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2023-11-17docs: automarkup: linkify git revsVegard Nossum
There aren't a ton of references to commits in the documentation, but they do exist, and we can use automarkup to linkify them to make them easier to follow. Use something like this to find references to commits: git grep -P 'commit.*[0-9a-f]{8,}' Documentation/ Also fix a few of these to standardize on the exact format that is already used in changelogs. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20231027115420.205279-1-vegard.nossum@oracle.com
2023-09-01docs/bpf: Fix "file doesn't exist" warnings in {llvm_reloc,btf}.rstEduard Zingerman
scripts/documentation-file-ref-check reports warnings for (valid) cross-links of form: :ref:`Documentation/bpf/btf <BTF_Ext_Section>` Adding extension to the file name helps to avoid the warning, e.g: :ref:`Documentation/bpf/btf.rst <BTF_Ext_Section>` Fixes: be4033d36070 ("docs/bpf: Add description for CO-RE relocations") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Closes: https://lore.kernel.org/oe-kbuild-all/202309010804.G3MpXo59-lkp@intel.com Link: https://lore.kernel.org/bpf/20230901125935.487972-1-eddyz87@gmail.com
2023-08-30docs/bpf: Add description for CO-RE relocationsEduard Zingerman
Add a section on CO-RE relocations to llvm_relo.rst. Describe relevant .BTF.ext structure, `enum bpf_core_relo_kind` and `struct bpf_core_relo` in some detail. Description is based on doc-strings from: - include/uapi/linux/bpf.h:struct bpf_core_relo - tools/lib/bpf/relo_core.c:__bpf_core_types_match() Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20230826222912.2560865-2-eddyz87@gmail.com
2023-06-29bpf: Replace deprecated -target with --target= for ClangFangrui Song
The -target option has been deprecated since clang 3.4 in 2013. Therefore, use the preferred --target=bpf form instead. This also matches how we use --target= in scripts/Makefile.clang. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277 Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com
2022-11-25docs/bpf: Update btf selftests program and add linkRong Tao
Commit c64779e24e88("selftests/bpf: Merge most of test_btf into test_progs") renamed the BTF selftest from 'test_btf.c' to 'prog_tests/btf.c'. Signed-off-by: Rong Tao <rongtao@cestc.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/tencent_1FA6904156E8E599CAE4ABDBE80F22830106@qq.com
2022-07-19docs/bpf: Update documentation for BTF_KIND_FUNCIndu Bhagat
The vlen bits in the BTF type of kind BTF_KIND_FUNC are used to convey the linkage information for functions. The Linux kernel only supports linkage values of BTF_FUNC_STATIC and BTF_FUNC_GLOBAL at this time. Signed-off-by: Indu Bhagat <indu.bhagat@oracle.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20220714223310.1140097-1-indu.bhagat@oracle.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-07docs/bpf: Update documentation for BTF_KIND_ENUM64 supportYonghong Song
Add BTF_KIND_ENUM64 documentation in btf.rst. Also fixed a typo for section number for BTF_KIND_TYPE_TAG from 2.2.17 to 2.2.18, and fixed a type size issue for BTF_KIND_ENUM. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220607062724.3728215-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27docs/bpf: clarify how btf_type_tag gets encoded in the type chainYonghong Song
Clarify where the BTF_KIND_TYPE_TAG gets encoded in the type chain, so applications and kernel can properly parse them. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154627.665163-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-20docs/bpf: update BPF map definition exampleAndrii Nakryiko
Use BTF-defined map definition in the documentation example. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120060529.1890907-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-11-17bpf, docs: Change underline in btf to match style guideDave Tucker
This changes the type of underline used to follow the guidelines in Documentation/doc-guide/sphinx.rst which also ensures that the headings are rendered at the correct level in the HTML sidebar Signed-off-by: Dave Tucker <dave@dtucker.co.uk> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/981b27485cc294206480df36fca46817e2553e39.1636749493.git.dave@dtucker.co.uk
2021-11-11docs/bpf: Update documentation for BTF_KIND_TYPE_TAG supportYonghong Song
Add BTF_KIND_TYPE_TAG documentation in btf.rst. 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/20211112012656.1509082-1-yhs@fb.com
2021-10-22docs/bpf: Update documentation for BTF_KIND_DECL_TAG typedef supportYonghong Song
Add BTF_KIND_DECL_TAG typedef support in btf.rst. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211021195649.4020514-1-yhs@fb.com
2021-10-18bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAGYonghong Song
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
2021-09-14docs/bpf: Add documentation for BTF_KIND_TAGYonghong Song
Add BTF_KIND_TAG documentation in btf.rst. 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/20210914223103.249100-1-yhs@fb.com
2021-03-04bpf: Document BTF_KIND_FLOAT in btf.rstIlya Leoshkevich
Also document the expansion of the kind bitfield. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210226202256.116518-11-iii@linux.ibm.com
2020-08-25bpf: Update .BTF_ids section in btf.rst with sets infoJiri Olsa
Updating btf.rst doc with info about BTF_SET_START/END macros. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200825192124.710397-12-jolsa@kernel.org
2020-07-13bpf: Add info about .BTF_ids section to btf.rstJiri Olsa
Updating btf.rst doc with info about .BTF_ids section Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-8-jolsa@kernel.org
2019-06-14Merge tag 'v5.2-rc4' into mauroJonathan Corbet
We need to pick up post-rc1 changes to various document files so they don't get lost in Mauro's massive RST conversion push.
2019-06-08docs: bpf: get rid of two warningsMauro Carvalho Chehab
Documentation/bpf/btf.rst:154: WARNING: Unexpected indentation. Documentation/bpf/btf.rst:163: WARNING: Unexpected indentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-14bpf: btf: fix the brackets of BTF_INT_OFFSET()Gary Lin
'VAL' should be protected by the brackets. v2: * Squash the fix for Documentation/bpf/btf.rst Fixes: 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") Signed-off-by: Gary Lin <glin@suse.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-09docs/btf: fix the missing section marksGary Lin
The section titles of 3.4 and 3.5 are not marked correctly. Signed-off-by: Gary Lin <glin@suse.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2019-04-12 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Improve BPF verifier scalability for large programs through two optimizations: i) remove verifier states that are not useful in pruning, ii) stop walking parentage chain once first LIVE_READ is seen. Combined gives approx 20x speedup. Increase limits for accepting large programs under root, and add various stress tests, from Alexei. 2) Implement global data support in BPF. This enables static global variables for .data, .rodata and .bss sections to be properly handled which allows for more natural program development. This also opens up the possibility to optimize program workflow by compiling ELFs only once and later only rewriting section data before reload, from Daniel and with test cases and libbpf refactoring from Joe. 3) Add config option to generate BTF type info for vmlinux as part of the kernel build process. DWARF debug info is converted via pahole to BTF. Latter relies on libbpf and makes use of BTF deduplication algorithm which results in 100x savings compared to DWARF data. Resulting .BTF section is typically about 2MB in size, from Andrii. 4) Add BPF verifier support for stack access with variable offset from helpers and add various test cases along with it, from Andrey. 5) Extend bpf_skb_adjust_room() growth BPF helper to mark inner MAC header so that L2 encapsulation can be used for tc tunnels, from Alan. 6) Add support for input __sk_buff context in BPF_PROG_TEST_RUN so that users can define a subset of allowed __sk_buff fields that get fed into the test program, from Stanislav. 7) Add bpf fs multi-dimensional array tests for BTF test suite and fix up various UBSAN warnings in bpftool, from Yonghong. 8) Generate a pkg-config file for libbpf, from Luca. 9) Dump program's BTF id in bpftool, from Prashant. 10) libbpf fix to use smaller BPF log buffer size for AF_XDP's XDP program, from Magnus. 11) kallsyms related fixes for the case when symbols are not present in BPF selftests and samples, from Daniel ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-09bpf: add specification for BTF Var and DataSec kindsDaniel Borkmann
This adds the BTF specification and UAPI bits for supporting BTF Var and DataSec kinds. This is following LLVM upstream commit ac4082b77e07 ("[BPF] Add BTF Var and DataSec Support") which has been merged recently. Var itself is for describing a global variable and DataSec to describe ELF sections e.g. data/bss/rodata sections that hold one or multiple global variables. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-26bpf, doc: fix BTF docs reflow of bullet listJesper Dangaard Brouer
Section 2.2.1 BTF_KIND_INT a bullet list was collapsed due to text reflow in commit 9ab5305dbe3f ("docs/btf: reflow text to fill up to 78 characters"). This patch correct the mistake. Also adjust next bullet list, which is used for comparison, to get rendered the same way. Fixes: 9ab5305dbe3f ("docs/btf: reflow text to fill up to 78 characters") Link: https://www.kernel.org/doc/html/latest/bpf/btf.html#btf-kind-int Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-02docs/btf: reflow text to fill up to 78 charactersAndrii Nakryiko
Reflow paragraphs to more fully and evenly fill 78 character lines. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-02docs/btf: fix typos, improve wordingAndrii Nakryiko
Fix various typos, some of the formatting and wording for Documentation/btf.rst. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-22bpf: btf: add btf documentationYonghong Song
This patch added documentation for BTF (BPF Debug Format). The document is placed under linux:Documentation/bpf directory. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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