match glibc/lsb cancellation abi on i386

[musl] / src / thread / pthread_create.c

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index af6ccf0..9f22b4c 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -1,5 +1,10 @@
 #include "pthread_impl.h"
 
+#ifdef __pthread_unwind_next
+#undef __pthread_unwind_next
+#define __pthread_unwind_next __pthread_unwind_next_3
+#endif
+
 void __pthread_unwind_next(struct __ptcb *cb)
 {
        int i, j, not_finished;
@@ -10,9 +15,6 @@ void __pthread_unwind_next(struct __ptcb *cb)
        self = pthread_self();
        if (self->cancel) self->result = PTHREAD_CANCELLED;
 
-       if (!a_fetch_add(&libc.threads_minus_1, -1))
-               exit(0);
-
        LOCK(&self->exitlock);
 
        not_finished = self->tsd_used;
@@ -28,33 +30,48 @@ void __pthread_unwind_next(struct __ptcb *cb)
                }
        }
 
-       if (self->detached && self->map_base)
+       /* Mark this thread dead before decrementing count */
+       self->dead = 1;
+
+       if (!a_fetch_add(&libc.threads_minus_1, -1))
+               exit(0);
+
+       if (self->detached && self->map_base) {
+               syscall(__NR_rt_sigprocmask, SIG_BLOCK, (long)(uint64_t[1]){-1},0,8);
                __unmapself(self->map_base, self->map_size);
+       }
 
-       __syscall_exit(0);
+       syscall(SYS_exit, 0);
 }
 
 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 || (!self->cancelasync && !self->cancelpoint))
-               return;
-       docancel(self);
+       if (self->canceldisable) return;
+       if (self->cancelasync || (self->cancelpoint==1 && PC_AT_SYS(ctx)))
+               docancel(self);
 }
 
 static void cancelpt(int x)
 {
        struct pthread *self = __pthread_self();
        if (self->canceldisable) return;
-       self->cancelpoint = x;
-       if (self->cancel) docancel(self);
+       if ((self->cancelpoint+=x)==1 && x>=0 && self->cancel)
+               docancel(self);
 }
 
 /* "rsyscall" is a mechanism by which a thread can synchronously force all
@@ -73,9 +90,19 @@ static struct {
 
 static void rsyscall_handler(int sig, siginfo_t *si, void *ctx)
 {
-       if (rs.cnt == libc.threads_minus_1) return;
+       struct pthread *self = __pthread_self();
+
+       if (si->si_code > 0 || si->si_pid != self->pid ||
+               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);
+               return;
+       }
 
-       if (syscall6(rs.nr, rs.arg[0], rs.arg[1], rs.arg[2],
+       if (syscall(rs.nr, rs.arg[0], rs.arg[1], rs.arg[2],
                rs.arg[3], rs.arg[4], rs.arg[5]) < 0 && !rs.err) rs.err=errno;
 
        a_inc(&rs.cnt);
@@ -124,7 +151,7 @@ static int rsyscall(int nr, long a, long b, long c, long d, long e, long f)
        while((i=rs.cnt)) __wait(&rs.cnt, 0, i, 1);
 
        if (rs.err) errno = rs.err, ret = -1;
-       else ret = syscall6(nr, a, b, c, d, e, f);
+       else ret = syscall(nr, a, b, c, d, e, f);
 
        UNLOCK(&rs.lock);
        return ret;
@@ -134,6 +161,7 @@ static void init_threads()
 {
        struct sigaction sa = { .sa_flags = SA_SIGINFO | SA_RESTART };
        libc.lock = __lock;
+       libc.lockfile = __lockfile;
        libc.cancelpt = cancelpt;
        libc.rsyscall = rsyscall;
        sa.sa_sigaction = cancel_handler;
@@ -173,12 +201,12 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
        if (!init && ++init) init_threads();
 
        if (!attr) attr = &default_attr;
-       guard = ROUND(attr->__guardsize + DEFAULT_GUARD_SIZE);
-       size = guard + ROUND(attr->__stacksize + DEFAULT_STACK_SIZE);
+       guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);
+       size = guard + ROUND(attr->_a_stacksize + DEFAULT_STACK_SIZE);
        size += __pthread_tsd_size;
        map = mmap(0, size, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANON, -1, 0);
        if (!map) return EAGAIN;
-       mprotect(map, guard, PROT_NONE);
+       if (guard) mprotect(map, guard, PROT_NONE);
 
        tsd = map + size - __pthread_tsd_size;
        new = (void *)(tsd - sizeof *new - PAGE_SIZE%sizeof *new);
@@ -190,7 +218,7 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
        new->start_arg = arg;
        new->self = new;
        new->tsd = (void *)tsd;
-       new->detached = attr->__detach;
+       new->detached = attr->_a_detach;
        new->attr = *attr;
        memcpy(new->tlsdesc, self->tlsdesc, sizeof new->tlsdesc);
        new->tlsdesc[1] = (uintptr_t)new;