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| author | Kumar Kartikeya Dwivedi <[email protected]> | 2021-10-02 01:17:54 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <[email protected]> | 2021-10-06 00:07:42 +0000 |
| commit | 9dbe6015636c19f929a7f7b742f27f303ff6069d (patch) | |
| tree | fdc16578ed21cc313a0e035468e9c9cfa508d4d9 /tools/lib/bpf/bpf.c | |
| parent | bpf: Enable TCP congestion control kfunc from modules (diff) | |
| download | kernel-9dbe6015636c19f929a7f7b742f27f303ff6069d.tar.gz kernel-9dbe6015636c19f929a7f7b742f27f303ff6069d.zip | |
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 <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Diffstat (limited to 'tools/lib/bpf/bpf.c')
| -rw-r--r-- | tools/lib/bpf/bpf.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 2401fad090c5..7d1741ceaa32 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -264,6 +264,7 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr) attr.line_info_rec_size = load_attr->line_info_rec_size; attr.line_info_cnt = load_attr->line_info_cnt; attr.line_info = ptr_to_u64(load_attr->line_info); + attr.fd_array = ptr_to_u64(load_attr->fd_array); if (load_attr->name) memcpy(attr.prog_name, load_attr->name, |