This patch adds tests for dynptrs, which include cases that the
verifier needs to reject (for example, invalid bpf_dynptr_put usages
and invalid writes/reads), as well as cases that should successfully
pass.
Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
.../testing/selftests/bpf/prog_tests/dynptr.c | 136 ++++
.../testing/selftests/bpf/progs/dynptr_fail.c | 582 ++++++++++++++++++
.../selftests/bpf/progs/dynptr_success.c | 206 +++++++
3 files changed, 924 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..fa287d498d0b
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Facebook */
+
+#include <test_progs.h>
+#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 */
+ {"missing_put", "Unreleased reference id=1"},
+ {"missing_put_callback", "Unreleased reference id"},
+ {"put_nonalloc", "Expected an initialized malloc dynptr as arg #1"},
+ {"put_data_slice", "type=dynptr_mem expected=fp"},
+ {"put_uninit_dynptr", "arg 1 is an unacquired reference"},
+ {"use_after_put", "Expected an initialized dynptr as arg #3"},
+ {"alloc_twice", "Arg #3 dynptr has to be an uninitialized dynptr"},
+ {"add_dynptr_to_map1", "invalid indirect read from stack"},
+ {"add_dynptr_to_map2", "invalid indirect read from stack"},
+ {"ringbuf_invalid_access", "invalid mem access 'scalar'"},
+ {"ringbuf_invalid_api", "type=dynptr_mem expected=alloc_mem"},
+ {"ringbuf_out_of_bounds", "value is outside of the allowed memory range"},
+ {"data_slice_out_of_bounds", "value is outside of the allowed memory range"},
+ {"data_slice_use_after_put", "invalid mem access 'scalar'"},
+ {"invalid_helper1", "invalid indirect read from stack"},
+ {"invalid_helper2", "Expected an initialized dynptr as arg #3"},
+ {"invalid_write1", "Expected an initialized malloc dynptr as arg #1"},
+ {"invalid_write2", "Expected an initialized dynptr as arg #3"},
+ {"invalid_write3", "Expected an initialized malloc dynptr as arg #1"},
+ {"invalid_write4", "arg 1 is an unacquired reference"},
+ {"invalid_read1", "invalid read from stack"},
+ {"invalid_read2", "cannot pass in non-zero dynptr offset"},
+ {"invalid_read3", "invalid read from stack"},
+ {"invalid_offset", "invalid write to stack"},
+ {"global", "R3 type=map_value expected=fp"},
+ {"put_twice", "arg 1 is an unacquired reference"},
+ {"put_twice_callback", "arg 1 is an unacquired reference"},
+ {"zero_slice_access", "invalid access to memory, mem_size=0 off=0 size=1"},
+ /* success cases */
+ {"test_basic", NULL},
+ {"test_data_slice", NULL},
+ {"test_ringbuf", NULL},
+ {"test_alloc_zero_bytes", 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..dfa4593fa94a
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c
@@ -0,0 +1,582 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Facebook */
+
+#include <string.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#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 sample {
+ int pid;
+ long value;
+ char comm[16];
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_RINGBUF);
+} ringbuf SEC(".maps");
+
+int err = 0;
+int val;
+
+/* Every bpf_dynptr_alloc call must have a corresponding bpf_dynptr_put call */
+SEC("?raw_tp/sys_nanosleep")
+int missing_put(void *ctx)
+{
+ struct bpf_dynptr mem;
+
+ bpf_dynptr_alloc(8, 0, &mem);
+
+ /* missing a call to bpf_dynptr_put(&mem) */
+
+ return 0;
+}
+
+static int missing_put_callback_fn(__u32 index, void *data)
+{
+ struct bpf_dynptr ptr;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ val = index;
+
+ /* missing bpf_dynptr_put(&ptr) */
+
+ return 0;
+}
+
+/* Any dynptr initialized within a callback must have bpf_dynptr_put called */
+SEC("?raw_tp/sys_nanosleep")
+int missing_put_callback(void *ctx)
+{
+ bpf_loop(10, missing_put_callback_fn, NULL, 0);
+ return 0;
+}
+
+/* A non-alloc-ed dynptr can't be used by bpf_dynptr_put */
+SEC("?raw_tp/sys_nanosleep")
+int put_nonalloc(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr);
+
+ /* this should fail */
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/* A data slice from a dynptr can't be used by bpf_dynptr_put */
+SEC("?raw_tp/sys_nanosleep")
+int put_data_slice(void *ctx)
+{
+ struct bpf_dynptr ptr;
+ void *data;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ data = bpf_dynptr_data(&ptr, 0, 8);
+ if (!data)
+ goto done;
+
+ /* this should fail */
+ bpf_dynptr_put(data);
+
+done:
+ bpf_dynptr_put(&ptr);
+ return 0;
+}
+
+/* Can't call bpf_dynptr_put on a non-initialized dynptr */
+SEC("?raw_tp/sys_nanosleep")
+int put_uninit_dynptr(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ /* this should fail */
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/* A dynptr can't be used after bpf_dynptr_put has been called on it */
+SEC("?raw_tp/sys_nanosleep")
+int use_after_put(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+ char read_data[64] = {};
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
+
+ bpf_dynptr_put(&ptr);
+
+ /* this should fail */
+ bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
+
+ return 0;
+}
+
+/*
+ * Can't bpf_dynptr_alloc an existing allocated bpf_dynptr that bpf_dynptr_put
+ * hasn't been called on yet
+ */
+SEC("?raw_tp/sys_nanosleep")
+int alloc_twice(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ /* this should fail */
+ bpf_dynptr_alloc(2, 0, &ptr);
+
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/*
+ * Can't access a ring buffer record after submit or discard has been called
+ * on the dynptr
+ */
+SEC("?raw_tp/sys_nanosleep")
+int ringbuf_invalid_access(void *ctx)
+{
+ struct bpf_dynptr ptr;
+ struct sample *sample;
+
+ err = 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 */
+ err = sample->pid;
+
+ return 0;
+
+done:
+ bpf_ringbuf_discard_dynptr(&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;
+
+ err = 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 access memory outside a ringbuf record range */
+SEC("?raw_tp/sys_nanosleep")
+int ringbuf_out_of_bounds(void *ctx)
+{
+ struct bpf_dynptr ptr;
+ struct sample *sample;
+
+ err = bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr);
+ sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample));
+ if (!sample)
+ goto done;
+
+ /* Can't access beyond sample range */
+ *(__u8 *)((void *)sample + sizeof(*sample)) = 123;
+
+ bpf_ringbuf_submit_dynptr(&ptr, 0);
+
+ return 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;
+
+ err = bpf_dynptr_alloc(sizeof(val), 0, &ptr);
+
+ /* this should fail */
+ bpf_map_update_elem(&array_map1, &key, &ptr, 0);
+
+ bpf_dynptr_put(&ptr);
+
+ 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_dynptr_alloc(sizeof(val), 0, &x.ptr);
+
+ /* this should fail */
+ bpf_map_update_elem(&array_map2, &key, &x, 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 = {};
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ /* this should fail */
+ bpf_strncmp((const char *)&ptr, sizeof(ptr), "hello!");
+
+ bpf_dynptr_put(&ptr);
+
+ 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] = {};
+
+ bpf_dynptr_alloc(sizeof(val), 0, &ptr);
+
+ /* this should fail */
+ bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 8, 0);
+
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/* A data slice can't be accessed out of bounds */
+SEC("?raw_tp/sys_nanosleep")
+int data_slice_out_of_bounds(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+ void *data;
+
+ bpf_dynptr_alloc(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_dynptr_put(&ptr);
+ return 0;
+}
+
+/* A data slice can't be used after bpf_dynptr_put is called */
+SEC("?raw_tp/sys_nanosleep")
+int data_slice_use_after_put(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+ void *data;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ data = bpf_dynptr_data(&ptr, 0, 8);
+ if (!data)
+ goto done;
+
+ bpf_dynptr_put(&ptr);
+
+ /* this should fail */
+ val = *(__u8 *)data;
+
+done:
+ bpf_dynptr_put(&ptr);
+ return 0;
+}
+
+/* A bpf_dynptr can't be used as a dynptr if it's been written into */
+SEC("?raw_tp/sys_nanosleep")
+int invalid_write1(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+ __u8 x = 0;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ memcpy(&ptr, &x, sizeof(x));
+
+ /* this should fail */
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/*
+ * A bpf_dynptr can't be used as a dynptr if an offset into it has been
+ * written into
+ */
+SEC("?raw_tp/sys_nanosleep")
+int invalid_write2(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+ char read_data[64] = {};
+ __u8 x = 0, y = 0;
+
+ bpf_dynptr_alloc(sizeof(x), 0, &ptr);
+
+ memcpy((void *)&ptr + 8, &y, sizeof(y));
+
+ /* this should fail */
+ bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
+
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/*
+ * A bpf_dynptr can't be used as a dynptr if a non-const offset into it
+ * has been written into
+ */
+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_dynptr_alloc(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_dynptr_put(&ptr);
+
+ 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;
+ __u64 x = 0;
+
+ bpf_dynptr_alloc(sizeof(x), 0, &ptr);
+
+ bpf_loop(10, invalid_write4_callback, &ptr, 0);
+
+ /* this should fail */
+ bpf_dynptr_put(&ptr);
+
+ 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_dynptr_alloc(4, 0, &global_dynptr);
+
+ bpf_dynptr_put(&global_dynptr);
+
+ return 0;
+}
+
+/* A direct read should fail */
+SEC("?raw_tp/sys_nanosleep")
+int invalid_read1(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+ __u32 x = 2;
+
+ bpf_dynptr_alloc(sizeof(x), 0, &ptr);
+
+ /* this should fail */
+ val = *(int *)&ptr;
+
+ bpf_dynptr_put(&ptr);
+
+ 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] = {};
+ __u64 x = 0;
+
+ bpf_dynptr_alloc(sizeof(x), 0, &ptr);
+
+ /* this should fail */
+ bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 1, 0);
+
+ bpf_dynptr_put(&ptr);
+
+ 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 = {};
+ struct bpf_dynptr ptr2 = {};
+
+ bpf_dynptr_alloc(sizeof(val), 0, &ptr1);
+ bpf_dynptr_alloc(sizeof(val), 0, &ptr2);
+
+ /* this should fail */
+ memcpy(&val, (void *)&ptr1 + 8, sizeof(val));
+
+ bpf_dynptr_put(&ptr1);
+ bpf_dynptr_put(&ptr2);
+
+ return 0;
+}
+
+/* Calling bpf_dynptr_alloc on an offset should fail */
+SEC("?raw_tp/sys_nanosleep")
+int invalid_offset(void *ctx)
+{
+ struct bpf_dynptr ptr = {};
+
+ /* this should fail */
+ bpf_dynptr_alloc(sizeof(val), 0, &ptr + 1);
+
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+/* Can't call bpf_dynptr_put twice */
+SEC("?raw_tp/sys_nanosleep")
+int put_twice(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ bpf_dynptr_put(&ptr);
+
+ /* this second put should fail */
+ bpf_dynptr_put(&ptr);
+
+ return 0;
+}
+
+static int put_twice_callback_fn(__u32 index, void *data)
+{
+ /* this should fail */
+ bpf_dynptr_put(data);
+ val = index;
+ return 0;
+}
+
+/* Test that calling bpf_dynptr_put twice, where the 2nd put happens within a
+ * calback function, fails
+ */
+SEC("?raw_tp/sys_nanosleep")
+int put_twice_callback(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ bpf_dynptr_alloc(8, 0, &ptr);
+
+ bpf_dynptr_put(&ptr);
+
+ bpf_loop(10, put_twice_callback_fn, &ptr, 0);
+
+ return 0;
+}
+
+/* Can't access memory in a zero-slice */
+SEC("?raw_tp/sys_nanosleep")
+int zero_slice_access(void *ctx)
+{
+ struct bpf_dynptr ptr;
+ void *data;
+
+ bpf_dynptr_alloc(0, 0, &ptr);
+
+ data = bpf_dynptr_data(&ptr, 0, 0);
+ if (!data)
+ goto done;
+
+ /* this should fail */
+ *(__u8 *)data = 23;
+
+ val = *(__u8 *)data;
+
+done:
+ bpf_dynptr_put(&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..bbb34943a6c6
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Facebook */
+
+#include <string.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+#include "errno.h"
+
+char _license[] SEC("license") = "GPL";
+
+int pid;
+int err;
+int val;
+
+struct sample {
+ int pid;
+ int seq;
+ long value;
+ char comm[16];
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_RINGBUF);
+} ringbuf SEC(".maps");
+
+SEC("tp/syscalls/sys_enter_nanosleep")
+int test_basic(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;
+
+ err = bpf_dynptr_alloc(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_dynptr_put(&ptr);
+ return 0;
+}
+
+SEC("tp/syscalls/sys_enter_nanosleep")
+int test_data_slice(void *ctx)
+{
+ struct bpf_dynptr ptr;
+ __u32 alloc_size = 16;
+ void *data;
+
+ if (bpf_get_current_pid_tgid() >> 32 != pid)
+ return 0;
+
+ /* test passing in an invalid flag */
+ err = bpf_dynptr_alloc(alloc_size, 1, &ptr);
+ if (err != -EINVAL) {
+ err = 1;
+ goto done;
+ }
+ bpf_dynptr_put(&ptr);
+
+ err = bpf_dynptr_alloc(alloc_size, 0, &ptr);
+ if (err)
+ goto done;
+
+ /* Try getting a data slice that is out of range */
+ data = bpf_dynptr_data(&ptr, alloc_size + 1, 1);
+ if (data) {
+ err = 2;
+ goto done;
+ }
+
+ /* Try getting more bytes than available */
+ data = bpf_dynptr_data(&ptr, 0, alloc_size + 1);
+ if (data) {
+ err = 3;
+ goto done;
+ }
+
+ data = bpf_dynptr_data(&ptr, 0, sizeof(int));
+ if (!data) {
+ err = 4;
+ goto done;
+ }
+
+ *(__u32 *)data = 999;
+
+ err = bpf_probe_read_kernel(&val, sizeof(val), data);
+ if (err)
+ goto done;
+
+ if (val != *(int *)data)
+ err = 5;
+
+done:
+ bpf_dynptr_put(&ptr);
+ 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 += val;
+
+ 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 = 123;
+
+ /* Can pass dynptr to callback functions */
+ bpf_loop(10, ringbuf_callback, &ptr, 0);
+
+ bpf_ringbuf_submit_dynptr(&ptr, 0);
+
+ return 0;
+
+done:
+ bpf_ringbuf_discard_dynptr(&ptr, 0);
+ return 0;
+}
+
+SEC("tp/syscalls/sys_enter_nanosleep")
+int test_alloc_zero_bytes(void *ctx)
+{
+ struct bpf_dynptr ptr;
+ void *data;
+ __u8 x = 0;
+
+ if (bpf_get_current_pid_tgid() >> 32 != pid)
+ return 0;
+
+ err = bpf_dynptr_alloc(0, 0, &ptr);
+ if (err)
+ goto done;
+
+ err = bpf_dynptr_write(&ptr, 0, &x, sizeof(x));
+ if (err != -E2BIG) {
+ err = 1;
+ goto done;
+ }
+
+ err = bpf_dynptr_read(&x, sizeof(x), &ptr, 0);
+ if (err != -E2BIG) {
+ err = 2;
+ goto done;
+ }
+ err = 0;
+
+ /* try to access memory we don't have access to */
+ data = bpf_dynptr_data(&ptr, 0, 1);
+ if (data) {
+ err = 3;
+ goto done;
+ }
+
+ data = bpf_dynptr_data(&ptr, 0, 0);
+ if (!data) {
+ err = 4;
+ goto done;
+ }
+
+done:
+ bpf_dynptr_put(&ptr);
+ return 0;
+}
--
2.30.2
