- Pass a ucontext_t to _set_curthread. If non-NULL the new thread is set

  as curthread in the new context, so that it will be set automatically when
  the thread is switched to.  This fixes a race where we'd run for a little
  while with curthread unset in _thread_start.

Reviewed by:	jeff

3 files changed, 7 insertions, 7 deletions

diff --git a/lib/libthr/thread/thr_create.c b/lib/libthr/thread/thr_create.c
index 539a7c5..3ad7dc0 100644
--- a/lib/libthr/thread/thr_create.c
+++ b/lib/libthr/thread/thr_create.c
@@ -116,7 +116,8 @@ _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	getcontext(&new_thread->ctx);
 	new_thread->ctx.uc_stack.ss_sp = new_thread->stack;
 	new_thread->ctx.uc_stack.ss_size = pattr->stacksize_attr;
-	makecontext(&new_thread->ctx, _thread_start, 1, new_thread);
+	makecontext(&new_thread->ctx, _thread_start, 0);
+	new_thread->arch_id = _set_curthread(&new_thread->ctx, new_thread);
 
 	/* Copy the thread attributes: */
 	memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
@@ -208,12 +209,11 @@ _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 }
 
 void
-_thread_start(pthread_t thread)
+_thread_start(void)
 {
-	thread->arch_id = _set_curthread(thread);
 
 	/* Run the current thread's start routine with argument: */
-	pthread_exit(thread->start_routine(thread->arg));
+	pthread_exit(curthread->start_routine(curthread->arg));
 
 	/* This point should never be reached. */
 	PANIC("Thread has resumed after exit");
diff --git a/lib/libthr/thread/thr_init.c b/lib/libthr/thread/thr_init.c
index 6a6fd45..1a0c648 100644
--- a/lib/libthr/thread/thr_init.c
+++ b/lib/libthr/thread/thr_init.c
@@ -219,7 +219,7 @@ _thread_init(void)
 		PANIC("Cannot allocate memory for initial thread");
 	}
 	_thread_initial = pthread;
-	pthread->arch_id = _set_curthread(pthread);
+	pthread->arch_id = _set_curthread(NULL, pthread);
 
 	/* Zero the initial thread structure: */
 	memset(pthread, 0, sizeof(struct pthread));
diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h
index 7cc10e3..6399d21 100644
--- a/lib/libthr/thread/thr_private.h
+++ b/lib/libthr/thread/thr_private.h
@@ -686,7 +686,7 @@ char    *ttyname_r(int, char *, size_t);
 void	_cond_wait_backout(pthread_t);
 int     _find_thread(pthread_t);
 pthread_t _get_curthread(void);
-void	*_set_curthread(struct pthread *);
+void	*_set_curthread(ucontext_t *, struct pthread *);
 void	_retire_thread(void *arch_id);
 void	*_thread_stack_alloc(size_t, size_t);
 void	_thread_stack_free(void *, size_t, size_t);
@@ -720,7 +720,7 @@ void    _thread_dump_info(void);
 void    _thread_init(void);
 void	_thread_sig_wrapper(int sig, siginfo_t *info, ucontext_t *context);
 void	_thread_printf(int fd, const char *, ...);
-void    _thread_start(pthread_t);
+void    _thread_start(void);
 void	_thread_seterrno(pthread_t, int);
 pthread_addr_t _thread_gc(pthread_addr_t);
 void	_thread_enter_cancellation_point(void);