diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/dynptr_success.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/dynptr_success.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c index e1fba28e4a86..a0391f9da2d4 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_success.c +++ b/tools/testing/selftests/bpf/progs/dynptr_success.c @@ -680,3 +680,233 @@ out: bpf_ringbuf_discard_dynptr(&ptr_buf, 0); return XDP_DROP; } + +void *user_ptr; +/* Contains the copy of the data pointed by user_ptr. + * Size 384 to make it not fit into a single kernel chunk when copying + * but less than the maximum bpf stack size (512). + */ +char expected_str[384]; +__u32 test_len[7] = {0/* placeholder */, 0, 1, 2, 255, 256, 257}; + +typedef int (*bpf_read_dynptr_fn_t)(struct bpf_dynptr *dptr, u32 off, + u32 size, const void *unsafe_ptr); + +/* Returns the offset just before the end of the maximum sized xdp fragment. + * Any write larger than 32 bytes will be split between 2 fragments. + */ +__u32 xdp_near_frag_end_offset(void) +{ + const __u32 headroom = 256; + const __u32 max_frag_size = __PAGE_SIZE - headroom - sizeof(struct skb_shared_info); + + /* 32 bytes before the approximate end of the fragment */ + return max_frag_size - 32; +} + +/* Use __always_inline on test_dynptr_probe[_str][_xdp]() and callbacks + * of type bpf_read_dynptr_fn_t to prevent compiler from generating + * indirect calls that make program fail to load with "unknown opcode" error. + */ +static __always_inline void test_dynptr_probe(void *ptr, bpf_read_dynptr_fn_t bpf_read_dynptr_fn) +{ + char buf[sizeof(expected_str)]; + struct bpf_dynptr ptr_buf; + int i; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return; + + err = bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(buf), 0, &ptr_buf); + + bpf_for(i, 0, ARRAY_SIZE(test_len)) { + __u32 len = test_len[i]; + + err = err ?: bpf_read_dynptr_fn(&ptr_buf, 0, test_len[i], ptr); + if (len > sizeof(buf)) + break; + err = err ?: bpf_dynptr_read(&buf, len, &ptr_buf, 0, 0); + + if (err || bpf_memcmp(expected_str, buf, len)) + err = 1; + + /* Reset buffer and dynptr */ + __builtin_memset(buf, 0, sizeof(buf)); + err = err ?: bpf_dynptr_write(&ptr_buf, 0, buf, len, 0); + } + bpf_ringbuf_discard_dynptr(&ptr_buf, 0); +} + +static __always_inline void test_dynptr_probe_str(void *ptr, + bpf_read_dynptr_fn_t bpf_read_dynptr_fn) +{ + char buf[sizeof(expected_str)]; + struct bpf_dynptr ptr_buf; + __u32 cnt, i; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(buf), 0, &ptr_buf); + + bpf_for(i, 0, ARRAY_SIZE(test_len)) { + __u32 len = test_len[i]; + + cnt = bpf_read_dynptr_fn(&ptr_buf, 0, len, ptr); + if (cnt != len) + err = 1; + + if (len > sizeof(buf)) + continue; + err = err ?: bpf_dynptr_read(&buf, len, &ptr_buf, 0, 0); + if (!len) + continue; + if (err || bpf_memcmp(expected_str, buf, len - 1) || buf[len - 1] != '\0') + err = 1; + } + bpf_ringbuf_discard_dynptr(&ptr_buf, 0); +} + +static __always_inline void test_dynptr_probe_xdp(struct xdp_md *xdp, void *ptr, + bpf_read_dynptr_fn_t bpf_read_dynptr_fn) +{ + struct bpf_dynptr ptr_xdp; + char buf[sizeof(expected_str)]; + __u32 off, i; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return; + + off = xdp_near_frag_end_offset(); + err = bpf_dynptr_from_xdp(xdp, 0, &ptr_xdp); + + bpf_for(i, 0, ARRAY_SIZE(test_len)) { + __u32 len = test_len[i]; + + err = err ?: bpf_read_dynptr_fn(&ptr_xdp, off, len, ptr); + if (len > sizeof(buf)) + continue; + err = err ?: bpf_dynptr_read(&buf, len, &ptr_xdp, off, 0); + if (err || bpf_memcmp(expected_str, buf, len)) + err = 1; + /* Reset buffer and dynptr */ + __builtin_memset(buf, 0, sizeof(buf)); + err = err ?: bpf_dynptr_write(&ptr_xdp, off, buf, len, 0); + } +} + +static __always_inline void test_dynptr_probe_str_xdp(struct xdp_md *xdp, void *ptr, + bpf_read_dynptr_fn_t bpf_read_dynptr_fn) +{ + struct bpf_dynptr ptr_xdp; + char buf[sizeof(expected_str)]; + __u32 cnt, off, i; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return; + + off = xdp_near_frag_end_offset(); + err = bpf_dynptr_from_xdp(xdp, 0, &ptr_xdp); + if (err) + return; + + bpf_for(i, 0, ARRAY_SIZE(test_len)) { + __u32 len = test_len[i]; + + cnt = bpf_read_dynptr_fn(&ptr_xdp, off, len, ptr); + if (cnt != len) + err = 1; + + if (len > sizeof(buf)) + continue; + err = err ?: bpf_dynptr_read(&buf, len, &ptr_xdp, off, 0); + + if (!len) + continue; + if (err || bpf_memcmp(expected_str, buf, len - 1) || buf[len - 1] != '\0') + err = 1; + + __builtin_memset(buf, 0, sizeof(buf)); + err = err ?: bpf_dynptr_write(&ptr_xdp, off, buf, len, 0); + } +} + +SEC("xdp") +int test_probe_read_user_dynptr(struct xdp_md *xdp) +{ + test_dynptr_probe(user_ptr, bpf_probe_read_user_dynptr); + if (!err) + test_dynptr_probe_xdp(xdp, user_ptr, bpf_probe_read_user_dynptr); + return XDP_PASS; +} + +SEC("xdp") +int test_probe_read_kernel_dynptr(struct xdp_md *xdp) +{ + test_dynptr_probe(expected_str, bpf_probe_read_kernel_dynptr); + if (!err) + test_dynptr_probe_xdp(xdp, expected_str, bpf_probe_read_kernel_dynptr); + return XDP_PASS; +} + +SEC("xdp") +int test_probe_read_user_str_dynptr(struct xdp_md *xdp) +{ + test_dynptr_probe_str(user_ptr, bpf_probe_read_user_str_dynptr); + if (!err) + test_dynptr_probe_str_xdp(xdp, user_ptr, bpf_probe_read_user_str_dynptr); + return XDP_PASS; +} + +SEC("xdp") +int test_probe_read_kernel_str_dynptr(struct xdp_md *xdp) +{ + test_dynptr_probe_str(expected_str, bpf_probe_read_kernel_str_dynptr); + if (!err) + test_dynptr_probe_str_xdp(xdp, expected_str, bpf_probe_read_kernel_str_dynptr); + return XDP_PASS; +} + +SEC("fentry.s/" SYS_PREFIX "sys_nanosleep") +int test_copy_from_user_dynptr(void *ctx) +{ + test_dynptr_probe(user_ptr, bpf_copy_from_user_dynptr); + return 0; +} + +SEC("fentry.s/" SYS_PREFIX "sys_nanosleep") +int test_copy_from_user_str_dynptr(void *ctx) +{ + test_dynptr_probe_str(user_ptr, bpf_copy_from_user_str_dynptr); + return 0; +} + +static int bpf_copy_data_from_user_task(struct bpf_dynptr *dptr, u32 off, + u32 size, const void *unsafe_ptr) +{ + struct task_struct *task = bpf_get_current_task_btf(); + + return bpf_copy_from_user_task_dynptr(dptr, off, size, unsafe_ptr, task); +} + +static int bpf_copy_data_from_user_task_str(struct bpf_dynptr *dptr, u32 off, + u32 size, const void *unsafe_ptr) +{ + struct task_struct *task = bpf_get_current_task_btf(); + + return bpf_copy_from_user_task_str_dynptr(dptr, off, size, unsafe_ptr, task); +} + +SEC("fentry.s/" SYS_PREFIX "sys_nanosleep") +int test_copy_from_user_task_dynptr(void *ctx) +{ + test_dynptr_probe(user_ptr, bpf_copy_data_from_user_task); + return 0; +} + +SEC("fentry.s/" SYS_PREFIX "sys_nanosleep") +int test_copy_from_user_task_str_dynptr(void *ctx) +{ + test_dynptr_probe_str(user_ptr, bpf_copy_data_from_user_task_str); + return 0; +} |