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2024-01-23selftests/bpf: Update LLVM Phabricator linksNathan Chancellor1-16/+16
reviews.llvm.org was LLVM's Phabricator instances for code review. It has been abandoned in favor of GitHub pull requests. While the majority of links in the kernel sources still work because of the work Fangrui has done turning the dynamic Phabricator instance into a static archive, there are some issues with that work, so preemptively convert all the links in the kernel sources to point to the commit on GitHub. Most of the commits have the corresponding differential review link in the commit message itself so there should not be any loss of fidelity in the relevant information. Additionally, fix a typo in the xdpwall.c print ("LLMV" -> "LLVM") while in the area. Link: https://discourse.llvm.org/t/update-on-github-pull-requests/71540/172 Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240111-bpf-update-llvm-phabricator-links-v2-1-9a7ae976bd64@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-28selftests/bpf: Override PKG_CONFIG for static buildsAkihiko Odaki1-1/+1
A library may need to depend on additional archive files for static builds so pkg-config should be instructed to list them. Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20231125084253.85025-3-akihiko.odaki@daynix.com
2022-10-19bpf/docs: Summarize CI system and deny listsDaniel Müller1-1/+41
This change adds a brief summary of the BPF continuous integration (CI) to the BPF selftest documentation. The summary focuses not so much on actual workings of the CI, as it is maintained outside of the repository, but aims to document the few bits of it that are sourced from this repository and that developers may want to adjust as part of patch submissions: the BPF kernel configuration and the deny list file(s). Changelog: - v1->v2: - use s390x instead of s390 for consistency Signed-off-by: Daniel Müller <deso@posteo.net> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221018164015.1970862-1-deso@posteo.net Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-10-18bpf/docs: Update README for most recent vmtest.shDaniel Müller1-5/+6
Since commit 40b09653b197 ("selftests/bpf: Adjust vmtest.sh to use local kernel configuration") the vmtest.sh script no longer downloads a kernel configuration but uses the local, in-repository one. This change updates the README, which still mentions the old behavior. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221017232458.1272762-1-deso@posteo.net
2022-09-02selftests/bpf: Store BPF object files with .bpf.o extensionDaniel Müller1-4/+4
BPF object files are, in a way, the final artifact produced as part of the ahead-of-time compilation process. That makes them somewhat special compared to "regular" object files, which are a intermediate build artifacts that can typically be removed safely. As such, it can make sense to name them differently to make it easier to spot this difference at a glance. Among others, libbpf-bootstrap [0] has established the extension .bpf.o for BPF object files. It seems reasonable to follow this example and establish the same denomination for selftest build artifacts. To that end, this change adjusts the corresponding part of the build system and the test programs loading BPF object files to work with .bpf.o files. [0] https://github.com/libbpf/libbpf-bootstrap Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220901222253.1199242-1-deso@posteo.net
2022-03-07bpf/docs: Update list of architectures supported.KP Singh1-1/+1
vmtest.sh also supports s390x now. Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220307133048.1287644-2-kpsingh@kernel.org
2022-03-07bpf/docs: Update vmtest docs for static linkingKP Singh1-0/+8
Dynamic linking when compiling on the host can cause issues when the libc version does not match the one in the VM image. Update the docs to explain how to do this. Before: ./vmtest.sh -- ./test_progs -t test_ima ./test_progs: /usr/lib/libc.so.6: version `GLIBC_2.33' not found (required by ./test_progs) After: LDLIBS=-static ./vmtest.sh -- ./test_progs -t test_ima test_ima:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Reported-by: "Geyslan G. Bem" <geyslan@gmail.com> Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220307133048.1287644-1-kpsingh@kernel.org
2022-01-27selftests/bpf: specify pahole version requirement for btf_tag testYonghong Song1-0/+2
Specify pahole version requirement (1.23) for btf_tag subtests btf_type_tag_user_{mod1, mod2, vmlinux}. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154622.663337-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-11-11selftests/bpf: Clarify llvm dependency with btf_tag selftestYonghong Song1-4/+5
btf_tag selftest needs certain llvm versions (>= llvm14). Make it clear in the selftests README.rst file. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211112012651.1508549-1-yhs@fb.com
2021-10-18bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAGYonghong Song1-2/+2
Patch set [1] introduced BTF_KIND_TAG to allow tagging declarations for struct/union, struct/union field, var, func and func arguments and these tags will be encoded into dwarf. They are also encoded to btf by llvm for the bpf target. After BTF_KIND_TAG is introduced, we intended to use it for kernel __user attributes. But kernel __user is actually a type attribute. Upstream and internal discussion showed it is not a good idea to mix declaration attribute and type attribute. So we proposed to introduce btf_type_tag as a type attribute and existing btf_tag renamed to btf_decl_tag ([2]). This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some other declarations with *_tag to *_decl_tag to make it clear the tag is for declaration. In the future, BTF_KIND_TYPE_TAG might be introduced per [3]. [1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/ [2] https://reviews.llvm.org/D111588 [3] https://reviews.llvm.org/D111199 Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG") Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG") Fixes: 5c07f2fec003 ("bpftool: Add support for BTF_KIND_TAG") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
2021-09-26bpf: selftest: A bpf prog that has a 32bit scalar spillMartin KaFai Lau1-0/+13
It is a simplified example that can trigger a 32bit scalar spill. The const scalar is refilled and added to a skb->data later. Since the reg state of the 32bit scalar spill is not saved now, adding the refilled reg to skb->data and then comparing it with skb->data_end cannot verify the skb->data access. With the earlier verifier patch and the llvm patch [1]. The verifier can correctly verify the bpf prog. Here is the snippet of the verifier log that leads to verifier conclusion that the packet data is unsafe to read. The log is from the kerne without the previous verifier patch to save the <8-byte scalar spill. 67: R0=inv1 R1=inv17 R2=invP2 R3=inv1 R4=pkt(id=0,off=68,r=102,imm=0) R5=inv102 R6=pkt(id=0,off=62,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 67: (63) *(u32 *)(r10 -12) = r5 68: R0=inv1 R1=inv17 R2=invP2 R3=inv1 R4=pkt(id=0,off=68,r=102,imm=0) R5=inv102 R6=pkt(id=0,off=62,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmm???? ... 101: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R6_w=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm 101: (61) r1 = *(u32 *)(r10 -12) 102: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6_w=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm 102: (bc) w1 = w1 103: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6_w=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm 103: (0f) r7 += r1 last_idx 103 first_idx 67 regs=2 stack=0 before 102: (bc) w1 = w1 regs=2 stack=0 before 101: (61) r1 = *(u32 *)(r10 -12) 104: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R1_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6_w=pkt(id=0,off=70,r=102,imm=0) R7_w=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm ... 127: R0_w=inv1 R1=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9_w=invP17 R10=fp0 fp-16=mmmmmmmm 127: (bf) r1 = r7 128: R0_w=inv1 R1_w=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9_w=invP17 R10=fp0 fp-16=mmmmmmmm 128: (07) r1 += 8 129: R0_w=inv1 R1_w=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9_w=invP17 R10=fp0 fp-16=mmmmmmmm 129: (b4) w0 = 1 130: R0=inv1 R1=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=invP17 R10=fp0 fp-16=mmmmmmmm 130: (2d) if r1 > r8 goto pc-66 R0=inv1 R1=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=invP17 R10=fp0 fp-16=mmmmmmmm 131: R0=inv1 R1=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=invP17 R10=fp0 fp-16=mmmmmmmm 131: (69) r6 = *(u16 *)(r7 +0) invalid access to packet, off=0 size=2, R7(id=3,off=0,r=0) R7 offset is outside of the packet [1]: https://reviews.llvm.org/D109073 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210922004947.626286-1-kafai@fb.com
2021-09-15selftests/bpf: Skip btf_tag test if btf_tag attribute not supportedYonghong Song1-0/+14
Commit c240ba287890 ("selftests/bpf: Add a test with a bpf program with btf_tag attributes") added btf_tag selftest to test BTF_KIND_TAG generation from C source code, and to test kernel validation of generated BTF types. But if an old clang (clang 13 or earlier) is used, the following compiler warning may be seen: progs/tag.c:23:20: warning: unknown attribute 'btf_tag' ignored and the test itself is marked OK. The compiler warning is bad and the test itself shouldn't be marked OK. This patch added the check for btf_tag attribute support. If btf_tag is not supported by the clang, the attribute will not be used in the code and the test will be marked as skipped. For example, with clang 13: ./test_progs -t btf_tag #21 btf_tag:SKIP Summary: 1/0 PASSED, 1 SKIPPED, 0 FAILED The selftests/README.rst is updated to clarify when the btf_tag test may be skipped. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210915061036.2577971-1-yhs@fb.com
2021-07-23selftests/bpf: Document vmtest.sh dependenciesEvgeniy Litvinenko1-0/+7
Add a list of vmtest script dependencies to make it easier for new contributors to get going. Signed-off-by: Evgeniy Litvinenko <evgeniyl@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210723223645.907802-1-evgeniyl@fb.com
2021-05-28bpf, docs: Add llvm_reloc.rst to explain llvm bpf relocationsYonghong Song1-0/+19
LLVM upstream commit https://reviews.llvm.org/D102712 made some changes to bpf relocations to make them llvm linker lld friendly. The scope of existing relocations R_BPF_64_{64,32} is narrowed and new relocations R_BPF_64_{ABS32,ABS64,NODYLD32} are introduced. Let us add some documentation about llvm bpf relocations so people can understand how to resolve them properly in their respective tools. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210526152457.335210-1-yhs@fb.com
2021-04-23selftests/bpf: Document latest Clang fix expectations for linking testsAndrii Nakryiko1-0/+9
Document which fixes are required to generate correct static linking selftests. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210423181348.1801389-19-andrii@kernel.org
2021-03-30bpf: selftests: Update clang requirement in README.rst for testing kfunc callMartin KaFai Lau1-0/+14
This patch updates the README.rst to specify the clang requirement to compile the bpf selftests that call kernel function. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210330054156.2933804-1-kafai@fb.com
2021-03-09selftests/bpf: Add BTF_KIND_FLOAT to test_core_reloc_sizeIlya Leoshkevich1-0/+9
Verify that bpf_core_field_size() is working correctly with floats. Also document the required clang version. Suggested-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210309005649.162480-2-iii@linux.ibm.com
2021-03-04selftests/bpf: Add a verifier scale test with unknown bounded loopYonghong Song1-0/+39
The original bcc pull request https://github.com/iovisor/bcc/pull/3270 exposed a verifier failure with Clang 12/13 while Clang 4 works fine. Further investigation exposed two issues: Issue 1: LLVM may generate code which uses less refined value. The issue is fixed in LLVM patch: https://reviews.llvm.org/D97479 Issue 2: Spills with initial value 0 are marked as precise which makes later state pruning less effective. This is my rough initial analysis and further investigation is needed to find how to improve verifier pruning in such cases. With the above LLVM patch, for the new loop6.c test, which has smaller loop bound compared to original test, I got: $ test_progs -s -n 10/16 ... stack depth 64 processed 390735 insns (limit 1000000) max_states_per_insn 87 total_states 8658 peak_states 964 mark_read 6 #10/16 loop6.o:OK Use the original loop bound, i.e., commenting out "#define WORKAROUND", I got: $ test_progs -s -n 10/16 ... BPF program is too large. Processed 1000001 insn stack depth 64 processed 1000001 insns (limit 1000000) max_states_per_insn 91 total_states 23176 peak_states 5069 mark_read 6 ... #10/16 loop6.o:FAIL The purpose of this patch is to provide a regression test for the above LLVM fix and also provide a test case for further analyzing the verifier pruning issue. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Zhenwei Pi <pizhenwei@bytedance.com> Link: https://lore.kernel.org/bpf/20210226223810.236472-1-yhs@fb.com
2021-02-04bpf/selftests: Add a short note about vmtest.sh in README.rstKP Singh1-0/+24
Add a short note to make contributors aware of the existence of the script. The documentation does not intentionally document all the options of the script to avoid mentioning it in two places (it's available in the usage / help message of the script). Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210204194544.3383814-3-kpsingh@kernel.org
2020-11-24selftest/bpf: Fix rst formatting in readmeAndrei Matei1-13/+15
A couple of places in the readme had invalid rst formatting causing the rendering to be off. This patch fixes them with minimal edits. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201122022205.57229-2-andreimatei1@gmail.com
2020-11-24selftest/bpf: Fix link in readmeAndrei Matei1-1/+4
The link was bad because of invalid rst; it was pointing to itself and was rendering badly. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201122022205.57229-1-andreimatei1@gmail.com
2020-10-09selftests/bpf: Add profiler testAlexei Starovoitov1-0/+38
The main purpose of the profiler test to check different llvm generation patterns to make sure the verifier can load these large programs. Note that profiler.inc.h test doesn't follow strict kernel coding style. The code was formatted in the kernel style, but variable declarations are kept as-is to preserve original llvm IR pattern. profiler1.c should pass with older and newer llvm profiler[23].c may fail on older llvm that don't have: https://reviews.llvm.org/D85570 because llvm may do speculative code motion optimization that will generate code like this: // r9 is a pointer to map_value // r7 is a scalar 17: bf 96 00 00 00 00 00 00 r6 = r9 18: 0f 76 00 00 00 00 00 00 r6 += r7 19: a5 07 01 00 01 01 00 00 if r7 < 257 goto +1 20: bf 96 00 00 00 00 00 00 r6 = r9 // r6 is used here The verifier will reject such code with the error: "math between map_value pointer and register with unbounded min value is not allowed" At insn 18 the r7 is indeed unbounded. The later insn 19 checks the bounds and the insn 20 undoes map_value addition. It is currently impossible for the verifier to understand such speculative pointer arithmetic. Hence llvm D85570 addresses it on the compiler side. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201009011240.48506-4-alexei.starovoitov@gmail.com
2020-08-20selftests/bpf: List newest Clang built-ins needed for some CO-RE selftestsAndrii Nakryiko1-0/+21
Record which built-ins are optional and needed for some of recent BPF CO-RE subtests. Document Clang diff that fixed corner-case issue with __builtin_btf_type_id(). Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200820061411.1755905-4-andriin@fb.com
2020-05-23selftests/bpf: Add general instructions for test executionAlan Maguire1-0/+2
Getting a clean BPF selftests run involves ensuring latest trunk LLVM/clang are used, pahole is recent (>=1.16) and config matches the specified config file as closely as possible. Add to bpf_devel_QA.rst and point tools/testing/selftests/bpf/README.rst to it. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/1590146674-25485-1-git-send-email-alan.maguire@oracle.com
2020-05-13tools/bpf: selftests : Explain bpf_iter test failures with llvm 10.0.0Yonghong Song1-0/+43
Commit 6879c042e105 ("tools/bpf: selftests: Add bpf_iter selftests") added self tests for bpf_iter feature. But two subtests ipv6_route and netlink needs llvm latest 10.x release branch or trunk due to a bug in llvm BPF backend. This patch added the file README.rst to document these two failures so people using llvm 10.0.0 can be aware of them. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200513180215.2949237-1-yhs@fb.com
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