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 X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24CDDC3F68F for ; Thu, 26 Dec 2019 02:45:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F152920828 for ; Thu, 26 Dec 2019 02:45:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577328354; bh=yv/C6ljrIx/+HyZFKoUjNShUUTPWwuzsvZUkhYKmp/U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=s0rhXCWHruSwds3cqO10z57AT4Sg4mJl2SYPTNEmrttbLUKhAoH6M1dvQnP9EVrAT i25SmrNwoFeLtGBU4CJOFhPYitJUGkzfhL8du5N7KnFdPcGhJ3qtH3sENaAZH4Ta3k fUchAqf+gtTSYXysNVhGzyNx4MROMJMpzO2tslHE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726933AbfLZCpx (ORCPT ); Wed, 25 Dec 2019 21:45:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:50342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726885AbfLZCpx (ORCPT ); Wed, 25 Dec 2019 21:45:53 -0500 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C0B762075B; Thu, 26 Dec 2019 02:45:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577328352; bh=yv/C6ljrIx/+HyZFKoUjNShUUTPWwuzsvZUkhYKmp/U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sw/DrybP2qxeugrbQatqVZwWIem16gtpKDpAM5KEYW+DDcj0+ciN5hUIHYRnqLMG4 a/xVf3l2RMRBwhyIDMOaGzjFMpQ0i0RUWT525uT2XvUNfe8fa5pLiSAQE5t3cFIH2i js6ogOvSBDDeV5fmYqrUHt/HX0INiiU73O+3rGow= Date: Thu, 26 Dec 2019 11:45:47 +0900 From: Masami Hiramatsu To: Jisheng Zhang Cc: Catalin Marinas , Will Deacon , Steven Rostedt , Ingo Molnar , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , Mark Rutland , Jonathan Corbet , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-doc@vger.kernel.org" Subject: Re: [PATCH v7 2/3] ftrace: introduce FTRACE_IP_EXTENSION Message-Id: <20191226114547.bb5bc2d5ae5ecf6290a90fa7@kernel.org> In-Reply-To: <20191225172836.7f381759@xhacker.debian> References: <20191225172625.69811b3e@xhacker.debian> <20191225172836.7f381759@xhacker.debian> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 25 Dec 2019 09:42:52 +0000 Jisheng Zhang wrote: > On some architectures, the DYNAMIC_FTRACE_WITH_REGS is implemented by > gcc's -fpatchable-function-entry option. Take arm64 for example, arm64 > makes use of GCC -fpatchable-function-entry=2 option to insert two > nops. When the function is traced, the first nop will be modified to > the LR saver, then the second nop to "bl ". we need to > update ftrace_location() to recognise these two instructions as being > part of ftrace. To do this, we introduce FTRACE_IP_EXTENSION to let > ftrace_location search IP, IP + FTRACE_IP_EXTENSION range. > Looks good to me. Reviewed-by: Masami Hiramatsu Thanks! > Signed-off-by: Jisheng Zhang > Suggested-by: Steven Rostedt (VMware) > --- > include/linux/ftrace.h | 4 ++++ > kernel/trace/ftrace.c | 2 +- > 2 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > index 7247d35c3d16..05a03b2a2f39 100644 > --- a/include/linux/ftrace.h > +++ b/include/linux/ftrace.h > @@ -20,6 +20,10 @@ > > #include > > +#ifndef FTRACE_IP_EXTENSION > +#define FTRACE_IP_EXTENSION 0 > +#endif > + > /* > * If the arch supports passing the variable contents of > * function_trace_op as the third parameter back from the > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index 74439ab5c2b6..a8cfea502369 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -1590,7 +1590,7 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end) > */ > unsigned long ftrace_location(unsigned long ip) > { > - return ftrace_location_range(ip, ip); > + return ftrace_location_range(ip, ip + FTRACE_IP_EXTENSION); > } > > /** > -- > 2.24.1 > -- Masami Hiramatsu