From patchwork Tue May 10 12:26:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12845009 X-Patchwork-Delegate: bpf@iogearbox.net 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 3FA8FC433F5 for ; Tue, 10 May 2022 12:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241783AbiEJMaf (ORCPT ); Tue, 10 May 2022 08:30:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241315AbiEJMae (ORCPT ); Tue, 10 May 2022 08:30:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 091B32A3BCC; Tue, 10 May 2022 05:26:36 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 6ADA360BC7; Tue, 10 May 2022 12:26:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4299C385D1; Tue, 10 May 2022 12:26:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652185595; bh=o6pr4aEKnsuBWeR6c+TMqGIX3kzbG/HCwBHVhWAiShk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AMe/u5kBsK4EBGCkAW7+zHByhyYMrGWf/Ay65sArsNnhPnyNFrBKBqchudJXyp9GT /0z5oAXpD1jvUyhdc+QFGutH+0jLPLld8rg57L2epSB8269F0UexyPuvFogy+DwDWG Olez/OuFc83MrkeKhx9ynX4N+N9jUjfUJWy8zMQAWphdsBb5rwINUvTCYjDbL8dVTd s1xmrOcAOVhfpCUvGTvR109NCDlVkD2KrggPaD66HP93WV0RuOpZjEUIGaN7bSzi7X 7rcqqsIf0L5+S4nIgvWm2SSn8zyAzfiVxSvpL9oboEL6+6VF3CPT1yJoZA79wMZ7lH EPQfCtpCNYkag== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu Cc: Christoph Hellwig , netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt Subject: [PATCHv6 bpf-next 1/5] kallsyms: Make kallsyms_on_each_symbol generally available Date: Tue, 10 May 2022 14:26:12 +0200 Message-Id: <20220510122616.2652285-2-jolsa@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220510122616.2652285-1-jolsa@kernel.org> References: <20220510122616.2652285-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Making kallsyms_on_each_symbol generally available, so it can be used outside CONFIG_LIVEPATCH option in following changes. Rather than adding another ifdef option let's make the function generally available (when CONFIG_KALLSYMS option is defined). Cc: Christoph Hellwig Reviewed-by: Masami Hiramatsu Signed-off-by: Jiri Olsa --- include/linux/kallsyms.h | 7 ++++++- kernel/kallsyms.c | 2 -- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index ce1bd2fbf23e..ad39636e0c3f 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -65,11 +65,11 @@ static inline void *dereference_symbol_descriptor(void *ptr) return ptr; } +#ifdef CONFIG_KALLSYMS int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data); -#ifdef CONFIG_KALLSYMS /* Lookup the address for a symbol. Returns 0 if not found. */ unsigned long kallsyms_lookup_name(const char *name); @@ -163,6 +163,11 @@ static inline bool kallsyms_show_value(const struct cred *cred) return false; } +static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, + unsigned long), void *data) +{ + return -EOPNOTSUPP; +} #endif /*CONFIG_KALLSYMS*/ static inline void print_ip_sym(const char *loglvl, unsigned long ip) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 79f2eb617a62..fdfd308bebc4 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -228,7 +228,6 @@ unsigned long kallsyms_lookup_name(const char *name) return module_kallsyms_lookup_name(name); } -#ifdef CONFIG_LIVEPATCH /* * Iterate over all symbols in vmlinux. For symbols from modules use * module_kallsyms_on_each_symbol instead. @@ -251,7 +250,6 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, } return 0; } -#endif /* CONFIG_LIVEPATCH */ static unsigned long get_symbol_pos(unsigned long addr, unsigned long *symbolsize, From patchwork Tue May 10 12:26:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12845011 X-Patchwork-Delegate: bpf@iogearbox.net 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 7FA6BC433EF for ; Tue, 10 May 2022 12:27:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241808AbiEJMbW (ORCPT ); Tue, 10 May 2022 08:31:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241841AbiEJMbF (ORCPT ); Tue, 10 May 2022 08:31:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDDCF2A8075; Tue, 10 May 2022 05:26:50 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 9DE95B81D0D; Tue, 10 May 2022 12:26:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 896A7C385C6; Tue, 10 May 2022 12:26:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652185608; bh=4tSnxtGwl/IrBm/BYNkLwz3pYQwniu4SdQTWFo0rExw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uPNMTCMGcljqb7HB4LPEc2IIMbzfT1qXxnU8fXrsQlfZu/zT2KLQb9CtsyLGY5tM6 oGkxGCZjZeeJFldGgXkAlrID/yOa0Wq6toOldYTht82VtatOMAtqJ3jUU9bDgKBc7v aHTCMYi3MqrbTV4we+HnVQM/FQF0hxlCvQA7E+knnp0QEixfkfnSAalQSeheQjPpXb w1Qp1Rdm+vCQvv5bwttK/qRC4PDqZST6IDezPvVB373lzH9L6GAglux+ZBp8nGJsa4 ockb9OCx8Qfj5f5hSGq4569R526eskCgkJ5E/6p1tgL7rxrSWj8bFYAtEN4hgsXAB8 Q2QlN+y4uonRA== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt , Christoph Hellwig Subject: [PATCHv6 bpf-next 2/5] ftrace: Add ftrace_lookup_symbols function Date: Tue, 10 May 2022 14:26:13 +0200 Message-Id: <20220510122616.2652285-3-jolsa@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220510122616.2652285-1-jolsa@kernel.org> References: <20220510122616.2652285-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Adding ftrace_lookup_symbols function that resolves array of symbols with single pass over kallsyms. The user provides array of string pointers with count and pointer to allocated array for resolved values. int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) It iterates all kallsyms symbols and tries to loop up each in provided symbols array with bsearch. The symbols array needs to be sorted by name for this reason. We also check each symbol to pass ftrace_location, because this API will be used for fprobe symbols resolving. Suggested-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Reviewed-by: Masami Hiramatsu Signed-off-by: Jiri Olsa --- include/linux/ftrace.h | 6 ++++ kernel/kallsyms.c | 1 + kernel/trace/ftrace.c | 62 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 4816b7e11047..820500430eae 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -303,6 +303,8 @@ int unregister_ftrace_function(struct ftrace_ops *ops); extern void ftrace_stub(unsigned long a0, unsigned long a1, struct ftrace_ops *op, struct ftrace_regs *fregs); + +int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs); #else /* !CONFIG_FUNCTION_TRACER */ /* * (un)register_ftrace_function must be a macro since the ops parameter @@ -313,6 +315,10 @@ extern void ftrace_stub(unsigned long a0, unsigned long a1, static inline void ftrace_kill(void) { } static inline void ftrace_free_init_mem(void) { } static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } +static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_FUNCTION_TRACER */ struct ftrace_func_entry { diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index fdfd308bebc4..fbdf8d3279ac 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -29,6 +29,7 @@ #include #include #include +#include /* * These will be re-linked against their real values diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4f1d2f5e7263..07d87c7a525d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7964,3 +7964,65 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_unlock(&ftrace_lock); return ret; } + +static int symbols_cmp(const void *a, const void *b) +{ + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; + + return strcmp(*str_a, *str_b); +} + +struct kallsyms_data { + unsigned long *addrs; + const char **syms; + size_t cnt; + size_t found; +}; + +static int kallsyms_callback(void *data, const char *name, + struct module *mod, unsigned long addr) +{ + struct kallsyms_data *args = data; + + if (!bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp)) + return 0; + + addr = ftrace_location(addr); + if (!addr) + return 0; + + args->addrs[args->found++] = addr; + return args->found == args->cnt ? 1 : 0; +} + +/** + * ftrace_lookup_symbols - Lookup addresses for array of symbols + * + * @sorted_syms: array of symbols pointers symbols to resolve, + * must be alphabetically sorted + * @cnt: number of symbols/addresses in @syms/@addrs arrays + * @addrs: array for storing resulting addresses + * + * This function looks up addresses for array of symbols provided in + * @syms array (must be alphabetically sorted) and stores them in + * @addrs array, which needs to be big enough to store at least @cnt + * addresses. + * + * This function returns 0 if all provided symbols are found, + * -ESRCH otherwise. + */ +int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) +{ + struct kallsyms_data args; + int err; + + args.addrs = addrs; + args.syms = sorted_syms; + args.cnt = cnt; + args.found = 0; + err = kallsyms_on_each_symbol(kallsyms_callback, &args); + if (err < 0) + return err; + return args.found == args.cnt ? 0 : -ESRCH; +} From patchwork Tue May 10 12:26:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12845013 X-Patchwork-Delegate: bpf@iogearbox.net 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 ECB23C433FE for ; Tue, 10 May 2022 12:28:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241847AbiEJMb7 (ORCPT ); Tue, 10 May 2022 08:31:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241889AbiEJMbJ (ORCPT ); Tue, 10 May 2022 08:31:09 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 826FE2B52CB; Tue, 10 May 2022 05:27:01 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 1B29A60C52; Tue, 10 May 2022 12:27:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17923C385C2; Tue, 10 May 2022 12:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652185620; bh=pSjwjxMQ0Xqxg/DyGW31H8wuzBaHCcrF1uhKi6HzOQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GBTDNT2eENPnjoiPrBKgL7K+DJzPVKFFVBUaSWivU7jsvEz3DwIQKy+ZfiaJUuJ8J 9w04UXPhvw1eaGfQue85hU08Wmou4fDRsK/BQsiE+gTu0nv9RwDPI6tnCKULdugoWK KVVK83/rrdq93zxaZ5uuV9Pn48c/8nzy9+BI6N0XiEABe2tVrJGFKbS23SofSwHb7t haXzFui5SrxK1Rzlx+FCspRPf9oNovhxpg0tOAhPw9lLQM5qKHyJKzO6jCY8WAIzwd gkVhLTE+/sf8VCr93SVNjioDE9+rka9tuuBrxJIbDl4ZiBmhKdleeXDkhgQT1G8Ggj PKyIdx/QDmuuQ== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt , Christoph Hellwig Subject: [PATCHv6 bpf-next 3/5] fprobe: Resolve symbols with ftrace_lookup_symbols Date: Tue, 10 May 2022 14:26:14 +0200 Message-Id: <20220510122616.2652285-4-jolsa@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220510122616.2652285-1-jolsa@kernel.org> References: <20220510122616.2652285-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Using ftrace_lookup_symbols to speed up symbols lookup in register_fprobe_syms API. Acked-by: Masami Hiramatsu Signed-off-by: Jiri Olsa --- kernel/trace/fprobe.c | 32 ++++++++++++-------------------- 1 file changed, 12 insertions(+), 20 deletions(-) diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 89d9f994ebb0..aac63ca9c3d1 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -85,39 +85,31 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data, } NOKPROBE_SYMBOL(fprobe_exit_handler); +static int symbols_cmp(const void *a, const void *b) +{ + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; + + return strcmp(*str_a, *str_b); +} + /* Convert ftrace location address from symbols */ static unsigned long *get_ftrace_locations(const char **syms, int num) { - unsigned long addr, size; unsigned long *addrs; - int i; /* Convert symbols to symbol address */ addrs = kcalloc(num, sizeof(*addrs), GFP_KERNEL); if (!addrs) return ERR_PTR(-ENOMEM); - for (i = 0; i < num; i++) { - addr = kallsyms_lookup_name(syms[i]); - if (!addr) /* Maybe wrong symbol */ - goto error; - - /* Convert symbol address to ftrace location. */ - if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size) - goto error; + /* ftrace_lookup_symbols expects sorted symbols */ + sort(syms, num, sizeof(*syms), symbols_cmp, NULL); - addr = ftrace_location_range(addr, addr + size - 1); - if (!addr) /* No dynamic ftrace there. */ - goto error; + if (!ftrace_lookup_symbols(syms, num, addrs)) + return addrs; - addrs[i] = addr; - } - - return addrs; - -error: kfree(addrs); - return ERR_PTR(-ENOENT); } From patchwork Tue May 10 12:26:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12845010 X-Patchwork-Delegate: bpf@iogearbox.net 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 200C2C433F5 for ; Tue, 10 May 2022 12:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241796AbiEJMbU (ORCPT ); Tue, 10 May 2022 08:31:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241908AbiEJMbL (ORCPT ); Tue, 10 May 2022 08:31:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC83B2A1FDE; Tue, 10 May 2022 05:27:13 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 499F460BCC; Tue, 10 May 2022 12:27:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CC7CC385C2; Tue, 10 May 2022 12:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652185632; bh=SeZYGVo+C/Ti73sLThBUppeds9nAxA0/otvgvdLHc5I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HizxagiGVF4VCmSTPu9ZyBCa8JnenDjBuqn44iirNuSEakoHnpf0fs+qbLNZtXZYK OJ9FC0GNdSvxg0fDiWvI8unNvti0owq3m3TvXqkfRfXGPjtwjHEOHa7cWWXgQR8laq hlfFxPoaUKtKSHFFDBJfKycbxXmV1hab2ATi/T9pbtLuOJgNFHOncaYhm0bNaOXFdi IrH0AZjFaDIxCHVdTTHCUFNx6etz2RPDBHne8D5r5WlX+aQvMV8mdg51Wrdh7pi6di IVbkLtY/cRb42vOkyJrPSE6tLTp5yeHjREPTBtqZe52/Fwis8fdZBkw3+0AUPo28vQ 9DNScoGC/n48g== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt , Christoph Hellwig Subject: [PATCHv6 bpf-next 4/5] bpf: Resolve symbols with ftrace_lookup_symbols for kprobe multi link Date: Tue, 10 May 2022 14:26:15 +0200 Message-Id: <20220510122616.2652285-5-jolsa@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220510122616.2652285-1-jolsa@kernel.org> References: <20220510122616.2652285-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Using kallsyms_lookup_names function to speed up symbols lookup in kprobe multi link attachment and replacing with it the current kprobe_multi_resolve_syms function. This speeds up bpftrace kprobe attachment: # perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* { } i:ms:1 { exit(); }' ... 6.5681 +- 0.0225 seconds time elapsed ( +- 0.34% ) After: # perf stat -r 5 -e cycles ./src/bpftrace -e 'kprobe:x* { } i:ms:1 { exit(); }' ... 0.5661 +- 0.0275 seconds time elapsed ( +- 4.85% ) Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa --- kernel/trace/bpf_trace.c | 112 +++++++++++++++++++++++---------------- 1 file changed, 66 insertions(+), 46 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f15b826f9899..7fd11c17558d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2229,6 +2229,59 @@ struct bpf_kprobe_multi_run_ctx { unsigned long entry_ip; }; +struct user_syms { + const char **syms; + char *buf; +}; + +static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) +{ + unsigned long __user usymbol; + const char **syms = NULL; + char *buf = NULL, *p; + int err = -ENOMEM; + unsigned int i; + + syms = kvmalloc(cnt * sizeof(*syms), GFP_KERNEL); + if (!syms) + goto error; + + buf = kvmalloc(cnt * KSYM_NAME_LEN, GFP_KERNEL); + if (!buf) + goto error; + + for (p = buf, i = 0; i < cnt; i++) { + if (__get_user(usymbol, usyms + i)) { + err = -EFAULT; + goto error; + } + err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); + if (err == KSYM_NAME_LEN) + err = -E2BIG; + if (err < 0) + goto error; + syms[i] = p; + p += err + 1; + } + + us->syms = syms; + us->buf = buf; + return 0; + +error: + if (err) { + kvfree(syms); + kvfree(buf); + } + return err; +} + +static void free_user_syms(struct user_syms *us) +{ + kvfree(us->syms); + kvfree(us->buf); +} + static void bpf_kprobe_multi_link_release(struct bpf_link *link) { struct bpf_kprobe_multi_link *kmulti_link; @@ -2349,53 +2402,12 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip, kprobe_multi_link_prog_run(link, entry_ip, regs); } -static int -kprobe_multi_resolve_syms(const void __user *usyms, u32 cnt, - unsigned long *addrs) +static int symbols_cmp(const void *a, const void *b) { - unsigned long addr, size; - const char __user **syms; - int err = -ENOMEM; - unsigned int i; - char *func; - - size = cnt * sizeof(*syms); - syms = kvzalloc(size, GFP_KERNEL); - if (!syms) - return -ENOMEM; + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; - func = kmalloc(KSYM_NAME_LEN, GFP_KERNEL); - if (!func) - goto error; - - if (copy_from_user(syms, usyms, size)) { - err = -EFAULT; - goto error; - } - - for (i = 0; i < cnt; i++) { - err = strncpy_from_user(func, syms[i], KSYM_NAME_LEN); - if (err == KSYM_NAME_LEN) - err = -E2BIG; - if (err < 0) - goto error; - err = -EINVAL; - addr = kallsyms_lookup_name(func); - if (!addr) - goto error; - if (!kallsyms_lookup_size_offset(addr, &size, NULL)) - goto error; - addr = ftrace_location_range(addr, addr + size - 1); - if (!addr) - goto error; - addrs[i] = addr; - } - - err = 0; -error: - kvfree(syms); - kfree(func); - return err; + return strcmp(*str_a, *str_b); } int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) @@ -2441,7 +2453,15 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr goto error; } } else { - err = kprobe_multi_resolve_syms(usyms, cnt, addrs); + struct user_syms us; + + err = copy_user_syms(&us, usyms, cnt); + if (err) + goto error; + + sort(us.syms, cnt, sizeof(*us.syms), symbols_cmp, NULL); + err = ftrace_lookup_symbols(us.syms, cnt, addrs); + free_user_syms(&us); if (err) goto error; } From patchwork Tue May 10 12:26:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12845012 X-Patchwork-Delegate: bpf@iogearbox.net 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 79180C433F5 for ; Tue, 10 May 2022 12:27:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241835AbiEJMbf (ORCPT ); Tue, 10 May 2022 08:31:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241815AbiEJMbY (ORCPT ); Tue, 10 May 2022 08:31:24 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB8A12A3760; Tue, 10 May 2022 05:27:26 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 87C6BB81BD8; Tue, 10 May 2022 12:27:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FCC6C385A6; Tue, 10 May 2022 12:27:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652185644; bh=IXtTKnWWf2sdyXq5urSn2z0rdlL4RzojJ6aPpiupcEo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PlHI/DvKS1DWL3xxCC8D5d/KL4LNAmZOE+DVdtJtTpzZLfteuyd7TQF1jr/7eI0sX HJEZxb2e3mHyFBSdb6HZqpWMNOYXC3h27MMrO9jPrmZK99+wFy6Aj195TQyVsuV9me N2UFG0r7AMCrNzRc7NzarPYRy2nx1wiQBNltEkVI/4wpW1RY1MgB0TOwiuNJn7tcHJ u+epSnvJYYawDjBEIvAU4UEuJKibVAhqNWqFE1Yfu1MIsEwxch7+z5ep/vrfIT4nPa BOAeZaXF/E2g0gTDfTow2ZMl5TXYtHPqk1CmbLGTfWDrXozF4Q/1WYwx+USnehJYiT kq0vTo1b2QBYg== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt , Christoph Hellwig Subject: [PATCHv6 bpf-next 5/5] selftests/bpf: Add attach bench test Date: Tue, 10 May 2022 14:26:16 +0200 Message-Id: <20220510122616.2652285-6-jolsa@kernel.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220510122616.2652285-1-jolsa@kernel.org> References: <20220510122616.2652285-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Adding test that reads all functions from ftrace available_filter_functions file and attach them all through kprobe_multi API. It also prints stats info with -v option, like on my setup: test_bench_attach: found 48712 functions test_bench_attach: attached in 1.069s test_bench_attach: detached in 0.373s Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa --- .../bpf/prog_tests/kprobe_multi_test.c | 143 ++++++++++++++++++ .../selftests/bpf/progs/kprobe_multi_empty.c | 12 ++ 2 files changed, 155 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/kprobe_multi_empty.c diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index c56db65d4c15..816eacededd1 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -2,6 +2,9 @@ #include #include "kprobe_multi.skel.h" #include "trace_helpers.h" +#include "kprobe_multi_empty.skel.h" +#include "bpf/libbpf_internal.h" +#include "bpf/hashmap.h" static void kprobe_multi_test_run(struct kprobe_multi *skel, bool test_return) { @@ -301,6 +304,144 @@ static void test_attach_api_fails(void) kprobe_multi__destroy(skel); } +static inline __u64 get_time_ns(void) +{ + struct timespec t; + + clock_gettime(CLOCK_MONOTONIC, &t); + return (__u64) t.tv_sec * 1000000000 + t.tv_nsec; +} + +static size_t symbol_hash(const void *key, void *ctx __maybe_unused) +{ + return str_hash((const char *) key); +} + +static bool symbol_equal(const void *key1, const void *key2, void *ctx __maybe_unused) +{ + return strcmp((const char *) key1, (const char *) key2) == 0; +} + +static int get_syms(char ***symsp, size_t *cntp) +{ + size_t cap = 0, cnt = 0, i; + char *name, **syms = NULL; + struct hashmap *map; + char buf[256]; + FILE *f; + int err; + + /* + * The available_filter_functions contains many duplicates, + * but other than that all symbols are usable in kprobe multi + * interface. + * Filtering out duplicates by using hashmap__add, which won't + * add existing entry. + */ + f = fopen("/sys/kernel/debug/tracing/available_filter_functions", "r"); + if (!f) + return -EINVAL; + + map = hashmap__new(symbol_hash, symbol_equal, NULL); + if (IS_ERR(map)) + goto error; + + while (fgets(buf, sizeof(buf), f)) { + /* skip modules */ + if (strchr(buf, '[')) + continue; + if (sscanf(buf, "%ms$*[^\n]\n", &name) != 1) + continue; + /* + * We attach to almost all kernel functions and some of them + * will cause 'suspicious RCU usage' when fprobe is attached + * to them. Filter out the current culprits - arch_cpu_idle + * and rcu_* functions. + */ + if (!strcmp(name, "arch_cpu_idle")) + continue; + if (!strncmp(name, "rcu_", 4)) + continue; + err = hashmap__add(map, name, NULL); + if (err) { + free(name); + if (err == -EEXIST) + continue; + goto error; + } + err = libbpf_ensure_mem((void **) &syms, &cap, + sizeof(*syms), cnt + 1); + if (err) { + free(name); + goto error; + } + syms[cnt] = name; + cnt++; + } + + *symsp = syms; + *cntp = cnt; + +error: + fclose(f); + hashmap__free(map); + if (err) { + for (i = 0; i < cnt; i++) + free(syms[cnt]); + free(syms); + } + return err; +} + +static void test_bench_attach(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + struct kprobe_multi_empty *skel = NULL; + long attach_start_ns, attach_end_ns; + long detach_start_ns, detach_end_ns; + double attach_delta, detach_delta; + struct bpf_link *link = NULL; + char **syms = NULL; + size_t cnt, i; + + if (!ASSERT_OK(get_syms(&syms, &cnt), "get_syms")) + return; + + skel = kprobe_multi_empty__open_and_load(); + if (!ASSERT_OK_PTR(skel, "kprobe_multi_empty__open_and_load")) + goto cleanup; + + opts.syms = (const char **) syms; + opts.cnt = cnt; + + attach_start_ns = get_time_ns(); + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe_empty, + NULL, &opts); + attach_end_ns = get_time_ns(); + + if (!ASSERT_OK_PTR(link, "bpf_program__attach_kprobe_multi_opts")) + goto cleanup; + + detach_start_ns = get_time_ns(); + bpf_link__destroy(link); + detach_end_ns = get_time_ns(); + + attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0; + detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0; + + printf("%s: found %lu functions\n", __func__, cnt); + printf("%s: attached in %7.3lfs\n", __func__, attach_delta); + printf("%s: detached in %7.3lfs\n", __func__, detach_delta); + +cleanup: + kprobe_multi_empty__destroy(skel); + if (syms) { + for (i = 0; i < cnt; i++) + free(syms[i]); + free(syms); + } +} + void test_kprobe_multi_test(void) { if (!ASSERT_OK(load_kallsyms(), "load_kallsyms")) @@ -320,4 +461,6 @@ void test_kprobe_multi_test(void) test_attach_api_syms(); if (test__start_subtest("attach_api_fails")) test_attach_api_fails(); + if (test__start_subtest("bench_attach")) + test_bench_attach(); } diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi_empty.c b/tools/testing/selftests/bpf/progs/kprobe_multi_empty.c new file mode 100644 index 000000000000..e76e499aca39 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/kprobe_multi_empty.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +SEC("kprobe.multi/") +int test_kprobe_empty(struct pt_regs *ctx) +{ + return 0; +}