Re: CVS commit: src/lib/libpthread

[Ryo ONODERA <ryo%tetera.org@localhost>]

Hi,

I have two problematic pkgsrc packages at least.
Of course these programs have misuses and/or bugs, however I feel that
dealing pt_magic in pthread_equal() is too hasty for pkgsrc.

multimedia/handbrake (internal libbluray):
The invalid thread pointer is not NULL.
pthread_equal t1: 0xffffffffffffffff
pthread_equal t2: 0x7073b25e2000

Another one is lang/mono6:
The invalid thread pointer is not 0xffffffffffffffff.
pthread_equal t1: 0x7b066d4d7800
pthread_equal t2: 0x60f5f000

Of course, it is desirable to fix every misuses and bugs in pkgsrc.
However it is impossible for now (at least for me).

"Kamil Rytarowski" <kamil%netbsd.org@localhost> writes:

> Module Name:	src
> Committed By:	kamil
> Date:		Sat Feb  8 17:06:03 UTC 2020
>
> Modified Files:
> 	src/lib/libpthread: pthread.c
>
> Log Message:
> 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.
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.163 -r1.164 src/lib/libpthread/pthread.c
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>
> Modified files:
>
> Index: src/lib/libpthread/pthread.c
> diff -u src/lib/libpthread/pthread.c:1.163 src/lib/libpthread/pthread.c:1.164
> --- src/lib/libpthread/pthread.c:1.163	Wed Feb  5 14:56:04 2020
> +++ src/lib/libpthread/pthread.c	Sat Feb  8 17:06:03 2020
> @@ -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 @@ pthread_equal(pthread_t t1, pthread_t t2
>  	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);
>

-- 
Ryo ONODERA // ryo%tetera.org@localhost
PGP fingerprint = 82A2 DC91 76E0 A10A 8ABB  FD1B F404 27FA C7D1 15F3