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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A7C9BCCD19A for ; Mon, 17 Nov 2025 02:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Mime-Version:References:In-Reply-To:Message-Id:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=p3oKwKkWyG/vWyIwRaVTyBxc1jr/03v4pA2jr8mdbyo=; b=S5O+65rNFxXqbqejTMnhqvVzQU LwxpzQPqKp3yyTF32h/FJOO8LWwethPUlRld6pCh1ImnH9oeQwcbDAWl5/jgiWXKlrXo+zKgTiLuW ToO0aaZE8AuMVHza2AdMNJpNxQ2Mvpcnh+g/7TEDlDvReByGTMvNWivb3XmgXiM/S4VtuRNi3P9mJ WqRZqxBM4VVtdafmFAwHd82gN1AWkSN0WVCJPrTa7fVR8xEZ8hJi+pmnOjR+vKQLbbLcNP/WZORaB v5TFDlsDMvaTtvqlaN/ky20fu0LhwdlBBPw7V4jbaWcHYHKAoznsp4CKfeKBsI0BHf9RDGZGbXWol d6Y4mjuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vKpGF-0000000FK6z-3ick; Mon, 17 Nov 2025 02:46:35 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vKpGC-0000000FK6a-3e3m for linux-arm-kernel@lists.infradead.org; Mon, 17 Nov 2025 02:46:34 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 0634D4074F; Mon, 17 Nov 2025 02:46:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18A73C4CEF5; Mon, 17 Nov 2025 02:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763347590; bh=WckId20dWoL3Sm2pBxpsSPNRW6RlT7Dsm6IF/ZnMV/g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Jv4IAyaOD4AVcvfTrSXXHEBQWq8KCAZsS3yOCC2ZnSa5zb9dGp0KP5yw9+FkNhSXf Apxz61+p14sURJhwVI6iUiRc69h5MBTw5i3wWuyKrzbLN4uTEMYFBwVGt9ZDrXMmBi SOlUmJ3/3vhGqX0zd3OTjVJUj1eh8QAHYTlwh7xypVKk7iHspdR4kdfLvYbnsp4uoO edfQ44DEBLWhjcTRBMH8cJNNQA0o5WFGgn8/SdAfWOUFoNU60L+dBGgXjYpWjCpbL6 qf4fG0tQVBbmRJMWv+kTiO0SluBlkGhXpgd2qghlM1dcPcACURQ5U4Hp2qELemiAzO yey6qXzWDSfXg== Date: Mon, 17 Nov 2025 11:46:24 +0900 From: Masami Hiramatsu (Google) To: Will Deacon Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Steven Rostedt , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Mathieu Desnoyers , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/2] tracing/wprobe: Fix to avoid inifinite watchpoint exception on arm64 Message-Id: <20251117114624.5fc972e65edac5bb91caa4b2@kernel.org> In-Reply-To: References: <176179481538.959775.12326313742393696258.stgit@devnote2> <20251104223735.4164f224790ea0aea267dff1@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251116_184632_959913_14F04D9B X-CRM114-Status: GOOD ( 16.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 14 Nov 2025 16:17:06 +0000 Will Deacon wrote: > On Tue, Nov 04, 2025 at 10:37:35PM +0900, Masami Hiramatsu wrote: > > Gently ping. > > > > There is a bugfix (or strange behavior) on arm64 hw breakpoint but > > to fix it cleanly, it should change the perf itself (but I'm not > > sure why arm64 changes the behavior only for the default overflow > > handlers.) Anyone knows it? > > It's because GDB expects to handle the stepping itself when using the > ptrace interface (with a custom overflow handler to deliver SIGTRAP). Hmm, would you mean GDB for user program? If so, it expects hw breakpoint is used by: - user-space ptrace (for GDB) - kernel-space perf (must be default overflow handler) And not expects to be used by - kernel-space custom overflow handler This series is to handle the third use case. Thank you, -- Masami Hiramatsu (Google)