From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34DC6C77B73 for ; Sun, 23 Apr 2023 10:39:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229588AbjDWKjs (ORCPT ); Sun, 23 Apr 2023 06:39:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjDWKjq (ORCPT ); Sun, 23 Apr 2023 06:39:46 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2BE10E67; Sun, 23 Apr 2023 03:39:43 -0700 (PDT) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8AxJ_DuCkVkkAohAA--.51665S3; Sun, 23 Apr 2023 18:39:42 +0800 (CST) Received: from [10.130.0.149] (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8BxmrLqCkVkAcE2AA--.8595S3; Sun, 23 Apr 2023 18:39:38 +0800 (CST) Subject: Re: [PATCH] MIPS: uprobes: Restore thread.trap_nr To: Bagas Sanjaya , Thomas Bogendoerfer References: <1682213883-3654-1-git-send-email-yangtiezhu@loongson.cn> Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn, Oleg Nesterov , Srikar Dronamraju From: Tiezhu Yang Message-ID: Date: Sun, 23 Apr 2023 18:39:38 +0800 User-Agent: Mozilla/5.0 (X11; Linux mips64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID: AQAAf8BxmrLqCkVkAcE2AA--.8595S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoW7Aw1Utr1fCryxtFW7urWkXrb_yoW8GFyrpa 1DAws8KaykAa4UJayUJa18ZayYvrs5JrsxC3W7Ja4xZ3yqgFyqqFs29r42g3ZxWr1xtr1S q3W7ZFy2yayDA37anT9S1TB71UUUUUJqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU bS8YFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l n4kS14v26r1Y6r17M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6x ACxx1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y6r17McIj6I8E 87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lc7I2V7IY0V AS07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwCFI7km 07C267AKxVWUXVWUAwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r 1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWU JVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r 1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1U YxBIdaVFxhVjvjDU0xZFpf9x07jFa0PUUUUU= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cc: Oleg Nesterov Srikar Dronamraju On 04/23/2023 11:08 AM, Bagas Sanjaya wrote: > On Sun, Apr 23, 2023 at 09:38:03AM +0800, Tiezhu Yang wrote: >> thread.trap_nr is saved in arch_uprobe_pre_xol(), it should be restored >> in arch_uprobe_{post,abort}_xol() accordingly, actually it was only done >> in the post function, just do it in the abort function too, this change >> is similar with x86 and powerpc. > > I'm confused (please fix up grammar, spelling, and punctuation). Can you > explain why thread.trap_nr should be restored somewhere else? Also, what > x86/powerpc changes as reference? > Here is the related first commit for x86 in 2012: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0326f5a94dde When xol insn itself triggers the signal, restart the original insn, in this case, UTASK_SSTEP_TRAPPED is set [1], it does *abort_xol() instead of *post_xol() [2], then should do the restore operations. Maybe Oleg and Srikar could give more detailed backgrounds, thank you. https://lore.kernel.org/lkml/1682213883-3654-1-git-send-email-yangtiezhu@loongson.cn/ [1] https://elixir.bootlin.com/linux/latest/source/kernel/events/uprobes.c#L1980 [2] https://elixir.bootlin.com/linux/latest/source/kernel/events/uprobes.c#L2268 Thanks, Tiezhu