Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

bpftool: Add support for custom BTF path in prog load/loadall 

This patch exposes the btf_custom_path feature to bpftool, allowing users
to specify a custom BTF file when loading BPF programs using prog load or
prog loadall commands.

The argument 'btf_custom_path' in libbpf is used for those kernels that
don't have CONFIG_DEBUG_INFO_BTF enabled but still want to perform CO-RE
relocations.

Suggested-by: Quentin Monnet <qmo@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20250516144708.298652-1-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiayuan Chen 2025-05-16 22:47:02 +08:00 committed by Alexei Starovoitov
parent 92de53d247
commit 1ae7a84ed8
3 changed files with 21 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
tools/bpf/bpftool/Documentation/bpftool-prog.rst
View File

@ -31,7 +31,7 @@ PROG COMMANDS
| **bpftool** **prog dump xlated** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] [**visual**] }]
| **bpftool** **prog dump jited** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] }]
| **bpftool** **prog pin** *PROG* *FILE*
| **bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* [**type** *TYPE*] [**map** { **idx** *IDX* | **name** *NAME* } *MAP*] [{ **offload_dev** | **xdpmeta_dev** } *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
| **bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* [**type** *TYPE*] [**map** { **idx** *IDX* | **name** *NAME* } *MAP*] [{ **offload_dev** | **xdpmeta_dev** } *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**] [**kernel_btf** *BTF_FILE*]
| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
| **bpftool** **prog tracelog**
@ -127,7 +127,7 @@ bpftool prog pin *PROG* *FILE*
Note: *FILE* must be located in *bpffs* mount. It must not contain a dot
character ('.'), which is reserved for future extensions of *bpffs*.
bpftool prog { load | loadall } *OBJ* *PATH* [type *TYPE*] [map { idx *IDX* | name *NAME* } *MAP*] [{ offload_dev | xdpmeta_dev } *NAME*] [pinmaps *MAP_DIR*] [autoattach]
bpftool prog { load | loadall } *OBJ* *PATH* [type *TYPE*] [map { idx *IDX* | name *NAME* } *MAP*] [{ offload_dev | xdpmeta_dev } *NAME*] [pinmaps *MAP_DIR*] [autoattach] [kernel_btf *BTF_FILE*]
Load bpf program(s) from binary *OBJ* and pin as *PATH*. **bpftool prog
load** pins only the first program from the *OBJ* as *PATH*. **bpftool prog
loadall** pins all programs from the *OBJ* under *PATH* directory. **type**
@ -153,6 +153,12 @@ bpftool prog { load | loadall } *OBJ* *PATH* [type *TYPE*] [map { idx *IDX* | na
program does not support autoattach, bpftool falls back to regular pinning
for that program instead.
The **kernel_btf** option allows specifying an external BTF file to replace
the system's own vmlinux BTF file for CO-RE relocations. Note that any
other feature relying on BTF (such as fentry/fexit programs, struct_ops)
requires the BTF file for the actual kernel running on the host, often
exposed at /sys/kernel/btf/vmlinux.
Note: *PATH* must be located in *bpffs* mount. It must not contain a dot
character ('.'), which is reserved for future extensions of *bpffs*.

4
tools/bpf/bpftool/bash-completion/bpftool
View File

@ -505,13 +505,13 @@ _bpftool()
_bpftool_get_map_names
return 0
;;
pinned|pinmaps)
pinned|pinmaps|kernel_btf)
_filedir
return 0
;;
*)
COMPREPLY=( $( compgen -W "map" -- "$cur" ) )
_bpftool_once_attr 'type pinmaps autoattach'
_bpftool_once_attr 'type pinmaps autoattach kernel_btf'
_bpftool_one_of_list 'offload_dev xdpmeta_dev'
return 0
;;

12
tools/bpf/bpftool/prog.c
View File

@ -1681,8 +1681,17 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
} else if (is_prefix(*argv, "autoattach")) {
auto_attach = true;
NEXT_ARG();
} else if (is_prefix(*argv, "kernel_btf")) {
NEXT_ARG();
if (!REQ_ARGS(1))
goto err_free_reuse_maps;
open_opts.btf_custom_path = GET_ARG();
} else {
p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
p_err("expected no more arguments, "
"'type', 'map', 'offload_dev', 'xdpmeta_dev', 'pinmaps', "
"'autoattach', or 'kernel_btf', got: '%s'?",
*argv);
goto err_free_reuse_maps;
}
@ -2474,6 +2483,7 @@ static int do_help(int argc, char **argv)
" [map { idx IDX | name NAME } MAP]\\\n"
" [pinmaps MAP_DIR]\n"
" [autoattach]\n"
" [kernel_btf BTF_FILE]\n"
" %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"
" %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"
" %1$s %2$s run PROG \\\n"