xref: /third_party/musl/src/mman/mmap.c (revision 570af302)
1#include <unistd.h>
2#include <sys/mman.h>
3#include <errno.h>
4#include <stdint.h>
5#include <limits.h>
6#include "syscall.h"
7
8static void dummy(void) { }
9weak_alias(dummy, __vm_wait);
10
11#define UNIT SYSCALL_MMAP2_UNIT
12#define OFF_MASK ((-0x2000ULL << (8*sizeof(syscall_arg_t)-1)) | (UNIT-1))
13
14void *__mmap(void *start, size_t len, int prot, int flags, int fd, off_t off)
15{
16	long ret;
17	if (off & OFF_MASK) {
18		errno = EINVAL;
19		return MAP_FAILED;
20	}
21	if (len >= PTRDIFF_MAX) {
22		errno = ENOMEM;
23		return MAP_FAILED;
24	}
25	if (len == 0) {
26                errno = EINVAL;
27                return MAP_FAILED;
28	}
29	if (flags & MAP_FIXED) {
30		__vm_wait();
31	}
32#ifdef SYS_mmap2
33	ret = __syscall(SYS_mmap2, start, len, prot, flags, fd, off/UNIT);
34#else
35	ret = __syscall(SYS_mmap, start, len, prot, flags, fd, off);
36#endif
37	/* Fixup incorrect EPERM from kernel. */
38	if (ret == -EPERM && !start && (flags&MAP_ANON) && !(flags&MAP_FIXED))
39		ret = -ENOMEM;
40	return (void *)__syscall_ret(ret);
41}
42
43
44#ifdef HOOK_ENABLE
45void* __libc_mmap(void*, size_t, int, int, int, off_t);
46weak_alias(__mmap, __libc_mmap);
47weak_alias(__libc_mmap, mmap64);
48#else
49weak_alias(__mmap, mmap);
50weak_alias(mmap, mmap64);
51#endif // HOOK_ENABLE
52
53/*
54Adapter function for lldb to not deal with 64-bit arguments on 32-bit systems
55Issue I661Z1
56Test: Build and boot devices.
57*/
58void *__lldb_mmap(void *start, size_t len, int prot, int flags, int fd, intptr_t off) {
59	return mmap(start, len, prot, flags, fd, off);
60}
61