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selftests/bpf: Add tests for sleepable tracepoint programs
Cover all three sleepable tracepoint types (tp_btf.s, raw_tp.s, tp.s) and sys_exit (via bpf_task_pt_regs) with functional tests using bpf_copy_from_user() on getcwd. Verify alias and bare SEC variants, bpf_prog_test_run_raw_tp() with BPF_F_TEST_RUN_ON_CPU rejection, attach-time rejection on non-faultable tracepoints, and load-time rejection for sleepable tp_btf on non-faultable tracepoints. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20260422-sleepable_tracepoints-v13-6-99005dff21ef@meta.com Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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Lines changed: 287 additions & 2 deletions

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‎tools/testing/selftests/bpf/prog_tests/sleepable_tracepoints.c‎

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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
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#include <test_progs.h>
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#include <unistd.h>
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#include "test_sleepable_tracepoints.skel.h"
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#include "test_sleepable_tracepoints_fail.skel.h"
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static void run_test(struct test_sleepable_tracepoints *skel)
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{
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char buf[PATH_MAX] = "/";
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skel->bss->target_pid = getpid();
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skel->bss->prog_triggered = 0;
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skel->bss->err = 0;
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skel->bss->copied_byte = 0;
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syscall(__NR_getcwd, buf, sizeof(buf));
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ASSERT_EQ(skel->bss->prog_triggered, 1, "prog_triggered");
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ASSERT_EQ(skel->bss->err, 0, "err");
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ASSERT_EQ(skel->bss->copied_byte, '/', "copied_byte");
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}
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static void run_auto_attach_test(struct bpf_program *prog,
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struct test_sleepable_tracepoints *skel)
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{
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struct bpf_link *link;
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link = bpf_program__attach(prog);
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if (!ASSERT_OK_PTR(link, "prog_attach"))
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return;
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run_test(skel);
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bpf_link__destroy(link);
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}
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static void test_attach_only(struct bpf_program *prog)
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{
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struct bpf_link *link;
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link = bpf_program__attach(prog);
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if (ASSERT_OK_PTR(link, "attach"))
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bpf_link__destroy(link);
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}
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static void test_attach_reject(struct bpf_program *prog)
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{
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struct bpf_link *link;
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link = bpf_program__attach(prog);
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if (!ASSERT_ERR_PTR(link, "attach_should_fail"))
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bpf_link__destroy(link);
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}
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static void test_raw_tp_bare(struct test_sleepable_tracepoints *skel)
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{
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struct bpf_link *link;
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link = bpf_program__attach_raw_tracepoint(skel->progs.handle_raw_tp_bare,
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"sys_enter");
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if (ASSERT_OK_PTR(link, "attach"))
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bpf_link__destroy(link);
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}
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static void test_tp_bare(struct test_sleepable_tracepoints *skel)
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{
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struct bpf_link *link;
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link = bpf_program__attach_tracepoint(skel->progs.handle_tp_bare,
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"syscalls", "sys_enter_getcwd");
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if (ASSERT_OK_PTR(link, "attach"))
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bpf_link__destroy(link);
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}
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static void test_test_run(struct test_sleepable_tracepoints *skel)
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{
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__u64 args[2] = {0x1234ULL, 0x5678ULL};
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LIBBPF_OPTS(bpf_test_run_opts, topts,
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.ctx_in = args,
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.ctx_size_in = sizeof(args),
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);
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int fd, err;
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fd = bpf_program__fd(skel->progs.handle_test_run);
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err = bpf_prog_test_run_opts(fd, &topts);
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ASSERT_OK(err, "test_run");
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ASSERT_EQ(topts.retval, args[0] + args[1], "test_run_retval");
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}
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static void test_test_run_on_cpu_reject(struct test_sleepable_tracepoints *skel)
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{
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__u64 args[2] = {};
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LIBBPF_OPTS(bpf_test_run_opts, topts,
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.ctx_in = args,
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.ctx_size_in = sizeof(args),
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.flags = BPF_F_TEST_RUN_ON_CPU,
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);
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int fd, err;
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fd = bpf_program__fd(skel->progs.handle_test_run);
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err = bpf_prog_test_run_opts(fd, &topts);
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ASSERT_ERR(err, "test_run_on_cpu_reject");
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}
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void test_sleepable_tracepoints(void)
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{
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struct test_sleepable_tracepoints *skel;
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skel = test_sleepable_tracepoints__open_and_load();
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if (!ASSERT_OK_PTR(skel, "open_and_load"))
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return;
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if (test__start_subtest("tp_btf"))
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run_auto_attach_test(skel->progs.handle_sys_enter_tp_btf, skel);
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if (test__start_subtest("raw_tp"))
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run_auto_attach_test(skel->progs.handle_sys_enter_raw_tp, skel);
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if (test__start_subtest("tracepoint"))
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run_auto_attach_test(skel->progs.handle_sys_enter_tp, skel);
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if (test__start_subtest("sys_exit"))
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run_auto_attach_test(skel->progs.handle_sys_exit_tp, skel);
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if (test__start_subtest("tracepoint_alias"))
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test_attach_only(skel->progs.handle_sys_enter_tp_alias);
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if (test__start_subtest("raw_tracepoint_alias"))
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test_attach_only(skel->progs.handle_sys_enter_raw_tp_alias);
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if (test__start_subtest("raw_tp_bare"))
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test_raw_tp_bare(skel);
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if (test__start_subtest("tp_bare"))
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test_tp_bare(skel);
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if (test__start_subtest("test_run"))
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test_test_run(skel);
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if (test__start_subtest("test_run_on_cpu_reject"))
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test_test_run_on_cpu_reject(skel);
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if (test__start_subtest("raw_tp_non_faultable"))
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test_attach_reject(skel->progs.handle_raw_tp_non_faultable);
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if (test__start_subtest("tp_non_syscall"))
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test_attach_reject(skel->progs.handle_tp_non_syscall);
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if (test__start_subtest("tp_btf_non_faultable_reject"))
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RUN_TESTS(test_sleepable_tracepoints_fail);
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test_sleepable_tracepoints__destroy(skel);
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}

‎tools/testing/selftests/bpf/progs/test_sleepable_tracepoints.c‎

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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
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#include <vmlinux.h>
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#include <asm/unistd.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_core_read.h>
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#include <bpf/bpf_helpers.h>
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char _license[] SEC("license") = "GPL";
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int target_pid;
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int prog_triggered;
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long err;
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char copied_byte;
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static int copy_getcwd_arg(char *ubuf)
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{
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err = bpf_copy_from_user(&copied_byte, sizeof(copied_byte), ubuf);
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if (err)
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return err;
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prog_triggered = 1;
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return 0;
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}
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SEC("tp_btf.s/sys_enter")
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int BPF_PROG(handle_sys_enter_tp_btf, struct pt_regs *regs, long id)
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{
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if ((bpf_get_current_pid_tgid() >> 32) != target_pid ||
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id != __NR_getcwd)
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return 0;
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return copy_getcwd_arg((void *)PT_REGS_PARM1_SYSCALL(regs));
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}
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SEC("raw_tp.s/sys_enter")
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int BPF_PROG(handle_sys_enter_raw_tp, struct pt_regs *regs, long id)
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{
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if ((bpf_get_current_pid_tgid() >> 32) != target_pid ||
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id != __NR_getcwd)
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return 0;
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return copy_getcwd_arg((void *)PT_REGS_PARM1_CORE_SYSCALL(regs));
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}
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SEC("tp.s/syscalls/sys_enter_getcwd")
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int handle_sys_enter_tp(struct syscall_trace_enter *args)
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{
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if ((bpf_get_current_pid_tgid() >> 32) != target_pid)
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return 0;
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return copy_getcwd_arg((void *)args->args[0]);
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}
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SEC("tp.s/syscalls/sys_exit_getcwd")
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int handle_sys_exit_tp(struct syscall_trace_exit *args)
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{
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struct pt_regs *regs;
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if ((bpf_get_current_pid_tgid() >> 32) != target_pid)
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return 0;
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regs = (struct pt_regs *)bpf_task_pt_regs(bpf_get_current_task_btf());
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return copy_getcwd_arg((void *)PT_REGS_PARM1_CORE_SYSCALL(regs));
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}
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SEC("raw_tp.s")
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int BPF_PROG(handle_raw_tp_bare, struct pt_regs *regs, long id)
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{
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return 0;
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}
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SEC("tp.s")
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int handle_tp_bare(void *ctx)
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{
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return 0;
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}
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SEC("tracepoint.s/syscalls/sys_enter_getcwd")
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int handle_sys_enter_tp_alias(struct syscall_trace_enter *args)
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{
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return 0;
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}
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SEC("raw_tracepoint.s/sys_enter")
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int BPF_PROG(handle_sys_enter_raw_tp_alias, struct pt_regs *regs, long id)
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{
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return 0;
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}
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SEC("raw_tp.s/sys_enter")
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int BPF_PROG(handle_test_run, struct pt_regs *regs, long id)
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{
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if ((__u64)regs == 0x1234ULL && (__u64)id == 0x5678ULL)
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return (__u64)regs + (__u64)id;
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return 0;
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}
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SEC("raw_tp.s/sched_switch")
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int BPF_PROG(handle_raw_tp_non_faultable, bool preempt,
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struct task_struct *prev, struct task_struct *next)
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{
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return 0;
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}
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SEC("tp.s/sched/sched_switch")
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int handle_tp_non_syscall(void *ctx)
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{
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return 0;
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}

‎tools/testing/selftests/bpf/progs/test_sleepable_tracepoints_fail.c‎

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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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char _license[] SEC("license") = "GPL";
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/* Sleepable program on a non-faultable tracepoint should fail to load */
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SEC("tp_btf.s/sched_switch")
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__failure __msg("Sleepable program cannot attach to non-faultable tracepoint")
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int BPF_PROG(handle_sched_switch, bool preempt,
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struct task_struct *prev, struct task_struct *next)
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{
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return 0;
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}

‎tools/testing/selftests/bpf/verifier/sleepable.c‎

Lines changed: 15 additions & 2 deletions
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.runs = -1,
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},
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{
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"sleepable raw tracepoint reject",
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"sleepable raw tracepoint accept",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_TRACING,
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.expected_attach_type = BPF_TRACE_RAW_TP,
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.kfunc = "sys_enter",
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.result = ACCEPT,
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.flags = BPF_F_SLEEPABLE,
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.runs = -1,
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},
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{
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"sleepable raw tracepoint reject non-faultable",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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.expected_attach_type = BPF_TRACE_RAW_TP,
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.kfunc = "sched_switch",
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.result = REJECT,
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.errstr = "Only fentry/fexit/fsession/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable",
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.errstr = "Sleepable program cannot attach to non-faultable tracepoint",
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.flags = BPF_F_SLEEPABLE,
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.runs = -1,
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},

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