bpf: Avoid storing modifier to info->btf_id (275517ff) · Commits · 戴 / test

info->btf_id expects the btf_id of a struct, so it should store the final result after skipping modifiers (if any). It also takes this chanace to add a missing newline in one of the bpf_log() messages. Signed-off-by:

Martin KaFai Lau <kafai@fb.com> Signed-off-by:

Alexei Starovoitov <ast@kernel.org> Acked-by:

Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200109003456.3855176-1-kafai@fb.com

kernel/bpf/btf.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -3697,7 +3697,6 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,

		/* this is a pointer to another type */
		info->reg_type = PTR_TO_BTF_ID;
		info->btf_id = t->type;

		if (tgt_prog) {
		ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type);
		@@ -3708,10 +3707,14 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
		return false;
		}
		}

		info->btf_id = t->type;
		t = btf_type_by_id(btf, t->type);
		/* skip modifiers */
		while (btf_type_is_modifier(t))
		while (btf_type_is_modifier(t)) {
		info->btf_id = t->type;
		t = btf_type_by_id(btf, t->type);
		}
		if (!btf_type_is_struct(t)) {
		bpf_log(log,
		"func '%s' arg%d type %s is not a struct\n",
		@@ -3737,7 +3740,7 @@ int btf_struct_access(struct bpf_verifier_log *log,
		again:
		tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
		if (!btf_type_is_struct(t)) {
		bpf_log(log, "Type '%s' is not a struct", tname);
		bpf_log(log, "Type '%s' is not a struct\n", tname);
		return -EINVAL;
		}

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