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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 610FAC71153 for ; Mon, 4 Sep 2023 19:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8tAXnYyt5Up+sIQ21UeVYFii6bHl5JOzYtPpk31Tztw=; b=fgpOnVEffAhahM rYoavjE3LlKuz0cJ7MON9Jm2OfIMWPqlZPtM0czuv0x2egnLVJ4DepvhLK1fgPAimoNIwQyAIKci3 6MrRZyNuQ5TVly787oZWpSCtunRxr/HWNB32TxL63HJWe4R2Qba1mFcMmak8Vw+tXjEtKebMMVyyg DZlNT7G+Xde79axtFoPE05wKsF2VddvljnBxjKMent8kszsGfue5hM2q7QcMx8a65st5JU+MkSKpo aLygL0nQGBUTMUZwngIiEBcSeqfD8CM21pJDxFqdtBwV8HXvsWdJ4xhEbNBXYQ9ipr0CUqSQStcAc y5CkJN0MJTZN1RLi5igQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qdFbY-004ib1-2x; Mon, 04 Sep 2023 19:51:24 +0000 Received: from mail-lf1-x134.google.com ([2a00:1450:4864:20::134]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qdFbU-004iaI-0k for linux-arm-kernel@lists.infradead.org; Mon, 04 Sep 2023 19:51:22 +0000 Received: by mail-lf1-x134.google.com with SMTP id 2adb3069b0e04-500b0f06136so3157356e87.0 for ; Mon, 04 Sep 2023 12:51:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1693857073; x=1694461873; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=3AUBpdzY9yVap/s/23ZdGK7PcPt7+ENwXsRxdz18Anc=; b=aPGkZ9wOrgT531m3D45GvU9DLQlDAaoDREroXYP8nYnWJYw075Vj9KqNyfKdNF6z2Q 48P1Q/mssUS5lk0de7YdOw6CtD1q+X12ip9x7H5H+la1m+oWlwlBIcOO0HcmaEgV90kS 9xbDjKkWtet2LjmAbBVDc0cypsq2yEilg/FRAbxeo1eXMsnTvbA8yPY+9kGhA7suwKLk GXRMPDX46VqkqaKTeciCezvV8ZvjQVrIOoAPadU+UqJBQCfJpuMPHSzYWrzSQ0FN1reg 31gAn66mTSBuDRvCoUTPcPSBN/6UCmtCnGqWyLO04WAw+ZhghvspVOMh047petUKXtKu t/4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693857073; x=1694461873; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=3AUBpdzY9yVap/s/23ZdGK7PcPt7+ENwXsRxdz18Anc=; b=iZrfI+XJyYqFb60ZvFZIuE6JcrV1wLU/bTAXq8km/w8J0uiLLmOvLAELrYN9KVV4Ly NCS+eU4TvtIo8WJ/Je16rpaJBXUS69Xc4Wh6QCyNU3B130zTRgdSY8lJOleCnigwSdpZ 8MEXs4oMA97mbCgT8hkTUEUOZ4toEzzSc91lRQSbeC02n7hDq4Frk+9F+Hvmt6KOnkJP k6F14HEGngsrWl5+91MpE0d0IXZ1fp4U5Ue1IH/SSAcmz8aQMsjclPXDWEL/afT1pw1V R8x5DIHtRv/otAvExVGhcdLbSxclNQRvJyEh2jCCiQiSyipLOktHtskxe7RAg7l08rc1 01Tg== X-Gm-Message-State: AOJu0YwvbxeZ9C5+qQLm2xXmrQ4IrVboab1KD4Gn0DvxbK479yg/ujgo Hn7bYFzc87oCCnh5tqkHcjk= X-Google-Smtp-Source: AGHT+IEe5hqM2tLSPD19i5CtW5J/dyVWXpmEWt1LF6g64hsvkH9kl2jvCYwAFLOu+VdQnzFX3w1cLA== X-Received: by 2002:a19:ca12:0:b0:500:dc8d:c344 with SMTP id a18-20020a19ca12000000b00500dc8dc344mr6345801lfg.48.1693857072696; Mon, 04 Sep 2023 12:51:12 -0700 (PDT) Received: from krava ([83.240.60.62]) by smtp.gmail.com with ESMTPSA id qc8-20020a170906d8a800b0099275c59bc9sm6560549ejb.33.2023.09.04.12.51.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Sep 2023 12:51:12 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Mon, 4 Sep 2023 21:51:10 +0200 To: Rong Tao Cc: olsajiri@gmail.com, andrii@kernel.org, daniel@iogearbox.net, sdf@google.com, Rong Tao , Alexei Starovoitov , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Hao Luo , Mykola Lysenko , Shuah Khan , Maxime Coquelin , Alexandre Torgue , Yafang Shao , "open list:BPF [GENERAL] (Safe Dynamic Programs and Tools)" , open list , "open list:KERNEL SELFTEST FRAMEWORK" , "moderated list:ARM/STM32 ARCHITECTURE" , "moderated list:ARM/STM32 ARCHITECTURE" Subject: Re: [PATCH bpf-next v10 1/2] selftests/bpf: trace_helpers.c: optimize kallsyms cache Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230904_125120_295765_EDBDB2A1 X-CRM114-Status: GOOD ( 32.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Sep 04, 2023 at 09:01:20AM +0800, Rong Tao wrote: > From: Rong Tao > > Static ksyms often have problems because the number of symbols exceeds the > MAX_SYMS limit. Like changing the MAX_SYMS from 300000 to 400000 in > commit e76a014334a6("selftests/bpf: Bump and validate MAX_SYMS") solves > the problem somewhat, but it's not the perfect way. > > This commit uses dynamic memory allocation, which completely solves the > problem caused by the limitation of the number of kallsyms. At the same > time, add APIs: > > load_kallsyms_local() > ksym_search_local() > ksym_get_addr_local() missing free_kallsyms_local > diff --git a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c > index 9d768e083714..13e618317c8b 100644 > --- a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c > +++ b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c > @@ -302,16 +302,18 @@ void test_fill_link_info(void) > { > struct test_fill_link_info *skel; > int i; > + struct ksyms *ksyms; > > skel = test_fill_link_info__open_and_load(); > if (!ASSERT_OK_PTR(skel, "skel_open")) > return; > > /* load kallsyms to compare the addr */ > - if (!ASSERT_OK(load_kallsyms_refresh(), "load_kallsyms_refresh")) > + ksyms = load_kallsyms_local(); > + if (!ASSERT_OK_PTR(ksyms, "load_kallsyms_local")) > goto cleanup; actually I don't see why this test should need refreshed kallsyms, it doesn't load/unload testmod, I think it can use global ksyms > > - kprobe_addr = ksym_get_addr(KPROBE_FUNC); > + kprobe_addr = ksym_get_addr_local(ksyms, KPROBE_FUNC); > if (test__start_subtest("kprobe_link_info")) > test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, false); > if (test__start_subtest("kretprobe_link_info")) > @@ -329,7 +331,7 @@ void test_fill_link_info(void) > > qsort(kmulti_syms, KMULTI_CNT, sizeof(kmulti_syms[0]), symbols_cmp_r); > for (i = 0; i < KMULTI_CNT; i++) > - kmulti_addrs[i] = ksym_get_addr(kmulti_syms[i]); > + kmulti_addrs[i] = ksym_get_addr_local(ksyms, kmulti_syms[i]); > if (test__start_subtest("kprobe_multi_link_info")) > test_kprobe_multi_fill_link_info(skel, false, false); > if (test__start_subtest("kretprobe_multi_link_info")) > @@ -339,4 +341,5 @@ void test_fill_link_info(void) > > cleanup: > test_fill_link_info__destroy(skel); > + free_kallsyms_local(ksyms); > } > diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c > index 1fbe7e4ac00a..532b05ae2da4 100644 > --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c > +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c > @@ -4,6 +4,8 @@ > #include "trace_helpers.h" > #include "bpf/libbpf_internal.h" > > +static struct ksyms *ksyms; > + > static void kprobe_multi_testmod_check(struct kprobe_multi *skel) > { > ASSERT_EQ(skel->bss->kprobe_testmod_test1_result, 1, "kprobe_test1_result"); > @@ -50,12 +52,12 @@ static void test_testmod_attach_api_addrs(void) > LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); > unsigned long long addrs[3]; > > - addrs[0] = ksym_get_addr("bpf_testmod_fentry_test1"); > - ASSERT_NEQ(addrs[0], 0, "ksym_get_addr"); > - addrs[1] = ksym_get_addr("bpf_testmod_fentry_test2"); > - ASSERT_NEQ(addrs[1], 0, "ksym_get_addr"); > - addrs[2] = ksym_get_addr("bpf_testmod_fentry_test3"); > - ASSERT_NEQ(addrs[2], 0, "ksym_get_addr"); > + addrs[0] = ksym_get_addr_local(ksyms, "bpf_testmod_fentry_test1"); > + ASSERT_NEQ(addrs[0], 0, "ksym_get_addr_local"); > + addrs[1] = ksym_get_addr_local(ksyms, "bpf_testmod_fentry_test2"); > + ASSERT_NEQ(addrs[1], 0, "ksym_get_addr_local"); > + addrs[2] = ksym_get_addr_local(ksyms, "bpf_testmod_fentry_test3"); > + ASSERT_NEQ(addrs[2], 0, "ksym_get_addr_local"); > > opts.addrs = (const unsigned long *) addrs; > opts.cnt = ARRAY_SIZE(addrs); > @@ -79,11 +81,19 @@ static void test_testmod_attach_api_syms(void) > > void serial_test_kprobe_multi_testmod_test(void) > { > - if (!ASSERT_OK(load_kallsyms_refresh(), "load_kallsyms_refresh")) > + ksyms = load_kallsyms_local(); > + if (!ASSERT_OK_PTR(ksyms, "load_kallsyms_local")) > return; > > if (test__start_subtest("testmod_attach_api_syms")) > test_testmod_attach_api_syms(); > + > + ksyms = load_kallsyms_refresh(ksyms); > + if (!ASSERT_OK_PTR(ksyms, "load_kallsyms_refresh")) > + return; hm, this refresh is not needed right? the test got the fresh kallsyms above and both test_testmod_attach_api_syms and test_testmod_attach_api_addrs should be happy > + > if (test__start_subtest("testmod_attach_api_addrs")) > test_testmod_attach_api_addrs(); > + > + free_kallsyms_local(ksyms); > } > diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c > index f83d9f65c65b..d64c4ef336e1 100644 > --- a/tools/testing/selftests/bpf/trace_helpers.c > +++ b/tools/testing/selftests/bpf/trace_helpers.c > @@ -14,104 +14,171 @@ > #include > #include > #include > +#include "bpf/libbpf_internal.h" > > #define TRACEFS_PIPE "/sys/kernel/tracing/trace_pipe" > #define DEBUGFS_PIPE "/sys/kernel/debug/tracing/trace_pipe" > > -#define MAX_SYMS 400000 > -static struct ksym syms[MAX_SYMS]; > -static int sym_cnt; > +struct ksyms { > + struct ksym *syms; > + size_t sym_cap; > + size_t sym_cnt; > +}; > + > +static struct ksyms *ksyms; > + > +static int ksyms__add_symbol(struct ksyms *ksyms, const char *name, > + unsigned long addr) extra white space in here ^^^ > +{ > + void *tmp; > + > + tmp = strdup(name); > + if (!tmp) > + return -ENOMEM; > + ksyms->syms[ksyms->sym_cnt].addr = addr; > + ksyms->syms[ksyms->sym_cnt].name = tmp; > + > + ksyms->sym_cnt++; > + > + return 0; > +} > + > +void free_kallsyms_local(struct ksyms *ksyms) > +{ > + unsigned int i; > + > + if (!ksyms) > + return; > + > + if (!ksyms->syms) { > + free(ksyms); > + return; > + } > + > + for (i = 0; i < ksyms->sym_cnt; i++) > + free(ksyms->syms[i].name); > + free(ksyms->syms); > + free(ksyms); > +} > > static int ksym_cmp(const void *p1, const void *p2) > { > return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr; > } > > -int load_kallsyms_refresh(void) > +struct ksyms *load_kallsyms_refresh(struct ksyms *ksyms) > { > FILE *f; > char func[256], buf[256]; > char symbol; > void *addr; > - int i = 0; > + int ret; > > - sym_cnt = 0; > + /* flush kallsyms, free the previously allocated dynamic memory */ > + free_kallsyms_local(ksyms); > > f = fopen("/proc/kallsyms", "r"); > if (!f) > - return -ENOENT; > + return NULL; > + > + ksyms = calloc(1, sizeof(struct ksyms)); > + if (!ksyms) > + return NULL; I wonder it could be easier not to allocate ksyms, but just let the caller to pass the pointer to 'ksym' variable on stack.. but there might be other problems, so I guess this is fine > > while (fgets(buf, sizeof(buf), f)) { > if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3) > break; > if (!addr) > continue; > - if (i >= MAX_SYMS) > - return -EFBIG; > > - syms[i].addr = (long) addr; > - syms[i].name = strdup(func); > - i++; > + ret = libbpf_ensure_mem((void **) &ksyms->syms, &ksyms->sym_cap, > + sizeof(struct ksym), ksyms->sym_cnt + 1); > + if (ret) > + goto error; > + ret = ksyms__add_symbol(ksyms, func, (unsigned long)addr); > + if (ret) > + goto error; > } > fclose(f); > - sym_cnt = i; > - qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp); > - return 0; > + qsort(ksyms->syms, ksyms->sym_cnt, sizeof(struct ksym), ksym_cmp); > + return ksyms; > + > +error: > + free_kallsyms_local(ksyms); > + return NULL; > +} > + > +struct ksyms *load_kallsyms_local(void) > +{ > + return load_kallsyms_refresh(NULL); I think we can have just: struct ksyms *load_kallsyms_local(struct ksyms *ksyms); I don't see reason for load_kallsyms_refresh functions, perhaps it's leftover because I don't see the function in the changelog thanks, jirka _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel