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52dbd67d |
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08-Feb-2024 |
Jose E. Marchesi <jose.marchesi@oracle.com> |
bpf: Abstract loop unrolling pragmas in BPF selftests [Changes from V1: - Avoid conflict by rebasing with latest master.] Some BPF tests use loop unrolling compiler pragmas that are clang specific and not supported by GCC. These pragmas, along with their GCC equivalences are: #pragma clang loop unroll_count(N) #pragma GCC unroll N #pragma clang loop unroll(full) #pragma GCC unroll 65534 #pragma clang loop unroll(disable) #pragma GCC unroll 1 #pragma unroll [aka #pragma clang loop unroll(enable)] There is no GCC equivalence to this pragma. It enables unrolling on loops that the compiler would not ordinarily unroll even with -O2|-funroll-loops, but it is not equivalent to full unrolling either. This patch adds a new header progs/bpf_compiler.h that defines the following macros, which correspond to each pair of compiler-specific pragmas above: __pragma_loop_unroll_count(N) __pragma_loop_unroll_full __pragma_loop_no_unroll __pragma_loop_unroll The selftests using loop unrolling pragmas are then changed to include the header and use these macros in place of the explicit pragmas. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240208203612.29611-1-jose.marchesi@oracle.com
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c27aa462 |
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06-Feb-2024 |
Jose E. Marchesi <jose.marchesi@oracle.com> |
bpf: Use -Wno-address-of-packed-member in some selftests [Differences from V2: - Remove conditionals in the source files pragmas, as the pragma is supported by both GCC and clang.] Both GCC and clang implement the -Wno-address-of-packed-member warning, which is enabled by -Wall, that warns about taking the address of a packed struct field when it can lead to an "unaligned" address. This triggers the following errors (-Werror) when building three particular BPF selftests with GCC: progs/test_cls_redirect.c 986 | if (ipv4_is_fragment((void *)&encap->ip)) { progs/test_cls_redirect_dynptr.c 410 | pkt_ipv4_checksum((void *)&encap_gre->ip); progs/test_cls_redirect.c 521 | pkt_ipv4_checksum((void *)&encap_gre->ip); progs/test_tc_tunnel.c 232 | set_ipv4_csum((void *)&h_outer.ip); These warnings do not signal any real problem in the tests as far as I can see. This patch adds pragmas to these test files that inhibit the -Waddress-of-packed-member warning. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240206102330.7113-1-jose.marchesi@oracle.com
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df71a42c |
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16-Feb-2023 |
Taichi Nishimura <awkrail01@gmail.com> |
Fix typos in selftest/bpf files Run spell checker on files in selftest/bpf and fixed typos. Signed-off-by: Taichi Nishimura <awkrail01@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/bpf/20230216085537.519062-1-awkrail01@gmail.com
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c22bdd28 |
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28-Sep-2021 |
Andrii Nakryiko <andrii@kernel.org> |
selftests/bpf: Switch SEC("classifier*") usage to a strict SEC("tc") Convert all SEC("classifier*") uses to a new and strict SEC("tc") section name. In reference_tracking selftests switch from ambiguous searching by program title (section name) to non-ambiguous searching by name in some selftests, getting closer to completely removing bpf_object__find_program_by_title(). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210928161946.2512801-4-andrii@kernel.org
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256eab48 |
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06-May-2021 |
Andrii Nakryiko <andrii@kernel.org> |
selftests/bpf: Stop using static variables for passing data to/from user-space In preparation of skipping emitting static variables in BPF skeletons, switch all current selftests uses of static variables to pass data between BPF and user-space to use global variables. All non-read-only `static volatile` variables become just plain global variables by dropping `static volatile` part. Read-only `static volatile const` variables, though, still require `volatile` modifier, otherwise compiler will ignore whatever values are set from user-space. Few static linker tests are using name-conflicting static variables to validate that static linker still properly handles static variables and doesn't trip up on name conflicts. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210507054119.270888-4-andrii@kernel.org
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6b8838be |
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09-Feb-2021 |
Jesper Dangaard Brouer <brouer@redhat.com> |
selftests/bpf: Use bpf_check_mtu in selftest test_cls_redirect This demonstrate how bpf_check_mtu() helper can easily be used together with bpf_skb_adjust_room() helper, prior to doing size adjustment, as delta argument is already setup. Hint: This specific test can be selected like this: ./test_progs -t cls_redirect Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/161287791481.790810.4444271170546646080.stgit@firesoul
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ee333df5 |
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03-Sep-2020 |
Andrii Nakryiko <andriin@fb.com> |
selftests/bpf: Add __noinline variant of cls_redirect selftest As one of the most complicated and close-to-real-world programs, cls_redirect is a good candidate to exercise libbpf's logic of handling bpf2bpf calls. So add variant with using explicit __noinline for majority of functions except few most basic ones. If those few functions are inlined, verifier starts to complain about program instruction limit of 1mln instructions being exceeded, most probably due to instruction overhead of doing a sub-program call. Convert user-space part of selftest to have to sub-tests: with and without inlining. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/20200903203542.15944-15-andriin@fb.com
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c4ba153b |
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02-Jun-2020 |
Daniel Borkmann <daniel@iogearbox.net> |
bpf, selftests: Adapt cls_redirect to call csum_level helper Adapt bpf_skb_adjust_room() to pass in BPF_F_ADJ_ROOM_NO_CSUM_RESET flag and use the new bpf_csum_level() helper to inc/dec the checksum level by one after the encap/decap. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/e7458f10e3f3d795307cbc5ad870112671d9c6f7.1591108731.git.daniel@iogearbox.net
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23458901 |
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24-Apr-2020 |
Lorenz Bauer <lmb@cloudflare.com> |
selftests/bpf: Add cls_redirect classifier cls_redirect is a TC clsact based replacement for the glb-redirect iptables module available at [1]. It enables what GitHub calls "second chance" flows [2], similarly proposed by the Beamer paper [3]. In contrast to glb-redirect, it also supports migrating UDP flows as long as connected sockets are used. cls_redirect is in production at Cloudflare, as part of our own L4 load balancer. We have modified the encapsulation format slightly from glb-redirect: glbgue_chained_routing.private_data_type has been repurposed to form a version field and several flags. Both have been arranged in a way that a private_data_type value of zero matches the current glb-redirect behaviour. This means that cls_redirect will understand packets in glb-redirect format, but not vice versa. The test suite only covers basic features. For example, cls_redirect will correctly forward path MTU discovery packets, but this is not exercised. It is also possible to switch the encapsulation format to GRE on the last hop, which is also not tested. There are two major distinctions from glb-redirect: first, cls_redirect relies on receiving encapsulated packets directly from a router. This is because we don't have access to the neighbour tables from BPF, yet. See forward_to_next_hop for details. Second, cls_redirect performs decapsulation instead of using separate ipip and sit tunnel devices. This avoids issues with the sit tunnel [4] and makes deploying the classifier easier: decapsulated packets appear on the same interface, so existing firewall rules continue to work as expected. The code base started it's life on v4.19, so there are most likely still hold overs from old workarounds. In no particular order: - The function buf_off is required to defeat a clang optimization that leads to the verifier rejecting the program due to pointer arithmetic in the wrong order. - The function pkt_parse_ipv6 is force inlined, because it would otherwise be rejected due to returning a pointer to stack memory. - The functions fill_tuple and classify_tcp contain kludges, because we've run out of function arguments. - The logic in general is rather nested, due to verifier restrictions. I think this is either because the verifier loses track of constants on the stack, or because it can't track enum like variables. 1: https://github.com/github/glb-director/tree/master/src/glb-redirect 2: https://github.com/github/glb-director/blob/master/docs/development/second-chance-design.md 3: https://www.usenix.org/conference/nsdi18/presentation/olteanu 4: https://github.com/github/glb-director/issues/64 Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200424185556.7358-2-lmb@cloudflare.com
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