From: Ingo Molnar <mingo@elte.hu>
To: "Török Edwin" <edwintorok@gmail.com>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
LKML <linux-kernel@vger.kernel.org>,
Arjan van de Ven <arjan@infradead.org>
Subject: Re: Improve hackbench
Date: Fri, 4 Jan 2008 13:54:20 +0100 [thread overview]
Message-ID: <20080104125420.GA20981@elte.hu> (raw)
In-Reply-To: <477E1DC3.5020803@gmail.com>
* Török Edwin <edwintorok@gmail.com> wrote:
> On x86-64 there's a bug [*], that causes hackbench to segfault when
> compiled with optimizations:
> in reap_worker():
> int status;
> ...
> pthread_join(id, (void **)(void *)&status);
>
> That is not correct, sizeof(void*) > sizeof(int) on x86-64.
> Something gets overwritten on the stack, I tried with gcc
> -fstack-protector, but it doesn't detect it !?
> After applying the patch, it no longer segfaults.
>
> This patch fixes it:
> --- hackbench.c 2008-01-04 10:08:26.000000000 +0200
> +++ ../hackbench.c 2008-01-04 13:45:22.000000000 +0200
> @@ -241,8 +241,10 @@
> wait(&status);
> if (!WIFEXITED(status))
> exit(1);
> - } else
> - pthread_join(id, (void **)(void *)&status);
> + } else {
> + void* status;
> + pthread_join(id, (void **)&status);
> + }
> }
thanks, applied & updated the file.
Ingo
next prev parent reply other threads:[~2008-01-04 13:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-04 6:06 Improve hackbench Zhang, Yanmin
2008-01-04 8:10 ` Ingo Molnar
2008-01-04 11:51 ` Török Edwin
2008-01-04 12:54 ` Ingo Molnar [this message]
2008-01-07 1:10 ` Zhang, Yanmin
2008-01-04 12:44 ` Lee Revell
2008-01-07 1:27 ` Zhang, Yanmin
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