diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/dynptr_success.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/dynptr_success.c | 353 |
1 files changed, 348 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c index bfcc85686cf0..a0391f9da2d4 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_success.c +++ b/tools/testing/selftests/bpf/progs/dynptr_success.c @@ -1,20 +1,19 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2022 Facebook */ +#include <vmlinux.h> #include <string.h> #include <stdbool.h> -#include <linux/bpf.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include "bpf_misc.h" -#include "bpf_kfuncs.h" #include "errno.h" char _license[] SEC("license") = "GPL"; int pid, err, val; -struct sample { +struct ringbuf_sample { int pid; int seq; long value; @@ -121,7 +120,7 @@ int test_dynptr_data(void *ctx) static int ringbuf_callback(__u32 index, void *data) { - struct sample *sample; + struct ringbuf_sample *sample; struct bpf_dynptr *ptr = (struct bpf_dynptr *)data; @@ -138,7 +137,7 @@ SEC("?tp/syscalls/sys_enter_nanosleep") int test_ringbuf(void *ctx) { struct bpf_dynptr ptr; - struct sample *sample; + struct ringbuf_sample *sample; if (bpf_get_current_pid_tgid() >> 32 != pid) return 0; @@ -567,3 +566,347 @@ int BPF_PROG(test_dynptr_skb_tp_btf, void *skb, void *location) return 1; } + +static inline int bpf_memcmp(const char *a, const char *b, u32 size) +{ + int i; + + bpf_for(i, 0, size) { + if (a[i] != b[i]) + return a[i] < b[i] ? -1 : 1; + } + return 0; +} + +SEC("?tp/syscalls/sys_enter_nanosleep") +int test_dynptr_copy(void *ctx) +{ + char data[] = "hello there, world!!"; + char buf[32] = {'\0'}; + __u32 sz = sizeof(data); + struct bpf_dynptr src, dst; + + bpf_ringbuf_reserve_dynptr(&ringbuf, sz, 0, &src); + bpf_ringbuf_reserve_dynptr(&ringbuf, sz, 0, &dst); + + /* Test basic case of copying contiguous memory backed dynptrs */ + err = bpf_dynptr_write(&src, 0, data, sz, 0); + err = err ?: bpf_dynptr_copy(&dst, 0, &src, 0, sz); + err = err ?: bpf_dynptr_read(buf, sz, &dst, 0, 0); + err = err ?: bpf_memcmp(data, buf, sz); + + /* Test that offsets are handled correctly */ + err = err ?: bpf_dynptr_copy(&dst, 3, &src, 5, sz - 5); + err = err ?: bpf_dynptr_read(buf, sz - 5, &dst, 3, 0); + err = err ?: bpf_memcmp(data + 5, buf, sz - 5); + + bpf_ringbuf_discard_dynptr(&src, 0); + bpf_ringbuf_discard_dynptr(&dst, 0); + return 0; +} + +SEC("xdp") +int test_dynptr_copy_xdp(struct xdp_md *xdp) +{ + struct bpf_dynptr ptr_buf, ptr_xdp; + char data[] = "qwertyuiopasdfghjkl"; + char buf[32] = {'\0'}; + __u32 len = sizeof(data); + int i, chunks = 200; + + /* ptr_xdp is backed by non-contiguous memory */ + bpf_dynptr_from_xdp(xdp, 0, &ptr_xdp); + bpf_ringbuf_reserve_dynptr(&ringbuf, len * chunks, 0, &ptr_buf); + + /* Destination dynptr is backed by non-contiguous memory */ + bpf_for(i, 0, chunks) { + err = bpf_dynptr_write(&ptr_buf, i * len, data, len, 0); + if (err) + goto out; + } + + err = bpf_dynptr_copy(&ptr_xdp, 0, &ptr_buf, 0, len * chunks); + if (err) + goto out; + + bpf_for(i, 0, chunks) { + __builtin_memset(buf, 0, sizeof(buf)); + err = bpf_dynptr_read(&buf, len, &ptr_xdp, i * len, 0); + if (err) + goto out; + if (bpf_memcmp(data, buf, len) != 0) + goto out; + } + + /* Source dynptr is backed by non-contiguous memory */ + __builtin_memset(buf, 0, sizeof(buf)); + bpf_for(i, 0, chunks) { + err = bpf_dynptr_write(&ptr_buf, i * len, buf, len, 0); + if (err) + goto out; + } + + err = bpf_dynptr_copy(&ptr_buf, 0, &ptr_xdp, 0, len * chunks); + if (err) + goto out; + + bpf_for(i, 0, chunks) { + __builtin_memset(buf, 0, sizeof(buf)); + err = bpf_dynptr_read(&buf, len, &ptr_buf, i * len, 0); + if (err) + goto out; + if (bpf_memcmp(data, buf, len) != 0) + goto out; + } + + /* Both source and destination dynptrs are backed by non-contiguous memory */ + err = bpf_dynptr_copy(&ptr_xdp, 2, &ptr_xdp, len, len * (chunks - 1)); + if (err) + goto out; + + bpf_for(i, 0, chunks - 1) { + __builtin_memset(buf, 0, sizeof(buf)); + err = bpf_dynptr_read(&buf, len, &ptr_xdp, 2 + i * len, 0); + if (err) + goto out; + if (bpf_memcmp(data, buf, len) != 0) + goto out; + } + + if (bpf_dynptr_copy(&ptr_xdp, 2000, &ptr_xdp, 0, len * chunks) != -E2BIG) + err = 1; + +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; +} |