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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 1CD89CA9EA0 for ; Tue, 22 Oct 2019 12:54:37 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E55082075A for ; Tue, 22 Oct 2019 12:54:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Hf/h9cH6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E55082075A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject: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=bSyXPCv+ZGjwHSlZEv71HhGPtwqHDFJq7N3FPWtO9Tk=; b=Hf/h9cH6qN3qNP rqoZEIqvCxhahiEdfD1ABFiu7I+Mmydk5xESFTwCVXD3FjhWnHHLoU8hEPj60Jtgje9w/XSpeq9gQ dC9ckG1yIkEHyGCephwIPUtyHzwNu+AD7GLzYb177k0yCeWV375a5UUWWa9+3ZzNBW9rsNiYMCipa Yyj0CT4mIlnU90uVrHwd/RsejxRfWmKCJKrFMAH7bKcItZng3ksek7RNJMaPOyxsu9LlK5PtpfoZW /1f9oN70qFUt6eZYV4h/x5tmY6X8XTzLzmK+YeDZQjEOob5kPpyA0VsgyZroeEEI2uNWZ+/T6LnDF UYAgogJGPT0IgKR9W8Yg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iMtgK-0006V6-Gh; Tue, 22 Oct 2019 12:54:36 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iMtgG-0006Tp-6F for linux-arm-kernel@lists.infradead.org; Tue, 22 Oct 2019 12:54:34 +0000 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 EC95C2075A; Tue, 22 Oct 2019 12:54:29 +0000 (UTC) Date: Tue, 22 Oct 2019 08:54:28 -0400 From: Steven Rostedt To: Mark Rutland Subject: Re: [PATCH 1/8] ftrace: add ftrace_init_nop() Message-ID: <20191022085428.75cfaad6@gandalf.local.home> In-Reply-To: <20191022112811.GA11583@lakrids.cambridge.arm.com> References: <20191021163426.9408-1-mark.rutland@arm.com> <20191021163426.9408-2-mark.rutland@arm.com> <20191021140756.613a1bac@gandalf.local.home> <20191022112811.GA11583@lakrids.cambridge.arm.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191022_055432_272029_A14C63B4 X-CRM114-Status: GOOD ( 22.39 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jthierry@redhat.com, will@kernel.org, ard.biesheuvel@linaro.org, peterz@infradead.org, catalin.marinas@arm.com, deller@gmx.de, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, takahiro.akashi@linaro.org, mingo@redhat.com, james.morse@arm.com, jeyu@kernel.org, amit.kachhap@arm.com, svens@stackframe.org, duwe@suse.de, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 22 Oct 2019 12:28:11 +0100 Mark Rutland wrote: > > To make the name even better, let's just rename it to: > > > > ftrace_nop_initialization() > > > > I think that may be the best description for it. > > Perhaps ftrace_nop_initialize(), so that it's not a noun? > > I've made it ftrace_nop_initialization() in my branch for now. I'm fine with ftrace_nop_initialize(). > > > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > > > index f296d89be757..afd7e210e595 100644 > > > --- a/kernel/trace/ftrace.c > > > +++ b/kernel/trace/ftrace.c > > > @@ -2493,15 +2493,22 @@ struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) > > > return &iter->pg->records[iter->index]; > > > } > > > > > > +#ifndef ftrace_init_nop > > > +static int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) > > > +{ > > > + return ftrace_make_nop(mod, rec, MCOUNT_ADDR); > > > +} > > > +#endif > > > > Can you place the above in the ftrace.h header. That's where that would > > belong. > > > > #ifndef ftrace_init_nop > > struct module; > > static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) > > { > > return ftrace_make_nop(mod, rec, MCOUNT_ADDR); > > } > > #endif > > True. > > I've put this immediately after ftrace_make_nop() in the header, and > given it a kerneldoc comment. There's a declaration for struct module at > the top of the header, so I've just relied on that > > That looks like: > > | /** > | * ftrace_init_nop - initialize a nop call site > | * @mod: module structure if called by module load initialization > | * @rec: the mcount call site record Perhaps say "mcount/fentry" > | * > | * This is a very sensitive operation and great care needs > | * to be taken by the arch. The operation should carefully > | * read the location, check to see if what is read is indeed > | * what we expect it to be, and then on success of the compare, > | * it should write to the location. > | * > | * The code segment at @rec->ip should be as initialized by the "should be as" is a bit confusing. What about? "The code segment at @rec->ip should contain the contents created by the compiler". -- Steve > | * compiler > | * > | * Return must be: > | * 0 on success > | * -EFAULT on error reading the location > | * -EINVAL on a failed compare of the contents > | * -EPERM on error writing to the location > | * Any other value will be considered a failure. > | */ > | #ifndef ftrace_init_nop > | static int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) > | { > | return ftrace_make_nop(mod, rec, MCOUNT_ADDR); > | } > | #endif > > Thanks, > Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel