[src/trunk]: src/lib/libpthread Change the behavior of pthread_equal()

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4b062fbe6c9c
branches:  trunk
changeset: 744639:4b062fbe6c9c
user:      kamil <kamil%NetBSD.org@localhost>
date:      Sat Feb 08 17:06:03 2020 +0000

description:
Change the behavior of pthread_equal()

On error when not aborting, do not return EINVAL as it has a side effect
of being interpreted as matching threads. For invalid threads return
unmatched.

Check pthreads for NULL, before accessing pt_magic field. This avoids
faults on comparision with a NULL pointer.

This behavior is in the scope of UB, but should be easier to deal with
buggy software.

diffstat:

 lib/libpthread/pthread.c |  12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diffs (34 lines):

diff -r c4648db21980 -r 4b062fbe6c9c lib/libpthread/pthread.c
--- a/lib/libpthread/pthread.c  Sat Feb 08 14:35:47 2020 +0000
+++ b/lib/libpthread/pthread.c  Sat Feb 08 17:06:03 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread.c,v 1.163 2020/02/05 14:56:04 ryoon Exp $      */
+/*     $NetBSD: pthread.c,v 1.164 2020/02/08 17:06:03 kamil Exp $      */
 
 /*-
  * Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008, 2020
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread.c,v 1.163 2020/02/05 14:56:04 ryoon Exp $");
+__RCSID("$NetBSD: pthread.c,v 1.164 2020/02/08 17:06:03 kamil Exp $");
 
 #define        __EXPOSE_STACK  1
 
@@ -770,11 +770,11 @@
        if (__predict_false(__uselibcstub))
                return __libc_thr_equal_stub(t1, t2);
 
-       pthread__error(EINVAL, "Invalid thread",
-           t1->pt_magic == PT_MAGIC);
+       pthread__error(0, "Invalid thread",
+           (t1 != NULL) && (t1->pt_magic == PT_MAGIC));
 
-       pthread__error(EINVAL, "Invalid thread",
-           t2->pt_magic == PT_MAGIC);
+       pthread__error(0, "Invalid thread",
+           (t2 != NULL) && (t2->pt_magic == PT_MAGIC));
 
        /* Nothing special here. */
        return (t1 == t2);