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Message-Id: <20210721000822.40958-3-alexei.starovoitov@gmail.com>
Date: Tue, 20 Jul 2021 17:08:20 -0700
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: davem@...emloft.net
Cc: daniel@...earbox.net, andrii@...nel.org, netdev@...r.kernel.org,
bpf@...r.kernel.org, kernel-team@...com
Subject: [PATCH bpf-next 2/4] libbpf: Split bpf_core_apply_relo() into bpf_program indepdent helper.
From: Alexei Starovoitov <ast@...nel.org>
bpf_core_apply_relo() doesn't need to know bpf_program internals
and hashmap details.
Signed-off-by: Alexei Starovoitov <ast@...nel.org>
---
tools/lib/bpf/libbpf.c | 117 +++++++++++++++++++++++++----------------
1 file changed, 71 insertions(+), 46 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 57af20574f06..4f71b4218f14 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5972,26 +5972,13 @@ static int insn_bytes_to_bpf_size(__u32 sz)
* 5. *(T *)(rX + <off>) = rY, where T is one of {u8, u16, u32, u64};
* 6. *(T *)(rX + <off>) = <imm>, where T is one of {u8, u16, u32, u64}.
*/
-static int bpf_core_patch_insn(struct bpf_program *prog,
- const struct bpf_core_relo *relo,
- int relo_idx,
- const struct bpf_core_relo_res *res)
+static int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
+ int insn_idx, const struct bpf_core_relo *relo,
+ int relo_idx, const struct bpf_core_relo_res *res)
{
- const char *prog_name = prog->name;
__u32 orig_val, new_val;
- struct bpf_insn *insn;
- int insn_idx;
__u8 class;
- if (relo->insn_off % BPF_INSN_SZ)
- return -EINVAL;
- insn_idx = relo->insn_off / BPF_INSN_SZ;
- /* adjust insn_idx from section frame of reference to the local
- * program's frame of reference; (sub-)program code is not yet
- * relocated, so it's enough to just subtract in-section offset
- */
- insn_idx = insn_idx - prog->sec_insn_off;
- insn = &prog->insns[insn_idx];
class = BPF_CLASS(insn->code);
if (res->poison) {
@@ -6077,7 +6064,6 @@ static int bpf_core_patch_insn(struct bpf_program *prog,
if (!is_ldimm64_insn(insn) ||
insn[0].src_reg != 0 || insn[0].off != 0 ||
- insn_idx + 1 >= prog->insns_cnt ||
insn[1].code != 0 || insn[1].dst_reg != 0 ||
insn[1].src_reg != 0 || insn[1].off != 0) {
pr_warn("prog '%s': relo #%d: insn #%d (LDIMM64) has unexpected form\n",
@@ -6227,19 +6213,17 @@ static void *u32_as_hash_key(__u32 x)
* between multiple relocations for the same type ID and is updated as some
* of the candidates are pruned due to structural incompatibility.
*/
-static int bpf_core_apply_relo(struct bpf_program *prog,
- const struct bpf_core_relo *relo,
- int relo_idx,
- const struct btf *local_btf,
- struct hashmap *cand_cache)
+static int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn,
+ int insn_idx,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ struct core_cand_list *cands)
{
struct bpf_core_spec local_spec, cand_spec, targ_spec = {};
- const void *type_key = u32_as_hash_key(relo->type_id);
struct bpf_core_relo_res cand_res, targ_res;
const struct btf_type *local_type;
const char *local_name;
- struct core_cand_list *cands = NULL;
- const char *prog_name = prog->name;
__u32 local_id;
const char *spec_str;
int i, j, err;
@@ -6257,12 +6241,6 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
if (str_is_empty(spec_str))
return -EINVAL;
- if (prog->obj->gen_loader) {
- pr_warn("// TODO core_relo: prog %td insn[%d] %s %s kind %d\n",
- prog - prog->obj->programs, relo->insn_off / 8,
- local_name, spec_str, relo->kind);
- return -ENOTSUP;
- }
err = bpf_core_parse_spec(local_btf, local_id, spec_str, relo->kind, &local_spec);
if (err) {
pr_warn("prog '%s': relo #%d: parsing [%d] %s %s + %s failed: %d\n",
@@ -6293,20 +6271,6 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
return -EOPNOTSUPP;
}
- if (!hashmap__find(cand_cache, type_key, (void **)&cands)) {
- cands = bpf_core_find_cands(prog->obj, local_btf, local_id);
- if (IS_ERR(cands)) {
- pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld\n",
- prog_name, relo_idx, local_id, btf_kind_str(local_type),
- local_name, PTR_ERR(cands));
- return PTR_ERR(cands);
- }
- err = hashmap__set(cand_cache, type_key, cands, NULL, NULL);
- if (err) {
- bpf_core_free_cands(cands);
- return err;
- }
- }
for (i = 0, j = 0; i < cands->len; i++) {
err = bpf_core_spec_match(&local_spec, cands->cands[i].btf,
@@ -6391,7 +6355,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
patch_insn:
/* bpf_core_patch_insn() should know how to handle missing targ_spec */
- err = bpf_core_patch_insn(prog, relo, relo_idx, &targ_res);
+ err = bpf_core_patch_insn(prog_name, insn, insn_idx, relo, relo_idx, &targ_res);
if (err) {
pr_warn("prog '%s': relo #%d: failed to patch insn #%zu: %d\n",
prog_name, relo_idx, relo->insn_off / BPF_INSN_SZ, err);
@@ -6401,6 +6365,67 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
return 0;
}
+static int bpf_core_apply_relo(struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ struct hashmap *cand_cache)
+{
+ const void *type_key = u32_as_hash_key(relo->type_id);
+ struct core_cand_list *cands = NULL;
+ const char *prog_name = prog->name;
+ const struct btf_type *local_type;
+ const char *local_name;
+ __u32 local_id = relo->type_id;
+ struct bpf_insn *insn;
+ int insn_idx, err;
+
+ if (relo->insn_off % BPF_INSN_SZ)
+ return -EINVAL;
+ insn_idx = relo->insn_off / BPF_INSN_SZ;
+ /* adjust insn_idx from section frame of reference to the local
+ * program's frame of reference; (sub-)program code is not yet
+ * relocated, so it's enough to just subtract in-section offset
+ */
+ insn_idx = insn_idx - prog->sec_insn_off;
+ if (insn_idx > prog->insns_cnt)
+ return -EINVAL;
+ insn = &prog->insns[insn_idx];
+
+ local_type = btf__type_by_id(local_btf, local_id);
+ if (!local_type)
+ return -EINVAL;
+
+ local_name = btf__name_by_offset(local_btf, local_type->name_off);
+ if (!local_name)
+ return -EINVAL;
+
+ if (prog->obj->gen_loader) {
+ pr_warn("// TODO core_relo: prog %td insn[%d] %s kind %d\n",
+ prog - prog->obj->programs, relo->insn_off / 8,
+ local_name, relo->kind);
+ return -ENOTSUP;
+ }
+
+ if (relo->kind != BPF_TYPE_ID_LOCAL &&
+ !hashmap__find(cand_cache, type_key, (void **)&cands)) {
+ cands = bpf_core_find_cands(prog->obj, local_btf, local_id);
+ if (IS_ERR(cands)) {
+ pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld\n",
+ prog_name, relo_idx, local_id, btf_kind_str(local_type),
+ local_name, PTR_ERR(cands));
+ return PTR_ERR(cands);
+ }
+ err = hashmap__set(cand_cache, type_key, cands, NULL, NULL);
+ if (err) {
+ bpf_core_free_cands(cands);
+ return err;
+ }
+ }
+
+ return bpf_core_apply_relo_insn(prog_name, insn, insn_idx, relo, relo_idx, local_btf, cands);
+}
+
static int
bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
{
--
2.30.2
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