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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2021-10-02 06:47:56 +0530 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-10-05 17:07:42 -0700 |
| commit | 18f4fccbf314fdb07d276f4cd3eaf53f1825550d (patch) | |
| tree | aa75df537590490fe9cd09ec10265cc2ab1c4d3d /tools/lib/bpf/bpf_gen_internal.h | |
| parent | 466b2e13971ef65cd7b621ca3044be14028b002b (diff) | |
| download | linux-18f4fccbf314fdb07d276f4cd3eaf53f1825550d.tar.bz2 | |
libbpf: Update gen_loader to emit BTF_KIND_FUNC relocations
This change updates the BPF syscall loader to relocate BTF_KIND_FUNC
relocations, with support for weak kfunc relocations. The general idea
is to move map_fds to loader map, and also use the data for storing
kfunc BTF fds. Since both reuse the fd_array parameter, they need to be
kept together.
For map_fds, we reserve MAX_USED_MAPS slots in a region, and for kfunc,
we reserve MAX_KFUNC_DESCS. This is done so that insn->off has more
chances of being <= INT16_MAX than treating data map as a sparse array
and adding fd as needed.
When the MAX_KFUNC_DESCS limit is reached, we fall back to the sparse
array model, so that as long as it does remain <= INT16_MAX, we pass an
index relative to the start of fd_array.
We store all ksyms in an array where we try to avoid calling the
bpf_btf_find_by_name_kind helper, and also reuse the BTF fd that was
already stored. This also speeds up the loading process compared to
emitting calls in all cases, in later tests.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-9-memxor@gmail.com
Diffstat (limited to 'tools/lib/bpf/bpf_gen_internal.h')
| -rw-r--r-- | tools/lib/bpf/bpf_gen_internal.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/tools/lib/bpf/bpf_gen_internal.h b/tools/lib/bpf/bpf_gen_internal.h index 615400391e57..70eccbffefb1 100644 --- a/tools/lib/bpf/bpf_gen_internal.h +++ b/tools/lib/bpf/bpf_gen_internal.h @@ -7,6 +7,15 @@ struct ksym_relo_desc { const char *name; int kind; int insn_idx; + bool is_weak; +}; + +struct ksym_desc { + const char *name; + int ref; + int kind; + int off; + int insn; }; struct bpf_gen { @@ -24,6 +33,10 @@ struct bpf_gen { int relo_cnt; char attach_target[128]; int attach_kind; + struct ksym_desc *ksyms; + __u32 nr_ksyms; + int fd_array; + int nr_fd_array; }; void bpf_gen__init(struct bpf_gen *gen, int log_level); @@ -36,6 +49,7 @@ void bpf_gen__prog_load(struct bpf_gen *gen, struct bpf_prog_load_params *load_a void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u32 value_size); void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx); void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *name, enum bpf_attach_type type); -void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, int kind, int insn_idx); +void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, int kind, + int insn_idx); #endif |