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 D486CC433EF for ; Thu, 3 Mar 2022 11:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232871AbiCCLcc (ORCPT ); Thu, 3 Mar 2022 06:32:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232742AbiCCLbM (ORCPT ); Thu, 3 Mar 2022 06:31:12 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F59A17BC6E for ; Thu, 3 Mar 2022 03:30:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=h6GcArmVpCRO3FrdKqhyu7r+UQXJ+Ln2TbiItmpPfmo=; b=Y9Ws6ORDAYMbcyq+LRvY4qvaMK QdPe8H2E7wf2/vD38QR2ZAo+TvZSLvmqlvolB6fVPZDO4t1LWI6uXLpJz5Jb/haPVVOaMURH2MITV CdyEV7tmalYfEBvBxNCzS4D5uZn0K31OfYJ1ESS38nlm45lavO9w00BkRSn1rUpn01257MK4uwZMO ezvideJjOeCvTI7SgcH9/b/uzAj9OvL8bGBd0uxyw7PSMYMAPFqJgOorpLHGFQ8bTE4HerYV+IBT0 J6DsyO2BkB26pmFMnDXNc5m59URlnv0gxXUHr6XHi0i8ONVfF6wTTVbbJkM0tLJ4kFHsH2mphj7HK XQhlQPpw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPjeg-00EtpZ-Vq; Thu, 03 Mar 2022 11:29:59 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id F036A30214E; Thu, 3 Mar 2022 12:29:56 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 5620A3002F5F6; Thu, 3 Mar 2022 12:29:56 +0100 (CET) Message-ID: <20220303112825.924414182@infradead.org> User-Agent: quilt/0.66 Date: Thu, 03 Mar 2022 12:23:37 +0100 From: Peter Zijlstra To: x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com, jpoimboe@redhat.com, andrew.cooper3@citrix.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, ndesaulniers@google.com, keescook@chromium.org, samitolvanen@google.com, mark.rutland@arm.com, alyssa.milburn@intel.com, mbenes@suse.cz, rostedt@goodmis.org, mhiramat@kernel.org, alexei.starovoitov@gmail.com Subject: [PATCH v3 16/39] x86/ibt,ftrace: Search for __fentry__ location References: <20220303112321.422525803@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Have ftrace_location() search the symbol for the __fentry__ location when it isn't at func+0 and use this for {,un}register_ftrace_direct(). This avoids a whole bunch of assumptions about __fentry__ being at func+0. Suggested-by: Steven Rostedt Signed-off-by: Peter Zijlstra (Intel) --- kernel/trace/ftrace.c | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1578,7 +1578,25 @@ unsigned long ftrace_location_range(unsi */ unsigned long ftrace_location(unsigned long ip) { - return ftrace_location_range(ip, ip); + struct dyn_ftrace *rec; + unsigned long offset; + unsigned long size; + + rec = lookup_rec(ip, ip); + if (!rec) { + if (!kallsyms_lookup_size_offset(ip, &size, &offset)) + goto out; + + /* map sym+0 to __fentry__ */ + if (!offset) + rec = lookup_rec(ip, ip + size - 1); + } + + if (rec) + return rec->ip; + +out: + return 0; } /** @@ -4962,7 +4980,8 @@ ftrace_match_addr(struct ftrace_hash *ha { struct ftrace_func_entry *entry; - if (!ftrace_location(ip)) + ip = ftrace_location(ip); + if (!ip) return -EINVAL; if (remove) { @@ -5110,11 +5129,16 @@ int register_ftrace_direct(unsigned long struct ftrace_func_entry *entry; struct ftrace_hash *free_hash = NULL; struct dyn_ftrace *rec; - int ret = -EBUSY; + int ret = -ENODEV; mutex_lock(&direct_mutex); + ip = ftrace_location(ip); + if (!ip) + goto out_unlock; + /* See if there's a direct function at @ip already */ + ret = -EBUSY; if (ftrace_find_rec_direct(ip)) goto out_unlock; @@ -5222,6 +5246,10 @@ int unregister_ftrace_direct(unsigned lo mutex_lock(&direct_mutex); + ip = ftrace_location(ip); + if (!ip) + goto out_unlock; + entry = find_direct_entry(&ip, NULL); if (!entry) goto out_unlock;