From: Alexei Starovoitov ast@kernel.org
mainline inclusion from mainline-5.17-rc1 commit 74753e1462e77349525daf9eb60ea21ed92d3a97 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-------------------------------------------------
To prepare relo_core.c to be compiled in the kernel and the user space replace btf__type_by_id with btf_type_by_id.
In libbpf btf__type_by_id and btf_type_by_id have different behavior.
bpf_core_apply_relo_insn() needs behavior of uapi btf__type_by_id vs internal btf_type_by_id, but type_id range check is already done in bpf_core_apply_relo(), so it's safe to replace it everywhere. The kernel btf_type_by_id() does the check anyway. It doesn't hurt.
Suggested-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20211201181040.23337-2-alexei.starovoitov@gmail.... (cherry picked from commit 74753e1462e77349525daf9eb60ea21ed92d3a97) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/lib/bpf/btf.c | 2 +- tools/lib/bpf/libbpf_internal.h | 2 +- tools/lib/bpf/relo_core.c | 19 ++++++++----------- 3 files changed, 10 insertions(+), 13 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index d686ac3b4cc8..f8fc8500d275 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -449,7 +449,7 @@ const struct btf *btf__base_btf(const struct btf *btf) }
/* internal helper returning non-const pointer to a type */ -struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id) +struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id) { if (type_id == 0) return &btf_void; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 5835c34c8b4f..fc63c7bb68fd 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -170,7 +170,7 @@ static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) struct btf; struct btf_type;
-struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id); +struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id); const char *btf_kind_str(const struct btf_type *t); const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index b5b8956a1be8..c0904f4cb514 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -51,7 +51,7 @@ static bool is_flex_arr(const struct btf *btf, return false;
/* has to be the last member of enclosing struct */ - t = btf__type_by_id(btf, acc->type_id); + t = btf_type_by_id(btf, acc->type_id); return acc->idx == btf_vlen(t) - 1; }
@@ -388,7 +388,7 @@ static int bpf_core_match_member(const struct btf *local_btf, return 0;
local_id = local_acc->type_id; - local_type = btf__type_by_id(local_btf, local_id); + local_type = btf_type_by_id(local_btf, local_id); local_member = btf_members(local_type) + local_acc->idx; local_name = btf__name_by_offset(local_btf, local_member->name_off);
@@ -580,7 +580,7 @@ static int bpf_core_calc_field_relo(const char *prog_name, return -EUCLEAN; /* request instruction poisoning */
acc = &spec->spec[spec->len - 1]; - t = btf__type_by_id(spec->btf, acc->type_id); + t = btf_type_by_id(spec->btf, acc->type_id);
/* a[n] accessor needs special handling */ if (!acc->name) { @@ -729,7 +729,7 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo, case BPF_ENUMVAL_VALUE: if (!spec) return -EUCLEAN; /* request instruction poisoning */ - t = btf__type_by_id(spec->btf, spec->spec[0].type_id); + t = btf_type_by_id(spec->btf, spec->spec[0].type_id); e = btf_enum(t) + spec->spec[0].idx; *val = e->val; break; @@ -805,8 +805,8 @@ static int bpf_core_calc_relo(const char *prog_name, if (res->orig_sz != res->new_sz) { const struct btf_type *orig_t, *new_t;
- orig_t = btf__type_by_id(local_spec->btf, res->orig_type_id); - new_t = btf__type_by_id(targ_spec->btf, res->new_type_id); + orig_t = btf_type_by_id(local_spec->btf, res->orig_type_id); + new_t = btf_type_by_id(targ_spec->btf, res->new_type_id);
/* There are two use cases in which it's safe to * adjust load/store's mem size: @@ -1054,7 +1054,7 @@ static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec) int i;
type_id = spec->root_type_id; - t = btf__type_by_id(spec->btf, type_id); + t = btf_type_by_id(spec->btf, type_id); s = btf__name_by_offset(spec->btf, t->name_off);
libbpf_print(level, "[%u] %s %s", type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s); @@ -1158,10 +1158,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, int i, j, err;
local_id = relo->type_id; - local_type = btf__type_by_id(local_btf, local_id); - if (!local_type) - return -EINVAL; - + local_type = btf_type_by_id(local_btf, local_id); local_name = btf__name_by_offset(local_btf, local_type->name_off); if (!local_name) return -EINVAL;