From 8a20655749c625dcc4debdfdeeaa0cf8bb85c203 Mon Sep 17 00:00:00 2001 From: Mykyta Yatsenko Date: Wed, 22 Apr 2026 12:41:11 -0700 Subject: [PATCH] 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 Acked-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/bpf/20260422-sleepable_tracepoints-v13-6-99005dff21ef@meta.com Signed-off-by: Kumar Kartikeya Dwivedi --- .../bpf/prog_tests/sleepable_tracepoints.c | 142 ++++++++++++++++++ .../bpf/progs/test_sleepable_tracepoints.c | 112 ++++++++++++++ .../progs/test_sleepable_tracepoints_fail.c | 18 +++ .../selftests/bpf/verifier/sleepable.c | 17 ++- 4 files changed, 287 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/sleepable_tracepoints.c create mode 100644 tools/testing/selftests/bpf/progs/test_sleepable_tracepoints.c create mode 100644 tools/testing/selftests/bpf/progs/test_sleepable_tracepoints_fail.c diff --git a/tools/testing/selftests/bpf/prog_tests/sleepable_tracepoints.c b/tools/testing/selftests/bpf/prog_tests/sleepable_tracepoints.c new file mode 100644 index 0000000000000..19500b785ee32 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/sleepable_tracepoints.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "test_sleepable_tracepoints.skel.h" +#include "test_sleepable_tracepoints_fail.skel.h" + +static void run_test(struct test_sleepable_tracepoints *skel) +{ + char buf[PATH_MAX] = "/"; + + skel->bss->target_pid = getpid(); + skel->bss->prog_triggered = 0; + skel->bss->err = 0; + skel->bss->copied_byte = 0; + + syscall(__NR_getcwd, buf, sizeof(buf)); + + ASSERT_EQ(skel->bss->prog_triggered, 1, "prog_triggered"); + ASSERT_EQ(skel->bss->err, 0, "err"); + ASSERT_EQ(skel->bss->copied_byte, '/', "copied_byte"); +} + +static void run_auto_attach_test(struct bpf_program *prog, + struct test_sleepable_tracepoints *skel) +{ + struct bpf_link *link; + + link = bpf_program__attach(prog); + if (!ASSERT_OK_PTR(link, "prog_attach")) + return; + + run_test(skel); + bpf_link__destroy(link); +} + +static void test_attach_only(struct bpf_program *prog) +{ + struct bpf_link *link; + + link = bpf_program__attach(prog); + if (ASSERT_OK_PTR(link, "attach")) + bpf_link__destroy(link); +} + +static void test_attach_reject(struct bpf_program *prog) +{ + struct bpf_link *link; + + link = bpf_program__attach(prog); + if (!ASSERT_ERR_PTR(link, "attach_should_fail")) + bpf_link__destroy(link); +} + +static void test_raw_tp_bare(struct test_sleepable_tracepoints *skel) +{ + struct bpf_link *link; + + link = bpf_program__attach_raw_tracepoint(skel->progs.handle_raw_tp_bare, + "sys_enter"); + if (ASSERT_OK_PTR(link, "attach")) + bpf_link__destroy(link); +} + +static void test_tp_bare(struct test_sleepable_tracepoints *skel) +{ + struct bpf_link *link; + + link = bpf_program__attach_tracepoint(skel->progs.handle_tp_bare, + "syscalls", "sys_enter_getcwd"); + if (ASSERT_OK_PTR(link, "attach")) + bpf_link__destroy(link); +} + +static void test_test_run(struct test_sleepable_tracepoints *skel) +{ + __u64 args[2] = {0x1234ULL, 0x5678ULL}; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .ctx_in = args, + .ctx_size_in = sizeof(args), + ); + int fd, err; + + fd = bpf_program__fd(skel->progs.handle_test_run); + err = bpf_prog_test_run_opts(fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, args[0] + args[1], "test_run_retval"); +} + +static void test_test_run_on_cpu_reject(struct test_sleepable_tracepoints *skel) +{ + __u64 args[2] = {}; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .ctx_in = args, + .ctx_size_in = sizeof(args), + .flags = BPF_F_TEST_RUN_ON_CPU, + ); + int fd, err; + + fd = bpf_program__fd(skel->progs.handle_test_run); + err = bpf_prog_test_run_opts(fd, &topts); + ASSERT_ERR(err, "test_run_on_cpu_reject"); +} + +void test_sleepable_tracepoints(void) +{ + struct test_sleepable_tracepoints *skel; + + skel = test_sleepable_tracepoints__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_and_load")) + return; + + if (test__start_subtest("tp_btf")) + run_auto_attach_test(skel->progs.handle_sys_enter_tp_btf, skel); + if (test__start_subtest("raw_tp")) + run_auto_attach_test(skel->progs.handle_sys_enter_raw_tp, skel); + if (test__start_subtest("tracepoint")) + run_auto_attach_test(skel->progs.handle_sys_enter_tp, skel); + if (test__start_subtest("sys_exit")) + run_auto_attach_test(skel->progs.handle_sys_exit_tp, skel); + if (test__start_subtest("tracepoint_alias")) + test_attach_only(skel->progs.handle_sys_enter_tp_alias); + if (test__start_subtest("raw_tracepoint_alias")) + test_attach_only(skel->progs.handle_sys_enter_raw_tp_alias); + if (test__start_subtest("raw_tp_bare")) + test_raw_tp_bare(skel); + if (test__start_subtest("tp_bare")) + test_tp_bare(skel); + if (test__start_subtest("test_run")) + test_test_run(skel); + if (test__start_subtest("test_run_on_cpu_reject")) + test_test_run_on_cpu_reject(skel); + if (test__start_subtest("raw_tp_non_faultable")) + test_attach_reject(skel->progs.handle_raw_tp_non_faultable); + if (test__start_subtest("tp_non_syscall")) + test_attach_reject(skel->progs.handle_tp_non_syscall); + if (test__start_subtest("tp_btf_non_faultable_reject")) + RUN_TESTS(test_sleepable_tracepoints_fail); + + test_sleepable_tracepoints__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_sleepable_tracepoints.c b/tools/testing/selftests/bpf/progs/test_sleepable_tracepoints.c new file mode 100644 index 0000000000000..254f7fd895d9f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sleepable_tracepoints.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +int target_pid; +int prog_triggered; +long err; +char copied_byte; + +static int copy_getcwd_arg(char *ubuf) +{ + err = bpf_copy_from_user(&copied_byte, sizeof(copied_byte), ubuf); + if (err) + return err; + + prog_triggered = 1; + return 0; +} + +SEC("tp_btf.s/sys_enter") +int BPF_PROG(handle_sys_enter_tp_btf, struct pt_regs *regs, long id) +{ + if ((bpf_get_current_pid_tgid() >> 32) != target_pid || + id != __NR_getcwd) + return 0; + + return copy_getcwd_arg((void *)PT_REGS_PARM1_SYSCALL(regs)); +} + +SEC("raw_tp.s/sys_enter") +int BPF_PROG(handle_sys_enter_raw_tp, struct pt_regs *regs, long id) +{ + if ((bpf_get_current_pid_tgid() >> 32) != target_pid || + id != __NR_getcwd) + return 0; + + return copy_getcwd_arg((void *)PT_REGS_PARM1_CORE_SYSCALL(regs)); +} + +SEC("tp.s/syscalls/sys_enter_getcwd") +int handle_sys_enter_tp(struct syscall_trace_enter *args) +{ + if ((bpf_get_current_pid_tgid() >> 32) != target_pid) + return 0; + + return copy_getcwd_arg((void *)args->args[0]); +} + +SEC("tp.s/syscalls/sys_exit_getcwd") +int handle_sys_exit_tp(struct syscall_trace_exit *args) +{ + struct pt_regs *regs; + + if ((bpf_get_current_pid_tgid() >> 32) != target_pid) + return 0; + + regs = (struct pt_regs *)bpf_task_pt_regs(bpf_get_current_task_btf()); + return copy_getcwd_arg((void *)PT_REGS_PARM1_CORE_SYSCALL(regs)); +} + +SEC("raw_tp.s") +int BPF_PROG(handle_raw_tp_bare, struct pt_regs *regs, long id) +{ + return 0; +} + +SEC("tp.s") +int handle_tp_bare(void *ctx) +{ + return 0; +} + +SEC("tracepoint.s/syscalls/sys_enter_getcwd") +int handle_sys_enter_tp_alias(struct syscall_trace_enter *args) +{ + return 0; +} + +SEC("raw_tracepoint.s/sys_enter") +int BPF_PROG(handle_sys_enter_raw_tp_alias, struct pt_regs *regs, long id) +{ + return 0; +} + +SEC("raw_tp.s/sys_enter") +int BPF_PROG(handle_test_run, struct pt_regs *regs, long id) +{ + if ((__u64)regs == 0x1234ULL && (__u64)id == 0x5678ULL) + return (__u64)regs + (__u64)id; + + return 0; +} + +SEC("raw_tp.s/sched_switch") +int BPF_PROG(handle_raw_tp_non_faultable, bool preempt, + struct task_struct *prev, struct task_struct *next) +{ + return 0; +} + +SEC("tp.s/sched/sched_switch") +int handle_tp_non_syscall(void *ctx) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/test_sleepable_tracepoints_fail.c b/tools/testing/selftests/bpf/progs/test_sleepable_tracepoints_fail.c new file mode 100644 index 0000000000000..1a0748a9520bb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sleepable_tracepoints_fail.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +/* Sleepable program on a non-faultable tracepoint should fail to load */ +SEC("tp_btf.s/sched_switch") +__failure __msg("Sleepable program cannot attach to non-faultable tracepoint") +int BPF_PROG(handle_sched_switch, bool preempt, + struct task_struct *prev, struct task_struct *next) +{ + return 0; +} diff --git a/tools/testing/selftests/bpf/verifier/sleepable.c b/tools/testing/selftests/bpf/verifier/sleepable.c index c2b7f5ebf168c..6dabc55229455 100644 --- a/tools/testing/selftests/bpf/verifier/sleepable.c +++ b/tools/testing/selftests/bpf/verifier/sleepable.c @@ -76,7 +76,20 @@ .runs = -1, }, { - "sleepable raw tracepoint reject", + "sleepable raw tracepoint accept", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACING, + .expected_attach_type = BPF_TRACE_RAW_TP, + .kfunc = "sys_enter", + .result = ACCEPT, + .flags = BPF_F_SLEEPABLE, + .runs = -1, +}, +{ + "sleepable raw tracepoint reject non-faultable", .insns = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), @@ -85,7 +98,7 @@ .expected_attach_type = BPF_TRACE_RAW_TP, .kfunc = "sched_switch", .result = REJECT, - .errstr = "Only fentry/fexit/fsession/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable", + .errstr = "Sleepable program cannot attach to non-faultable tracepoint", .flags = BPF_F_SLEEPABLE, .runs = -1, }, -- 2.47.3