From patchwork Mon Jan 16 10:10:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13102848 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 AD275C54EBE for ; Mon, 16 Jan 2023 10:11:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230352AbjAPKLz (ORCPT ); Mon, 16 Jan 2023 05:11:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230322AbjAPKLb (ORCPT ); Mon, 16 Jan 2023 05:11:31 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0382C1C325; Mon, 16 Jan 2023 02:10:31 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 7874E60EA3; Mon, 16 Jan 2023 10:10:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BA3EC433D2; Mon, 16 Jan 2023 10:10:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673863830; bh=nkpwAW7WkQw33GL/9d/cQC6dVxlOEMv1ZO7oANvYQrs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vi/UjNC0ZlE0C2mJtzndE1230MWYdWbvsp6ZQhWPHwTfrUx+HmNIpthbZdBRoVUFb Gs96Cvh4q+ZfT/EOEYzeW3vN1D1Oz5m2GfjMTA7DN3nKRTrhbWk589jlHQxWpDZ3CC yCbbMxNQiuicO6/peQFACH3va66AYS8CxfK3GtIjWwCio7HFF/rGcqq/YoeBiPEddx O42d/mkjnsSGAXOnvkJOI+pYAGMXC5CRkFSLGGrK7C2TprYPHBJtXTGJkP7zvdouVy Wo0TYdOXZ2DilCoHDbW0/DaDlLFUqYfWvN8kinxmlLfu6JIRzlAaAL6rwYFVBdWWU2 AJR0sXZLRn7uA== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Zhen Lei Cc: Song Liu , bpf@vger.kernel.org, live-patching@vger.kernel.org, linux-modules@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Joe Lawrence , Steven Rostedt , Masami Hiramatsu , Mark Rutland , Luis Chamberlain Subject: [PATCHv3 bpf-next 1/3] livepatch: Improve the search performance of module_kallsyms_on_each_symbol() Date: Mon, 16 Jan 2023 11:10:07 +0100 Message-Id: <20230116101009.23694-2-jolsa@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116101009.23694-1-jolsa@kernel.org> References: <20230116101009.23694-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: From: Zhen Lei Currently we traverse all symbols of all modules to find the specified function for the specified module. But in reality, we just need to find the given module and then traverse all the symbols in it. Let's add a new parameter 'const char *modname' to function module_kallsyms_on_each_symbol(), then we can compare the module names directly in this function and call hook 'fn' after matching. If 'modname' is NULL, the symbols of all modules are still traversed for compatibility with other usage cases. Phase1: mod1-->mod2..(subsequent modules do not need to be compared) | Phase2: -->f1-->f2-->f3 Assuming that there are m modules, each module has n symbols on average, then the time complexity is reduced from O(m * n) to O(m) + O(n). Reviewed-by: Petr Mladek Acked-by: Song Liu Signed-off-by: Zhen Lei Signed-off-by: Jiri Olsa Acked-by: Miroslav Benes Reviewed-by: Luis Chamberlain --- include/linux/module.h | 6 ++++-- kernel/livepatch/core.c | 10 +--------- kernel/module/kallsyms.c | 13 ++++++++++++- kernel/trace/bpf_trace.c | 2 +- kernel/trace/ftrace.c | 2 +- 5 files changed, 19 insertions(+), 14 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index 8c5909c0076c..514bc81568c5 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -879,11 +879,13 @@ static inline bool module_sig_ok(struct module *module) #endif /* CONFIG_MODULE_SIG */ #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) -int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data); #else -static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +static inline int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data) { diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 201f0c0482fb..c973ed9e42f8 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -118,7 +118,6 @@ static struct klp_object *klp_find_object(struct klp_patch *patch, } struct klp_find_arg { - const char *objname; const char *name; unsigned long addr; unsigned long count; @@ -148,15 +147,9 @@ static int klp_find_callback(void *data, const char *name, { struct klp_find_arg *args = data; - if ((mod && !args->objname) || (!mod && args->objname)) - return 0; - if (strcmp(args->name, name)) return 0; - if (args->objname && strcmp(args->objname, mod->name)) - return 0; - return klp_match_callback(data, addr); } @@ -164,7 +157,6 @@ static int klp_find_object_symbol(const char *objname, const char *name, unsigned long sympos, unsigned long *addr) { struct klp_find_arg args = { - .objname = objname, .name = name, .addr = 0, .count = 0, @@ -172,7 +164,7 @@ static int klp_find_object_symbol(const char *objname, const char *name, }; if (objname) - module_kallsyms_on_each_symbol(klp_find_callback, &args); + module_kallsyms_on_each_symbol(objname, klp_find_callback, &args); else kallsyms_on_each_match_symbol(klp_match_callback, name, &args); diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index 4523f99b0358..ab2376a1be88 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -494,7 +494,8 @@ unsigned long module_kallsyms_lookup_name(const char *name) return ret; } -int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data) { @@ -509,6 +510,9 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, if (mod->state == MODULE_STATE_UNFORMED) continue; + if (modname && strcmp(modname, mod->name)) + continue; + /* Use rcu_dereference_sched() to remain compliant with the sparse tool */ preempt_disable(); kallsyms = rcu_dereference_sched(mod->kallsyms); @@ -525,6 +529,13 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, if (ret != 0) goto out; } + + /* + * The given module is found, the subsequent modules do not + * need to be compared. + */ + if (modname) + break; } out: mutex_unlock(&module_mutex); diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 23ce498bca97..095f7f8d34a1 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2735,7 +2735,7 @@ static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u3 int err; /* We return either err < 0 in case of error, ... */ - err = module_kallsyms_on_each_symbol(module_callback, &args); + err = module_kallsyms_on_each_symbol(NULL, module_callback, &args); if (err) { kprobe_multi_put_modules(args.mods, args.mods_cnt); kfree(args.mods); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 442438b93fe9..d249a55d9005 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -8324,7 +8324,7 @@ int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *a found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); if (found_all) return 0; - found_all = module_kallsyms_on_each_symbol(kallsyms_callback, &args); + found_all = module_kallsyms_on_each_symbol(NULL, kallsyms_callback, &args); return found_all ? 0 : -ESRCH; } From patchwork Mon Jan 16 10:10:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13102849 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 CA9F4C677F1 for ; Mon, 16 Jan 2023 10:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230378AbjAPKMR (ORCPT ); Mon, 16 Jan 2023 05:12:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230423AbjAPKLr (ORCPT ); Mon, 16 Jan 2023 05:11:47 -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 2770C1C338; Mon, 16 Jan 2023 02:10:48 -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 50E1CCE0FCE; Mon, 16 Jan 2023 10:10:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9FE4C433EF; Mon, 16 Jan 2023 10:10:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673863844; bh=5DDT8Sp02eS1UEuJrxq7KZNSFlE8WBC2+6m3PvubtEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Iib2yqsI9K98A+b1/5n83yg1wvLFR1FV8TAD5jiMPWZO1hXNjmkqAEX5OThpS2MP7 hA54/st207p32lHNWhVSqHDZ3bhh5iRASVca22fhvj8/y/XwCPf+jMNR7KbPQMbqHL s2JfxygBq3KIdNzfMvl40c6buL0wD+o/5Pt2ZW8hFcJnxnkin97XPJhv0k4M4EkiVz wwTwyJwzYV1yOQmi5nN25/quxViPdePcjX+Hz/tn89z7IiINaerZVtYhKyO/nUNJwT zp0nqXeh6cj7EojkoEYPEXAqyrOEz7BvfEBmAI6iXFSswij5t2cgFzbbC0YIqyPPs0 1Nb5uax8KS4Wg== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Zhen Lei Cc: Song Liu , bpf@vger.kernel.org, live-patching@vger.kernel.org, linux-modules@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Joe Lawrence , Steven Rostedt , Masami Hiramatsu , Mark Rutland , Luis Chamberlain Subject: [PATCHv3 bpf-next 2/3] selftests/bpf: Add serial_test_kprobe_multi_bench_attach_kernel/module tests Date: Mon, 16 Jan 2023 11:10:08 +0100 Message-Id: <20230116101009.23694-3-jolsa@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116101009.23694-1-jolsa@kernel.org> References: <20230116101009.23694-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: Add bench test for module portion of the symbols as well. # ./test_progs -v -t kprobe_multi_bench_attach_module bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_kprobe_multi_bench_attach:PASS:get_syms 0 nsec test_kprobe_multi_bench_attach:PASS:kprobe_multi_empty__open_and_load 0 nsec test_kprobe_multi_bench_attach:PASS:bpf_program__attach_kprobe_multi_opts 0 nsec test_kprobe_multi_bench_attach: found 26620 functions test_kprobe_multi_bench_attach: attached in 0.182s test_kprobe_multi_bench_attach: detached in 0.082s #96 kprobe_multi_bench_attach_module:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Successfully unloaded bpf_testmod.ko. It's useful for testing kprobe multi link modules resolving. Acked-by: Song Liu Signed-off-by: Jiri Olsa --- .../bpf/prog_tests/kprobe_multi_test.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) 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 c6f37e825f11..113dba349a57 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -322,7 +322,7 @@ static bool symbol_equal(long key1, long key2, void *ctx __maybe_unused) return strcmp((const char *) key1, (const char *) key2) == 0; } -static int get_syms(char ***symsp, size_t *cntp) +static int get_syms(char ***symsp, size_t *cntp, bool kernel) { size_t cap = 0, cnt = 0, i; char *name = NULL, **syms = NULL; @@ -349,8 +349,9 @@ static int get_syms(char ***symsp, size_t *cntp) } while (fgets(buf, sizeof(buf), f)) { - /* skip modules */ - if (strchr(buf, '[')) + if (kernel && strchr(buf, '[')) + continue; + if (!kernel && !strchr(buf, '[')) continue; free(name); @@ -404,7 +405,7 @@ static int get_syms(char ***symsp, size_t *cntp) return err; } -void serial_test_kprobe_multi_bench_attach(void) +static void test_kprobe_multi_bench_attach(bool kernel) { LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); struct kprobe_multi_empty *skel = NULL; @@ -415,7 +416,7 @@ void serial_test_kprobe_multi_bench_attach(void) char **syms = NULL; size_t cnt = 0, i; - if (!ASSERT_OK(get_syms(&syms, &cnt), "get_syms")) + if (!ASSERT_OK(get_syms(&syms, &cnt, kernel), "get_syms")) return; skel = kprobe_multi_empty__open_and_load(); @@ -453,6 +454,14 @@ void serial_test_kprobe_multi_bench_attach(void) } } +void serial_test_kprobe_multi_bench_attach(void) +{ + if (test__start_subtest("kernel")) + test_kprobe_multi_bench_attach(true); + if (test__start_subtest("modules")) + test_kprobe_multi_bench_attach(false); +} + void test_kprobe_multi_test(void) { if (!ASSERT_OK(load_kallsyms(), "load_kallsyms")) From patchwork Mon Jan 16 10:10:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13102850 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 DD758C54EBE for ; Mon, 16 Jan 2023 10:12:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230418AbjAPKMc (ORCPT ); Mon, 16 Jan 2023 05:12:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230330AbjAPKLv (ORCPT ); Mon, 16 Jan 2023 05:11:51 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3303818B1C; Mon, 16 Jan 2023 02:10:58 -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 dfw.source.kernel.org (Postfix) with ESMTPS id C3CC260F39; Mon, 16 Jan 2023 10:10:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3DE8C433F0; Mon, 16 Jan 2023 10:10:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673863857; bh=IYqjSfm/4iKQ0ywLB3Y11j9UHVRbAESNh3zYmnkHGmE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eDok/yObDwAM7e10Ag1VEGnqyKMYdCFu6c7l+7AtAo/fsfV2JwINN+kxxDW1t3PfK iQylAU3y4JQ7PCTjMsR2d/JF7wZrhHWhyEaxzWOgHawsHni6hjrfzh7RdplWlEtC1x Ex8yZQNcd37SRQ2I9jbkmFwvazXuL8USf5miwULKTmj/De4T/BPPI6iFv6Z7GiwUnf G2s2dBsGsJ9Li581GxRzct3rSQZLQbWlG39QL/m53R4zAxOXuiUr28TBOtHpOMapK2 v8677GPYtjiorHzuuQWqaL+tQ3PjBjilBqGl+DRUUP/Y8D8SN8ndlnpnn5UhB3cgz/ YNWp5DyA7saxQ== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Zhen Lei Cc: bpf@vger.kernel.org, live-patching@vger.kernel.org, linux-modules@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Joe Lawrence , Steven Rostedt , Masami Hiramatsu , Mark Rutland , Luis Chamberlain Subject: [PATCHv3 bpf-next 3/3] bpf: Change modules resolving for kprobe multi link Date: Mon, 16 Jan 2023 11:10:09 +0100 Message-Id: <20230116101009.23694-4-jolsa@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116101009.23694-1-jolsa@kernel.org> References: <20230116101009.23694-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: We currently use module_kallsyms_on_each_symbol that iterates all modules/symbols and we try to lookup each such address in user provided symbols/addresses to get list of used modules. This fix instead only iterates provided kprobe addresses and calls __module_address on each to get list of used modules. This turned out ot be simpler and also bit faster. On my setup with workload (executed 10 times): # test_progs -t kprobe_multi_bench_attach/modules Current code: Performance counter stats for './test.sh' (5 runs): 76,081,161,596 cycles:k ( +- 0.47% ) 18.3867 +- 0.0992 seconds time elapsed ( +- 0.54% ) With the fix: Performance counter stats for './test.sh' (5 runs): 74,079,889,063 cycles:k ( +- 0.04% ) 17.8514 +- 0.0218 seconds time elapsed ( +- 0.12% ) Signed-off-by: Jiri Olsa Reviewed-by: Zhen Lei Reviewed-by: Petr Mladek --- kernel/trace/bpf_trace.c | 93 ++++++++++++++++++++-------------------- 1 file changed, 47 insertions(+), 46 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 095f7f8d34a1..8124f1ad0d4a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2682,69 +2682,77 @@ static void symbols_swap_r(void *a, void *b, int size, const void *priv) } } -struct module_addr_args { - unsigned long *addrs; - u32 addrs_cnt; +struct modules_array { struct module **mods; int mods_cnt; int mods_cap; }; -static int module_callback(void *data, const char *name, - struct module *mod, unsigned long addr) +static int add_module(struct modules_array *arr, struct module *mod) { - struct module_addr_args *args = data; struct module **mods; - /* We iterate all modules symbols and for each we: - * - search for it in provided addresses array - * - if found we check if we already have the module pointer stored - * (we iterate modules sequentially, so we can check just the last - * module pointer) - * - take module reference and store it - */ - if (!bsearch(&addr, args->addrs, args->addrs_cnt, sizeof(addr), - bpf_kprobe_multi_addrs_cmp)) - return 0; - - if (args->mods && args->mods[args->mods_cnt - 1] == mod) - return 0; - - if (args->mods_cnt == args->mods_cap) { - args->mods_cap = max(16, args->mods_cap * 3 / 2); - mods = krealloc_array(args->mods, args->mods_cap, sizeof(*mods), GFP_KERNEL); + if (arr->mods_cnt == arr->mods_cap) { + arr->mods_cap = max(16, arr->mods_cap * 3 / 2); + mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); if (!mods) return -ENOMEM; - args->mods = mods; + arr->mods = mods; } - if (!try_module_get(mod)) - return -EINVAL; - - args->mods[args->mods_cnt] = mod; - args->mods_cnt++; + arr->mods[arr->mods_cnt] = mod; + arr->mods_cnt++; return 0; } +static bool has_module(struct modules_array *arr, struct module *mod) +{ + int i; + + for (i = arr->mods_cnt - 1; i >= 0; i--) { + if (arr->mods[i] == mod) + return true; + } + return false; +} + static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) { - struct module_addr_args args = { - .addrs = addrs, - .addrs_cnt = addrs_cnt, - }; - int err; + struct modules_array arr = {}; + u32 i, err = 0; + + for (i = 0; i < addrs_cnt; i++) { + struct module *mod; + + preempt_disable(); + mod = __module_address(addrs[i]); + /* Either no module or we it's already stored */ + if (!mod || has_module(&arr, mod)) { + preempt_enable(); + continue; + } + if (!try_module_get(mod)) + err = -EINVAL; + preempt_enable(); + if (err) + break; + err = add_module(&arr, mod); + if (err) { + module_put(mod); + break; + } + } /* We return either err < 0 in case of error, ... */ - err = module_kallsyms_on_each_symbol(NULL, module_callback, &args); if (err) { - kprobe_multi_put_modules(args.mods, args.mods_cnt); - kfree(args.mods); + kprobe_multi_put_modules(arr.mods, arr.mods_cnt); + kfree(arr.mods); return err; } /* or number of modules found if everything is ok. */ - *mods = args.mods; - return args.mods_cnt; + *mods = arr.mods; + return arr.mods_cnt; } int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) @@ -2857,13 +2865,6 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr bpf_kprobe_multi_cookie_cmp, bpf_kprobe_multi_cookie_swap, link); - } else { - /* - * We need to sort addrs array even if there are no cookies - * provided, to allow bsearch in get_modules_for_addrs. - */ - sort(addrs, cnt, sizeof(*addrs), - bpf_kprobe_multi_addrs_cmp, NULL); } err = get_modules_for_addrs(&link->mods, addrs, cnt);