1#include <unistd.h>
2#include <errno.h>
3#include "libc.h"
4#include "lock.h"
5#include "pthread_impl.h"
6#include "fork_impl.h"
7
8static volatile int *const dummy_lockptr = 0;
9
10weak_alias(dummy_lockptr, __at_quick_exit_lockptr);
11weak_alias(dummy_lockptr, __atexit_lockptr);
12weak_alias(dummy_lockptr, __gettext_lockptr);
13weak_alias(dummy_lockptr, __locale_lockptr);
14weak_alias(dummy_lockptr, __random_lockptr);
15weak_alias(dummy_lockptr, __sem_open_lockptr);
16weak_alias(dummy_lockptr, __stdio_ofl_lockptr);
17weak_alias(dummy_lockptr, __syslog_lockptr);
18weak_alias(dummy_lockptr, __timezone_lockptr);
19weak_alias(dummy_lockptr, __bump_lockptr);
20
21weak_alias(dummy_lockptr, __vmlock_lockptr);
22
23static volatile int *const *const atfork_locks[] = {
24 &__at_quick_exit_lockptr,
25 &__atexit_lockptr,
26 &__gettext_lockptr,
27 &__locale_lockptr,
28 &__random_lockptr,
29 &__sem_open_lockptr,
30 &__stdio_ofl_lockptr,
31 &__syslog_lockptr,
32 &__timezone_lockptr,
33 &__bump_lockptr,
34};
35
36static void dummy(int x) { }
37weak_alias(dummy, __fork_handler);
38weak_alias(dummy, __malloc_atfork);
39weak_alias(dummy, __aio_atfork);
40weak_alias(dummy, __pthread_key_atfork);
41weak_alias(dummy, __ldso_atfork);
42
43static void dummy_0(void) { }
44weak_alias(dummy_0, __tl_lock);
45weak_alias(dummy_0, __tl_unlock);
46
47pid_t fork(void)
48{
49 sigset_t set;
50 __fork_handler(-1);
51 __block_app_sigs(&set);
52 int need_locks = libc.need_locks > 0;
53 if (need_locks) {
54 __ldso_atfork(-1);
55 __pthread_key_atfork(-1);
56 __aio_atfork(-1);
57 __inhibit_ptc();
58 for (int i=0; i<sizeof atfork_locks/sizeof *atfork_locks; i++)
59 if (*atfork_locks[i]) LOCK(*atfork_locks[i]);
60 __malloc_atfork(-1);
61 __tl_lock();
62 }
63 pthread_t self=__pthread_self(), next=self->next;
64 pid_t ret = _Fork();
65 int errno_save = errno;
66 if (need_locks) {
67 if (!ret) {
68 for (pthread_t td=next; td!=self; td=td->next)
69 td->tid = -1;
70 if (__vmlock_lockptr) {
71 __vmlock_lockptr[0] = 0;
72 __vmlock_lockptr[1] = 0;
73 }
74 }
75 __tl_unlock();
76 __malloc_atfork(!ret);
77 for (int i=0; i<sizeof atfork_locks/sizeof *atfork_locks; i++)
78 if (*atfork_locks[i])
79 if (ret) UNLOCK(*atfork_locks[i]);
80 else **atfork_locks[i] = 0;
81 __release_ptc();
82 if (ret) __aio_atfork(0);
83 __pthread_key_atfork(!ret);
84 __ldso_atfork(!ret);
85 }
86 __restore_sigs(&set);
87 __fork_handler(!ret);
88 if (ret<0) errno = errno_save;
89 return ret;
90}