new file mode 100644
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018 Facebook */
+
+#ifndef _LINUX_BTF_H
+#define _LINUX_BTF_H 1
+
+#include <linux/types.h>
+
+struct btf;
+struct btf_type;
+
+/* Figure out the size of a type_id. If type_id is a modifier
+ * (e.g. const), it will be resolved to find out the type with size.
+ *
+ * For example:
+ * In describing "const void *", type_id is "const" and "const"
+ * refers to "void *". The return type will be "void *".
+ *
+ * If type_id is a simple "int", then return type will be "int".
+ *
+ * @btf: struct btf object
+ * @type_id: Find out the size of type_id. The type_id of the return
+ * type is set to *type_id.
+ * @ret_size: It can be NULL. If not NULL, the size of the return
+ * type is set to *ret_size.
+ * Return: The btf_type (resolved to another type with size info if needed).
+ * NULL is returned if type_id itself does not have size info
+ * (e.g. void) or it cannot be resolved to another type that
+ * has size info.
+ * *type_id and *ret_size will not be changed in the
+ * NULL return case.
+ */
+const struct btf_type *btf_type_id_size(const struct btf *btf,
+ u32 *type_id,
+ u32 *ret_size);
+
+#endif
@@ -105,6 +105,50 @@
*
* In the first pass, it still does some verifications (e.g.
* checking the name is a valid offset to the string section).
+ *
+ * Pass #2
+ * ~~~~~~~
+ * The main focus is to resolve a btf_type that is referring
+ * to another type.
+ *
+ * We have to ensure the referring type:
+ * 1) does exist in the BTF (i.e. in btf->types[])
+ * 2) does not cause a loop:
+ * struct A {
+ * struct B b;
+ * };
+ *
+ * struct B {
+ * struct A a;
+ * };
+ *
+ * btf_type_needs_resolve() decides if a btf_type needs
+ * to be resolved.
+ *
+ * The needs_resolve type implements the "resolve()" ops which
+ * essentially does a DFS and detects backedge.
+ *
+ * During resolve (or DFS), different C types have different
+ * "RESOLVED" conditions.
+ *
+ * When resolving a BTF_KIND_STRUCT, we need to resolve all its
+ * members because a member is always referring to another
+ * type. A struct's member can be treated as "RESOLVED" if
+ * it is referring to a BTF_KIND_PTR. Otherwise, the
+ * following valid C struct would be rejected:
+ *
+ * struct A {
+ * int m;
+ * struct A *a;
+ * };
+ *
+ * When resolving a BTF_KIND_PTR, it needs to keep resolving if
+ * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
+ * detect a pointer loop, e.g.:
+ * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
+ * ^ |
+ * +-----------------------------------------+
+ *
*/
#define BITS_PER_U64 (sizeof(u64) * BITS_PER_BYTE)
@@ -123,12 +167,19 @@
i < btf_type_vlen(struct_type); \
i++, member++)
+#define for_each_member_from(i, from, struct_type, member) \
+ for (i = from, member = btf_type_member(struct_type) + from; \
+ i < btf_type_vlen(struct_type); \
+ i++, member++)
+
struct btf {
union {
struct btf_header *hdr;
void *data;
};
struct btf_type **types;
+ u32 *resolved_ids;
+ u32 *resolved_sizes;
const char *strings;
void *nohdr_data;
u32 nr_types;
@@ -136,10 +187,42 @@ struct btf {
u32 data_size;
};
+enum verifier_phase {
+ CHECK_META,
+ CHECK_TYPE,
+};
+
+struct resolve_vertex {
+ const struct btf_type *t;
+ u32 type_id;
+ u16 next_member;
+};
+
+enum visit_state {
+ NOT_VISITED,
+ VISITED,
+ RESOLVED,
+};
+
+enum resolve_mode {
+ RESOLVE_TBD, /* To Be Determined */
+ RESOLVE_PTR, /* Resolving for Pointer */
+ RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
+ * or array
+ */
+};
+
+#define MAX_RESOLVE_DEPTH 32
+
struct btf_verifier_env {
struct btf *btf;
+ u8 *visit_states;
+ struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
struct bpf_verifier_log log;
u32 log_type_id;
+ u32 top_stack;
+ enum verifier_phase phase;
+ enum resolve_mode resolve_mode;
};
static const char * const btf_kind_str[NR_BTF_KINDS] = {
@@ -163,6 +246,8 @@ struct btf_kind_operations {
s32 (*check_meta)(struct btf_verifier_env *env,
const struct btf_type *t,
u32 meta_left);
+ int (*resolve)(struct btf_verifier_env *env,
+ const struct resolve_vertex *v);
void (*log_details)(struct btf_verifier_env *env,
const struct btf_type *t);
};
@@ -170,6 +255,102 @@ struct btf_kind_operations {
static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
static struct btf_type btf_void;
+static bool btf_type_is_modifier(const struct btf_type *t)
+{
+ /* Some of them is not strictly a C modifier
+ * but they are grouped into the same bucket
+ * for BTF concern:
+ * A type (t) that refers to another
+ * type through t->type AND its size cannot
+ * be determined without following the t->type.
+ *
+ * ptr does not fall into this bucket
+ * because its size is always sizeof(void *).
+ */
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_CONST:
+ case BTF_KIND_RESTRICT:
+ return true;
+ };
+
+ return false;
+}
+
+static bool btf_type_is_void(const struct btf_type *t)
+{
+ /* void => no type and size info.
+ * Hence, FWD is also treated as void.
+ */
+ return t == &btf_void || BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
+}
+
+static bool btf_type_is_void_or_null(const struct btf_type *t)
+{
+ return !t || btf_type_is_void(t);
+}
+
+/* union is only a special case of struct:
+ * all its offsetof(member) == 0
+ */
+static bool btf_type_is_struct(const struct btf_type *t)
+{
+ u8 kind = BTF_INFO_KIND(t->info);
+
+ return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
+}
+
+static bool btf_type_is_array(const struct btf_type *t)
+{
+ return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
+}
+
+static bool btf_type_is_ptr(const struct btf_type *t)
+{
+ return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
+}
+
+static bool btf_type_is_int(const struct btf_type *t)
+{
+ return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
+}
+
+/* What types need to be resolved?
+ *
+ * btf_type_is_modifier() is an obvious one.
+ *
+ * btf_type_is_struct() because its member refers to
+ * another type (through member->type).
+
+ * btf_type_is_array() because its element (array->type)
+ * refers to another type. Array can be thought of a
+ * special case of struct while array just has the same
+ * member-type repeated by array->nelems of times.
+ */
+static bool btf_type_needs_resolve(const struct btf_type *t)
+{
+ return btf_type_is_modifier(t) ||
+ btf_type_is_ptr(t) ||
+ btf_type_is_struct(t) ||
+ btf_type_is_array(t);
+}
+
+/* t->size can be used */
+static bool btf_type_has_size(const struct btf_type *t)
+{
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_INT:
+ case BTF_KIND_FLOAT:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ return true;
+ };
+
+ return false;
+}
+
static const char *btf_int_encoding_str(u8 encoding)
{
if (encoding == 0)
@@ -232,6 +413,14 @@ static const char *btf_name_by_offset(const struct btf *btf, u32 offset)
return "(invalid-name-offset)";
}
+static const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
+{
+ if (type_id > btf->nr_types)
+ return NULL;
+
+ return btf->types[type_id];
+}
+
__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
const char *fmt, ...)
{
@@ -306,6 +495,15 @@ static void btf_verifier_log_member(struct btf_verifier_env *env,
if (!bpf_verifier_log_needed(log))
return;
+ /* The CHECK_META phase already did a btf dump.
+ *
+ * If member is logged again, it must hit an error in
+ * parsing this member. It is useful to print out which
+ * struct this member belongs to.
+ */
+ if (env->phase != CHECK_META)
+ btf_verifier_log_type(env, struct_type, NULL);
+
__btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
btf_name_by_offset(btf, member->name),
member->type, member->offset);
@@ -367,15 +565,176 @@ static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
static void btf_free(struct btf *btf)
{
kvfree(btf->types);
+ kvfree(btf->resolved_sizes);
+ kvfree(btf->resolved_ids);
kvfree(btf->data);
kfree(btf);
}
+static int env_resolve_init(struct btf_verifier_env *env)
+{
+ struct btf *btf = env->btf;
+ u32 nr_types = btf->nr_types;
+ u32 *resolved_sizes = NULL;
+ u32 *resolved_ids = NULL;
+ u8 *visit_states = NULL;
+
+ /* +1 for btf_void */
+ resolved_sizes = kvzalloc((nr_types + 1) * sizeof(*resolved_sizes),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!resolved_sizes)
+ goto nomem;
+
+ resolved_ids = kvzalloc((nr_types + 1) * sizeof(*resolved_ids),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!resolved_ids)
+ goto nomem;
+
+ visit_states = kvzalloc((nr_types + 1) * sizeof(*visit_states),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!visit_states)
+ goto nomem;
+
+ btf->resolved_sizes = resolved_sizes;
+ btf->resolved_ids = resolved_ids;
+ env->visit_states = visit_states;
+
+ return 0;
+
+nomem:
+ kvfree(resolved_sizes);
+ kvfree(resolved_ids);
+ kvfree(visit_states);
+ return -ENOMEM;
+}
+
static void btf_verifier_env_free(struct btf_verifier_env *env)
{
+ kvfree(env->visit_states);
kfree(env);
}
+static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
+ const struct btf_type *next_type)
+{
+ switch (env->resolve_mode) {
+ case RESOLVE_TBD:
+ /* int, enum or void is a sink */
+ return !btf_type_needs_resolve(next_type);
+ case RESOLVE_PTR:
+ /* int, enum, void, struct or array is a sink for ptr */
+ return !btf_type_is_modifier(next_type) &&
+ !btf_type_is_ptr(next_type);
+ case RESOLVE_STRUCT_OR_ARRAY:
+ /* int, enum, void or ptr is a sink for struct and array */
+ return !btf_type_is_modifier(next_type) &&
+ !btf_type_is_array(next_type) &&
+ !btf_type_is_struct(next_type);
+ default:
+ BUG_ON(1);
+ };
+}
+
+static bool env_type_is_resolved(const struct btf_verifier_env *env,
+ u32 type_id)
+{
+ return env->visit_states[type_id] == RESOLVED;
+}
+
+static int env_stack_push(struct btf_verifier_env *env,
+ const struct btf_type *t, u32 type_id)
+{
+ struct resolve_vertex *v;
+
+ if (env->top_stack == MAX_RESOLVE_DEPTH)
+ return -E2BIG;
+
+ if (env->visit_states[type_id] != NOT_VISITED)
+ return -EEXIST;
+
+ env->visit_states[type_id] = VISITED;
+
+ v = &env->stack[env->top_stack++];
+ v->t = t;
+ v->type_id = type_id;
+ v->next_member = 0;
+
+ if (env->resolve_mode == RESOLVE_TBD) {
+ if (btf_type_is_ptr(t))
+ env->resolve_mode = RESOLVE_PTR;
+ else if (btf_type_is_struct(t) || btf_type_is_array(t))
+ env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
+ }
+
+ return 0;
+}
+
+static void env_stack_set_next_member(struct btf_verifier_env *env,
+ u16 next_member)
+{
+ env->stack[env->top_stack - 1].next_member = next_member;
+}
+
+static void env_stack_pop_resolved(struct btf_verifier_env *env,
+ u32 resolved_type_id,
+ u32 resolved_size)
+{
+ u32 type_id = env->stack[--(env->top_stack)].type_id;
+ struct btf *btf = env->btf;
+
+ btf->resolved_sizes[type_id] = resolved_size;
+ btf->resolved_ids[type_id] = resolved_type_id;
+ env->visit_states[type_id] = RESOLVED;
+}
+
+static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
+{
+ return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
+}
+
+/* The input param "type_id" must point to a needs_resolve type */
+static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
+ u32 *type_id)
+{
+ *type_id = btf->resolved_ids[*type_id];
+ return btf_type_by_id(btf, *type_id);
+}
+
+const struct btf_type *btf_type_id_size(const struct btf *btf,
+ u32 *type_id, u32 *ret_size)
+{
+ const struct btf_type *size_type;
+ u32 size_type_id = *type_id;
+ u32 size = 0;
+
+ size_type = btf_type_by_id(btf, size_type_id);
+ if (btf_type_is_void_or_null(size_type))
+ return NULL;
+
+ if (btf_type_has_size(size_type)) {
+ size = size_type->size;
+ } else if (btf_type_is_array(size_type)) {
+ size = btf->resolved_sizes[size_type_id];
+ } else if (btf_type_is_ptr(size_type)) {
+ size = sizeof(void *);
+ } else {
+ if (WARN_ON_ONCE(!btf_type_is_modifier(size_type)))
+ return NULL;
+
+ size = btf->resolved_sizes[size_type_id];
+ size_type_id = btf->resolved_ids[size_type_id];
+ size_type = btf_type_by_id(btf, size_type_id);
+ if (btf_type_is_void(size_type))
+ return NULL;
+ }
+
+ *type_id = size_type_id;
+ if (ret_size)
+ *ret_size = size;
+
+ return size_type;
+}
+
static int btf_df_check_meta(struct btf_verifier_env *env,
const struct btf_type *t,
u32 meta_left)
@@ -384,6 +743,13 @@ static int btf_df_check_meta(struct btf_verifier_env *env,
return -ENOTSUPP;
}
+static int btf_df_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ btf_verifier_log_basic(env, v->t, "Unsupported resolve");
+ return -EINVAL;
+}
+
static void btf_df_log(struct btf_verifier_env *env,
const struct btf_type *t)
{
@@ -392,6 +758,7 @@ static void btf_df_log(struct btf_verifier_env *env,
static struct btf_kind_operations df_ops = {
.check_meta = btf_df_check_meta,
+ .resolve = btf_df_resolve,
.log_details = btf_df_log,
};
@@ -459,6 +826,7 @@ static void btf_int_log(struct btf_verifier_env *env,
const struct btf_kind_operations int_ops = {
.check_meta = btf_int_check_meta,
+ .resolve = btf_df_resolve,
.log_details = btf_int_log,
};
@@ -481,6 +849,104 @@ static int btf_ref_type_check_meta(struct btf_verifier_env *env,
return 0;
}
+static int btf_modifier_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *t = v->t;
+ const struct btf_type *next_type;
+ u32 next_type_id = t->type;
+ struct btf *btf = env->btf;
+ u32 next_type_size = 0;
+
+ next_type = btf_type_by_id(btf, next_type_id);
+ if (!next_type) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ /* "typedef void new_void", "const void"...etc */
+ if (btf_type_is_void(next_type))
+ goto resolved;
+
+ if (!env_type_is_resolve_sink(env, next_type) &&
+ !env_type_is_resolved(env, next_type_id))
+ return env_stack_push(env, next_type, next_type_id);
+
+ /* Figure out the resolved next_type_id with size.
+ * They will be stored in the current modifier's
+ * resolved_ids and resolved_sizes such that it can
+ * save us a few type-following when we use it later (e.g. in
+ * pretty print).
+ */
+ if (!btf_type_id_size(btf, &next_type_id, &next_type_size) &&
+ !btf_type_is_void(btf_type_id_resolve(btf, &next_type_id))) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+resolved:
+ env_stack_pop_resolved(env, next_type_id, next_type_size);
+
+ return 0;
+}
+
+static int btf_ptr_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *next_type;
+ const struct btf_type *t = v->t;
+ u32 next_type_id = t->type;
+ struct btf *btf = env->btf;
+ u32 next_type_size = 0;
+
+ next_type = btf_type_by_id(btf, next_type_id);
+ if (!next_type) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ /* "void *" */
+ if (btf_type_is_void(next_type))
+ goto resolved;
+
+ if (!env_type_is_resolve_sink(env, next_type) &&
+ !env_type_is_resolved(env, next_type_id))
+ return env_stack_push(env, next_type, next_type_id);
+
+ /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
+ * the modifier may have stopped resolving when it was resolved
+ * to a ptr (last-resolved-ptr).
+ *
+ * We now need to continue from the last-resolved-ptr to
+ * ensure the last-resolved-ptr will not referring back to
+ * the currenct ptr (t).
+ */
+ if (btf_type_is_modifier(next_type)) {
+ const struct btf_type *resolved_type;
+ u32 resolved_type_id;
+
+ resolved_type_id = next_type_id;
+ resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+ if (btf_type_is_ptr(resolved_type) &&
+ !env_type_is_resolve_sink(env, resolved_type) &&
+ !env_type_is_resolved(env, resolved_type_id))
+ return env_stack_push(env, resolved_type,
+ resolved_type_id);
+ }
+
+ if (!btf_type_id_size(btf, &next_type_id, &next_type_size) &&
+ !btf_type_is_void(btf_type_id_resolve(btf, &next_type_id))) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+resolved:
+ env_stack_pop_resolved(env, next_type_id, 0);
+
+ return 0;
+}
+
static void btf_ref_type_log(struct btf_verifier_env *env,
const struct btf_type *t)
{
@@ -489,16 +955,19 @@ static void btf_ref_type_log(struct btf_verifier_env *env,
static struct btf_kind_operations modifier_ops = {
.check_meta = btf_ref_type_check_meta,
+ .resolve = btf_modifier_resolve,
.log_details = btf_ref_type_log,
};
static struct btf_kind_operations ptr_ops = {
.check_meta = btf_ref_type_check_meta,
+ .resolve = btf_ptr_resolve,
.log_details = btf_ref_type_log,
};
static struct btf_kind_operations fwd_ops = {
.check_meta = btf_ref_type_check_meta,
+ .resolve = btf_df_resolve,
.log_details = btf_ref_type_log,
};
@@ -537,6 +1006,61 @@ static s32 btf_array_check_meta(struct btf_verifier_env *env,
return meta_needed;
}
+static int btf_array_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_array *array = btf_type_array(v->t);
+ const struct btf_type *elem_type;
+ u32 elem_type_id = array->type;
+ struct btf *btf = env->btf;
+ u32 elem_size;
+
+ elem_type = btf_type_by_id(btf, elem_type_id);
+ if (btf_type_is_void_or_null(elem_type)) {
+ btf_verifier_log_type(env, v->t,
+ "Invalid elem");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, elem_type) &&
+ !env_type_is_resolved(env, elem_type_id))
+ return env_stack_push(env, elem_type, elem_type_id);
+
+ elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
+ if (!elem_type) {
+ btf_verifier_log_type(env, v->t, "Invalid elem");
+ return -EINVAL;
+ }
+
+ if (btf_type_is_int(elem_type)) {
+ int int_type_data = btf_type_int(elem_type);
+ u16 nr_bits = BTF_INT_BITS(int_type_data);
+ u16 nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
+
+ /* Put more restriction on array of int. The int cannot
+ * be a bit field and it must be either u8/u16/u32/u64.
+ */
+ if (BITS_PER_BYTE_MASKED(nr_bits) ||
+ BTF_INT_OFFSET(int_type_data) ||
+ (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
+ nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64))) {
+ btf_verifier_log_type(env, v->t,
+ "Invalid array of int");
+ return -EINVAL;
+ }
+ }
+
+ if (array->nelems && elem_size > U32_MAX / array->nelems) {
+ btf_verifier_log_type(env, v->t,
+ "Array size overflows U32_MAX");
+ return -EINVAL;
+ }
+
+ env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
+
+ return 0;
+}
+
static void btf_array_log(struct btf_verifier_env *env,
const struct btf_type *t)
{
@@ -548,6 +1072,7 @@ static void btf_array_log(struct btf_verifier_env *env,
static struct btf_kind_operations array_ops = {
.check_meta = btf_array_check_meta,
+ .resolve = btf_array_resolve,
.log_details = btf_array_log,
};
@@ -607,6 +1132,50 @@ static s32 btf_struct_check_meta(struct btf_verifier_env *env,
return meta_needed;
}
+static int btf_struct_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_member *member;
+ u16 i;
+
+ /* Before continue resolving the next_member,
+ * ensure the last member is indeed resolved to a
+ * type with size info.
+ */
+ if (v->next_member) {
+ const struct btf_member *last_member;
+ u16 last_member_type_id;
+
+ last_member = btf_type_member(v->t) + v->next_member - 1;
+ last_member_type_id = last_member->type;
+ if (WARN_ON_ONCE(!env_type_is_resolved(env,
+ last_member_type_id)))
+ return -EINVAL;
+ }
+
+ for_each_member_from(i, v->next_member, v->t, member) {
+ u32 member_type_id = member->type;
+ const struct btf_type *member_type = btf_type_by_id(env->btf,
+ member_type_id);
+
+ if (btf_type_is_void_or_null(member_type)) {
+ btf_verifier_log_member(env, v->t, member,
+ "Invalid member");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, member_type) &&
+ !env_type_is_resolved(env, member_type_id)) {
+ env_stack_set_next_member(env, i + 1);
+ return env_stack_push(env, member_type, member_type_id);
+ }
+ }
+
+ env_stack_pop_resolved(env, 0, 0);
+
+ return 0;
+}
+
static void btf_struct_log(struct btf_verifier_env *env,
const struct btf_type *t)
{
@@ -615,6 +1184,7 @@ static void btf_struct_log(struct btf_verifier_env *env,
static struct btf_kind_operations struct_ops = {
.check_meta = btf_struct_check_meta,
+ .resolve = btf_struct_resolve,
.log_details = btf_struct_log,
};
@@ -668,6 +1238,7 @@ static void btf_enum_log(struct btf_verifier_env *env,
struct btf_kind_operations enum_ops = {
.check_meta = btf_enum_check_meta,
+ .resolve = btf_df_resolve,
.log_details = btf_enum_log,
};
@@ -749,9 +1320,104 @@ static int btf_check_all_metas(struct btf_verifier_env *env)
return 0;
}
+static int btf_resolve(struct btf_verifier_env *env,
+ const struct btf_type *t, u32 type_id)
+{
+ const struct resolve_vertex *v;
+ int err = 0;
+
+ env->resolve_mode = RESOLVE_TBD;
+ env_stack_push(env, t, type_id);
+ while (!err && (v = env_stack_peak(env))) {
+ env->log_type_id = v->type_id;
+ err = btf_type_ops(v->t)->resolve(env, v);
+ }
+
+ env->log_type_id = type_id;
+ if (err == -E2BIG)
+ btf_verifier_log_type(env, t,
+ "Exceeded max resolving depth:%u",
+ MAX_RESOLVE_DEPTH);
+ else if (err == -EEXIST)
+ btf_verifier_log_type(env, t, "Loop detected");
+
+ return err;
+}
+
+static bool btf_resolve_valid(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 type_id)
+{
+ struct btf *btf = env->btf;
+
+ if (!env_type_is_resolved(env, type_id))
+ return false;
+
+ if (btf_type_is_struct(t))
+ return !btf->resolved_ids[type_id] &&
+ !btf->resolved_sizes[type_id];
+
+ if (btf_type_is_modifier(t) || btf_type_is_ptr(t)) {
+ t = btf_type_id_resolve(btf, &type_id);
+ return t && !btf_type_is_modifier(t);
+ }
+
+ if (btf_type_is_array(t)) {
+ const struct btf_array *array = btf_type_array(t);
+ const struct btf_type *elem_type;
+ u32 elem_type_id = array->type;
+ u32 elem_size;
+
+ elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
+ return elem_type && !btf_type_is_modifier(elem_type) &&
+ (array->nelems * elem_size ==
+ btf->resolved_sizes[type_id]);
+ }
+
+ return false;
+}
+
+static int btf_check_all_types(struct btf_verifier_env *env)
+{
+ struct btf *btf = env->btf;
+ u32 type_id;
+ int err;
+
+ err = env_resolve_init(env);
+ if (err)
+ return err;
+
+ env->phase++;
+ for (type_id = 1; type_id <= btf->nr_types; type_id++) {
+ const struct btf_type *t = btf_type_by_id(btf, type_id);
+
+ env->log_type_id = type_id;
+ if (btf_type_needs_resolve(t) &&
+ !env_type_is_resolved(env, type_id)) {
+ err = btf_resolve(env, t, type_id);
+ if (err)
+ return err;
+ }
+
+ if (btf_type_needs_resolve(t) &&
+ !btf_resolve_valid(env, t, type_id)) {
+ btf_verifier_log_type(env, t, "Invalid resolve state");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
static int btf_parse_type_sec(struct btf_verifier_env *env)
{
- return btf_check_all_metas(env);
+ int err;
+
+ err = btf_check_all_metas(env);
+ if (err)
+ return err;
+
+ return btf_check_all_types(env);
}
static int btf_parse_str_sec(struct btf_verifier_env *env)