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 1AD1AC433FE for ; Fri, 18 Nov 2022 02:21:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240752AbiKRCVg (ORCPT ); Thu, 17 Nov 2022 21:21:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240865AbiKRCVW (ORCPT ); Thu, 17 Nov 2022 21:21:22 -0500 Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B57F898EE; Thu, 17 Nov 2022 18:21:05 -0800 (PST) Received: by mail-pj1-x1036.google.com with SMTP id k2-20020a17090a4c8200b002187cce2f92so1858203pjh.2; Thu, 17 Nov 2022 18:21:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=i3BD6KdwfNBTB7Fnsaz9FREs8E44p9DXUf5vn7BdD0w=; b=OTLA+G7SYay4ADMh5CEPzIxBLQEIqE16eawWj64+57dzGEt08SY+rrKvrRF6GeEYKo iM3YJOAVybaIFfSeF/YbOal3UxvOs/kOK+A5T8Y8Vi4lEhLdfnGC1UtN8b5T1mOlKVaA AcfFWZZfIOlohDV6Cutn7un3STbLjeAwaxgMU+UPadSEEv5/Z6zXAXJ6Sbz1Rbza58hw vo8t1Q8SFCmBfJVgvZLIdxKI4TheVrjkFH3m3A5OnnR0JOWlx0IUXlD03t+dkpoKsSii 1RqhXh0WHw/DW8SGM4gH4jR46LdXPtdX4l+1c0jQvdJ/sUqUiel8BwH6LrcTrU17aXCS 20WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=i3BD6KdwfNBTB7Fnsaz9FREs8E44p9DXUf5vn7BdD0w=; b=kEqmRTiHTN6ZyjQRUAYlGPRMpiYUBdyn8S0LHDNn5IVSDdOAKRueqepWEJWTo1BKrH P9gbBGcACaJjTwzxAa+jSbltzakT61YhqgNWIuA+gcKi1D+oCZuOduAOHWAPUe3XH7Np rjSjTW1/qFKi9XhF7mMJ++WqnAqXO6otwx4BrlljIqcoaMBHdvD7mbKMDCbsBlVnHs40 qTvr7B9djuabJCf2DauH3/DU546zaRoU6+w8GENrKPMqmc8YNeQKrFiyNYolJpgUNCC4 r835G+d7AcmepcCQy+qGI2Rs46e1RHkZ7T2hBoJTN9jVZdszjFeFFPP412UrGAcph9Tc U8Pg== X-Gm-Message-State: ANoB5pnGJN+DgEmWrgGUQ/Z79rjQcEnMs0SQogLL+g7RkXAVsymCDQn4 l33K0f6+eQcFT0bEEiUuD+w= X-Google-Smtp-Source: AA0mqf630a3AKhp1spPdsc92llm3gHidXjk95TW+7WJyOu9u8aZoy+uKMxQQNe6ke+ZrSyIxUgKAhQ== X-Received: by 2002:a17:90a:9403:b0:218:6a4e:e44a with SMTP id r3-20020a17090a940300b002186a4ee44amr5817190pjo.6.1668738064853; Thu, 17 Nov 2022 18:21:04 -0800 (PST) Received: from MacBook-Pro-5.local ([2620:10d:c090:400::5:411c]) by smtp.gmail.com with ESMTPSA id q14-20020a170902dace00b00179e1f08634sm2134851plx.222.2022.11.17.18.21.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 18:21:04 -0800 (PST) Date: Thu, 17 Nov 2022 18:21:00 -0800 From: Alexei Starovoitov To: David Vernet Cc: bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, memxor@gmail.com, yhs@fb.com, song@kernel.org, sdf@google.com, john.fastabend@gmail.com, kpsingh@kernel.org, jolsa@kernel.org, haoluo@google.com, tj@kernel.org, kernel-team@fb.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH bpf-next v7 3/3] bpf/selftests: Add selftests for new task kfuncs Message-ID: <20221118022100.qqer2hzuaahcgrml@MacBook-Pro-5.local> References: <20221117032402.2356776-1-void@manifault.com> <20221117032402.2356776-4-void@manifault.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221117032402.2356776-4-void@manifault.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 16, 2022 at 09:24:02PM -0600, David Vernet wrote: > A previous change added a series of kfuncs for storing struct > task_struct objects as referenced kptrs. This patch adds a new > task_kfunc test suite for validating their expected behavior. > > Signed-off-by: David Vernet > --- > tools/testing/selftests/bpf/DENYLIST.s390x | 1 + > .../selftests/bpf/prog_tests/task_kfunc.c | 159 +++++++++++ > .../selftests/bpf/progs/task_kfunc_common.h | 71 +++++ > .../selftests/bpf/progs/task_kfunc_failure.c | 259 ++++++++++++++++++ > .../selftests/bpf/progs/task_kfunc_success.c | 149 ++++++++++ > 5 files changed, 639 insertions(+) > create mode 100644 tools/testing/selftests/bpf/prog_tests/task_kfunc.c > create mode 100644 tools/testing/selftests/bpf/progs/task_kfunc_common.h > create mode 100644 tools/testing/selftests/bpf/progs/task_kfunc_failure.c > create mode 100644 tools/testing/selftests/bpf/progs/task_kfunc_success.c > > diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x > index be4e3d47ea3e..97e522828d6c 100644 > --- a/tools/testing/selftests/bpf/DENYLIST.s390x > +++ b/tools/testing/selftests/bpf/DENYLIST.s390x > @@ -53,6 +53,7 @@ skc_to_unix_sock # could not attach BPF object unexpecte > socket_cookie # prog_attach unexpected error: -524 (trampoline) > stacktrace_build_id # compare_map_keys stackid_hmap vs. stackmap err -2 errno 2 (?) > tailcalls # tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls (?) > +task_kfunc # JIT does not support calling kernel function > task_local_storage # failed to auto-attach program 'trace_exit_creds': -524 (trampoline) > test_bpffs # bpffs test failed 255 (iterator) > test_bprm_opts # failed to auto-attach program 'secure_exec': -524 (trampoline) > diff --git a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c > new file mode 100644 > index 000000000000..a3aa36a4beb3 > --- /dev/null > +++ b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c > @@ -0,0 +1,159 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ > + > +#define _GNU_SOURCE > +#include > +#include > +#include > + > +#include "task_kfunc_failure.skel.h" > +#include "task_kfunc_success.skel.h" > + > +static size_t log_buf_sz = 1 << 20; /* 1 MB */ > +static char obj_log_buf[1048576]; > + > +static struct task_kfunc_success *open_load_task_kfunc_skel(void) > +{ > + struct task_kfunc_success *skel; > + int err; > + > + skel = task_kfunc_success__open(); > + if (!ASSERT_OK_PTR(skel, "skel_open")) > + return NULL; > + > + skel->bss->pid = getpid(); > + > + err = task_kfunc_success__load(skel); > + if (!ASSERT_OK(err, "skel_load")) > + goto cleanup; > + > + return skel; > + > +cleanup: > + task_kfunc_success__destroy(skel); > + return NULL; > +} > + > +static void run_success_test(const char *prog_name) > +{ > + struct task_kfunc_success *skel; > + int status; > + pid_t child_pid; > + struct bpf_program *prog; > + struct bpf_link *link = NULL; > + > + skel = open_load_task_kfunc_skel(); > + if (!ASSERT_OK_PTR(skel, "open_load_skel")) > + return; > + > + if (!ASSERT_OK(skel->bss->err, "pre_spawn_err")) > + goto cleanup; > + > + prog = bpf_object__find_program_by_name(skel->obj, prog_name); > + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) > + goto cleanup; > + > + link = bpf_program__attach(prog); > + if (!ASSERT_OK_PTR(link, "attached_link")) > + goto cleanup; > + > + child_pid = fork(); > + if (!ASSERT_GT(child_pid, -1, "child_pid")) > + goto cleanup; > + if (child_pid == 0) > + _exit(0); > + waitpid(child_pid, &status, 0); > + > + ASSERT_OK(skel->bss->err, "post_wait_err"); > + > +cleanup: > + bpf_link__destroy(link); > + task_kfunc_success__destroy(skel); > +} > + > +static const char * const success_tests[] = { > + "test_task_acquire_release_argument", > + "test_task_acquire_release_current", > + "test_task_acquire_leave_in_map", > + "test_task_xchg_release", > + "test_task_get_release", > + "test_task_current_acquire_release", > +}; > + > +static struct { > + const char *prog_name; > + const char *expected_err_msg; > +} failure_tests[] = { > + {"task_kfunc_acquire_untrusted", "R1 must be referenced or trusted"}, > + {"task_kfunc_acquire_fp", "arg#0 pointer type STRUCT task_struct must point"}, > + {"task_kfunc_acquire_unsafe_kretprobe", "reg type unsupported for arg#0 function"}, > + {"task_kfunc_acquire_trusted_walked", "R1 must be referenced or trusted"}, > + {"task_kfunc_acquire_null", "arg#0 pointer type STRUCT task_struct must point"}, > + {"task_kfunc_acquire_unreleased", "Unreleased reference"}, > + {"task_kfunc_get_non_kptr_param", "arg#0 expected pointer to map value"}, > + {"task_kfunc_get_non_kptr_acquired", "arg#0 expected pointer to map value"}, > + {"task_kfunc_get_null", "arg#0 expected pointer to map value"}, > + {"task_kfunc_xchg_unreleased", "Unreleased reference"}, > + {"task_kfunc_get_unreleased", "Unreleased reference"}, > + {"task_kfunc_release_untrusted", "bpf_task_release arg#0 pointer had unexpected modifiers"}, > + {"task_kfunc_release_fp", "arg#0 pointer type STRUCT task_struct must point"}, > + {"task_kfunc_release_null", "bpf_task_release arg#0 pointer had unexpected modifiers"}, > + {"task_kfunc_release_unacquired", "release kernel function bpf_task_release expects"}, > +}; > + > +static void verify_fail(const char *prog_name, const char *expected_err_msg) > +{ > + LIBBPF_OPTS(bpf_object_open_opts, opts); > + struct task_kfunc_failure *skel; > + int err, i; > + > + opts.kernel_log_buf = obj_log_buf; > + opts.kernel_log_size = log_buf_sz; > + opts.kernel_log_level = 1; > + > + skel = task_kfunc_failure__open_opts(&opts); > + if (!ASSERT_OK_PTR(skel, "task_kfunc_failure__open_opts")) > + goto cleanup; > + > + for (i = 0; i < ARRAY_SIZE(failure_tests); i++) { > + struct bpf_program *prog; > + const char *curr_name = failure_tests[i].prog_name; > + > + prog = bpf_object__find_program_by_name(skel->obj, curr_name); > + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) > + goto cleanup; > + > + bpf_program__set_autoload(prog, !strcmp(curr_name, prog_name)); > + } > + > + err = task_kfunc_failure__load(skel); > + if (!ASSERT_ERR(err, "unexpected load success")) > + goto cleanup; > + > + if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) { > + fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg); > + fprintf(stderr, "Verifier output: %s\n", obj_log_buf); > + } > + > +cleanup: > + task_kfunc_failure__destroy(skel); > +} > + > +void test_task_kfunc(void) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(success_tests); i++) { > + if (!test__start_subtest(success_tests[i])) > + continue; > + > + run_success_test(success_tests[i]); > + } > + > + for (i = 0; i < ARRAY_SIZE(failure_tests); i++) { > + if (!test__start_subtest(failure_tests[i].prog_name)) > + continue; > + > + verify_fail(failure_tests[i].prog_name, failure_tests[i].expected_err_msg); > + } > +} > diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_common.h b/tools/testing/selftests/bpf/progs/task_kfunc_common.h > new file mode 100644 > index 000000000000..8489b952dc49 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/task_kfunc_common.h > @@ -0,0 +1,71 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ > + > +#ifndef _TASK_KFUNC_COMMON_H > +#define _TASK_KFUNC_COMMON_H > + > +#include > +#include > +#include > +#include > + > +struct __tasks_kfunc_map_value { > + struct task_struct __kptr_ref * task; > +}; > + > +struct hash_map { > + __uint(type, BPF_MAP_TYPE_HASH); > + __type(key, int); > + __type(value, struct __tasks_kfunc_map_value); > + __uint(max_entries, 1); > +} __tasks_kfunc_map SEC(".maps"); > + > +struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym; > +struct task_struct *bpf_task_kptr_get(struct task_struct **pp) __ksym; > +void bpf_task_release(struct task_struct *p) __ksym; > + > +static inline struct __tasks_kfunc_map_value *tasks_kfunc_map_value_lookup(struct task_struct *p) > +{ > + s32 pid; > + long status; > + > + status = bpf_probe_read_kernel(&pid, sizeof(pid), &p->pid); > + if (status) > + return NULL; > + > + return bpf_map_lookup_elem(&__tasks_kfunc_map, &pid); > +} > + > +static inline int tasks_kfunc_map_insert(struct task_struct *p) > +{ > + struct __tasks_kfunc_map_value local, *v; > + long status; > + struct task_struct *acquired, *old; > + s32 pid; > + > + status = bpf_probe_read_kernel(&pid, sizeof(pid), &p->pid); > + if (status) > + return status; > + > + local.task = NULL; > + status = bpf_map_update_elem(&__tasks_kfunc_map, &pid, &local, BPF_NOEXIST); > + if (status) > + return status; > + > + v = bpf_map_lookup_elem(&__tasks_kfunc_map, &pid); > + if (!v) { > + bpf_map_delete_elem(&__tasks_kfunc_map, &pid); > + return status; here it will return 0, but probably should be returning error? > + } > + > + acquired = bpf_task_acquire(p); > + old = bpf_kptr_xchg(&v->task, acquired); > + if (old) { > + bpf_task_release(old); > + return -EEXIST; > + } > + > + return 0; > +} > + > +#endif /* _TASK_KFUNC_COMMON_H */ > diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_failure.c b/tools/testing/selftests/bpf/progs/task_kfunc_failure.c > new file mode 100644 > index 000000000000..4c2e8a8f3544 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/task_kfunc_failure.c > @@ -0,0 +1,259 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ > + > +#include > +#include > +#include > + > +#include "task_kfunc_common.h" > + > +char _license[] SEC("license") = "GPL"; > + > +/* Prototype for all of the program trace events below: > + * > + * TRACE_EVENT(task_newtask, > + * TP_PROTO(struct task_struct *p, u64 clone_flags) > + */ > + > +static struct __tasks_kfunc_map_value *insert_lookup_task(struct task_struct *task) > +{ > + int status; > + > + status = tasks_kfunc_map_insert(task); > + if (status) > + return NULL; > + > + return tasks_kfunc_map_value_lookup(task); > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_acquire_untrusted, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired; > + struct __tasks_kfunc_map_value *v; > + > + v = insert_lookup_task(task); > + if (!v) > + return 0; > + > + /* Can't invoke bpf_task_acquire() on an untrusted pointer. */ > + acquired = bpf_task_acquire(v->task); > + bpf_task_release(acquired); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_acquire_fp, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired, *stack_task = (struct task_struct *)&clone_flags; > + > + /* Can't invoke bpf_task_acquire() on a random frame pointer. */ > + acquired = bpf_task_acquire((struct task_struct *)&stack_task); > + bpf_task_release(acquired); > + > + return 0; > +} > + > +SEC("kretprobe/free_task") > +int BPF_PROG(task_kfunc_acquire_unsafe_kretprobe, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired; > + > + acquired = bpf_task_acquire(task); > + /* Can't release a bpf_task_acquire()'d task without a NULL check. */ > + bpf_task_release(acquired); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_acquire_trusted_walked, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired; > + > + /* Can't invoke bpf_task_acquire() on a trusted pointer obtained from walking a struct. */ > + acquired = bpf_task_acquire(task->last_wakee); > + bpf_task_release(acquired); > + > + return 0; > +} > + > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_acquire_null, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired; > + > + /* Can't invoke bpf_task_acquire() on a NULL pointer. */ > + acquired = bpf_task_acquire(NULL); > + if (!acquired) > + return 0; > + bpf_task_release(acquired); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_acquire_unreleased, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired; > + > + acquired = bpf_task_acquire(task); > + > + /* Acquired task is never released. */ > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_get_non_kptr_param, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr; > + > + /* Cannot use bpf_task_kptr_get() on a non-kptr, even on a valid task. */ > + kptr = bpf_task_kptr_get(&task); > + if (!kptr) > + return 0; > + > + bpf_task_release(kptr); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_get_non_kptr_acquired, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr, *acquired; > + > + acquired = bpf_task_acquire(task); > + > + /* Cannot use bpf_task_kptr_get() on a non-kptr, even if it was acquired. */ > + kptr = bpf_task_kptr_get(&acquired); > + bpf_task_release(acquired); > + if (!kptr) > + return 0; > + > + bpf_task_release(kptr); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_get_null, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr; > + > + /* Cannot use bpf_task_kptr_get() on a NULL pointer. */ > + kptr = bpf_task_kptr_get(NULL); > + if (!kptr) > + return 0; > + > + bpf_task_release(kptr); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_xchg_unreleased, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr; > + struct __tasks_kfunc_map_value *v; > + > + v = insert_lookup_task(task); > + if (!v) > + return 0; > + > + kptr = bpf_kptr_xchg(&v->task, NULL); > + if (!kptr) > + return 0; > + > + /* Kptr retrieved from map is never released. */ > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_get_unreleased, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr; > + struct __tasks_kfunc_map_value *v; > + > + v = insert_lookup_task(task); > + if (!v) > + return 0; > + > + kptr = bpf_task_kptr_get(&v->task); > + if (!kptr) > + return 0; > + > + /* Kptr acquired above is never released. */ > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_release_untrusted, struct task_struct *task, u64 clone_flags) > +{ > + struct __tasks_kfunc_map_value *v; > + > + v = insert_lookup_task(task); > + if (!v) > + return 0; > + > + /* Can't invoke bpf_task_release() on an untrusted pointer. */ > + bpf_task_release(v->task); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_release_fp, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *acquired = (struct task_struct *)&clone_flags; > + > + /* Cannot release random frame pointer. */ > + bpf_task_release(acquired); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_release_null, struct task_struct *task, u64 clone_flags) > +{ > + struct __tasks_kfunc_map_value local, *v; > + long status; > + struct task_struct *acquired, *old; > + s32 pid; > + > + status = bpf_probe_read_kernel(&pid, sizeof(pid), &task->pid); > + if (status) > + return 0; > + > + local.task = NULL; > + status = bpf_map_update_elem(&__tasks_kfunc_map, &pid, &local, BPF_NOEXIST); > + if (status) > + return status; > + > + v = bpf_map_lookup_elem(&__tasks_kfunc_map, &pid); > + if (!v) > + return status; should be return error instead? > + > + acquired = bpf_task_acquire(task); > + > + old = bpf_kptr_xchg(&v->task, acquired); > + > + /* old cannot be passed to bpf_task_release() without a NULL check. */ > + bpf_task_release(old); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(task_kfunc_release_unacquired, struct task_struct *task, u64 clone_flags) > +{ > + /* Cannot release trusted task pointer which was not acquired. */ > + bpf_task_release(task); > + > + return 0; > +} > diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c > new file mode 100644 > index 000000000000..be4534b5ba2e > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c > @@ -0,0 +1,149 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ > + > +#include > +#include > +#include > + > +#include "task_kfunc_common.h" > + > +char _license[] SEC("license") = "GPL"; > + > +int err, pid; > + > +/* Prototype for all of the program trace events below: > + * > + * TRACE_EVENT(task_newtask, > + * TP_PROTO(struct task_struct *p, u64 clone_flags) > + */ > + > +static bool is_test_kfunc_task(void) > +{ > + int cur_pid = bpf_get_current_pid_tgid() >> 32; > + > + return pid == cur_pid; > +} > + > +static int test_acquire_release(struct task_struct *task) > +{ > + struct task_struct *acquired; > + > + acquired = bpf_task_acquire(task); > + bpf_task_release(acquired); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_acquire_release_argument, struct task_struct *task, u64 clone_flags) > +{ > + if (!is_test_kfunc_task()) > + return 0; > + > + return test_acquire_release(task); > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_acquire_release_current, struct task_struct *task, u64 clone_flags) > +{ > + if (!is_test_kfunc_task()) > + return 0; > + > + return test_acquire_release(bpf_get_current_task_btf()); > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_acquire_leave_in_map, struct task_struct *task, u64 clone_flags) > +{ > + long status; > + > + if (!is_test_kfunc_task()) > + return 0; > + > + status = tasks_kfunc_map_insert(task); > + if (status) > + err = 1; > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_xchg_release, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr; > + struct __tasks_kfunc_map_value *v; > + long status; > + > + if (!is_test_kfunc_task()) > + return 0; > + > + status = tasks_kfunc_map_insert(task); > + if (status) { > + err = 1; > + return 0; > + } > + > + v = tasks_kfunc_map_value_lookup(task); > + if (!v) { > + err = 2; > + return 0; > + } > + > + kptr = bpf_kptr_xchg(&v->task, NULL); > + if (!kptr) { > + err = 3; > + return 0; > + } > + > + bpf_task_release(kptr); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_get_release, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *kptr; > + struct __tasks_kfunc_map_value *v; > + long status; > + > + if (!is_test_kfunc_task()) > + return 0; > + > + status = tasks_kfunc_map_insert(task); > + if (status) { > + err = 1; > + return 0; > + } > + > + v = tasks_kfunc_map_value_lookup(task); > + if (!v) { > + err = 2; > + return 0; > + } > + > + kptr = bpf_task_kptr_get(&v->task); > + if (!kptr) { > + err = 3; > + return 0; > + } > + > + bpf_task_release(kptr); > + > + return 0; > +} > + > +SEC("tp_btf/task_newtask") > +int BPF_PROG(test_task_current_acquire_release, struct task_struct *task, u64 clone_flags) > +{ > + struct task_struct *current, *acquired; > + > + if (!is_test_kfunc_task()) > + return 0; > + > + current = bpf_get_current_task_btf(); > + acquired = bpf_task_acquire(current); > + bpf_task_release(acquired); > + > + return 0; > +} > -- > 2.38.1 >