Use a Thread Information Block in both single and multi-threaded programs.

This stores errno, the cancelation flags, and related bits for each thread
and is allocated by ld.so or libc.a.  This is an ABI break from 5.9-stable!

Make libpthread dlopen'able by moving the cancelation wrappers into libc
and doing locking and fork/errno handling via callbacks that libpthread
registers when it first initializes.  'errno' *must* be declared via
<errno.h> now!

Clean up libpthread's symbol exports like libc.

On powerpc, offset the TIB/TCB/TLS data from the register per the ELF spec.

Testing by various, particularly sthen@ and patrick@
ok kettenis@

4 files changed, 22 insertions, 137 deletions

diff --git a/lib/libc/thread/Makefile.inc b/lib/libc/thread/Makefile.inc
index b5d3cb147dc..8c0cecf92d7 100644
--- a/lib/libc/thread/Makefile.inc
+++ b/lib/libc/thread/Makefile.inc
@@ -1,5 +1,5 @@
-#	$OpenBSD: Makefile.inc,v 1.9 2015/04/07 01:27:07 guenther Exp $
+#	$OpenBSD: Makefile.inc,v 1.10 2016/05/07 19:05:22 guenther Exp $
 
 .PATH: ${LIBCSRCDIR}/thread
 
-SRCS+=	unithread_malloc_lock.c unithread_mutex.c unithread_tag.c atfork.c
+SRCS+=	callbacks.c atfork.c
diff --git a/lib/libc/thread/unithread_mutex.c b/lib/libc/thread/callbacks.c
index 44009de7c01..c57a931b08c 100644
--- a/lib/libc/thread/unithread_mutex.c
+++ b/lib/libc/thread/callbacks.c
@@ -1,7 +1,5 @@
-/* $OpenBSD: unithread_mutex.c,v 1.1 2007/06/05 18:11:48 kurt Exp $ */
-
 /*
- * Copyright (c) 2007 Kurt Miller <kurt@openbsd.org>
+ * Copyright (c) 2014 Philip Guenther <guenther@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -16,34 +14,29 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include <sys/types.h>
+#include <stdio.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
 #include "thread_private.h"
 
-WEAK_PROTOTYPE(_thread_mutex_lock);
-WEAK_PROTOTYPE(_thread_mutex_unlock);
-WEAK_PROTOTYPE(_thread_mutex_destroy);
-
-WEAK_ALIAS(_thread_mutex_lock);
-WEAK_ALIAS(_thread_mutex_unlock);
-WEAK_ALIAS(_thread_mutex_destroy);
-
-/* ARGSUSED */
 void
-WEAK_NAME(_thread_mutex_lock)(void **mutex)
+_thread_set_callbacks(const struct thread_callbacks *cb, size_t len)
 {
-	return;
-}
+	sigset_t allmask, omask;
 
-/* ARGSUSED */
-void
-WEAK_NAME(_thread_mutex_unlock)(void **mutex)
-{
-	return;
-}
+	if (sizeof(*cb) != len) {
+		fprintf(stderr, "library mismatch: libc expected %z but"
+		    " libpthread gave %z\n", sizeof(*cb), len);
+		fflush(stderr);
+		_exit(44);
+	}
 
-/* ARGSUSED */
-void
-WEAK_NAME(_thread_mutex_destroy)(void **mutex)
-{
-	return;
+	sigfillset(&allmask);
+	if (sigprocmask(SIG_BLOCK, &allmask, &omask) == 0) {
+		/* mprotect RW */
+		memcpy(&_thread_cb, cb, sizeof(_thread_cb));
+		/* mprotect RO | LOCKPERM | NOUNMAP */
+		sigprocmask(SIG_SETMASK, &omask, NULL);
+	}
 }
diff --git a/lib/libc/thread/unithread_malloc_lock.c b/lib/libc/thread/unithread_malloc_lock.c
deleted file mode 100644
index d813bc708f2..00000000000
--- a/lib/libc/thread/unithread_malloc_lock.c
+++ /dev/null
@@ -1,76 +0,0 @@
-/*	$OpenBSD: unithread_malloc_lock.c,v 1.9 2015/04/07 01:27:07 guenther Exp $	*/
-
-#include <sys/time.h>
-#include "thread_private.h"
-
-WEAK_PROTOTYPE(_thread_malloc_lock);
-WEAK_PROTOTYPE(_thread_malloc_unlock);
-
-WEAK_ALIAS(_thread_malloc_lock);
-WEAK_ALIAS(_thread_malloc_unlock);
-
-WEAK_PROTOTYPE(_thread_atexit_lock);
-WEAK_PROTOTYPE(_thread_atexit_unlock);
-
-WEAK_ALIAS(_thread_atexit_lock);
-WEAK_ALIAS(_thread_atexit_unlock);
-
-WEAK_PROTOTYPE(_thread_atfork_lock);
-WEAK_PROTOTYPE(_thread_atfork_unlock);
-
-WEAK_ALIAS(_thread_atfork_lock);
-WEAK_ALIAS(_thread_atfork_unlock);
-
-WEAK_PROTOTYPE(_thread_arc4_lock);
-WEAK_PROTOTYPE(_thread_arc4_unlock);
-
-WEAK_ALIAS(_thread_arc4_lock);
-WEAK_ALIAS(_thread_arc4_unlock);
-
-void
-WEAK_NAME(_thread_malloc_lock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_malloc_unlock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_atexit_lock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_atexit_unlock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_atfork_lock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_atfork_unlock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_arc4_lock)(void)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_arc4_unlock)(void)
-{
-	return;
-}
diff --git a/lib/libc/thread/unithread_tag.c b/lib/libc/thread/unithread_tag.c
deleted file mode 100644
index c7ac928b994..00000000000
--- a/lib/libc/thread/unithread_tag.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/* $OpenBSD: unithread_tag.c,v 1.1 2004/06/07 21:11:23 marc Exp $ */
-
-/* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */
-
-#include <sys/time.h>
-#include "thread_private.h"
-
-WEAK_PROTOTYPE(_thread_tag_lock);
-WEAK_PROTOTYPE(_thread_tag_unlock);
-WEAK_PROTOTYPE(_thread_tag_storage);
-
-WEAK_ALIAS(_thread_tag_lock);
-WEAK_ALIAS(_thread_tag_unlock);
-WEAK_ALIAS(_thread_tag_storage);
-
-void
-WEAK_NAME(_thread_tag_lock)(void **tag)
-{
-	return;
-}
-
-void
-WEAK_NAME(_thread_tag_unlock)(void **tag)
-{
-	return;
-}
-
-void   *
-WEAK_NAME(_thread_tag_storage)(void **tag, void *init, size_t initsz, void *err)
-{
-	return init;
-}