block all signals during rsyscall

[musl] / src / thread / pthread_create.c

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 9f22b4c..cdf36ff 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -1,5 +1,11 @@
 #include "pthread_impl.h"
 
+static void dummy_1(pthread_t self)
+{
+}
+weak_alias(dummy_1, __pthread_tsd_run_dtors);
+weak_alias(dummy_1, __sigtimer_handler);
+
 #ifdef __pthread_unwind_next
 #undef __pthread_unwind_next
 #define __pthread_unwind_next __pthread_unwind_next_3
@@ -7,28 +13,15 @@
 
 void __pthread_unwind_next(struct __ptcb *cb)
 {
-       int i, j, not_finished;
        pthread_t self;
 
        if (cb->__next) longjmp((void *)cb->__next->__jb, 1);
 
        self = pthread_self();
-       if (self->cancel) self->result = PTHREAD_CANCELLED;
 
        LOCK(&self->exitlock);
 
-       not_finished = self->tsd_used;
-       for (j=0; not_finished && j<PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
-               not_finished = 0;
-               for (i=0; i<PTHREAD_KEYS_MAX; i++) {
-                       if (self->tsd[i] && libc.tsd_keys[i]) {
-                               void *tmp = self->tsd[i];
-                               self->tsd[i] = 0;
-                               libc.tsd_keys[i](tmp);
-                               not_finished = 1;
-                       }
-               }
-       }
+       __pthread_tsd_run_dtors(self);
 
        /* Mark this thread dead before decrementing count */
        self->dead = 1;
@@ -47,22 +40,17 @@ void __pthread_unwind_next(struct __ptcb *cb)
 static void docancel(struct pthread *self)
 {
        struct __ptcb cb = { .__next = self->cancelbuf };
-       sigset_t set;
        self->canceldisable = 1;
        self->cancelasync = 0;
-       sigemptyset(&set);
-       sigaddset(&set, SIGCANCEL);
-       __libc_sigprocmask(SIG_UNBLOCK, &set, 0);
        __pthread_unwind_next(&cb);
 }
 
 static void cancel_handler(int sig, siginfo_t *si, void *ctx)
 {
        struct pthread *self = __pthread_self();
-       if (si->si_code > 0 || si->si_pid != self->pid) return;
-       self->cancel = 1;
-       if (self->canceldisable) return;
-       if (self->cancelasync || (self->cancelpoint==1 && PC_AT_SYS(ctx)))
+       if (si->si_code == SI_TIMER) __sigtimer_handler(self);
+       if (self->cancel && !self->canceldisable &&
+           (self->cancelasync || (self->cancelpoint==1 && PC_AT_SYS(ctx))))
                docancel(self);
 }
 
@@ -92,13 +80,12 @@ static void rsyscall_handler(int sig, siginfo_t *si, void *ctx)
 {
        struct pthread *self = __pthread_self();
 
-       if (si->si_code > 0 || si->si_pid != self->pid ||
-               rs.cnt == libc.threads_minus_1) return;
+       if (!rs.hold || rs.cnt == libc.threads_minus_1) return;
 
        /* Threads which have already decremented themselves from the
         * thread count must not increment rs.cnt or otherwise act. */
        if (self->dead) {
-               __wait(&rs.hold, 0, 1, 1);
+               sigfillset(&((ucontext_t *)ctx)->uc_sigmask);
                return;
        }
 
@@ -130,9 +117,9 @@ static int rsyscall(int nr, long a, long b, long c, long d, long e, long f)
        rs.arg[0] = a; rs.arg[1] = b;
        rs.arg[2] = c; rs.arg[3] = d;
        rs.arg[4] = d; rs.arg[5] = f;
-       rs.hold = 1;
        rs.err = 0;
        rs.cnt = 0;
+       rs.hold = 1;
 
        /* Dispatch signals until all threads respond */
        for (i=libc.threads_minus_1; i; i--)
@@ -164,18 +151,29 @@ static void init_threads()
        libc.lockfile = __lockfile;
        libc.cancelpt = cancelpt;
        libc.rsyscall = rsyscall;
+
+       sigfillset(&sa.sa_mask);
+       sa.sa_sigaction = rsyscall_handler;
+       __libc_sigaction(SIGSYSCALL, &sa, 0);
+
+       sigemptyset(&sa.sa_mask);
        sa.sa_sigaction = cancel_handler;
        __libc_sigaction(SIGCANCEL, &sa, 0);
+
        sigaddset(&sa.sa_mask, SIGSYSCALL);
        sigaddset(&sa.sa_mask, SIGCANCEL);
-       sa.sa_sigaction = rsyscall_handler;
-       __libc_sigaction(SIGSYSCALL, &sa, 0);
-       sigprocmask(SIG_UNBLOCK, &sa.sa_mask, 0);
+       __libc_sigprocmask(SIG_UNBLOCK, &sa.sa_mask, 0);
 }
 
 static int start(void *p)
 {
        struct pthread *self = p;
+       if (self->unblock_cancel) {
+               sigset_t set;
+               sigemptyset(&set);
+               sigaddset(&set, SIGCANCEL);
+               __libc_sigprocmask(SIG_UNBLOCK, &set, 0);
+       }
        pthread_exit(self->start(self->start_arg));
        return 0;
 }
@@ -220,6 +218,8 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
        new->tsd = (void *)tsd;
        new->detached = attr->_a_detach;
        new->attr = *attr;
+       new->unblock_cancel = self->cancel;
+       new->result = PTHREAD_CANCELED;
        memcpy(new->tlsdesc, self->tlsdesc, sizeof new->tlsdesc);
        new->tlsdesc[1] = (uintptr_t)new;
        stack = (void *)((uintptr_t)new-1 & ~(uintptr_t)15);