From 0cf7052a55128f7fd7905f6ae6eb995d6db76b52 Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Mon, 23 May 2022 14:07:12 -0700 Subject: [PATCH] selftests/bpf: Dynptr tests This patch adds tests for dynptrs, which include cases that the verifier needs to reject (for example, a bpf_ringbuf_reserve_dynptr without a corresponding bpf_ringbuf_submit/discard_dynptr) as well as cases that should successfully pass. Signed-off-by: Joanne Koong Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220523210712.3641569-7-joannelkoong@gmail.com --- .../testing/selftests/bpf/prog_tests/dynptr.c | 137 ++++ .../testing/selftests/bpf/progs/dynptr_fail.c | 588 ++++++++++++++++++ .../selftests/bpf/progs/dynptr_success.c | 164 +++++ 3 files changed, 889 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/dynptr_fail.c create mode 100644 tools/testing/selftests/bpf/progs/dynptr_success.c diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c new file mode 100644 index 000000000000..3c7aa82b98e2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Facebook */ + +#include +#include "dynptr_fail.skel.h" +#include "dynptr_success.skel.h" + +static size_t log_buf_sz = 1048576; /* 1 MB */ +static char obj_log_buf[1048576]; + +static struct { + const char *prog_name; + const char *expected_err_msg; +} dynptr_tests[] = { + /* failure cases */ + {"ringbuf_missing_release1", "Unreleased reference id=1"}, + {"ringbuf_missing_release2", "Unreleased reference id=2"}, + {"ringbuf_missing_release_callback", "Unreleased reference id"}, + {"use_after_invalid", "Expected an initialized dynptr as arg #3"}, + {"ringbuf_invalid_api", "type=mem expected=alloc_mem"}, + {"add_dynptr_to_map1", "invalid indirect read from stack"}, + {"add_dynptr_to_map2", "invalid indirect read from stack"}, + {"data_slice_out_of_bounds_ringbuf", "value is outside of the allowed memory range"}, + {"data_slice_out_of_bounds_map_value", "value is outside of the allowed memory range"}, + {"data_slice_use_after_release", "invalid mem access 'scalar'"}, + {"data_slice_missing_null_check1", "invalid mem access 'mem_or_null'"}, + {"data_slice_missing_null_check2", "invalid mem access 'mem_or_null'"}, + {"invalid_helper1", "invalid indirect read from stack"}, + {"invalid_helper2", "Expected an initialized dynptr as arg #3"}, + {"invalid_write1", "Expected an initialized dynptr as arg #1"}, + {"invalid_write2", "Expected an initialized dynptr as arg #3"}, + {"invalid_write3", "Expected an initialized ringbuf dynptr as arg #1"}, + {"invalid_write4", "arg 1 is an unacquired reference"}, + {"invalid_read1", "invalid read from stack"}, + {"invalid_read2", "cannot pass in dynptr at an offset"}, + {"invalid_read3", "invalid read from stack"}, + {"invalid_read4", "invalid read from stack"}, + {"invalid_offset", "invalid write to stack"}, + {"global", "type=map_value expected=fp"}, + {"release_twice", "arg 1 is an unacquired reference"}, + {"release_twice_callback", "arg 1 is an unacquired reference"}, + {"dynptr_from_mem_invalid_api", + "Unsupported reg type fp for bpf_dynptr_from_mem data"}, + + /* success cases */ + {"test_read_write", NULL}, + {"test_data_slice", NULL}, + {"test_ringbuf", NULL}, +}; + +static void verify_fail(const char *prog_name, const char *expected_err_msg) +{ + LIBBPF_OPTS(bpf_object_open_opts, opts); + struct bpf_program *prog; + struct dynptr_fail *skel; + int err; + + opts.kernel_log_buf = obj_log_buf; + opts.kernel_log_size = log_buf_sz; + opts.kernel_log_level = 1; + + skel = dynptr_fail__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "dynptr_fail__open_opts")) + 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; + + bpf_program__set_autoload(prog, true); + + bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize()); + + err = dynptr_fail__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: + dynptr_fail__destroy(skel); +} + +static void verify_success(const char *prog_name) +{ + struct dynptr_success *skel; + struct bpf_program *prog; + struct bpf_link *link; + + skel = dynptr_success__open(); + if (!ASSERT_OK_PTR(skel, "dynptr_success__open")) + return; + + skel->bss->pid = getpid(); + + bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize()); + + dynptr_success__load(skel); + if (!ASSERT_OK_PTR(skel, "dynptr_success__load")) + 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, "bpf_program__attach")) + goto cleanup; + + usleep(1); + + ASSERT_EQ(skel->bss->err, 0, "err"); + + bpf_link__destroy(link); + +cleanup: + dynptr_success__destroy(skel); +} + +void test_dynptr(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(dynptr_tests); i++) { + if (!test__start_subtest(dynptr_tests[i].prog_name)) + continue; + + if (dynptr_tests[i].expected_err_msg) + verify_fail(dynptr_tests[i].prog_name, + dynptr_tests[i].expected_err_msg); + else + verify_success(dynptr_tests[i].prog_name); + } +} diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c new file mode 100644 index 000000000000..d811cff73597 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -0,0 +1,588 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Facebook */ + +#include +#include +#include +#include +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +struct test_info { + int x; + struct bpf_dynptr ptr; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, struct bpf_dynptr); +} array_map1 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, struct test_info); +} array_map2 SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} array_map3 SEC(".maps"); + +struct sample { + int pid; + long value; + char comm[16]; +}; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); +} ringbuf SEC(".maps"); + +int err, val; + +static int get_map_val_dynptr(struct bpf_dynptr *ptr) +{ + __u32 key = 0, *map_val; + + bpf_map_update_elem(&array_map3, &key, &val, 0); + + map_val = bpf_map_lookup_elem(&array_map3, &key); + if (!map_val) + return -ENOENT; + + bpf_dynptr_from_mem(map_val, sizeof(*map_val), 0, ptr); + + return 0; +} + +/* Every bpf_ringbuf_reserve_dynptr call must have a corresponding + * bpf_ringbuf_submit/discard_dynptr call + */ +SEC("?raw_tp/sys_nanosleep") +int ringbuf_missing_release1(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + /* missing a call to bpf_ringbuf_discard/submit_dynptr */ + + return 0; +} + +SEC("?raw_tp/sys_nanosleep") +int ringbuf_missing_release2(void *ctx) +{ + struct bpf_dynptr ptr1, ptr2; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr1); + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr2); + + sample = bpf_dynptr_data(&ptr1, 0, sizeof(*sample)); + if (!sample) { + bpf_ringbuf_discard_dynptr(&ptr1, 0); + bpf_ringbuf_discard_dynptr(&ptr2, 0); + return 0; + } + + bpf_ringbuf_submit_dynptr(&ptr1, 0); + + /* missing a call to bpf_ringbuf_discard/submit_dynptr on ptr2 */ + + return 0; +} + +static int missing_release_callback_fn(__u32 index, void *data) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + /* missing a call to bpf_ringbuf_discard/submit_dynptr */ + + return 0; +} + +/* Any dynptr initialized within a callback must have bpf_dynptr_put called */ +SEC("?raw_tp/sys_nanosleep") +int ringbuf_missing_release_callback(void *ctx) +{ + bpf_loop(10, missing_release_callback_fn, NULL, 0); + return 0; +} + +/* Can't call bpf_ringbuf_submit/discard_dynptr on a non-initialized dynptr */ +SEC("?raw_tp/sys_nanosleep") +int ringbuf_release_uninit_dynptr(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* A dynptr can't be used after it has been invalidated */ +SEC("?raw_tp/sys_nanosleep") +int use_after_invalid(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(read_data), 0, &ptr); + + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0); + + return 0; +} + +/* Can't call non-dynptr ringbuf APIs on a dynptr ringbuf sample */ +SEC("?raw_tp/sys_nanosleep") +int ringbuf_invalid_api(void *ctx) +{ + struct bpf_dynptr ptr; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr); + sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample)); + if (!sample) + goto done; + + sample->pid = 123; + + /* invalid API use. need to use dynptr API to submit/discard */ + bpf_ringbuf_submit(sample, 0); + +done: + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* Can't add a dynptr to a map */ +SEC("?raw_tp/sys_nanosleep") +int add_dynptr_to_map1(void *ctx) +{ + struct bpf_dynptr ptr; + int key = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + /* this should fail */ + bpf_map_update_elem(&array_map1, &key, &ptr, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* Can't add a struct with an embedded dynptr to a map */ +SEC("?raw_tp/sys_nanosleep") +int add_dynptr_to_map2(void *ctx) +{ + struct test_info x; + int key = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &x.ptr); + + /* this should fail */ + bpf_map_update_elem(&array_map2, &key, &x, 0); + + bpf_ringbuf_submit_dynptr(&x.ptr, 0); + + return 0; +} + +/* A data slice can't be accessed out of bounds */ +SEC("?raw_tp/sys_nanosleep") +int data_slice_out_of_bounds_ringbuf(void *ctx) +{ + struct bpf_dynptr ptr; + void *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr); + + data = bpf_dynptr_data(&ptr, 0, 8); + if (!data) + goto done; + + /* can't index out of bounds of the data slice */ + val = *((char *)data + 8); + +done: + bpf_ringbuf_submit_dynptr(&ptr, 0); + return 0; +} + +SEC("?raw_tp/sys_nanosleep") +int data_slice_out_of_bounds_map_value(void *ctx) +{ + __u32 key = 0, map_val; + struct bpf_dynptr ptr; + void *data; + + get_map_val_dynptr(&ptr); + + data = bpf_dynptr_data(&ptr, 0, sizeof(map_val)); + if (!data) + return 0; + + /* can't index out of bounds of the data slice */ + val = *((char *)data + (sizeof(map_val) + 1)); + + return 0; +} + +/* A data slice can't be used after it has been released */ +SEC("?raw_tp/sys_nanosleep") +int data_slice_use_after_release(void *ctx) +{ + struct bpf_dynptr ptr; + struct sample *sample; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr); + sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample)); + if (!sample) + goto done; + + sample->pid = 123; + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + /* this should fail */ + val = sample->pid; + + return 0; + +done: + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* A data slice must be first checked for NULL */ +SEC("?raw_tp/sys_nanosleep") +int data_slice_missing_null_check1(void *ctx) +{ + struct bpf_dynptr ptr; + void *data; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr); + + data = bpf_dynptr_data(&ptr, 0, 8); + + /* missing if (!data) check */ + + /* this should fail */ + *(__u8 *)data = 3; + + bpf_ringbuf_submit_dynptr(&ptr, 0); + return 0; +} + +/* A data slice can't be dereferenced if it wasn't checked for null */ +SEC("?raw_tp/sys_nanosleep") +int data_slice_missing_null_check2(void *ctx) +{ + struct bpf_dynptr ptr; + __u64 *data1, *data2; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr); + + data1 = bpf_dynptr_data(&ptr, 0, 8); + data2 = bpf_dynptr_data(&ptr, 0, 8); + if (data1) + /* this should fail */ + *data2 = 3; + +done: + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +/* Can't pass in a dynptr as an arg to a helper function that doesn't take in a + * dynptr argument + */ +SEC("?raw_tp/sys_nanosleep") +int invalid_helper1(void *ctx) +{ + struct bpf_dynptr ptr; + + get_map_val_dynptr(&ptr); + + /* this should fail */ + bpf_strncmp((const char *)&ptr, sizeof(ptr), "hello!"); + + return 0; +} + +/* A dynptr can't be passed into a helper function at a non-zero offset */ +SEC("?raw_tp/sys_nanosleep") +int invalid_helper2(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + + get_map_val_dynptr(&ptr); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 8, 0); + + return 0; +} + +/* A bpf_dynptr is invalidated if it's been written into */ +SEC("?raw_tp/sys_nanosleep") +int invalid_write1(void *ctx) +{ + struct bpf_dynptr ptr; + void *data; + __u8 x = 0; + + get_map_val_dynptr(&ptr); + + memcpy(&ptr, &x, sizeof(x)); + + /* this should fail */ + data = bpf_dynptr_data(&ptr, 0, 1); + + return 0; +} + +/* + * A bpf_dynptr can't be used as a dynptr if it has been written into at a fixed + * offset + */ +SEC("?raw_tp/sys_nanosleep") +int invalid_write2(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + __u8 x = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + memcpy((void *)&ptr + 8, &x, sizeof(x)); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* + * A bpf_dynptr can't be used as a dynptr if it has been written into at a + * non-const offset + */ +SEC("?raw_tp/sys_nanosleep") +int invalid_write3(void *ctx) +{ + struct bpf_dynptr ptr; + char stack_buf[16]; + unsigned long len; + __u8 x = 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr); + + memcpy(stack_buf, &val, sizeof(val)); + len = stack_buf[0] & 0xf; + + memcpy((void *)&ptr + len, &x, sizeof(x)); + + /* this should fail */ + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +static int invalid_write4_callback(__u32 index, void *data) +{ + *(__u32 *)data = 123; + + return 0; +} + +/* If the dynptr is written into in a callback function, it should + * be invalidated as a dynptr + */ +SEC("?raw_tp/sys_nanosleep") +int invalid_write4(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_loop(10, invalid_write4_callback, &ptr, 0); + + /* this should fail */ + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* A globally-defined bpf_dynptr can't be used (it must reside as a stack frame) */ +struct bpf_dynptr global_dynptr; +SEC("?raw_tp/sys_nanosleep") +int global(void *ctx) +{ + /* this should fail */ + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &global_dynptr); + + bpf_ringbuf_discard_dynptr(&global_dynptr, 0); + + return 0; +} + +/* A direct read should fail */ +SEC("?raw_tp/sys_nanosleep") +int invalid_read1(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + /* this should fail */ + val = *(int *)&ptr; + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +/* A direct read at an offset should fail */ +SEC("?raw_tp/sys_nanosleep") +int invalid_read2(void *ctx) +{ + struct bpf_dynptr ptr; + char read_data[64]; + + get_map_val_dynptr(&ptr); + + /* this should fail */ + bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 1, 0); + + return 0; +} + +/* A direct read at an offset into the lower stack slot should fail */ +SEC("?raw_tp/sys_nanosleep") +int invalid_read3(void *ctx) +{ + struct bpf_dynptr ptr1, ptr2; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr1); + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr2); + + /* this should fail */ + memcpy(&val, (void *)&ptr1 + 8, sizeof(val)); + + bpf_ringbuf_discard_dynptr(&ptr1, 0); + bpf_ringbuf_discard_dynptr(&ptr2, 0); + + return 0; +} + +static int invalid_read4_callback(__u32 index, void *data) +{ + /* this should fail */ + val = *(__u32 *)data; + + return 0; +} + +/* A direct read within a callback function should fail */ +SEC("?raw_tp/sys_nanosleep") +int invalid_read4(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr); + + bpf_loop(10, invalid_read4_callback, &ptr, 0); + + bpf_ringbuf_submit_dynptr(&ptr, 0); + + return 0; +} + +/* Initializing a dynptr on an offset should fail */ +SEC("?raw_tp/sys_nanosleep") +int invalid_offset(void *ctx) +{ + struct bpf_dynptr ptr; + + /* this should fail */ + bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr + 1); + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +/* Can't release a dynptr twice */ +SEC("?raw_tp/sys_nanosleep") +int release_twice(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr); + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + /* this second release should fail */ + bpf_ringbuf_discard_dynptr(&ptr, 0); + + return 0; +} + +static int release_twice_callback_fn(__u32 index, void *data) +{ + /* this should fail */ + bpf_ringbuf_discard_dynptr(data, 0); + + return 0; +} + +/* Test that releasing a dynptr twice, where one of the releases happens + * within a calback function, fails + */ +SEC("?raw_tp/sys_nanosleep") +int release_twice_callback(void *ctx) +{ + struct bpf_dynptr ptr; + + bpf_ringbuf_reserve_dynptr(&ringbuf, 32, 0, &ptr); + + bpf_ringbuf_discard_dynptr(&ptr, 0); + + bpf_loop(10, release_twice_callback_fn, &ptr, 0); + + return 0; +} + +/* Reject unsupported local mem types for dynptr_from_mem API */ +SEC("?raw_tp/sys_nanosleep") +int dynptr_from_mem_invalid_api(void *ctx) +{ + struct bpf_dynptr ptr; + int x = 0; + + /* this should fail */ + bpf_dynptr_from_mem(&x, sizeof(x), 0, &ptr); + + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c new file mode 100644 index 000000000000..d67be48df4b2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/dynptr_success.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Facebook */ + +#include +#include +#include +#include "bpf_misc.h" +#include "errno.h" + +char _license[] SEC("license") = "GPL"; + +int pid, err, val; + +struct sample { + int pid; + int seq; + long value; + char comm[16]; +}; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); +} ringbuf SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} array_map SEC(".maps"); + +SEC("tp/syscalls/sys_enter_nanosleep") +int test_read_write(void *ctx) +{ + char write_data[64] = "hello there, world!!"; + char read_data[64] = {}, buf[64] = {}; + struct bpf_dynptr ptr; + int i; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr); + + /* Write data into the dynptr */ + err = err ?: bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data)); + + /* Read the data that was written into the dynptr */ + err = err ?: bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0); + + /* Ensure the data we read matches the data we wrote */ + for (i = 0; i < sizeof(read_data); i++) { + if (read_data[i] != write_data[i]) { + err = 1; + break; + } + } + + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +} + +SEC("tp/syscalls/sys_enter_nanosleep") +int test_data_slice(void *ctx) +{ + __u32 key = 0, val = 235, *map_val; + struct bpf_dynptr ptr; + __u32 map_val_size; + void *data; + + map_val_size = sizeof(*map_val); + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + bpf_map_update_elem(&array_map, &key, &val, 0); + + map_val = bpf_map_lookup_elem(&array_map, &key); + if (!map_val) { + err = 1; + return 0; + } + + bpf_dynptr_from_mem(map_val, map_val_size, 0, &ptr); + + /* Try getting a data slice that is out of range */ + data = bpf_dynptr_data(&ptr, map_val_size + 1, 1); + if (data) { + err = 2; + return 0; + } + + /* Try getting more bytes than available */ + data = bpf_dynptr_data(&ptr, 0, map_val_size + 1); + if (data) { + err = 3; + return 0; + } + + data = bpf_dynptr_data(&ptr, 0, sizeof(__u32)); + if (!data) { + err = 4; + return 0; + } + + *(__u32 *)data = 999; + + err = bpf_probe_read_kernel(&val, sizeof(val), data); + if (err) + return 0; + + if (val != *(int *)data) + err = 5; + + return 0; +} + +static int ringbuf_callback(__u32 index, void *data) +{ + struct sample *sample; + + struct bpf_dynptr *ptr = (struct bpf_dynptr *)data; + + sample = bpf_dynptr_data(ptr, 0, sizeof(*sample)); + if (!sample) + err = 2; + else + sample->pid += index; + + return 0; +} + +SEC("tp/syscalls/sys_enter_nanosleep") +int test_ringbuf(void *ctx) +{ + struct bpf_dynptr ptr; + struct sample *sample; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + val = 100; + + /* check that you can reserve a dynamic size reservation */ + err = bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); + + sample = err ? NULL : bpf_dynptr_data(&ptr, 0, sizeof(*sample)); + if (!sample) { + err = 1; + goto done; + } + + sample->pid = 10; + + /* Can pass dynptr to callback functions */ + bpf_loop(10, ringbuf_callback, &ptr, 0); + + if (sample->pid != 55) + err = 2; + +done: + bpf_ringbuf_discard_dynptr(&ptr, 0); + return 0; +}