From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99CE9F50F; Mon, 10 Nov 2025 04:58:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762750728; cv=none; b=RLfNdHi73774F0LcfqeBLlGNUnGXN3i4i4sJ8EpmjcvFI7lAfZv6Ng4wBKnjctw+l0iOeymJCFGi05tq5RWIbBSReSeUKEV/hIgPNvMA/coIshgh2M/27gmzqbTo9QBMBJcAk235+8lElYV9VpPSeoeJ3oK4fIgA3zBOkQv9mKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762750728; c=relaxed/simple; bh=nphcQOI1kfRbhu/YEFcCiq+ww3xH/5WIF7mQO+nNk/s=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=ORucI6RfwuU7qMRtT3tpUeUvk7Tep6T7lBmY3ulPY1sdSIL6u9NMmYWEO5bJ53S1paK9leWCuW4ollmnqV7caaUl5deJR+/CeMZgAx4S8ioIy0v9LGkjLLecEwgIIyPMIJKoE9+cdOc+x21sZ4cvmSrz3OBR5GDYouMbqTl8WHE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mpeSBHUr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mpeSBHUr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1E88C4CEF5; Mon, 10 Nov 2025 04:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762750728; bh=nphcQOI1kfRbhu/YEFcCiq+ww3xH/5WIF7mQO+nNk/s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mpeSBHUrB/nAOomS9Mm987ApUXi1jovyAG4bwh99uEGzMB114QdOPyCRJQ9fuRbiy UbseNPen+CZyVShhms1MusQb73Tc3A1nNEtM0OqILMCVf0yx1zrsFwPYjIbKdvLMZd OkyB5VhJ1H55wWqlrAg7KcJELMO5u2v1DWbz26ILez61BWbKSmoqcaSGAg4YE5rPxS dHN0ZRmTThIuJ0cqZdxKsqG31LUYoUn6xR6Zb/wvxwiQngoWFlaKblpcwOG6wh4vwn Cf/7Qmi5D2h15g5XLyO0/gMlmPJOS7JKVtZJgfObUE+uF/8nGAtTwf4+LUjCDsYdaf Jqps5kxDE7Zsw== Date: Mon, 10 Nov 2025 13:58:44 +0900 From: Masami Hiramatsu (Google) To: Ingo Molnar , Will Deacon , Kyle Huey Cc: Peter Zijlstra , 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, Will Deacon , Catalin Marinas , linux-arm-kernel@lists.infradead.org, "Masami Hiramatsu (Google)" Subject: Re: [PATCH 0/2] tracing/wprobe: Fix to avoid inifinite watchpoint exception on arm64 Message-Id: <20251110135844.1c205d59be44d76169fc5e54@kernel.org> In-Reply-To: <176179481538.959775.12326313742393696258.stgit@devnote2> References: <176179481538.959775.12326313742393696258.stgit@devnote2> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Ingo, Will, Ping? I also found that Kyle made a change on this area recently. Thank you, On Thu, 30 Oct 2025 12:26:55 +0900 "Masami Hiramatsu (Google)" wrote: > Hi, > > Here are patches which fixes a wprobe bug reported by Mark Brown on > arm64[1]. The root cause was that the infinite watchpoint exception on > the same instruction, because arm64 watchpoint exception happens before > the memory access has done, it needs to configure a single-step after > calling overflow handler. It does that only for the default overflow > handlers, and not for custom overflow handler registered via > hw_breakpoint interface. > > [1] https://lore.kernel.org/all/aPvwGhMBJqMKcC9D@finisterre.sirena.org.uk/ > > To fix this issue, this series introduces default_overflow_compatible > flag in the perf_event and use it for identifying default overflow > handlers instead of checking handler functions everytime[1/2], and > set it in wprobe[2/2]. > > Thank you, > > --- > > Masami Hiramatsu (Google) (2): > perf: Introduce default_overflow_compatible flag > tracing: wprobe: Make wprobe_handler default overflow_handler compatible > > > include/linux/perf_event.h | 9 ++------- > kernel/events/core.c | 2 ++ > kernel/trace/trace_wprobe.c | 7 +++++++ > 3 files changed, 11 insertions(+), 7 deletions(-) > > -- > Masami Hiramatsu (Google) -- Masami Hiramatsu (Google)