mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-12-13 10:46:33 +00:00
305 lines
6.9 KiB
Go
305 lines
6.9 KiB
Go
// Copyright 2023 The Libc Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
//go:build libc.membrk && !libc.memgrind && linux && (amd64 || arm64 || loong64)
|
|
|
|
// This is a debug-only version of the memory handling functions. When a
|
|
// program is built with -tags=libc.membrk a simple but safe version of malloc
|
|
// and friends is used that works like sbrk(2). Additionally free becomes a
|
|
// nop.
|
|
|
|
// The fixed heap is initially filled with random bytes from a full cycle PRNG,
|
|
// program startup time is substantially prolonged.
|
|
|
|
package libc // import "modernc.org/libc"
|
|
|
|
import (
|
|
"fmt"
|
|
"math"
|
|
"math/bits"
|
|
"runtime"
|
|
"strings"
|
|
"time"
|
|
"unsafe"
|
|
|
|
"modernc.org/mathutil"
|
|
)
|
|
|
|
const (
|
|
isMemBrk = true
|
|
|
|
heapSize = 1 << 30
|
|
)
|
|
|
|
var (
|
|
brkIndex uintptr
|
|
heap [heapSize]byte
|
|
heapP uintptr
|
|
heap0 uintptr
|
|
heapRecords []heapRecord
|
|
heapUsable = map[uintptr]Tsize_t{}
|
|
heapFree = map[uintptr]struct{}{}
|
|
rng *mathutil.FC32
|
|
)
|
|
|
|
type heapRecord struct {
|
|
p uintptr
|
|
pc uintptr
|
|
}
|
|
|
|
func (r *heapRecord) String() string {
|
|
return fmt.Sprintf("[p=%#0x usable=%v pc=%s]", r.p, Xmalloc_usable_size(nil, r.p), pc2origin(r.pc))
|
|
}
|
|
|
|
func init() {
|
|
if roundup(heapGuard, heapAlign) != heapGuard {
|
|
panic("internal error")
|
|
}
|
|
|
|
heap0 = uintptr(unsafe.Pointer(&heap[0]))
|
|
heapP = roundup(heap0, heapAlign)
|
|
var err error
|
|
if rng, err = mathutil.NewFC32(math.MinInt32, math.MaxInt32, true); err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
rng.Seed(time.Now().UnixNano())
|
|
for i := range heap {
|
|
heap[i] = byte(rng.Next())
|
|
}
|
|
}
|
|
|
|
func pc2origin(pc uintptr) string {
|
|
f := runtime.FuncForPC(pc)
|
|
var fn, fns string
|
|
var fl int
|
|
if f != nil {
|
|
fn, fl = f.FileLine(pc)
|
|
fns = f.Name()
|
|
if x := strings.LastIndex(fns, "."); x > 0 {
|
|
fns = fns[x+1:]
|
|
}
|
|
}
|
|
return fmt.Sprintf("%s:%d:%s", fn, fl, fns)
|
|
}
|
|
|
|
func malloc0(tls *TLS, pc uintptr, n0 Tsize_t, zero bool) (r uintptr) {
|
|
usable := roundup(uintptr(n0), heapAlign)
|
|
rq := usable + 2*heapGuard
|
|
if brkIndex+rq > uintptr(len(heap)) {
|
|
tls.setErrno(ENOMEM)
|
|
return 0
|
|
}
|
|
|
|
r, brkIndex = heapP+brkIndex, brkIndex+rq
|
|
heapRecords = append(heapRecords, heapRecord{p: r, pc: pc})
|
|
r += heapGuard
|
|
heapUsable[r] = Tsize_t(usable)
|
|
if zero {
|
|
n := uintptr(n0)
|
|
for i := uintptr(0); i < n; i++ {
|
|
*(*byte)(unsafe.Pointer(r + i)) = 0
|
|
}
|
|
}
|
|
return r
|
|
}
|
|
|
|
func Xmalloc(tls *TLS, n Tsize_t) (r uintptr) {
|
|
if __ccgo_strace {
|
|
trc("tls=%v n=%v, (%v:)", tls, n, origin(2))
|
|
defer func() { trc("-> %v", r) }()
|
|
}
|
|
|
|
if n > math.MaxInt {
|
|
tls.setErrno(ENOMEM)
|
|
return 0
|
|
}
|
|
|
|
if n == 0 {
|
|
// malloc(0) should return unique pointers
|
|
// (often expected and gnulib replaces malloc if malloc(0) returns 0)
|
|
n = 1
|
|
}
|
|
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
pc, _, _, _ := runtime.Caller(1)
|
|
return malloc0(tls, pc, n, false)
|
|
}
|
|
|
|
func Xcalloc(tls *TLS, m Tsize_t, n Tsize_t) (r uintptr) {
|
|
if __ccgo_strace {
|
|
trc("tls=%v m=%v n=%v, (%v:)", tls, m, n, origin(2))
|
|
defer func() { trc("-> %v", r) }()
|
|
}
|
|
|
|
hi, rq := bits.Mul(uint(m), uint(n))
|
|
if hi != 0 || rq > math.MaxInt {
|
|
tls.setErrno(ENOMEM)
|
|
return 0
|
|
}
|
|
|
|
if rq == 0 {
|
|
rq = 1
|
|
}
|
|
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
pc, _, _, _ := runtime.Caller(1)
|
|
return malloc0(tls, pc, Tsize_t(rq), true)
|
|
}
|
|
|
|
func Xrealloc(tls *TLS, p uintptr, n Tsize_t) (r uintptr) {
|
|
if __ccgo_strace {
|
|
trc("tls=%v p=%v n=%v, (%v:)", tls, p, n, origin(2))
|
|
defer func() { trc("-> %v", r) }()
|
|
}
|
|
|
|
if n == 0 {
|
|
Xfree(tls, p)
|
|
return 0
|
|
}
|
|
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
pc, _, _, _ := runtime.Caller(1)
|
|
if p == 0 {
|
|
return malloc0(tls, pc, n, false)
|
|
}
|
|
|
|
usable := heapUsable[p]
|
|
if usable == 0 {
|
|
panic(todo("realloc of unallocated memory: %#0x", p))
|
|
}
|
|
|
|
if usable >= n { // in place
|
|
return p
|
|
}
|
|
|
|
// malloc
|
|
r = malloc0(tls, pc, n, false)
|
|
copy(unsafe.Slice((*byte)(unsafe.Pointer(r)), usable), unsafe.Slice((*byte)(unsafe.Pointer(p)), usable))
|
|
Xfree(tls, p)
|
|
return r
|
|
}
|
|
|
|
func Xfree(tls *TLS, p uintptr) {
|
|
if __ccgo_strace {
|
|
trc("tls=%v p=%v, (%v:)", tls, p, origin(2))
|
|
}
|
|
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
if p == 0 {
|
|
return
|
|
}
|
|
|
|
if _, ok := heapUsable[p]; !ok {
|
|
panic(todo("free of unallocated memory: %#0x", p))
|
|
}
|
|
|
|
if _, ok := heapFree[p]; ok {
|
|
panic(todo("double free: %#0x", p))
|
|
}
|
|
|
|
heapFree[p] = struct{}{}
|
|
}
|
|
|
|
func Xmalloc_usable_size(tls *TLS, p uintptr) (r Tsize_t) {
|
|
if __ccgo_strace {
|
|
trc("tls=%v p=%v, (%v:)", tls, p, origin(2))
|
|
defer func() { trc("-> %v", r) }()
|
|
}
|
|
if p == 0 {
|
|
return 0
|
|
}
|
|
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
return heapUsable[p]
|
|
}
|
|
|
|
func MemAudit() (r []*MemAuditError) {
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
a := heapRecords
|
|
auditP := heap0
|
|
rng.Seek(0)
|
|
for _, v := range a {
|
|
heapP := v.p
|
|
mallocP := heapP + heapGuard
|
|
usable := heapUsable[mallocP]
|
|
for ; auditP < mallocP; auditP++ {
|
|
if g, e := *(*byte)(unsafe.Pointer(auditP)), byte(rng.Next()); g != e {
|
|
r = append(r, &MemAuditError{Caller: pc2origin(v.pc), Message: fmt.Sprintf("guard area before %#0x, %v is corrupted at %#0x, got %#02x, expected %#02x", mallocP, usable, auditP, g, e)})
|
|
}
|
|
}
|
|
for i := 0; Tsize_t(i) < usable; i++ {
|
|
rng.Next()
|
|
}
|
|
auditP = mallocP + uintptr(usable)
|
|
z := roundup(auditP, heapAlign)
|
|
z += heapGuard
|
|
for ; auditP < z; auditP++ {
|
|
if g, e := *(*byte)(unsafe.Pointer(auditP)), byte(rng.Next()); g != e {
|
|
r = append(r, &MemAuditError{Caller: pc2origin(v.pc), Message: fmt.Sprintf("guard area after %#0x, %v is corrupted at %#0x, got %#02x, expected %#02x", mallocP, usable, auditP, g, e)})
|
|
}
|
|
}
|
|
}
|
|
z := heap0 + uintptr(len(heap))
|
|
for ; auditP < z; auditP++ {
|
|
if g, e := *(*byte)(unsafe.Pointer(auditP)), byte(rng.Next()); g != e {
|
|
r = append(r, &MemAuditError{Caller: "-", Message: fmt.Sprintf("guard area after used heap is corrupted at %#0x, got %#02x, expected %#02x", auditP, g, e)})
|
|
return r // Report only the first fail
|
|
}
|
|
}
|
|
return r
|
|
}
|
|
|
|
func UsableSize(p uintptr) Tsize_t {
|
|
if p == 0 {
|
|
return 0
|
|
}
|
|
|
|
allocatorMu.Lock()
|
|
|
|
defer allocatorMu.Unlock()
|
|
|
|
return heapUsable[p]
|
|
}
|
|
|
|
// MemAuditStart locks the memory allocator, initializes and enables memory
|
|
// auditing. Finaly it unlocks the memory allocator.
|
|
//
|
|
// Some memory handling errors, like double free or freeing of unallocated
|
|
// memory, will panic when memory auditing is enabled.
|
|
//
|
|
// This memory auditing functionality has to be enabled using the libc.memgrind
|
|
// build tag.
|
|
//
|
|
// It is intended only for debug/test builds. It slows down memory allocation
|
|
// routines and it has additional memory costs.
|
|
func MemAuditStart() {}
|
|
|
|
// MemAuditReport locks the memory allocator, reports memory leaks, if any.
|
|
// Finally it disables memory auditing and unlocks the memory allocator.
|
|
//
|
|
// This memory auditing functionality has to be enabled using the libc.memgrind
|
|
// build tag.
|
|
//
|
|
// It is intended only for debug/test builds. It slows down memory allocation
|
|
// routines and it has additional memory costs.
|
|
func MemAuditReport() error { return nil }
|