1 #define _GNU_SOURCE
2 #include <string.h>
3 #include "pthread_impl.h"
4 #include "syscall.h"
5
6 hidden long __cancel(), __syscall_cp_asm(), __syscall_cp_c();
7
__cancel()8 long __cancel()
9 {
10 pthread_t self = __pthread_self();
11 if (self->canceldisable == PTHREAD_CANCEL_ENABLE || self->cancelasync)
12 pthread_exit(PTHREAD_CANCELED);
13 self->canceldisable = PTHREAD_CANCEL_DISABLE;
14 return -ECANCELED;
15 }
16
17 long __syscall_cp_asm(volatile void *, syscall_arg_t,
18 syscall_arg_t, syscall_arg_t, syscall_arg_t,
19 syscall_arg_t, syscall_arg_t, syscall_arg_t);
20
__syscall_cp_c(syscall_arg_t nr,syscall_arg_t u,syscall_arg_t v,syscall_arg_t w,syscall_arg_t x,syscall_arg_t y,syscall_arg_t z)21 long __syscall_cp_c(syscall_arg_t nr,
22 syscall_arg_t u, syscall_arg_t v, syscall_arg_t w,
23 syscall_arg_t x, syscall_arg_t y, syscall_arg_t z)
24 {
25 pthread_t self;
26 long r;
27 int st;
28
29 if ((st=(self=__pthread_self())->canceldisable)
30 && (st==PTHREAD_CANCEL_DISABLE || nr==SYS_close))
31 return __syscall(nr, u, v, w, x, y, z);
32
33 r = __syscall_cp_asm(&self->cancel, nr, u, v, w, x, y, z);
34 if (r==-EINTR && nr!=SYS_close && self->cancel &&
35 self->canceldisable != PTHREAD_CANCEL_DISABLE)
36 r = __cancel();
37 return r;
38 }
39
_sigaddset(sigset_t * set,int sig)40 static void _sigaddset(sigset_t *set, int sig)
41 {
42 unsigned s = sig-1;
43 set->__bits[s/8/sizeof *set->__bits] |= 1UL<<(s&8*sizeof *set->__bits-1);
44 }
45
46 extern hidden const char __cp_begin[1], __cp_end[1], __cp_cancel[1];
47
cancel_handler(int sig,siginfo_t * si,void * ctx)48 static void cancel_handler(int sig, siginfo_t *si, void *ctx)
49 {
50 pthread_t self = __pthread_self();
51 a_barrier();
52 if (!self->cancel || self->canceldisable == PTHREAD_CANCEL_DISABLE) return;
53 if(self->cancelasync){
54 pthread_exit(PTHREAD_CANCELED);
55 }
56 }
57
__testcancel()58 void __testcancel()
59 {
60 pthread_t self = __pthread_self();
61 if (self->cancel && !self->canceldisable)
62 __cancel();
63 }
64
init_cancellation()65 static void init_cancellation()
66 {
67 struct sigaction sa = {
68 .sa_flags = SA_SIGINFO | SA_RESTART,
69 .sa_sigaction = cancel_handler
70 };
71 memset(&sa.sa_mask, -1, _NSIG/8);
72 __libc_sigaction(SIGCANCEL, &sa, 0);
73 }
74
pthread_cancel(pthread_t t)75 int pthread_cancel(pthread_t t)
76 {
77 static int init;
78 if (!init) {
79 init_cancellation();
80 init = 1;
81 }
82 a_store(&t->cancel, 1);
83 if (t == pthread_self()) {
84 if (t->canceldisable == PTHREAD_CANCEL_ENABLE && t->cancelasync)
85 pthread_exit(PTHREAD_CANCELED);
86 return 0;
87 }
88 return pthread_kill(t, SIGCANCEL);
89 }
90