From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758134AbcFAMyP (ORCPT ); Wed, 1 Jun 2016 08:54:15 -0400 Received: from usplmg20.ericsson.net ([198.24.6.45]:56911 "EHLO usplmg20.ericsson.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752197AbcFAMyO (ORCPT ); Wed, 1 Jun 2016 08:54:14 -0400 X-AuditID: c618062d-f79886d000002334-64-574ed2020d49 Subject: Re: Possible race between PTRACE_SETVFPREGS and PTRACE_CONT on ARM? To: Russell King - ARM Linux References: <574C7CDB.7050103@ericsson.com> <20160530213529.GS19428@n2100.arm.linux.org.uk> CC: , From: Simon Marchi Organization: Ericsson AB Message-ID: <574EDAED.1050902@ericsson.com> Date: Wed, 1 Jun 2016 08:54:05 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <20160530213529.GS19428@n2100.arm.linux.org.uk> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrOLMWRmVeSWpSXmKPExsUyuXRPoC7TJb9wg65vNhabHl9jtbi8aw6b xaGpexkdmD0uX7vI7LF5Sb3H501yAcxRXDYpqTmZZalF+nYJXBl7z11hLzjIXrH7wG22BsYP rF2MnBwSAiYSXev7oGwxiQv31rOB2EICRxklZvXbdDFyAdnrGSWebTvOBJIQFvCR2HBkNyOI LQLUfOzgFxaIhliJLT17wWxmAS+J9yunMIPYbAJ6EvNW/wKr5xeQlNjQsBssziugLbHl9mWw ZSwCKhJrj00AqxEViJCYtf0HE0SNoMTJmU/AZnIK2EjM/rsfar6BxJFFc1ghbHmJ7W/nMEPc oCaxYvFClgmMQrOQtM9C0jILScsCRuZVjBylxQU5uelGBpsYgcF7TIJNdwfj/emehxgFOBiV eHgVLvqGC7EmlhVX5h5ilOBgVhLh3XzTL1yINyWxsiq1KD++qDQntfgQozQHi5I4r9gjxXAh gfTEktTs1NSC1CKYLBMHp1QD46Ezi9o+8ySuEW0Q+XbknYh7tX+B7KmLXt1cSj/EXjoclJPp tzpqJ7d2h3Pz26ZTh/ssGJs0fbpmvHp4jemZsuGu+j8WYmY9OeUmh3fviE9n9HToqIs6yNFp fSvnXSLTuhVrdXIiHuxPevR12X8Nc1vb3qbnbKcnC15e8mPT+RcCzHkV5zT6lFiKMxINtZiL ihMB9ChdHVoCAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16-05-30 05:35 PM, Russell King - ARM Linux wrote: > So, the gdb verisons I have here seem to be particularly poor - but with > some modifications, I can test out on iMX6 by forcing gdb to do the right > thing - by inserting a couple of "mov r0, r0" instructions after the > "break_here" label. I see that problem too with older versions, bisecting shows it has been fixed in commit 6e22494e5076 Do not skip prologue for asm (.S) files in gdb, which is included in gdb 7.10 and up. > With that, on a single CPU, it seems to work correctly every time, but > if I bring up a secondary CPU I start seeing the same problems you've > reported - which seems to need the following patch to solve. Please can > you check whether this resolves your problem? Yes that fixes the problem, the test case succeeds every time. I have stared at those lines in ptrace.c for some time, but couldn't find the problem. Thanks for looking into it!