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 63BA2EB64DD for ; Thu, 6 Jul 2023 04:36:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233045AbjGFEgi (ORCPT ); Thu, 6 Jul 2023 00:36:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjGFEgf (ORCPT ); Thu, 6 Jul 2023 00:36:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 549321BCE; Wed, 5 Jul 2023 21:36:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D7F2C6184A; Thu, 6 Jul 2023 04:36:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD284C433C8; Thu, 6 Jul 2023 04:36:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688618193; bh=AYmEf4kiL2UaxWitCr6OKYONu/l9HwO55saa1YDC5Y8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Gddoht5G/GUlhPxBTqrMlK5Oj7OiOV9NOdv1SyThjWB6I8cJQYLXAk2u374jXAtqk YbLmWyrMoOZdlr7m2lAbQgZQkyISqIcYh0tUN4N33wQxTL/tXjDBj41Ko7MBfR2r7n llEuWmAalJiBwIqEz/AJ0MCjgARqq15AeM3nyvb/s8vRS+1vgJOfvnbxIUFy7QVvcx JhkGQKO9m3ayCsukJ3loYcXzPznNwl5QVuthj8ddNz5CXF46LuyFJx63ZuuchonRy0 L0bykYpmt/VusjrF9ah7Hs0Fd0nnQVvJpyR99hCbdhO8s716bggQMfY/UrVWU3/Hl9 SNc/UlQHAS2LA== Date: Thu, 6 Jul 2023 13:36:30 +0900 From: Masami Hiramatsu (Google) To: Naveen N Rao Cc: , Steven Rostedt , Masami Hiramatsu , Srikar Dronamraju , Subject: Re: [PATCH v2] trace/kprobe: Display the actual notrace function when rejecting a probe Message-Id: <20230706133630.dc5b67322c840c8a2abd60a7@kernel.org> In-Reply-To: <20230609075809.434392-1-naveen@kernel.org> References: <20230609075809.434392-1-naveen@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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Naveen, Sorry I missed this patch. On Fri, 9 Jun 2023 13:28:09 +0530 Naveen N Rao wrote: > Trying to probe update_sd_lb_stats() using perf results in the below > message in the kernel log: > trace_kprobe: Could not probe notrace function _text > > This is because 'perf probe' specifies the kprobe location as an offset > from '_text': > $ sudo perf probe -D update_sd_lb_stats > p:probe/update_sd_lb_stats _text+1830728 > > However, the error message is misleading and doesn't help convey the > actual notrace function that is being probed. Fix this by looking up the > actual function name that is being probed. With this fix, we now get the > below message in the kernel log: > trace_kprobe: Could not probe notrace function update_sd_lb_stats.constprop.0 > > Signed-off-by: Naveen N Rao > --- > v2: Update within_notrace_func() stub macro with the second parameter to > fix the build error reported by the kernel test robot. > > - Naveen > > kernel/trace/trace_kprobe.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 74adb82331dd81..2d695db5425e7c 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -449,9 +449,8 @@ static bool __within_notrace_func(unsigned long addr) > return !ftrace_location_range(addr, addr + size - 1); > } > > -static bool within_notrace_func(struct trace_kprobe *tk) > +static bool within_notrace_func(struct trace_kprobe *tk, unsigned long addr) > { > - unsigned long addr = trace_kprobe_address(tk); > char symname[KSYM_NAME_LEN], *p; > > if (!__within_notrace_func(addr)) > @@ -471,12 +470,14 @@ static bool within_notrace_func(struct trace_kprobe *tk) > return true; > } > #else > -#define within_notrace_func(tk) (false) > +#define within_notrace_func(tk, addr) (false) > #endif Is this for avoiding redundant calling the trace_kprobe_address(tk)? If so, please pass only 'addr' to the function since 'tk' is only used for calling trace_kprobe_address(tk) in the within_notrace_func(). :) Thank you, > > /* Internal register function - just handle k*probes and flags */ > static int __register_trace_kprobe(struct trace_kprobe *tk) > { > + unsigned long addr = trace_kprobe_address(tk); > + char symname[KSYM_NAME_LEN]; > int i, ret; > > ret = security_locked_down(LOCKDOWN_KPROBES); > @@ -486,9 +487,9 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) > if (trace_kprobe_is_registered(tk)) > return -EINVAL; > > - if (within_notrace_func(tk)) { > + if (within_notrace_func(tk, addr)) { > pr_warn("Could not probe notrace function %s\n", > - trace_kprobe_symbol(tk)); > + lookup_symbol_name(addr, symname) ? trace_kprobe_symbol(tk) : symname); > return -EINVAL; > } > > > base-commit: e46ad59233cf16daf4f3b9dd080003f01ac940fe > -- > 2.40.1 > -- Masami Hiramatsu (Google)