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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>