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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2021-10-02 06:47:54 +0530 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-10-05 17:07:42 -0700 |
| commit | 9dbe6015636c19f929a7f7b742f27f303ff6069d (patch) | |
| tree | fdc16578ed21cc313a0e035468e9c9cfa508d4d9 /tools/testing/selftests/bpf/prog_tests/ksyms_module.c | |
| parent | 0e32dfc80bae53b05e9eda7eaf259f30ab9ba43a (diff) | |
libbpf: Support kernel module function calls
This patch adds libbpf support for kernel module function call support.
The fd_array parameter is used during BPF program load to pass module
BTFs referenced by the program. insn->off is set to index into this
array, but starts from 1, because insn->off as 0 is reserved for
btf_vmlinux.
We try to use existing insn->off for a module, since the kernel limits
the maximum distinct module BTFs for kfuncs to 256, and also because
index must never exceed the maximum allowed value that can fit in
insn->off (INT16_MAX). In the future, if kernel interprets signed offset
as unsigned for kfunc calls, this limit can be increased to UINT16_MAX.
Also introduce a btf__find_by_name_kind_own helper to start searching
from module BTF's start id when we know that the BTF ID is not present
in vmlinux BTF (in find_ksym_btf_id).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-7-memxor@gmail.com
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/ksyms_module.c')
0 files changed, 0 insertions, 0 deletions