Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751521AbaJRR7O (ORCPT ); Sat, 18 Oct 2014 13:59:14 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:48056 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751077AbaJRR7J (ORCPT ); Sat, 18 Oct 2014 13:59:09 -0400 Date: Sat, 18 Oct 2014 13:59:07 -0400 (EDT) Message-Id: <20141018.135907.356113264227709132.davem@davemloft.net> To: mroos@linux.ee Cc: iamjoonsoo.kim@lge.com, linux-kernel@vger.kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, akpm@linux-foundation.org, linux-mm@kvack.org, sparclinux@vger.kernel.org Subject: Re: unaligned accesses in SLAB etc. From: David Miller In-Reply-To: References: <20141016.162001.599580415052560455.davem@redhat.com> <20141016.165017.1151349565275102498.davem@davemloft.net> X-Mailer: Mew version 6.6 on Emacs 24.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Sat, 18 Oct 2014 10:59:09 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Meelis Roos Date: Fri, 17 Oct 2014 14:12:09 +0300 (EEST) > However, on top of mainline HEAD 3.17.0-09670-g0429fbc it explodes with > scheduler BUG - just reported to LKML + sched maintainers. task_stack_end_corrupted() cannot work properly on sparc64. It stores the magic value at "task_thread_info(p) + 1", but on sparc64 that's where we store the nested array of FPU register saves. In fact this facility could be corrupting FPU register state in certain circumstances. The current sparc64 design is intentional, the CPU stack grows down toward the thread_info, and the FPU stack saving area grows up from the end of thread_info. I don't want to define the array size of the fpregs save area explicitly and thereby placing an artificial limit there. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/