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Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/btf.c71
1 files changed, 45 insertions, 26 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 51e8b4bee0c8..10ac9efc662d 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5615,21 +5615,46 @@ static u8 bpf_ctx_convert_map[] = {
#undef BPF_MAP_TYPE
#undef BPF_LINK_TYPE
-const struct btf_member *
-btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
- const struct btf_type *t, enum bpf_prog_type prog_type,
- int arg)
+static const struct btf_type *find_canonical_prog_ctx_type(enum bpf_prog_type prog_type)
{
const struct btf_type *conv_struct;
- const struct btf_type *ctx_struct;
const struct btf_member *ctx_type;
- const char *tname, *ctx_tname;
conv_struct = bpf_ctx_convert.t;
- if (!conv_struct) {
- bpf_log(log, "btf_vmlinux is malformed\n");
+ if (!conv_struct)
return NULL;
- }
+ /* prog_type is valid bpf program type. No need for bounds check. */
+ ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
+ /* ctx_type is a pointer to prog_ctx_type in vmlinux.
+ * Like 'struct __sk_buff'
+ */
+ return btf_type_by_id(btf_vmlinux, ctx_type->type);
+}
+
+static int find_kern_ctx_type_id(enum bpf_prog_type prog_type)
+{
+ const struct btf_type *conv_struct;
+ const struct btf_member *ctx_type;
+
+ conv_struct = bpf_ctx_convert.t;
+ if (!conv_struct)
+ return -EFAULT;
+ /* prog_type is valid bpf program type. No need for bounds check. */
+ ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1;
+ /* ctx_type is a pointer to prog_ctx_type in vmlinux.
+ * Like 'struct sk_buff'
+ */
+ return ctx_type->type;
+}
+
+const struct btf_type *
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
+ const struct btf_type *t, enum bpf_prog_type prog_type,
+ int arg)
+{
+ const struct btf_type *ctx_type;
+ const char *tname, *ctx_tname;
+
t = btf_type_by_id(btf, t->type);
while (btf_type_is_modifier(t))
t = btf_type_by_id(btf, t->type);
@@ -5646,17 +5671,15 @@ btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
return NULL;
}
- /* prog_type is valid bpf program type. No need for bounds check. */
- ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
- /* ctx_struct is a pointer to prog_ctx_type in vmlinux.
- * Like 'struct __sk_buff'
- */
- ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
- if (!ctx_struct)
+
+ ctx_type = find_canonical_prog_ctx_type(prog_type);
+ if (!ctx_type) {
+ bpf_log(log, "btf_vmlinux is malformed\n");
/* should not happen */
return NULL;
+ }
again:
- ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
+ ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off);
if (!ctx_tname) {
/* should not happen */
bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
@@ -5677,10 +5700,10 @@ again:
/* bpf_user_pt_regs_t is a typedef, so resolve it to
* underlying struct and check name again
*/
- if (!btf_type_is_modifier(ctx_struct))
+ if (!btf_type_is_modifier(ctx_type))
return NULL;
- while (btf_type_is_modifier(ctx_struct))
- ctx_struct = btf_type_by_id(btf_vmlinux, ctx_struct->type);
+ while (btf_type_is_modifier(ctx_type))
+ ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type);
goto again;
}
return ctx_type;
@@ -5692,13 +5715,9 @@ static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
enum bpf_prog_type prog_type,
int arg)
{
- const struct btf_member *prog_ctx_type, *kern_ctx_type;
-
- prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
- if (!prog_ctx_type)
+ if (!btf_get_prog_ctx_type(log, btf, t, prog_type, arg))
return -ENOENT;
- kern_ctx_type = prog_ctx_type + 1;
- return kern_ctx_type->type;
+ return find_kern_ctx_type_id(prog_type);
}
int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type)