From: Martin KaFai Lau <kafai@fb.com>
Date: Wed, 8 Jan 2020 16:34:56 -0800
Subject: bpf: Avoid storing modifier to info->btf_id
Patch-mainline: v5.6-rc1
Git-commit: 275517ff452a535da5eef25b1c22e53fc50b0a12
References: bsc#1177028

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
Acked-by: Gary Lin <glin@suse.com>
---
 kernel/bpf/btf.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3697,7 +3697,6 @@ bool btf_ctx_access(int off, int size, e
 
 	/* 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, e
 			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_verifie
 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;
 	}