Commit Graph

23 Commits

Author SHA1 Message Date
Rong Tao
b74344cbed docs/bpf: Update btf selftests program and add link
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
2022-11-25 00:00:15 +01:00
Indu Bhagat
e5e23424e5 docs/bpf: Update documentation for BTF_KIND_FUNC
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>
2022-07-19 09:42:09 -07:00
Yonghong Song
61dbd59829 docs/bpf: Update documentation for BTF_KIND_ENUM64 support
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>
2022-06-07 10:20:44 -07:00
Yonghong Song
b72903847a docs/bpf: clarify how btf_type_tag gets encoded in the type chain
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>
2022-01-27 12:03:47 -08:00
Andrii Nakryiko
96c85308ee docs/bpf: update BPF map definition example
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>
2022-01-20 21:19:05 -08:00
Dave Tucker
3ff36bffaf bpf, docs: Change underline in btf to match style guide
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
2021-11-17 23:23:52 +01:00
Yonghong Song
d52f5c639d docs/bpf: Update documentation for BTF_KIND_TYPE_TAG support
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
2021-11-11 17:41:11 -08:00
Yonghong Song
5a8671349d docs/bpf: Update documentation for BTF_KIND_DECL_TAG typedef support
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
2021-10-22 17:04:44 -07:00
Yonghong Song
223f903e9c bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG
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: b5ea834dde ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd1036 ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec0 ("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
2021-10-18 18:35:36 -07:00
Yonghong Song
48f5a6c416 docs/bpf: Add documentation for BTF_KIND_TAG
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
2021-09-14 18:45:53 -07:00
Ilya Leoshkevich
6be6a0baff bpf: Document BTF_KIND_FLOAT in btf.rst
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
2021-03-04 18:31:53 -08:00
Jiri Olsa
68a26bc792 bpf: Update .BTF_ids section in btf.rst with sets info
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
2020-08-25 15:41:15 -07:00
Jiri Olsa
232ce4be29 bpf: Add info about .BTF_ids section to btf.rst
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
2020-07-13 10:42:03 -07:00
Jonathan Corbet
8afecfb0ec Linux 5.2-rc4
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Merge tag 'v5.2-rc4' into mauro

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.
2019-06-14 14:18:53 -06:00
Mauro Carvalho Chehab
d857a3ffd3 docs: bpf: get rid of two warnings
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>
2019-06-08 13:42:11 -06:00
Gary Lin
948dc8c99a bpf: btf: fix the brackets of BTF_INT_OFFSET()
'VAL' should be protected by the brackets.

v2:
* Squash the fix for Documentation/bpf/btf.rst

Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-14 10:05:18 +02:00
Gary Lin
3ef4641fbf docs/btf: fix the missing section marks
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>
2019-05-09 15:59:59 -07:00
David S. Miller
bb23581b9b Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
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>
2019-04-11 17:00:05 -07:00
Daniel Borkmann
f063c889c9 bpf: add specification for BTF Var and DataSec kinds
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>
2019-04-09 17:05:46 -07:00
Jesper Dangaard Brouer
f52c97d9df bpf, doc: fix BTF docs reflow of bullet list
Section 2.2.1 BTF_KIND_INT a bullet list was collapsed due to
text reflow in commit 9ab5305dbe ("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: 9ab5305dbe ("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>
2019-03-26 13:13:42 -07:00
Andrii Nakryiko
9ab5305dbe docs/btf: reflow text to fill up to 78 characters
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>
2019-03-02 00:40:04 +01:00
Andrii Nakryiko
5efc529fb4 docs/btf: fix typos, improve wording
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>
2019-03-02 00:40:04 +01:00
Yonghong Song
ffcf7ce933 bpf: btf: add btf documentation
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>
2019-01-22 23:50:02 -08:00