{
bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL;
struct bpf_core_cand_list cands = {};
+ struct bpf_core_relo_res targ_res;
struct bpf_core_spec *specs;
int err;
cands.len = cc->cnt;
/* cand_cache_mutex needs to span the cache lookup and
* copy of btf pointer into bpf_core_cand_list,
- * since module can be unloaded while bpf_core_apply_relo_insn
+ * since module can be unloaded while bpf_core_calc_relo_insn
* is working with module's btf.
*/
}
- err = bpf_core_apply_relo_insn((void *)ctx->log, insn, relo->insn_off / 8,
- relo, relo_idx, ctx->btf, &cands, specs);
+ err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs,
+ &targ_res);
+ if (err)
+ goto out;
+
+ err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx,
+ &targ_res);
+
out:
kfree(specs);
if (need_cands) {
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)
+static int bpf_core_resolve_relo(struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ struct hashmap *cand_cache,
+ struct bpf_core_relo_res *targ_res)
{
struct bpf_core_spec specs_scratch[3] = {};
const void *type_key = u32_as_hash_key(relo->type_id);
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];
+ int err;
local_type = btf__type_by_id(local_btf, local_id);
if (!local_type)
if (!local_name)
return -EINVAL;
- if (prog->obj->gen_loader) {
- const char *spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
-
- pr_debug("record_relo_core: prog %td insn[%d] %s %s %s final insn_idx %d\n",
- prog - prog->obj->programs, relo->insn_off / 8,
- btf_kind_str(local_type), local_name, spec_str, insn_idx);
- return record_relo_core(prog, relo, insn_idx);
- }
-
if (relo->kind != BPF_CORE_TYPE_ID_LOCAL &&
!hashmap__find(cand_cache, type_key, (void **)&cands)) {
cands = bpf_core_find_cands(prog->obj, local_btf, local_id);
}
}
- return bpf_core_apply_relo_insn(prog_name, insn, insn_idx, relo,
- relo_idx, local_btf, cands, specs_scratch);
+ return bpf_core_calc_relo_insn(prog_name, relo, relo_idx, local_btf, cands, specs_scratch,
+ targ_res);
}
static int
bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
{
const struct btf_ext_info_sec *sec;
+ struct bpf_core_relo_res targ_res;
const struct bpf_core_relo *rec;
const struct btf_ext_info *seg;
struct hashmap_entry *entry;
struct hashmap *cand_cache = NULL;
struct bpf_program *prog;
+ struct bpf_insn *insn;
const char *sec_name;
int i, err = 0, insn_idx, sec_idx;
sec_name, sec->num_info);
for_each_btf_ext_rec(seg, sec, i, rec) {
+ if (rec->insn_off % BPF_INSN_SZ)
+ return -EINVAL;
insn_idx = rec->insn_off / BPF_INSN_SZ;
prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx);
if (!prog) {
if (!prog->load)
continue;
- err = bpf_core_apply_relo(prog, rec, i, obj->btf, cand_cache);
+ /* 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];
+
+ if (prog->obj->gen_loader) {
+ err = record_relo_core(prog, rec, insn_idx);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n",
+ prog->name, i, err);
+ goto out;
+ }
+ continue;
+ }
+
+ err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res);
if (err) {
pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
prog->name, i, err);
goto out;
}
+
+ err = bpf_core_patch_insn(prog->name, insn, insn_idx, rec, i, &targ_res);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n",
+ prog->name, i, insn_idx, err);
+ goto out;
+ }
}
}
return 0;
}
-struct bpf_core_relo_res
-{
- /* expected value in the instruction, unless validate == false */
- __u32 orig_val;
- /* new value that needs to be patched up to */
- __u32 new_val;
- /* relocation unsuccessful, poison instruction, but don't fail load */
- bool poison;
- /* some relocations can't be validated against orig_val */
- bool validate;
- /* for field byte offset relocations or the forms:
- * *(T *)(rX + <off>) = rY
- * rX = *(T *)(rY + <off>),
- * we remember original and resolved field size to adjust direct
- * memory loads of pointers and integers; this is necessary for 32-bit
- * host kernel architectures, but also allows to automatically
- * relocate fields that were resized from, e.g., u32 to u64, etc.
- */
- bool fail_memsz_adjust;
- __u32 orig_sz;
- __u32 orig_type_id;
- __u32 new_sz;
- __u32 new_type_id;
-};
-
/* Calculate original and target relocation values, given local and target
* specs and relocation kind. These values are calculated for each candidate.
* If there are multiple candidates, resulting values should all be consistent
* 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(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)
+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)
{
__u32 orig_val, new_val;
__u8 class;
}
/*
- * CO-RE relocate single instruction.
+ * Calculate CO-RE relocation target result.
*
* The outline and important points of the algorithm:
* 1. For given local type, find corresponding candidate target types.
* between multiple relocations for the same type ID and is updated as some
* of the candidates are pruned due to structural incompatibility.
*/
-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 bpf_core_cand_list *cands,
- struct bpf_core_spec *specs_scratch)
+int bpf_core_calc_relo_insn(const char *prog_name,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ struct bpf_core_cand_list *cands,
+ struct bpf_core_spec *specs_scratch,
+ struct bpf_core_relo_res *targ_res)
{
struct bpf_core_spec *local_spec = &specs_scratch[0];
struct bpf_core_spec *cand_spec = &specs_scratch[1];
struct bpf_core_spec *targ_spec = &specs_scratch[2];
- struct bpf_core_relo_res cand_res, targ_res;
+ struct bpf_core_relo_res cand_res;
const struct btf_type *local_type;
const char *local_name;
__u32 local_id;
/* TYPE_ID_LOCAL relo is special and doesn't need candidate search */
if (relo->kind == BPF_CORE_TYPE_ID_LOCAL) {
/* bpf_insn's imm value could get out of sync during linking */
- memset(&targ_res, 0, sizeof(targ_res));
- targ_res.validate = false;
- targ_res.poison = false;
- targ_res.orig_val = local_spec->root_type_id;
- targ_res.new_val = local_spec->root_type_id;
- goto patch_insn;
+ memset(targ_res, 0, sizeof(*targ_res));
+ targ_res->validate = false;
+ targ_res->poison = false;
+ targ_res->orig_val = local_spec->root_type_id;
+ targ_res->new_val = local_spec->root_type_id;
+ return 0;
}
/* libbpf doesn't support candidate search for anonymous types */
return err;
if (j == 0) {
- targ_res = cand_res;
+ *targ_res = cand_res;
*targ_spec = *cand_spec;
} else if (cand_spec->bit_offset != targ_spec->bit_offset) {
/* if there are many field relo candidates, they
prog_name, relo_idx, cand_spec->bit_offset,
targ_spec->bit_offset);
return -EINVAL;
- } else if (cand_res.poison != targ_res.poison || cand_res.new_val != targ_res.new_val) {
+ } else if (cand_res.poison != targ_res->poison ||
+ cand_res.new_val != targ_res->new_val) {
/* all candidates should result in the same relocation
* decision and value, otherwise it's dangerous to
* proceed due to ambiguity
pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %u != %s %u\n",
prog_name, relo_idx,
cand_res.poison ? "failure" : "success", cand_res.new_val,
- targ_res.poison ? "failure" : "success", targ_res.new_val);
+ targ_res->poison ? "failure" : "success", targ_res->new_val);
return -EINVAL;
}
prog_name, relo_idx);
/* calculate single target relo result explicitly */
- err = bpf_core_calc_relo(prog_name, relo, relo_idx, local_spec, NULL, &targ_res);
+ err = bpf_core_calc_relo(prog_name, relo, relo_idx, local_spec, NULL, targ_res);
if (err)
return err;
}
-patch_insn:
- /* bpf_core_patch_insn() should know how to handle missing targ_spec */
- 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 #%u: %d\n",
- prog_name, relo_idx, relo->insn_off / 8, err);
- return -EINVAL;
- }
-
return 0;
}
__u32 bit_offset;
};
-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 bpf_core_cand_list *cands,
- struct bpf_core_spec *specs_scratch);
+struct bpf_core_relo_res {
+ /* expected value in the instruction, unless validate == false */
+ __u32 orig_val;
+ /* new value that needs to be patched up to */
+ __u32 new_val;
+ /* relocation unsuccessful, poison instruction, but don't fail load */
+ bool poison;
+ /* some relocations can't be validated against orig_val */
+ bool validate;
+ /* for field byte offset relocations or the forms:
+ * *(T *)(rX + <off>) = rY
+ * rX = *(T *)(rY + <off>),
+ * we remember original and resolved field size to adjust direct
+ * memory loads of pointers and integers; this is necessary for 32-bit
+ * host kernel architectures, but also allows to automatically
+ * relocate fields that were resized from, e.g., u32 to u64, etc.
+ */
+ bool fail_memsz_adjust;
+ __u32 orig_sz;
+ __u32 orig_type_id;
+ __u32 new_sz;
+ __u32 new_type_id;
+};
+
int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
const struct btf *targ_btf, __u32 targ_id);
size_t bpf_core_essential_name_len(const char *name);
+
+int bpf_core_calc_relo_insn(const char *prog_name,
+ const struct bpf_core_relo *relo, int relo_idx,
+ const struct btf *local_btf,
+ struct bpf_core_cand_list *cands,
+ struct bpf_core_spec *specs_scratch,
+ struct bpf_core_relo_res *targ_res);
+
+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);
+
#endif
projects / users / hch / xfs.git / commitdiff