overhaul implementation-internal signal protections

[musl] / src / time / timer_create.c

diff --git a/src/time/timer_create.c b/src/time/timer_create.c
index c107e15..3bcfa95 100644 (file)
--- a/src/time/timer_create.c
+++ b/src/time/timer_create.c
@@ -21,22 +21,37 @@ weak_alias(dummy_1, __pthread_tsd_run_dtors);
 static void cleanup_fromsig(void *p)
 {
        pthread_t self = __pthread_self();
+       __pthread_tsd_run_dtors(self);
        self->cancel = 0;
        self->cancelbuf = 0;
-       __pthread_tsd_run_dtors(self);
+       self->canceldisable = 0;
+       self->cancelasync = 0;
+       self->unblock_cancel = 0;
        longjmp(p, 1);
 }
 
-void __sigtimer_handler(pthread_t self)
+static void timer_handler(int sig, siginfo_t *si, void *ctx)
 {
+       pthread_t self = __pthread_self();
        jmp_buf jb;
        void (*notify)(union sigval) = (void (*)(union sigval))self->start;
        union sigval val = { .sival_ptr = self->start_arg };
 
-       if (setjmp(jb)) return;
-       pthread_cleanup_push(cleanup_fromsig, jb);
-       notify(val);
-       pthread_cleanup_pop(0);
+       if (!setjmp(jb) && si->si_code == SI_TIMER) {
+               pthread_cleanup_push(cleanup_fromsig, jb);
+               notify(val);
+               pthread_cleanup_pop(0);
+       }
+}
+
+static void install_handler()
+{
+       struct sigaction sa = {
+               .sa_sigaction = timer_handler,
+               .sa_flags = SA_SIGINFO | SA_RESTART
+       };
+       __libc_sigaction(SIGTIMER, &sa, 0);
+       __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, &SIGTIMER_SET, 0, 8);
 }
 
 static void *start(void *arg)
@@ -58,6 +73,7 @@ static void *start(void *arg)
 
 int timer_create(clockid_t clk, struct sigevent *evp, timer_t *res)
 {
+       static pthread_once_t once = PTHREAD_ONCE_INIT;
        pthread_t td;
        pthread_attr_t attr;
        int r;
@@ -80,6 +96,7 @@ int timer_create(clockid_t clk, struct sigevent *evp, timer_t *res)
                *res = (void *)timerid;
                break;
        case SIGEV_THREAD:
+               pthread_once(&once, install_handler);
                if (evp->sigev_notify_attributes)
                        attr = *evp->sigev_notify_attributes;
                else
@@ -93,7 +110,7 @@ int timer_create(clockid_t clk, struct sigevent *evp, timer_t *res)
                        return -1;
                }
                ksev.sigev_value.sival_ptr = 0;
-               ksev.sigev_signo = SIGCANCEL;
+               ksev.sigev_signo = SIGTIMER;
                ksev.sigev_notify = 4; /* SIGEV_THREAD_ID */
                ksev.sigev_tid = td->tid;
                r = syscall(SYS_timer_create, clk, &ksev, &timerid);