diff mbox series

[bpf-next,02/13] bpf: Avoid storing modifier to info->btf_id

Message ID 20191214004741.1652332-1-kafai@fb.com
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series Introduce BPF STRUCT_OPS | expand

Commit Message

Martin KaFai Lau Dec. 14, 2019, 12:47 a.m. UTC 
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>
---
 kernel/bpf/btf.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Comments

Yonghong Song Dec. 16, 2019, 9:34 p.m. UTC | #1 
On 12/13/19 4:47 PM, Martin KaFai Lau wrote:
> 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>

Acked-by: Yonghong Song <yhs@fb.com>
diff mbox series

Patch

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 7d40da240891..88359a4bccb0 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3696,7 +3696,6 @@  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);
@@ -3707,10 +3706,14 @@  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",
@@ -3736,7 +3739,7 @@  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;
 	}