From patchwork Mon Jul 31 11:13:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13334418 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 021E211C94 for ; Mon, 31 Jul 2023 11:13:21 +0000 (UTC) Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB570E53 for ; Mon, 31 Jul 2023 04:13:19 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id d9443c01a7336-1b8ad907ba4so26415305ad.0 for ; Mon, 31 Jul 2023 04:13:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690801999; x=1691406799; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=FfqZsjQyGTSU0bwRsgZK04gfvIMrCcP+ShIrBEJ4XdE=; b=RANsBFGZeWVdGkG859we/yMYqyfhQ0RD8QfM1JhE2QALhDcG7oJMq60LBz4X6Tpqpc g5rNkQQbULCQniLlSqF9G5p6xV5/gz00Wz/IPhdK0cFhs4RYdjP2+ohfMXh+Ais8c/2Y VuTATUNyn7Uv4n9T9UdDQtFBN5EuUxDuFIwQF9UUBzNjJMIOs5uEr2Gdcf/+chihkK33 KfMZNaIFPfPadYAUp1u2HJXYdrnRUgYWCEHalAe8zADUQ2N/EGmfadKR5uXsOEzPm7O0 miy0qaBvjNkCMZLwHirbmhWbkJfoAs+zl2UeUC0RVh5wCw5a+atp13/rxaPaCj4sBPBO C64Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690801999; x=1691406799; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FfqZsjQyGTSU0bwRsgZK04gfvIMrCcP+ShIrBEJ4XdE=; b=IxTgQLhshze31qXIhv8MoGyef9zC6EwKhfbCZv02fyjBlmrXo2gDJpufmLxLpddsgm n1iyRt241umMr/g6zJ4F8e8VSHgI6m+hvyufp8MBge6CuuU1V4+3G+exG7LbB1Y8bmMi 8HrPPN18sIkWfiORbFunj/T/UbholB63BF/Q80GTZDhKW2gKGBjWG0S+7MXa+K9i94bJ ZNKWDLkwlNjemon3fvDU/WMJTdA6+WZeEYvas/Nghzc1kfU7lR52rqIvY6zWUxMO/2dP Mb1Is5zQkZA4OShEIt84mkT08uBqNzrEA+j9d9h2j8jlb6IpgJGkzmaCVVxyrmT1AH3R w0wA== X-Gm-Message-State: ABy/qLYbqfb121OJ4nhO1am5VKvjKjvLARD6MEzQLeuw53Tiwjeey8K2 +B2D1YHFRTA/VO1Cr/c7TdE= X-Google-Smtp-Source: APBJJlEVDvcrWiU9UP65sXtINMg3Rxc3HMm0Tw6rKAChupp9UbpeOWCkj5g67yXwVyHivhUpJnYjAA== X-Received: by 2002:a17:902:ab96:b0:1bb:9675:8c06 with SMTP id f22-20020a170902ab9600b001bb96758c06mr7185014plr.35.1690801999113; Mon, 31 Jul 2023 04:13:19 -0700 (PDT) Received: from vultr.guest ([2001:19f0:ac02:e1:5400:4ff:fe86:7b43]) by smtp.gmail.com with ESMTPSA id c17-20020a170903235100b001b8422f1000sm8293862plh.201.2023.07.31.04.13.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 04:13:18 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org Cc: bpf@vger.kernel.org, Yafang Shao , Dan Carpenter Subject: [PATCH v3 bpf-next 1/2] bpf: Fix uninitialized symbol in bpf_perf_link_fill_kprobe() Date: Mon, 31 Jul 2023 11:13:12 +0000 Message-Id: <20230731111313.3745-2-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230731111313.3745-1-laoar.shao@gmail.com> References: <20230731111313.3745-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net The patch 1b715e1b0ec5: "bpf: Support ->fill_link_info for perf_event" from Jul 9, 2023, leads to the following Smatch static checker warning: kernel/bpf/syscall.c:3416 bpf_perf_link_fill_kprobe() error: uninitialized symbol 'type'. That can happens when uname is NULL. So fix it by verifying the uname when we really need to fill it. Fixes: 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/bpf/85697a7e-f897-4f74-8b43-82721bebc462@kili.mountain/ Signed-off-by: Yafang Shao Acked-by: Yonghong Song --- kernel/bpf/syscall.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7f4e8c3..166390f 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3378,14 +3378,14 @@ static int bpf_perf_link_fill_common(const struct perf_event *event, if (!ulen ^ !uname) return -EINVAL; - if (!uname) - return 0; err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, probe_offset, probe_addr); if (err) return err; + if (!uname) + return 0; if (buf) { len = strlen(buf); err = bpf_copy_to_user(uname, buf, ulen, len); From patchwork Mon Jul 31 11:13:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13334419 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D680D11C94 for ; Mon, 31 Jul 2023 11:13:24 +0000 (UTC) Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C5A8E4A for ; Mon, 31 Jul 2023 04:13:22 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id d9443c01a7336-1bb775625e2so27577235ad.1 for ; Mon, 31 Jul 2023 04:13:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690802002; x=1691406802; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=6lxfMRYvrLjkrUZbRs5YnuZaxTiCPwVqeQxfB5T48FU=; b=CbTenIduXEqqT2WG4VLZMJLWeWykygtwpatkCSoNoX/MDKLWjjnDyhVuFVWYAla6vI GgZoGSOcNRnw0focrj4sdlYoJebzSF8Qi77ON17h33KmL4qLoMpF7aJQe7C2igerfsKF uKTFHv1FqA8QnzEx3DJg/M4YNL9pXKhmMDLiX84Zyf6tagO72viQKsev1BtKSV0uFT/7 h2rSZgAysgEy9A6jzEPt4GI5846/mcfvyB1GSV7Cqa4aL1FJ56lbKBzf4BhnSJl0egKf 1LE+MG/c2Jnm9OQtJw8bg3KCmtduZ/UeJnDi0grQYTsYKH9BxXh5F9M0vs0AUCP47Pha zqtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690802002; x=1691406802; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6lxfMRYvrLjkrUZbRs5YnuZaxTiCPwVqeQxfB5T48FU=; b=bOf3FSf7lh+hp8AuNbTQOH0BCwUIEFc+6p0tdsVmDoNl7Yl6GdoyOX4klceQRoqjID gjx4YcKoJ7NSuNOvIS0XReD2Tjoez/SVI+rsrhYigrvtyyJFhs/GdDzutov1HBJMbqAx ZXMmQm1Ic/wINIyDbhhceHH3T0pcSkffImO7vmPQ6p9LAv412ixKiqWXUUcw618dXxNA INJUS7tJChKwethVw4SW9ER8VgMkh9Upn0eZqCArxGRNLXzRdHdlLewHs/caoghfmRf4 rO9RdmkEmC0ZmlgmFFvHpYvCrqu4FZN+ouyjDKDCNwuEeIeYZ0pn1t7MlL1LExZ6YKMk apWA== X-Gm-Message-State: ABy/qLYt8z+YQvJigWBl9GBJ6xYc300dDuJpSXPAydC7+hbsSkl01UEN gRlYdRpLtEEBZUkFU3942rU= X-Google-Smtp-Source: APBJJlEQ4Fc9E/BZoaeEexrWt3/AJeGapaAs9VC7higl2SrjsUBmpkgqwWVRx0hicOTzEfGwhDbxHA== X-Received: by 2002:a17:902:e745:b0:1b8:8682:62fb with SMTP id p5-20020a170902e74500b001b8868262fbmr11169390plf.4.1690802001562; Mon, 31 Jul 2023 04:13:21 -0700 (PDT) Received: from vultr.guest ([2001:19f0:ac02:e1:5400:4ff:fe86:7b43]) by smtp.gmail.com with ESMTPSA id c17-20020a170903235100b001b8422f1000sm8293862plh.201.2023.07.31.04.13.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 04:13:20 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org Cc: bpf@vger.kernel.org, Yafang Shao Subject: [PATCH v3 bpf-next 2/2] selftests/bpf: Add selftest for fill_link_info Date: Mon, 31 Jul 2023 11:13:13 +0000 Message-Id: <20230731111313.3745-3-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230731111313.3745-1-laoar.shao@gmail.com> References: <20230731111313.3745-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net Add selftest for the fill_link_info of uprobe, kprobe and tracepoint. The result: $ tools/testing/selftests/bpf/test_progs --name=fill_link_info #79/1 fill_link_info/kprobe_link_info:OK #79/2 fill_link_info/kretprobe_link_info:OK #79/3 fill_link_info/kprobe_fill_invalid_user_buff:OK #79/4 fill_link_info/tracepoint_link_info:OK #79/5 fill_link_info/uprobe_link_info:OK #79/6 fill_link_info/uretprobe_link_info:OK #79/7 fill_link_info/kprobe_multi_link_info:OK #79/8 fill_link_info/kretprobe_multi_link_info:OK #79/9 fill_link_info/kprobe_multi_ubuff:OK #79 fill_link_info:OK Summary: 1/9 PASSED, 0 SKIPPED, 0 FAILED The test case for kprobe_multi won't be run on aarch64, as it is not supported. Signed-off-by: Yafang Shao --- tools/testing/selftests/bpf/DENYLIST.aarch64 | 3 + .../selftests/bpf/prog_tests/fill_link_info.c | 369 +++++++++++++++++++++ .../selftests/bpf/progs/test_fill_link_info.c | 42 +++ 3 files changed, 414 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/fill_link_info.c create mode 100644 tools/testing/selftests/bpf/progs/test_fill_link_info.c diff --git a/tools/testing/selftests/bpf/DENYLIST.aarch64 b/tools/testing/selftests/bpf/DENYLIST.aarch64 index 3b61e8b..b2f46b6 100644 --- a/tools/testing/selftests/bpf/DENYLIST.aarch64 +++ b/tools/testing/selftests/bpf/DENYLIST.aarch64 @@ -12,3 +12,6 @@ kprobe_multi_test/skel_api # libbpf: failed to load BPF sk module_attach # prog 'kprobe_multi': failed to auto-attach: -95 fentry_test/fentry_many_args # fentry_many_args:FAIL:fentry_many_args_attach unexpected error: -524 fexit_test/fexit_many_args # fexit_many_args:FAIL:fexit_many_args_attach unexpected error: -524 +fill_link_info/kprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95 +fill_link_info/kretprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95 +fill_link_info/kprobe_multi_ubuff # bpf_program__attach_kprobe_multi_opts unexpected error: -95 diff --git a/tools/testing/selftests/bpf/prog_tests/fill_link_info.c b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c new file mode 100644 index 0000000..948ae60 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/fill_link_info.c @@ -0,0 +1,369 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 Yafang Shao */ + +#include +#include +#include +#include +#include "trace_helpers.h" +#include "test_fill_link_info.skel.h" + +#define TP_CAT "sched" +#define TP_NAME "sched_switch" +#define KPROBE_FUNC "tcp_rcv_established" +#define UPROBE_FILE "/proc/self/exe" +#define KMULTI_CNT (4) + +/* uprobe attach point */ +static noinline void uprobe_func(void) +{ + asm volatile (""); +} + +static int verify_perf_link_info(int fd, enum bpf_perf_event_type type, long addr, + ssize_t offset, ssize_t entry_offset) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + char buf[PATH_MAX]; + int err = 0; + + memset(&info, 0, sizeof(info)); + buf[0] = '\0'; + +again: + err = bpf_link_get_info_by_fd(fd, &info, &len); + if (!ASSERT_OK(err, "get_link_info")) + return -1; + + switch (info.type) { + case BPF_LINK_TYPE_PERF_EVENT: + if (!ASSERT_EQ(info.perf_event.type, type, "perf_type_match")) + return -1; + + switch (info.perf_event.type) { + case BPF_PERF_EVENT_KPROBE: + case BPF_PERF_EVENT_KRETPROBE: + ASSERT_EQ(info.perf_event.kprobe.offset, offset, "kprobe_offset"); + + /* In case kptr setting is not permitted or MAX_SYMS is reached */ + if (addr) + ASSERT_EQ(info.perf_event.kprobe.addr, addr + entry_offset, + "kprobe_addr"); + + if (!info.perf_event.kprobe.func_name) { + ASSERT_EQ(info.perf_event.kprobe.name_len, 0, "name_len"); + info.perf_event.kprobe.func_name = ptr_to_u64(&buf); + info.perf_event.kprobe.name_len = sizeof(buf); + goto again; + } + + err = strncmp(u64_to_ptr(info.perf_event.kprobe.func_name), KPROBE_FUNC, + strlen(KPROBE_FUNC)); + ASSERT_EQ(err, 0, "cmp_kprobe_func_name"); + break; + case BPF_PERF_EVENT_TRACEPOINT: + if (!info.perf_event.tracepoint.tp_name) { + ASSERT_EQ(info.perf_event.tracepoint.name_len, 0, "name_len"); + info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf); + info.perf_event.tracepoint.name_len = sizeof(buf); + goto again; + } + + err = strncmp(u64_to_ptr(info.perf_event.tracepoint.tp_name), TP_NAME, + strlen(TP_NAME)); + ASSERT_EQ(err, 0, "cmp_tp_name"); + break; + case BPF_PERF_EVENT_UPROBE: + case BPF_PERF_EVENT_URETPROBE: + ASSERT_EQ(info.perf_event.uprobe.offset, offset, "uprobe_offset"); + + if (!info.perf_event.uprobe.file_name) { + ASSERT_EQ(info.perf_event.uprobe.name_len, 0, "name_len"); + info.perf_event.uprobe.file_name = ptr_to_u64(&buf); + info.perf_event.uprobe.name_len = sizeof(buf); + goto again; + } + + err = strncmp(u64_to_ptr(info.perf_event.uprobe.file_name), UPROBE_FILE, + strlen(UPROBE_FILE)); + ASSERT_EQ(err, 0, "cmp_file_name"); + break; + default: + break; + } + break; + default: + switch (type) { + case BPF_PERF_EVENT_KPROBE: + case BPF_PERF_EVENT_KRETPROBE: + case BPF_PERF_EVENT_TRACEPOINT: + case BPF_PERF_EVENT_UPROBE: + case BPF_PERF_EVENT_URETPROBE: + err = -1; + break; + default: + break; + } + break; + } + return err; +} + +static void kprobe_fill_invalid_user_buffer(int fd) +{ + struct bpf_link_info info; + __u32 len = sizeof(info); + int err; + + memset(&info, 0, sizeof(info)); + + info.perf_event.kprobe.func_name = 0x1; /* invalid address */ + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "invalid_buff_and_len"); + + info.perf_event.kprobe.name_len = 64; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EFAULT, "invalid_buff"); + + info.perf_event.kprobe.func_name = 0; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "invalid_len"); + + ASSERT_EQ(info.perf_event.kprobe.addr, 0, "func_addr"); + ASSERT_EQ(info.perf_event.kprobe.offset, 0, "func_offset"); + ASSERT_EQ(info.perf_event.type, 0, "type"); +} + +static void test_kprobe_fill_link_info(struct test_fill_link_info *skel, + enum bpf_perf_event_type type, + bool retprobe, bool invalid) +{ + DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts, + .attach_mode = PROBE_ATTACH_MODE_LINK, + .retprobe = retprobe, + ); + ssize_t offset = 0, entry_offset = 0; + int link_fd, err; + long addr; + + skel->links.kprobe_run = bpf_program__attach_kprobe_opts(skel->progs.kprobe_run, + KPROBE_FUNC, &opts); + if (!ASSERT_OK_PTR(skel->links.kprobe_run, "attach_kprobe")) + return; + + link_fd = bpf_link__fd(skel->links.kprobe_run); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + return; + + addr = ksym_get_addr(KPROBE_FUNC); + if (!invalid) { + /* See also arch_adjust_kprobe_addr(). */ + if (skel->kconfig->CONFIG_X86_KERNEL_IBT) + entry_offset = 4; + err = verify_perf_link_info(link_fd, type, addr, offset, offset ?: entry_offset); + ASSERT_OK(err, "verify_perf_link_info"); + } else { + kprobe_fill_invalid_user_buffer(link_fd); + } + bpf_link__detach(skel->links.kprobe_run); +} + +static void test_tp_fill_link_info(struct test_fill_link_info *skel) +{ + int link_fd, err; + + skel->links.tp_run = bpf_program__attach_tracepoint(skel->progs.tp_run, TP_CAT, TP_NAME); + if (!ASSERT_OK_PTR(skel->links.tp_run, "attach_tp")) + return; + + link_fd = bpf_link__fd(skel->links.tp_run); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + return; + + err = verify_perf_link_info(link_fd, BPF_PERF_EVENT_TRACEPOINT, 0, 0, 0); + ASSERT_OK(err, "verify_perf_link_info"); + bpf_link__detach(skel->links.tp_run); +} + +static void test_uprobe_fill_link_info(struct test_fill_link_info *skel, + enum bpf_perf_event_type type, ssize_t offset, + bool retprobe) +{ + int link_fd, err; + + skel->links.uprobe_run = bpf_program__attach_uprobe(skel->progs.uprobe_run, retprobe, + 0, /* self pid */ + UPROBE_FILE, offset); + if (!ASSERT_OK_PTR(skel->links.uprobe_run, "attach_uprobe")) + return; + + link_fd = bpf_link__fd(skel->links.uprobe_run); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + return; + + err = verify_perf_link_info(link_fd, type, 0, offset, 0); + ASSERT_OK(err, "verify_perf_link_info"); + bpf_link__detach(skel->links.uprobe_run); +} + +static int verify_kmulti_link_info(int fd, const __u64 *addrs, bool retprobe) +{ + __u64 kmulti_addrs[KMULTI_CNT]; + struct bpf_link_info info; + __u32 len = sizeof(info); + int flags, i, err = 0; + + memset(&info, 0, sizeof(info)); + +again: + err = bpf_link_get_info_by_fd(fd, &info, &len); + if (!ASSERT_OK(err, "get_link_info")) + return -1; + + ASSERT_EQ(info.type, BPF_LINK_TYPE_KPROBE_MULTI, "kmulti_type"); + switch (info.type) { + case BPF_LINK_TYPE_KPROBE_MULTI: + ASSERT_EQ(info.kprobe_multi.count, KMULTI_CNT, "func_cnt"); + flags = info.kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN; + if (!retprobe) + ASSERT_EQ(flags, 0, "kmulti_flags"); + else + ASSERT_NEQ(flags, 0, "kretmulti_flags"); + + if (!info.kprobe_multi.addrs) { + info.kprobe_multi.addrs = ptr_to_u64(kmulti_addrs); + goto again; + } + for (i = 0; i < KMULTI_CNT; i++) + ASSERT_EQ(kmulti_addrs[i], addrs[i], "kmulti_addrs"); + break; + default: + err = -1; + break; + } + return err; +} + +static void verify_kmulti_user_buffer(int fd, const __u64 *addrs) +{ + __u64 kmulti_addrs[KMULTI_CNT]; + struct bpf_link_info info; + __u32 len = sizeof(info); + int err, i; + + memset(&info, 0, sizeof(info)); + + info.kprobe_multi.count = KMULTI_CNT; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "no_addr"); + + info.kprobe_multi.addrs = ptr_to_u64(kmulti_addrs); + info.kprobe_multi.count = 0; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EINVAL, "no_cnt"); + + for (i = 0; i < KMULTI_CNT; i++) + kmulti_addrs[i] = 0; + info.kprobe_multi.count = KMULTI_CNT - 1; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -ENOSPC, "smaller_cnt"); + for (i = 0; i < KMULTI_CNT - 1; i++) + ASSERT_EQ(kmulti_addrs[i], addrs[i], "kmulti_addrs"); + ASSERT_EQ(kmulti_addrs[i], 0, "kmulti_addrs"); + + for (i = 0; i < KMULTI_CNT; i++) + kmulti_addrs[i] = 0; + info.kprobe_multi.count = KMULTI_CNT + 1; + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, 0, "bigger_cnt"); + for (i = 0; i < KMULTI_CNT; i++) + ASSERT_EQ(kmulti_addrs[i], addrs[i], "kmulti_addrs"); + + info.kprobe_multi.count = KMULTI_CNT; + info.kprobe_multi.addrs = 0x1; /* invalid addr */ + err = bpf_link_get_info_by_fd(fd, &info, &len); + ASSERT_EQ(err, -EFAULT, "invalid_buff"); +} + +static int symbols_cmp_r(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); +} + +static void test_kprobe_multi_fill_link_info(struct test_fill_link_info *skel, + bool retprobe, bool buffer) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + const char *syms[KMULTI_CNT] = { + "schedule_timeout_interruptible", + "schedule_timeout_uninterruptible", + "schedule_timeout_idle", + "schedule_timeout_killable", + }; + __u64 addrs[KMULTI_CNT]; + int link_fd, i, err = 0; + + qsort(syms, KMULTI_CNT, sizeof(syms[0]), symbols_cmp_r); + opts.syms = syms; + opts.cnt = KMULTI_CNT; + opts.retprobe = retprobe; + skel->links.kmulti_run = bpf_program__attach_kprobe_multi_opts(skel->progs.kmulti_run, + NULL, &opts); + if (!ASSERT_OK_PTR(skel->links.kmulti_run, "attach_kprobe_multi")) + return; + + link_fd = bpf_link__fd(skel->links.kmulti_run); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + return; + + for (i = 0; i < KMULTI_CNT; i++) + addrs[i] = ksym_get_addr(syms[i]); + + if (!buffer) + err = verify_kmulti_link_info(link_fd, addrs, retprobe); + else + verify_kmulti_user_buffer(link_fd, addrs); + ASSERT_OK(err, "verify_kmulti_link_info"); + bpf_link__detach(skel->links.kmulti_run); +} + +void test_fill_link_info(void) +{ + struct test_fill_link_info *skel; + ssize_t offset; + + skel = test_fill_link_info__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + goto cleanup; + + /* load kallsyms to compare the addr */ + if (!ASSERT_OK(load_kallsyms_refresh(), "load_kallsyms_refresh")) + return; + if (test__start_subtest("kprobe_link_info")) + test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, false, false); + if (test__start_subtest("kretprobe_link_info")) + test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KRETPROBE, true, false); + if (test__start_subtest("kprobe_fill_invalid_user_buff")) + test_kprobe_fill_link_info(skel, BPF_PERF_EVENT_KPROBE, false, true); + if (test__start_subtest("tracepoint_link_info")) + test_tp_fill_link_info(skel); + + offset = get_uprobe_offset(&uprobe_func); + if (test__start_subtest("uprobe_link_info")) + test_uprobe_fill_link_info(skel, BPF_PERF_EVENT_UPROBE, offset, false); + if (test__start_subtest("uretprobe_link_info")) + test_uprobe_fill_link_info(skel, BPF_PERF_EVENT_URETPROBE, offset, true); + 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")) + test_kprobe_multi_fill_link_info(skel, true, false); + if (test__start_subtest("kprobe_multi_ubuff")) + test_kprobe_multi_fill_link_info(skel, true, true); + +cleanup: + test_fill_link_info__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_fill_link_info.c b/tools/testing/selftests/bpf/progs/test_fill_link_info.c new file mode 100644 index 0000000..564f402 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_fill_link_info.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 Yafang Shao */ + +#include "vmlinux.h" +#include +#include + +extern bool CONFIG_X86_KERNEL_IBT __kconfig __weak; + +/* This function is here to have CONFIG_X86_KERNEL_IBT + * used and added to object BTF. + */ +int unused(void) +{ + return CONFIG_X86_KERNEL_IBT ? 0 : 1; +} + +SEC("kprobe") +int BPF_PROG(kprobe_run) +{ + return 0; +} + +SEC("uprobe") +int BPF_PROG(uprobe_run) +{ + return 0; +} + +SEC("tracepoint") +int BPF_PROG(tp_run) +{ + return 0; +} + +SEC("kprobe.multi") +int BPF_PROG(kmulti_run) +{ + return 0; +} + +char _license[] SEC("license") = "GPL";