memory_linux.go RawHistoryFolder

1//go:build linux && (amd64 || arm64)
2
3package pam
4
5import (
6	"errors"
7	"strings"
8	"unsafe"
9)
10
11var ErrAllocation = errors.New("pam: native allocation failed")
12
13type nativeAllocator struct {
14	malloc func(uintptr) unsafe.Pointer
15	freeFn func(unsafe.Pointer)
16}
17
18// alloc returns zero-filled malloc-owned memory; free must come from the same
19// libc. Returning unsafe.Pointer directly avoids uintptr-to-pointer arithmetic.
20func (a *nativeAllocator) alloc(size uintptr) (unsafe.Pointer, error) {
21	p := a.malloc(size)
22	if p == nil {
23		return nil, ErrAllocation
24	}
25	clear(unsafe.Slice((*byte)(p), int(size)))
26	return p, nil
27}
28
29func (a *nativeAllocator) free(p unsafe.Pointer) { a.freeFn(p) }
30
31func nativeCString(a nativeMemory, text string) (unsafe.Pointer, error) {
32	if strings.ContainsRune(text, '\x00') {
33		return nil, ErrInvalidArgument
34	}
35	p, err := a.alloc(uintptr(len(text)) + 1)
36	if err != nil {
37		return nil, err
38	}
39	copy(unsafe.Slice((*byte)(p), len(text)+1), text)
40	return p, nil
41}