kernel/tools/testing/selftests/bpf/prog_tests/dynptr.c, branch linux-rolling-stable

selftests/bpf: Cover verifier checks for skb_meta dynptr type

2025-08-18T17:29:42Z

dynptr for skb metadata behaves the same way as the dynptr for skb data with one exception - writes to skb_meta dynptr don't invalidate existing skb and skb_meta slices. Duplicate those the skb dynptr tests which we can, since bpf_dynptr_from_skb_meta kfunc can be called only from TC BPF, to cover the skb_meta dynptr verifier checks. Also add a couple of new tests (skb_data_valid_*) to ensure we don't invalidate the slices in the mentioned case, which are specific to skb_meta dynptr. Signed-off-by: Jakub Sitnicki Signed-off-by: Martin KaFai Lau Reviewed-by: Jesse Brandeburg Link: https://patch.msgid.link/20250814-skb-metadata-thru-dynptr-v7-3-8a39e636e0fb@cloudflare.com

selftests/bpf: Increase xdp data size for arm64 64K page size

2025-07-26T01:20:43Z

With arm64 64K page size, the following 4 subtests failed: #97/25 dynptr/test_probe_read_user_dynptr:FAIL #97/26 dynptr/test_probe_read_kernel_dynptr:FAIL #97/27 dynptr/test_probe_read_user_str_dynptr:FAIL #97/28 dynptr/test_probe_read_kernel_str_dynptr:FAIL These failures are due to function bpf_dynptr_check_off_len() in include/linux/bpf.h where there is a test if (len > size || offset > size - len) return -E2BIG; With 64K page size, the 'offset' is greater than 'size - len', which caused the test failure. For 64KB page size, this patch increased the xdp buffer size from 5000 to 90000. The above 4 test failures are fixed as 'size' value is increased. But it introduced two new failures: #97/4 dynptr/test_dynptr_copy_xdp:FAIL #97/12 dynptr/test_dynptr_memset_xdp_chunks:FAIL These two failures will be addressed in subsequent patches. Signed-off-by: Yonghong Song Signed-off-by: Martin KaFai Lau Acked-by: Mykyta Yatsenko Link: https://patch.msgid.link/20250725043430.208469-1-yonghong.song@linux.dev

selftests/bpf: Add test cases for bpf_dynptr_memset()

2025-07-03T22:21:20Z

Add tests to verify the behavior of bpf_dynptr_memset(): * normal memset 0 * normal memset non-0 * memset with an offset * memset in dynptr that was adjusted * error: size overflow * error: offset+size overflow * error: readonly dynptr * memset into non-linear xdp dynptr Signed-off-by: Ihor Solodrai Signed-off-by: Andrii Nakryiko Acked-by: Mykyta Yatsenko Link: https://lore.kernel.org/bpf/20250702210309.3115903-3-isolodrai@meta.com

selftests/bpf: introduce tests for dynptr copy kfuncs

2025-05-13T01:32:47Z

Introduce selftests verifying newly-added dynptr copy kfuncs. Covering contiguous and non-contiguous memory backed dynptrs. Disable test_probe_read_user_str_dynptr that triggers bug in strncpy_from_user_nofault. Patch to fix the issue [1]. [1] https://patchwork.kernel.org/project/linux-mm/patch/20250422131449.57177-1-mykyta.yatsenko5@gmail.com/ Acked-by: Andrii Nakryiko Signed-off-by: Mykyta Yatsenko Link: https://lore.kernel.org/r/20250512205348.191079-4-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov

selftests/bpf: Add tests for bpf_dynptr_copy

2025-03-15T18:48:20Z

Add XDP setup type for dynptr tests, enabling testing for non-contiguous buffer. Add 2 tests: - test_dynptr_copy - verify correctness for the fast (contiguous buffer) code path. - test_dynptr_copy_xdp - verifies code paths that handle non-contiguous buffer. Signed-off-by: Mykyta Yatsenko Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250226183201.332713-4-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov

selftests/bpf: Expand skb dynptr selftests for tp_btf

2024-09-11T15:57:54Z

Add 3 test cases for skb dynptr used in tp_btf: - test_dynptr_skb_tp_btf: use skb dynptr in tp_btf and make sure it is read-only. - skb_invalid_ctx_fentry/skb_invalid_ctx_fexit: bpf_dynptr_from_skb should fail in fentry/fexit. In test_dynptr_skb_tp_btf, to trigger the tracepoint in kfree_skb, test_pkt_access is used for its test_run, as in kfree_skb.c. Because the test process is different from others, a new setup type is defined, i.e., SETUP_SKB_PROG_TP. The result is like: $ ./test_progs -t 'dynptr/test_dynptr_skb_tp_btf' #84/14 dynptr/test_dynptr_skb_tp_btf:OK #84 dynptr:OK #127 kfunc_dynptr_param:OK Summary: 2/1 PASSED, 0 SKIPPED, 0 FAILED $ ./test_progs -t 'dynptr/skb_invalid_ctx_f' #84/85 dynptr/skb_invalid_ctx_fentry:OK #84/86 dynptr/skb_invalid_ctx_fexit:OK #84 dynptr:OK #127 kfunc_dynptr_param:OK Summary: 2/2 PASSED, 0 SKIPPED, 0 FAILED Also fix two coding style nits (change spaces to tabs). Signed-off-by: Philo Lu Link: https://lore.kernel.org/r/20240911033719.91468-6-lulie@linux.alibaba.com Signed-off-by: Martin KaFai Lau

selftests/bpf: Accept mem from dynptr in helper funcs

2023-05-06T23:42:58Z

This ensures that buffers retrieved from dynptr_data are allowed to be passed in to helpers that take mem, like bpf_strncmp Signed-off-by: Daniel Rosenberg Link: https://lore.kernel.org/r/20230506013134.2492210-6-drosen@google.com Signed-off-by: Alexei Starovoitov

selftests/bpf: Test allowing NULL buffer in dynptr slice

2023-05-06T23:42:57Z

bpf_dynptr_slice(_rw) no longer requires a buffer for verification. If the buffer is needed, but not present, the function will return NULL. Signed-off-by: Daniel Rosenberg Link: https://lore.kernel.org/r/20230506013134.2492210-3-drosen@google.com Signed-off-by: Alexei Starovoitov

selftests/bpf: Add tests for dynptr convenience helpers

2023-04-27T08:40:52Z

Add various tests for the added dynptr convenience helpers. Signed-off-by: Joanne Koong Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230420071414.570108-6-joannelkoong@gmail.com

selftests/bpf: tests for using dynptrs to parse skb and xdp buffers

2023-03-01T18:05:19Z

Test skb and xdp dynptr functionality in the following ways: 1) progs/test_cls_redirect_dynptr.c * Rewrite "progs/test_cls_redirect.c" test to use dynptrs to parse skb data * This is a great example of how dynptrs can be used to simplify a lot of the parsing logic for non-statically known values. When measuring the user + system time between the original version vs. using dynptrs, and averaging the time for 10 runs (using "time ./test_progs -t cls_redirect"): original version: 0.092 sec with dynptrs: 0.078 sec 2) progs/test_xdp_dynptr.c * Rewrite "progs/test_xdp.c" test to use dynptrs to parse xdp data When measuring the user + system time between the original version vs. using dynptrs, and averaging the time for 10 runs (using "time ./test_progs -t xdp_attach"): original version: 0.118 sec with dynptrs: 0.094 sec 3) progs/test_l4lb_noinline_dynptr.c * Rewrite "progs/test_l4lb_noinline.c" test to use dynptrs to parse skb data When measuring the user + system time between the original version vs. using dynptrs, and averaging the time for 10 runs (using "time ./test_progs -t l4lb_all"): original version: 0.062 sec with dynptrs: 0.081 sec For number of processed verifier instructions: original version: 6268 insns with dynptrs: 2588 insns 4) progs/test_parse_tcp_hdr_opt_dynptr.c * Add sample code for parsing tcp hdr opt lookup using dynptrs. This logic is lifted from a real-world use case of packet parsing in katran [0], a layer 4 load balancer. The original version "progs/test_parse_tcp_hdr_opt.c" (not using dynptrs) is included here as well, for comparison. When measuring the user + system time between the original version vs. using dynptrs, and averaging the time for 10 runs (using "time ./test_progs -t parse_tcp_hdr_opt"): original version: 0.031 sec with dynptrs: 0.045 sec 5) progs/dynptr_success.c * Add test case "test_skb_readonly" for testing attempts at writes on a prog type with read-only skb ctx. * Add "test_dynptr_skb_data" for testing that bpf_dynptr_data isn't supported for skb progs. 6) progs/dynptr_fail.c * Add test cases "skb_invalid_data_slice{1,2,3,4}" and "xdp_invalid_data_slice{1,2}" for testing that helpers that modify the underlying packet buffer automatically invalidate the associated data slice. * Add test cases "skb_invalid_ctx" and "xdp_invalid_ctx" for testing that prog types that do not support bpf_dynptr_from_skb/xdp don't have access to the API. * Add test case "dynptr_slice_var_len{1,2}" for testing that variable-sized len can't be passed in to bpf_dynptr_slice * Add test case "skb_invalid_slice_write" for testing that writes to a read-only data slice are rejected by the verifier. * Add test case "data_slice_out_of_bounds_skb" for testing that writes to an area outside the slice are rejected. * Add test case "invalid_slice_rdwr_rdonly" for testing that prog types that don't allow writes to packet data don't accept any calls to bpf_dynptr_slice_rdwr. [0] https://github.com/facebookincubator/katran/blob/main/katran/lib/bpf/pckt_parsing.h Signed-off-by: Joanne Koong Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230301154953.641654-11-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov