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author | Jiri Kosina <jkosina@suse.cz> | 2023-11-01 02:07:35 +0300 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2023-11-01 02:07:35 +0300 |
commit | 20cd569d7ee8fce24e8753f0f43af6c420557b1f (patch) | |
tree | f559cfda594846795aa51c99d96f92d8c912851a /Documentation/bpf/btf.rst | |
parent | 62cc9c3cb3ec1bf31cc116146185ed97b450836a (diff) | |
parent | eeebfe6259ba2d5b0980eb7b0df384eb77e9e4f5 (diff) | |
download | linux-20cd569d7ee8fce24e8753f0f43af6c420557b1f.tar.xz |
Merge branch 'for-6.7/config_pm' into for-linus
- #ifdef CONFIG_PM removal from HID code (Thomas Weißschuh)
Diffstat (limited to 'Documentation/bpf/btf.rst')
-rw-r--r-- | Documentation/bpf/btf.rst | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst index f32db1f44ae9..e43c2fdafcd7 100644 --- a/Documentation/bpf/btf.rst +++ b/Documentation/bpf/btf.rst @@ -726,8 +726,8 @@ same as the one describe in :ref:`BTF_Type_String`. 4.2 .BTF.ext section -------------------- -The .BTF.ext section encodes func_info and line_info which needs loader -manipulation before loading into the kernel. +The .BTF.ext section encodes func_info, line_info and CO-RE relocations +which needs loader manipulation before loading into the kernel. The specification for .BTF.ext section is defined at ``tools/lib/bpf/btf.h`` and ``tools/lib/bpf/btf.c``. @@ -745,15 +745,20 @@ The current header of .BTF.ext section:: __u32 func_info_len; __u32 line_info_off; __u32 line_info_len; + + /* optional part of .BTF.ext header */ + __u32 core_relo_off; + __u32 core_relo_len; }; It is very similar to .BTF section. Instead of type/string section, it -contains func_info and line_info section. See :ref:`BPF_Prog_Load` for details -about func_info and line_info record format. +contains func_info, line_info and core_relo sub-sections. +See :ref:`BPF_Prog_Load` for details about func_info and line_info +record format. The func_info is organized as below.:: - func_info_rec_size + func_info_rec_size /* __u32 value */ btf_ext_info_sec for section #1 /* func_info for section #1 */ btf_ext_info_sec for section #2 /* func_info for section #2 */ ... @@ -773,7 +778,7 @@ Here, num_info must be greater than 0. The line_info is organized as below.:: - line_info_rec_size + line_info_rec_size /* __u32 value */ btf_ext_info_sec for section #1 /* line_info for section #1 */ btf_ext_info_sec for section #2 /* line_info for section #2 */ ... @@ -787,6 +792,20 @@ kernel API, the ``insn_off`` is the instruction offset in the unit of ``struct bpf_insn``. For ELF API, the ``insn_off`` is the byte offset from the beginning of section (``btf_ext_info_sec->sec_name_off``). +The core_relo is organized as below.:: + + core_relo_rec_size /* __u32 value */ + btf_ext_info_sec for section #1 /* core_relo for section #1 */ + btf_ext_info_sec for section #2 /* core_relo for section #2 */ + +``core_relo_rec_size`` specifies the size of ``bpf_core_relo`` +structure when .BTF.ext is generated. All ``bpf_core_relo`` structures +within a single ``btf_ext_info_sec`` describe relocations applied to +section named by ``btf_ext_info_sec->sec_name_off``. + +See :ref:`Documentation/bpf/llvm_reloc.rst <btf-co-re-relocations>` +for more information on CO-RE relocations. + 4.2 .BTF_ids section -------------------- |