status-go/vendor/modernc.org/libc/memgrind.go

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2022-03-10 09:44:48 +00:00
// Copyright 2021 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
// +build !libc.membrk,libc.memgrind
// This is a debug-only version of the memory handling functions. When a
// program is built with -tags=libc.memgrind the functions MemAuditStart and
// MemAuditReport can be used to check for memory leaks.
package libc // import "modernc.org/libc"
import (
"fmt"
"runtime"
"sort"
"strings"
"unsafe"
"modernc.org/libc/errno"
"modernc.org/libc/sys/types"
"modernc.org/memory"
)
const memgrind = true
type memReportItem struct {
p, pc uintptr
s string
}
func (it *memReportItem) String() string {
more := it.s
if more != "" {
a := strings.Split(more, "\n")
more = "\n\t\t" + strings.Join(a, "\n\t\t")
}
return fmt.Sprintf("\t%s: %#x%s", pc2origin(it.pc), it.p, more)
}
type memReport []memReportItem
func (r memReport) Error() string {
a := []string{"memory leaks"}
for _, v := range r {
a = append(a, v.String())
}
return strings.Join(a, "\n")
}
var (
allocator memory.Allocator
allocs map[uintptr]uintptr // addr: caller
allocsMore map[uintptr]string
frees map[uintptr]uintptr // addr: caller
memAudit memReport
memAuditEnabled bool
)
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)
}
// void *malloc(size_t size);
func Xmalloc(t *TLS, size types.Size_t) uintptr {
if size == 0 {
return 0
}
allocMu.Lock()
defer allocMu.Unlock()
p, err := allocator.UintptrCalloc(int(size))
if dmesgs {
dmesg("%v: %v -> %#x, %v", origin(1), size, p, err)
}
if err != nil {
t.setErrno(errno.ENOMEM)
return 0
}
if memAuditEnabled {
pc, _, _, ok := runtime.Caller(1)
if !ok {
panic("cannot obtain caller's PC")
}
delete(frees, p)
if pc0, ok := allocs[p]; ok {
dmesg("%v: malloc returns same address twice, previous call at %v:", pc2origin(pc), pc2origin(pc0))
panic(fmt.Errorf("%v: malloc returns same address twice, previous call at %v:", pc2origin(pc), pc2origin(pc0)))
}
allocs[p] = pc
}
return p
}
// void *calloc(size_t nmemb, size_t size);
func Xcalloc(t *TLS, n, size types.Size_t) uintptr {
rq := int(n * size)
if rq == 0 {
return 0
}
allocMu.Lock()
defer allocMu.Unlock()
p, err := allocator.UintptrCalloc(int(n * size))
if dmesgs {
dmesg("%v: %v -> %#x, %v", origin(1), n*size, p, err)
}
if err != nil {
t.setErrno(errno.ENOMEM)
return 0
}
if memAuditEnabled {
pc, _, _, ok := runtime.Caller(1)
if !ok {
panic("cannot obtain caller's PC")
}
delete(frees, p)
if pc0, ok := allocs[p]; ok {
dmesg("%v: calloc returns same address twice, previous call at %v:", pc2origin(pc), pc2origin(pc0))
panic(fmt.Errorf("%v: calloc returns same address twice, previous call at %v:", pc2origin(pc), pc2origin(pc0)))
}
allocs[p] = pc
}
return p
}
// void *realloc(void *ptr, size_t size);
func Xrealloc(t *TLS, ptr uintptr, size types.Size_t) uintptr {
allocMu.Lock()
defer allocMu.Unlock()
var pc uintptr
if memAuditEnabled {
var ok bool
if pc, _, _, ok = runtime.Caller(1); !ok {
panic("cannot obtain caller's PC")
}
if ptr != 0 {
if pc0, ok := frees[ptr]; ok {
dmesg("%v: realloc: double free of %#x, previous call at %v:", pc2origin(pc), ptr, pc2origin(pc0))
panic(fmt.Errorf("%v: realloc: double free of %#x, previous call at %v:", pc2origin(pc), ptr, pc2origin(pc0)))
}
if _, ok := allocs[ptr]; !ok {
dmesg("%v: %v: realloc, free of unallocated memory: %#x", origin(1), pc2origin(pc), ptr)
panic(fmt.Errorf("%v: realloc, free of unallocated memory: %#x", pc2origin(pc), ptr))
}
delete(allocs, ptr)
delete(allocsMore, ptr)
frees[ptr] = pc
}
}
p, err := allocator.UintptrRealloc(ptr, int(size))
if dmesgs {
dmesg("%v: %#x, %v -> %#x, %v", origin(1), ptr, size, p, err)
}
if err != nil {
t.setErrno(errno.ENOMEM)
return 0
}
if memAuditEnabled && p != 0 {
delete(frees, p)
if pc0, ok := allocs[p]; ok {
dmesg("%v: realloc returns same address twice, previous call at %v:", pc2origin(pc), pc2origin(pc0))
panic(fmt.Errorf("%v: realloc returns same address twice, previous call at %v:", pc2origin(pc), pc2origin(pc0)))
}
allocs[p] = pc
}
return p
}
// void free(void *ptr);
func Xfree(t *TLS, p uintptr) {
if p == 0 {
return
}
if dmesgs {
dmesg("%v: %#x", origin(1), p)
}
allocMu.Lock()
defer allocMu.Unlock()
sz := memory.UintptrUsableSize(p)
if memAuditEnabled {
pc, _, _, ok := runtime.Caller(1)
if !ok {
panic("cannot obtain caller's PC")
}
if pc0, ok := frees[p]; ok {
dmesg("%v: double free of %#x, previous call at %v:", pc2origin(pc), p, pc2origin(pc0))
panic(fmt.Errorf("%v: double free of %#x, previous call at %v:", pc2origin(pc), p, pc2origin(pc0)))
}
if _, ok := allocs[p]; !ok {
dmesg("%v: free of unallocated memory: %#x", pc2origin(pc), p)
panic(fmt.Errorf("%v: free of unallocated memory: %#x", pc2origin(pc), p))
}
delete(allocs, p)
delete(allocsMore, p)
frees[p] = pc
}
for i := uintptr(0); i < uintptr(sz); i++ {
*(*byte)(unsafe.Pointer(p + i)) = 0
}
allocator.UintptrFree(p)
}
func UsableSize(p uintptr) types.Size_t {
allocMu.Lock()
defer allocMu.Unlock()
if memAuditEnabled {
pc, _, _, ok := runtime.Caller(1)
if !ok {
panic("cannot obtain caller's PC")
}
if _, ok := allocs[p]; !ok {
dmesg("%v: usable size of unallocated memory: %#x", pc2origin(pc), p)
panic(fmt.Errorf("%v: usable size of unallocated memory: %#x", pc2origin(pc), p))
}
}
return types.Size_t(memory.UintptrUsableSize(p))
}
// MemAuditStart locks the memory allocator, initializes and enables memory
// auditing. Finally 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() {
allocMu.Lock()
defer allocMu.Unlock()
allocs = map[uintptr]uintptr{} // addr: caller
allocsMore = map[uintptr]string{}
frees = map[uintptr]uintptr{} // addr: caller
memAuditEnabled = true
}
// 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() (r error) {
allocMu.Lock()
defer func() {
allocs = nil
allocsMore = nil
frees = nil
memAuditEnabled = false
memAudit = nil
allocMu.Unlock()
}()
if len(allocs) != 0 {
for p, pc := range allocs {
memAudit = append(memAudit, memReportItem{p, pc, allocsMore[p]})
}
sort.Slice(memAudit, func(i, j int) bool {
return memAudit[i].String() < memAudit[j].String()
})
return memAudit
}
return nil
}
func MemAuditAnnotate(pc uintptr, s string) {
allocMu.Lock()
allocsMore[pc] = s
allocMu.Unlock()
}