff resolves a name offset from a base pointer. +//go:linkname reflect_resolveNameOff reflect.resolveNameOff +func reflect_resolveNameOff(ptrInModule unsafe.Pointer, off int32) unsafe.Pointer { + return unsafe.Pointer(resolveNameOff(ptrInModule, nameOff(off)).bytes) +} + +// reflect_resolveTypeOff resolves an *rtype offset from a base type. +//go:linkname reflect_resolveTypeOff reflect.resolveTypeOff +func reflect_resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer { + return unsafe.Pointer((*_type)(rtype).typeOff(typeOff(off))) +} + +// reflect_resolveTextOff resolves a function pointer offset from a base type. +//go:linkname reflect_resolveTextOff reflect.resolveTextOff +func reflect_resolveTextOff(rtype unsafe.Pointer, off int32) unsafe.Pointer { + return (*_type)(rtype).textOff(textOff(off)) + +} + +// reflectlite_resolveNameOff resolves a name offset from a base pointer. +//go:linkname reflectlite_resolveNameOff internal/reflectlite.resolveNameOff +func reflectlite_resolveNameOff(ptrInModule unsafe.Pointer, off int32) unsafe.Pointer { + return unsafe.Pointer(resolveNameOff(ptrInModule, nameOff(off)).bytes) +} + +// reflectlite_resolveTypeOff resolves an *rtype offset from a base type. +//go:linkname reflectlite_resolveTypeOff internal/reflectlite.resolveTypeOff +func reflectlite_resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer { + return unsafe.Pointer((*_type)(rtype).typeOff(typeOff(off))) +} + +// reflect_addReflectOff adds a pointer to the reflection offset lookup map. +//go:linkname reflect_addReflectOff reflect.addReflectOff +func reflect_addReflectOff(ptr unsafe.Pointer) int32 { + reflectOffsLock() + if reflectOffs.m == nil { + reflectOffs.m = make(map[int32]unsafe.Pointer) + reflectOffs.minv = make(map[unsafe.Pointer]int32) + reflectOffs.next = -1 + } + id, found := reflectOffs.minv[ptr] + if !found { + id = reflectOffs.next + reflectOffs.next-- // use negative offsets as IDs to aid debugging + reflectOffs.m[id] = ptr + reflectOffs.minv[ptr] = id + } + reflectOffsUnlock() + return id +} |