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 EF916C433FE for ; Thu, 19 May 2022 20:15:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244650AbiESUPT (ORCPT ); Thu, 19 May 2022 16:15:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230395AbiESUPS (ORCPT ); Thu, 19 May 2022 16:15:18 -0400 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 601AFED8FF; Thu, 19 May 2022 13:15:17 -0700 (PDT) Received: by mail-wm1-x330.google.com with SMTP id n124-20020a1c2782000000b003972dfca96cso1502624wmn.4; Thu, 19 May 2022 13:15:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=R5StGlz1vviurEeHp86Yc0NK8H+s2C5ct2HWFfXOqqI=; b=j2AsJkqpREZDVr3/wq7aBhPed9FdU4CLnUyO+TKagVnoCi9D3Cvo+38/9odRp9/ss4 egPEhRr5tmcCVrEmHJqZMpqS3eRmtevuI5JvI72sPbyiQecTSUfCdqlwLf9GQLbK2nlF qJM8JSjqzGruJ3K3JGZ4eG0f/WKwi/1/lzrL7zCudAyJoCrW1eQfKF/MWxM+AN9VFVOJ 3Qjzu5URJ9U+l4+W7XwCn0c0Z9pmQwslF3H2s8pcOy2zPHltAoVr5IKjHHtdzhA6fzr7 SATwahrsB7oyyBnpbjRJ4Onq6CRmceX7AUQjQDPAj7lF1eoZ2VDbP+k8ANpAmRb1Af+/ WROQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=R5StGlz1vviurEeHp86Yc0NK8H+s2C5ct2HWFfXOqqI=; b=7iyLJ5lI6ou6jqKQJ4iKbRGnDfFee43mwsLKrM0R8V5n59J36hhCnU9IpUMNK006CC +0yPEePNjiV1v9FrEZ5vlryDjUQCdMNFUsj5p6oFFHwbYNoH/gLwlahKFB5LZS4dfN/5 mCgHZR1oCNrCvF0td1JOuCccoPJmGbb4OPXyBwanU2Y/oby3o0veUhkRycb2K5yyey+7 QREhEp3c92IAQ3dpMtSGNtHNhPHgKs6YguPG2mMweKMA8qBkzD/lhIS2y+ky45ZWpTPg HwVl2kQ8aYTAL1LBQddUIsB1NaUoyXEL4ofiZtHyEnrB72gQomPF0dllIz7B2LrVzCrD 9Ikw== X-Gm-Message-State: AOAM531X56ojjmpxbXYQTuiE8/U2Kc2krbAf7iXzBHDB8bEwEFCbSihQ Yo5/RNLqkIkya6RtRC1Be+8= X-Google-Smtp-Source: ABdhPJxLMUXGCou2vx2P8DLUXT8bJ4Al4x/Zussdwmm1ENGEOmVNyzpdtA5dDAtGvqBShdpCvcbZsw== X-Received: by 2002:a1c:acc6:0:b0:38e:b184:7721 with SMTP id v189-20020a1cacc6000000b0038eb1847721mr5350152wme.94.1652991315822; Thu, 19 May 2022 13:15:15 -0700 (PDT) Received: from krava ([95.82.133.179]) by smtp.gmail.com with ESMTPSA id d27-20020adfa41b000000b0020d012692dbsm559144wra.18.2022.05.19.13.15.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 May 2022 13:15:15 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Thu, 19 May 2022 22:15:12 +0200 To: Yonghong Song Cc: Eugene Syromiatnikov , Masami Hiramatsu , Steven Rostedt , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan , linux-kselftest@vger.kernel.org Subject: Re: [PATCH bpf v4 3/3] libbpf, selftests/bpf: pass array of u64 values in kprobe_multi.addrs Message-ID: References: <0f500d9a17dcc1270c581f0b722be8f9d7ce781d.1652982525.git.esyr@redhat.com> <0468355f-1d95-d5df-4560-f9220c7a0d05@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0468355f-1d95-d5df-4560-f9220c7a0d05@fb.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, May 19, 2022 at 12:43:18PM -0700, Yonghong Song wrote: > > > On 5/19/22 11:14 AM, Eugene Syromiatnikov wrote: > > With the interface as defined, it is impossible to pass 64-bit kernel > > addresses from a 32-bit userspace process in BPF_LINK_TYPE_KPROBE_MULTI, > > which severly limits the useability of the interface, change the API > > to accept an array of u64 values instead of (kernel? user?) longs. > > This patch implements the user space part of the change (without > > the relevant kernel changes, since, as of now, an attempt to add > > kprobe_multi link will fail with -EOPNOTSUPP), to avoid changing > > the interface after a release. > > > > Fixes: 5117c26e877352bc ("libbpf: Add bpf_link_create support for multi kprobes") > > Fixes: ddc6b04989eb0993 ("libbpf: Add bpf_program__attach_kprobe_multi_opts function") > > Fixes: f7a11eeccb111854 ("selftests/bpf: Add kprobe_multi attach test") > > Fixes: 9271a0c7ae7a9147 ("selftests/bpf: Add attach test for bpf_program__attach_kprobe_multi_opts") > > Fixes: 2c6401c966ae1fbe ("selftests/bpf: Add kprobe_multi bpf_cookie test") > > Signed-off-by: Eugene Syromiatnikov > > --- > > tools/lib/bpf/bpf.h | 2 +- > > tools/lib/bpf/libbpf.c | 8 ++++---- > > tools/lib/bpf/libbpf.h | 2 +- > > tools/testing/selftests/bpf/prog_tests/bpf_cookie.c | 2 +- > > tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c | 8 ++++---- > > 5 files changed, 11 insertions(+), 11 deletions(-) > > > > diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h > > index f4b4afb..f677602 100644 > > --- a/tools/lib/bpf/bpf.h > > +++ b/tools/lib/bpf/bpf.h > > @@ -417,7 +417,7 @@ struct bpf_link_create_opts { > > __u32 flags; > > __u32 cnt; > > const char **syms; > > - const unsigned long *addrs; > > + const __u64 *addrs; > > Patch 2 and 3 will prevent supporting 64-bit kernel, 32-bit userspace for > kprobe_multi. So effectively, kprobe_multi only supports > 64-bit kernel and 64-bit user space. > This is definitely an option, but it would be great > if other people can chime in as well for whether this choice > is best or not. IIUC patch 3 is preparation for kernel change that will enable 32 bit userspace and 64 bit kernel, and Eugene will send it later sounds good to me jirka > > > const __u64 *cookies; > > } kprobe_multi; > > }; > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > > index 809fe20..03a14a6 100644 > > --- a/tools/lib/bpf/libbpf.c > > +++ b/tools/lib/bpf/libbpf.c > > @@ -10279,7 +10279,7 @@ static bool glob_match(const char *str, const char *pat) > > struct kprobe_multi_resolve { > > const char *pattern; > > - unsigned long *addrs; > > + __u64 *addrs; > > size_t cap; > > size_t cnt; > > }; > > @@ -10294,12 +10294,12 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, > > if (!glob_match(sym_name, res->pattern)) > > return 0; > > - err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long), > > + err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(__u64), > > res->cnt + 1); > > if (err) > > return err; > > - res->addrs[res->cnt++] = (unsigned long) sym_addr; > > + res->addrs[res->cnt++] = sym_addr; > > return 0; > > } > > @@ -10314,7 +10314,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > > }; > > struct bpf_link *link = NULL; > > char errmsg[STRERR_BUFSIZE]; > > - const unsigned long *addrs; > > + const __u64 *addrs; > > int err, link_fd, prog_fd; > > const __u64 *cookies; > > const char **syms; > > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h > > index 05dde85..ec1cb61 100644 > > --- a/tools/lib/bpf/libbpf.h > > +++ b/tools/lib/bpf/libbpf.h > > @@ -431,7 +431,7 @@ struct bpf_kprobe_multi_opts { > > /* array of function symbols to attach */ > > const char **syms; > > /* array of function addresses to attach */ > > - const unsigned long *addrs; > > + const __u64 *addrs; > > /* array of user-provided values fetchable through bpf_get_attach_cookie */ > > const __u64 *cookies; > > /* number of elements in syms/addrs/cookies arrays */ > > diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c > > index 923a613..5aa482a 100644 > > --- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c > > +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c > > @@ -137,7 +137,7 @@ static void kprobe_multi_link_api_subtest(void) > > cookies[6] = 7; > > cookies[7] = 8; > > - opts.kprobe_multi.addrs = (const unsigned long *) &addrs; > > + opts.kprobe_multi.addrs = (const __u64 *) &addrs; > > opts.kprobe_multi.cnt = ARRAY_SIZE(addrs); > > opts.kprobe_multi.cookies = (const __u64 *) &cookies; > > prog_fd = bpf_program__fd(skel->progs.test_kprobe); > > 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 b9876b5..fbf4cf2 100644 > > --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c > > +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c > > @@ -105,7 +105,7 @@ static void test_link_api_addrs(void) > > GET_ADDR("bpf_fentry_test7", addrs[6]); > > GET_ADDR("bpf_fentry_test8", addrs[7]); > > - opts.kprobe_multi.addrs = (const unsigned long*) addrs; > > + opts.kprobe_multi.addrs = (const __u64 *) addrs; > > opts.kprobe_multi.cnt = ARRAY_SIZE(addrs); > > test_link_api(&opts); > > } > > @@ -183,7 +183,7 @@ static void test_attach_api_addrs(void) > > GET_ADDR("bpf_fentry_test7", addrs[6]); > > GET_ADDR("bpf_fentry_test8", addrs[7]); > > - opts.addrs = (const unsigned long *) addrs; > > + opts.addrs = (const __u64 *) addrs; > > opts.cnt = ARRAY_SIZE(addrs); > > test_attach_api(NULL, &opts); > > } > > @@ -241,7 +241,7 @@ static void test_attach_api_fails(void) > > goto cleanup; > > /* fail_2 - both addrs and syms set */ > > - opts.addrs = (const unsigned long *) addrs; > > + opts.addrs = (const __u64 *) addrs; > > opts.syms = syms; > > opts.cnt = ARRAY_SIZE(syms); > > opts.cookies = NULL; > > @@ -255,7 +255,7 @@ static void test_attach_api_fails(void) > > goto cleanup; > > /* fail_3 - pattern and addrs set */ > > - opts.addrs = (const unsigned long *) addrs; > > + opts.addrs = (const __u64 *) addrs; > > opts.syms = NULL; > > opts.cnt = ARRAY_SIZE(syms); > > opts.cookies = NULL;