From patchwork Tue Nov 8 15:49:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 17109 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp2789910wru; Tue, 8 Nov 2022 07:50:49 -0800 (PST) X-Google-Smtp-Source: AMsMyM6E8TvNE4SNr9MgkMsMfcJJzVTK8tnsXTDlZIFdPFhuOolmV5N5lXXEVQ48D+IzSWoQEhEz X-Received: by 2002:a17:906:6a02:b0:7ae:2793:aa19 with SMTP id qw2-20020a1709066a0200b007ae2793aa19mr25612662ejc.265.1667922649020; Tue, 08 Nov 2022 07:50:49 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1667922649; cv=none; d=google.com; s=arc-20160816; b=HCI3Hew1xeQn8ReLSdTQL8w77CZSIQtbZZ8vLI/fHdjNeFVma80lyY8jsbgsVAo6k3 UFbAU5vC1CEqeSvKeLBSSSa9gPls8dE/MpgUNkHdj/jQYGX3+tEFBdciYoPOzw13tFfh BikJlcZLescBS1KQ137Lo826KuL/ianqCNlL44Rxio/UGZG7hy1z5NACAS4vue1lCzHU 05HraKPzpxPm1k2MSPEwoDnd/bt6Vk1fgdkI/07XFG1IzJQe3fq4TGZnZTC+6jIVYWB9 aE1snfDEjNd5XtuQT0eXMgAff0VcsT7aUNWwKEKbKDZzODFUyj5cPMgdgIgPsPuEO+IE KdfQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=bhJUyA552U4FqaRakyJu+yZIIGSvBKJx3aZwgIBBrNU=; b=sLKQzwuYHvuvIK4k0YLaYajJO19o4XeU0T92QlRwhUox+RQTZLrU8Y4cWx5buPwhqs oX7NUGkD1NtoDyfl7H/SUBogYZNhQ4SaA5qcDyFOV89ipmv9zs+5XongH//JZzDYaWYC 69gUTqRPOqgqimhrrlrpUT/7bVGH4zI0r9ZSd9IWbhqbVg9TzLpJ8I7PODg+y9jhIUOY THFlX988bt3C+ZhdaJXJnSAHkfnPAq9TNxxvfwXm/e/DbgE9w8WDhFiosKRifJxlM6o+ xcNeEva8MEKcanGdfc0HBwCpRIH12E/F2FIBhB+bEigqZ3Ga7MkUT06EDXbKmE901ag0 OJMg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=e5uC95qV; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id ga38-20020a1709070c2600b0078cc4a8a956si14044447ejc.881.2022.11.08.07.50.23; Tue, 08 Nov 2022 07:50:49 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=e5uC95qV; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234500AbiKHPtg (ORCPT + 99 others); Tue, 8 Nov 2022 10:49:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234503AbiKHPtc (ORCPT ); Tue, 8 Nov 2022 10:49:32 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 598721F632; Tue, 8 Nov 2022 07:49:30 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 6BC93CE1BCA; Tue, 8 Nov 2022 15:49:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E83FC433D6; Tue, 8 Nov 2022 15:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667922566; bh=tenO832RXqIzUnct3PpqMDsII++XyS6MTBY9g9P85NM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e5uC95qV8vPg4IZ5WeeExGQVZ4GsMyNBAnC4sPZbuJjM4tJDOoZJkLmigCbjaa7Gr t1GoUxswc2Xcron/MLuzYUaPhi4H+g4rPyinGWZUge8Zgo0u4rGk11Mv0arru2A6N4 JWPFDNnDhV+AxqcZdJ7A7cFQoxa2svfd6A/c+epU0MbDZq3SeJJ9ip8rMr0Cy4Ohq2 giY+eLHszhkMJD0nes5Ch/N6YZ/1QvE3wFdw5OpTME9D9TSiHSmPIDR7CVi34ywuFm Cj7qid+baiR1UhCbyTcGMRvGVS7rAk1965/Ort7BggIf51nALPXY3i7CO4OViWGYYC y6SovrSDWgrLQ== From: "Masami Hiramatsu (Google)" To: linux-trace-kernel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Steven Rostedt , mhiramat@kernel.org, Florent Revest , Mark Rutland , Will Deacon Subject: [RFC PATCH 1/9] fprobe: Pass entry_data to handlers Date: Wed, 9 Nov 2022 00:49:23 +0900 Message-Id: <166792256330.919356.14776044963704066797.stgit@devnote3> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <166792255429.919356.14116090269057513181.stgit@devnote3> References: <166792255429.919356.14116090269057513181.stgit@devnote3> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748943659561879301?= X-GMAIL-MSGID: =?utf-8?q?1748943659561879301?= From: Masami Hiramatsu (Google) Pass the private entry_data to the entry and exit handlers so that they can share the context data, something like saved function arguments etc. User must specify the private entry_data size by @entry_data_size field before registering the fprobe. Signed-off-by: Masami Hiramatsu (Google) --- include/linux/fprobe.h | 8 ++++++-- kernel/trace/bpf_trace.c | 2 +- kernel/trace/fprobe.c | 21 ++++++++++++++------- lib/test_fprobe.c | 6 ++++-- samples/fprobe/fprobe_example.c | 6 ++++-- 5 files changed, 29 insertions(+), 14 deletions(-) diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h index 1c2bde0ead73..e0d4e6136249 100644 --- a/include/linux/fprobe.h +++ b/include/linux/fprobe.h @@ -13,6 +13,7 @@ * @nmissed: The counter for missing events. * @flags: The status flag. * @rethook: The rethook data structure. (internal data) + * @entry_data_size: The private data storage size. * @entry_handler: The callback function for function entry. * @exit_handler: The callback function for function exit. */ @@ -29,9 +30,12 @@ struct fprobe { unsigned long nmissed; unsigned int flags; struct rethook *rethook; + size_t entry_data_size; - void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs); - void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs); + void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip, + struct pt_regs *regs, void *entry_data); + void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip, + struct pt_regs *regs, void *entry_data); }; /* This fprobe is soft-disabled. */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 1ed08967fb97..68c369452680 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2625,7 +2625,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, static void kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, - struct pt_regs *regs) + struct pt_regs *regs, void *data) { struct bpf_kprobe_multi_link *link; diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index e8143e368074..fa25d09c9d57 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -17,14 +17,16 @@ struct fprobe_rethook_node { struct rethook_node node; unsigned long entry_ip; + char data[]; }; static void fprobe_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct ftrace_regs *fregs) { struct fprobe_rethook_node *fpr; - struct rethook_node *rh; + struct rethook_node *rh = NULL; struct fprobe *fp; + void *entry_data = NULL; int bit; fp = container_of(ops, struct fprobe, ops); @@ -37,9 +39,6 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip, return; } - if (fp->entry_handler) - fp->entry_handler(fp, ip, ftrace_get_regs(fregs)); - if (fp->exit_handler) { rh = rethook_try_get(fp->rethook); if (!rh) { @@ -48,9 +47,16 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip, } fpr = container_of(rh, struct fprobe_rethook_node, node); fpr->entry_ip = ip; - rethook_hook(rh, ftrace_get_regs(fregs), true); + if (fp->entry_data_size) + entry_data = fpr->data; } + if (fp->entry_handler) + fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data); + + if (rh) + rethook_hook(rh, ftrace_get_regs(fregs), true); + out: ftrace_test_recursion_unlock(bit); } @@ -81,7 +87,8 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data, fpr = container_of(rh, struct fprobe_rethook_node, node); - fp->exit_handler(fp, fpr->entry_ip, regs); + fp->exit_handler(fp, fpr->entry_ip, regs, + fp->entry_data_size ? (void *)fpr->data : NULL); } NOKPROBE_SYMBOL(fprobe_exit_handler); @@ -146,7 +153,7 @@ static int fprobe_init_rethook(struct fprobe *fp, int num) for (i = 0; i < size; i++) { struct fprobe_rethook_node *node; - node = kzalloc(sizeof(*node), GFP_KERNEL); + node = kzalloc(sizeof(*node) + fp->entry_data_size, GFP_KERNEL); if (!node) { rethook_free(fp->rethook); fp->rethook = NULL; diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c index e0381b3ec410..34fa5a5bbda1 100644 --- a/lib/test_fprobe.c +++ b/lib/test_fprobe.c @@ -30,7 +30,8 @@ static noinline u32 fprobe_selftest_target2(u32 value) return (value / div_factor) + 1; } -static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs) +static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, + struct pt_regs *regs, void *data) { KUNIT_EXPECT_FALSE(current_test, preemptible()); /* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */ @@ -39,7 +40,8 @@ static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, struct entry_val = (rand1 / div_factor); } -static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs) +static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip, + struct pt_regs *regs, void *data) { unsigned long ret = regs_return_value(regs); diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c index e22da8573116..dd794990ad7e 100644 --- a/samples/fprobe/fprobe_example.c +++ b/samples/fprobe/fprobe_example.c @@ -48,7 +48,8 @@ static void show_backtrace(void) stack_trace_print(stacks, len, 24); } -static void sample_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs) +static void sample_entry_handler(struct fprobe *fp, unsigned long ip, + struct pt_regs *regs, void *data) { if (use_trace) /* @@ -63,7 +64,8 @@ static void sample_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_ show_backtrace(); } -static void sample_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs) +static void sample_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs, + void *data) { unsigned long rip = instruction_pointer(regs);