mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 15:16:39 +07:00
179cde8cef
This patch checks a few things of struct's members: 1) It has a valid size (e.g. a "const void" is invalid) 2) A member's size (+ its member's offset) does not exceed the containing struct's size. 3) The member's offset satisfies the alignment requirement The above can only be done after the needs_resolve member's type is resolved. Hence, the above is done together in btf_struct_resolve(). Each possible member's type (e.g. int, enum, modifier...) implements the check_member() ops which will be called from btf_struct_resolve(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
1785 lines
45 KiB
C
1785 lines
45 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright (c) 2018 Facebook */
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#include <uapi/linux/btf.h>
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#include <uapi/linux/types.h>
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/kernel.h>
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#include <linux/bpf_verifier.h>
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#include <linux/btf.h>
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/* BTF (BPF Type Format) is the meta data format which describes
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* the data types of BPF program/map. Hence, it basically focus
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* on the C programming language which the modern BPF is primary
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* using.
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*
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* ELF Section:
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* ~~~~~~~~~~~
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* The BTF data is stored under the ".BTF" ELF section
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*
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* struct btf_type:
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* ~~~~~~~~~~~~~~~
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* Each 'struct btf_type' object describes a C data type.
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* Depending on the type it is describing, a 'struct btf_type'
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* object may be followed by more data. F.e.
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* To describe an array, 'struct btf_type' is followed by
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* 'struct btf_array'.
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*
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* 'struct btf_type' and any extra data following it are
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* 4 bytes aligned.
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*
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* Type section:
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* ~~~~~~~~~~~~~
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* The BTF type section contains a list of 'struct btf_type' objects.
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* Each one describes a C type. Recall from the above section
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* that a 'struct btf_type' object could be immediately followed by extra
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* data in order to desribe some particular C types.
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*
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* type_id:
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* ~~~~~~~
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* Each btf_type object is identified by a type_id. The type_id
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* is implicitly implied by the location of the btf_type object in
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* the BTF type section. The first one has type_id 1. The second
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* one has type_id 2...etc. Hence, an earlier btf_type has
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* a smaller type_id.
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*
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* A btf_type object may refer to another btf_type object by using
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* type_id (i.e. the "type" in the "struct btf_type").
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*
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* NOTE that we cannot assume any reference-order.
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* A btf_type object can refer to an earlier btf_type object
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* but it can also refer to a later btf_type object.
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*
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* For example, to describe "const void *". A btf_type
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* object describing "const" may refer to another btf_type
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* object describing "void *". This type-reference is done
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* by specifying type_id:
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*
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* [1] CONST (anon) type_id=2
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* [2] PTR (anon) type_id=0
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*
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* The above is the btf_verifier debug log:
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* - Each line started with "[?]" is a btf_type object
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* - [?] is the type_id of the btf_type object.
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* - CONST/PTR is the BTF_KIND_XXX
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* - "(anon)" is the name of the type. It just
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* happens that CONST and PTR has no name.
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* - type_id=XXX is the 'u32 type' in btf_type
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*
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* NOTE: "void" has type_id 0
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*
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* String section:
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* ~~~~~~~~~~~~~~
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* The BTF string section contains the names used by the type section.
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* Each string is referred by an "offset" from the beginning of the
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* string section.
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*
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* Each string is '\0' terminated.
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*
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* The first character in the string section must be '\0'
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* which is used to mean 'anonymous'. Some btf_type may not
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* have a name.
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*/
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/* BTF verification:
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*
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* To verify BTF data, two passes are needed.
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*
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* Pass #1
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* ~~~~~~~
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* The first pass is to collect all btf_type objects to
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* an array: "btf->types".
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*
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* Depending on the C type that a btf_type is describing,
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* a btf_type may be followed by extra data. We don't know
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* how many btf_type is there, and more importantly we don't
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* know where each btf_type is located in the type section.
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*
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* Without knowing the location of each type_id, most verifications
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* cannot be done. e.g. an earlier btf_type may refer to a later
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* btf_type (recall the "const void *" above), so we cannot
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* check this type-reference in the first pass.
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*
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* In the first pass, it still does some verifications (e.g.
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* checking the name is a valid offset to the string section).
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*
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* Pass #2
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* ~~~~~~~
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* The main focus is to resolve a btf_type that is referring
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* to another type.
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*
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* We have to ensure the referring type:
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* 1) does exist in the BTF (i.e. in btf->types[])
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* 2) does not cause a loop:
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* struct A {
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* struct B b;
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* };
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*
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* struct B {
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* struct A a;
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* };
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*
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* btf_type_needs_resolve() decides if a btf_type needs
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* to be resolved.
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*
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* The needs_resolve type implements the "resolve()" ops which
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* essentially does a DFS and detects backedge.
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*
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* During resolve (or DFS), different C types have different
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* "RESOLVED" conditions.
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*
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* When resolving a BTF_KIND_STRUCT, we need to resolve all its
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* members because a member is always referring to another
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* type. A struct's member can be treated as "RESOLVED" if
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* it is referring to a BTF_KIND_PTR. Otherwise, the
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* following valid C struct would be rejected:
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*
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* struct A {
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* int m;
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* struct A *a;
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* };
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*
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* When resolving a BTF_KIND_PTR, it needs to keep resolving if
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* it is referring to another BTF_KIND_PTR. Otherwise, we cannot
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* detect a pointer loop, e.g.:
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* BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
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* ^ |
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* +-----------------------------------------+
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*
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*/
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#define BITS_PER_U64 (sizeof(u64) * BITS_PER_BYTE)
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#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
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#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
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#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
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#define BITS_ROUNDUP_BYTES(bits) \
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(BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
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/* 16MB for 64k structs and each has 16 members and
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* a few MB spaces for the string section.
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* The hard limit is S32_MAX.
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*/
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#define BTF_MAX_SIZE (16 * 1024 * 1024)
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/* 64k. We can raise it later. The hard limit is S32_MAX. */
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#define BTF_MAX_NR_TYPES 65535
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#define for_each_member(i, struct_type, member) \
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for (i = 0, member = btf_type_member(struct_type); \
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i < btf_type_vlen(struct_type); \
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i++, member++)
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#define for_each_member_from(i, from, struct_type, member) \
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for (i = from, member = btf_type_member(struct_type) + from; \
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i < btf_type_vlen(struct_type); \
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i++, member++)
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struct btf {
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union {
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struct btf_header *hdr;
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void *data;
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};
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struct btf_type **types;
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u32 *resolved_ids;
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u32 *resolved_sizes;
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const char *strings;
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void *nohdr_data;
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u32 nr_types;
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u32 types_size;
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u32 data_size;
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};
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enum verifier_phase {
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CHECK_META,
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CHECK_TYPE,
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};
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struct resolve_vertex {
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const struct btf_type *t;
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u32 type_id;
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u16 next_member;
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};
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enum visit_state {
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NOT_VISITED,
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VISITED,
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RESOLVED,
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};
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enum resolve_mode {
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RESOLVE_TBD, /* To Be Determined */
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RESOLVE_PTR, /* Resolving for Pointer */
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RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
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* or array
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*/
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};
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#define MAX_RESOLVE_DEPTH 32
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struct btf_verifier_env {
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struct btf *btf;
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u8 *visit_states;
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struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
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struct bpf_verifier_log log;
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u32 log_type_id;
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u32 top_stack;
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enum verifier_phase phase;
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enum resolve_mode resolve_mode;
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};
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static const char * const btf_kind_str[NR_BTF_KINDS] = {
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[BTF_KIND_UNKN] = "UNKNOWN",
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[BTF_KIND_INT] = "INT",
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[BTF_KIND_PTR] = "PTR",
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[BTF_KIND_ARRAY] = "ARRAY",
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[BTF_KIND_STRUCT] = "STRUCT",
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[BTF_KIND_UNION] = "UNION",
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[BTF_KIND_ENUM] = "ENUM",
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[BTF_KIND_FWD] = "FWD",
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[BTF_KIND_TYPEDEF] = "TYPEDEF",
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[BTF_KIND_VOLATILE] = "VOLATILE",
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[BTF_KIND_CONST] = "CONST",
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[BTF_KIND_RESTRICT] = "RESTRICT",
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};
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struct btf_kind_operations {
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s32 (*check_meta)(struct btf_verifier_env *env,
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const struct btf_type *t,
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u32 meta_left);
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int (*resolve)(struct btf_verifier_env *env,
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const struct resolve_vertex *v);
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int (*check_member)(struct btf_verifier_env *env,
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const struct btf_type *struct_type,
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const struct btf_member *member,
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const struct btf_type *member_type);
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void (*log_details)(struct btf_verifier_env *env,
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const struct btf_type *t);
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};
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static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
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static struct btf_type btf_void;
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static bool btf_type_is_modifier(const struct btf_type *t)
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{
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/* Some of them is not strictly a C modifier
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* but they are grouped into the same bucket
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* for BTF concern:
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* A type (t) that refers to another
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* type through t->type AND its size cannot
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* be determined without following the t->type.
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*
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* ptr does not fall into this bucket
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* because its size is always sizeof(void *).
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*/
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switch (BTF_INFO_KIND(t->info)) {
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case BTF_KIND_TYPEDEF:
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case BTF_KIND_VOLATILE:
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case BTF_KIND_CONST:
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case BTF_KIND_RESTRICT:
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return true;
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}
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return false;
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}
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static bool btf_type_is_void(const struct btf_type *t)
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{
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/* void => no type and size info.
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* Hence, FWD is also treated as void.
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*/
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return t == &btf_void || BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
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}
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static bool btf_type_is_void_or_null(const struct btf_type *t)
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{
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return !t || btf_type_is_void(t);
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}
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/* union is only a special case of struct:
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* all its offsetof(member) == 0
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*/
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static bool btf_type_is_struct(const struct btf_type *t)
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{
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u8 kind = BTF_INFO_KIND(t->info);
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return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
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}
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static bool btf_type_is_array(const struct btf_type *t)
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{
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return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
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}
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static bool btf_type_is_ptr(const struct btf_type *t)
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{
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return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
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}
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static bool btf_type_is_int(const struct btf_type *t)
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{
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return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
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}
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/* What types need to be resolved?
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*
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* btf_type_is_modifier() is an obvious one.
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*
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* btf_type_is_struct() because its member refers to
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* another type (through member->type).
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* btf_type_is_array() because its element (array->type)
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* refers to another type. Array can be thought of a
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* special case of struct while array just has the same
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* member-type repeated by array->nelems of times.
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*/
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static bool btf_type_needs_resolve(const struct btf_type *t)
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{
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return btf_type_is_modifier(t) ||
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btf_type_is_ptr(t) ||
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btf_type_is_struct(t) ||
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btf_type_is_array(t);
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}
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/* t->size can be used */
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static bool btf_type_has_size(const struct btf_type *t)
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{
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switch (BTF_INFO_KIND(t->info)) {
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case BTF_KIND_INT:
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case BTF_KIND_STRUCT:
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case BTF_KIND_UNION:
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case BTF_KIND_ENUM:
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return true;
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}
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return false;
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}
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static const char *btf_int_encoding_str(u8 encoding)
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{
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if (encoding == 0)
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return "(none)";
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else if (encoding == BTF_INT_SIGNED)
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return "SIGNED";
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else if (encoding == BTF_INT_CHAR)
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return "CHAR";
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else if (encoding == BTF_INT_BOOL)
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return "BOOL";
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else if (encoding == BTF_INT_VARARGS)
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return "VARARGS";
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else
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return "UNKN";
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}
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static u16 btf_type_vlen(const struct btf_type *t)
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{
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return BTF_INFO_VLEN(t->info);
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}
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static u32 btf_type_int(const struct btf_type *t)
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{
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return *(u32 *)(t + 1);
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}
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static const struct btf_array *btf_type_array(const struct btf_type *t)
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{
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return (const struct btf_array *)(t + 1);
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}
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static const struct btf_member *btf_type_member(const struct btf_type *t)
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{
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return (const struct btf_member *)(t + 1);
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}
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static const struct btf_enum *btf_type_enum(const struct btf_type *t)
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{
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return (const struct btf_enum *)(t + 1);
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}
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static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
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{
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return kind_ops[BTF_INFO_KIND(t->info)];
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}
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static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
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{
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return !BTF_STR_TBL_ELF_ID(offset) &&
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BTF_STR_OFFSET(offset) < btf->hdr->str_len;
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}
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static const char *btf_name_by_offset(const struct btf *btf, u32 offset)
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{
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if (!BTF_STR_OFFSET(offset))
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return "(anon)";
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else if (BTF_STR_OFFSET(offset) < btf->hdr->str_len)
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return &btf->strings[BTF_STR_OFFSET(offset)];
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else
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return "(invalid-name-offset)";
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}
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static const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
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{
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if (type_id > btf->nr_types)
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return NULL;
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return btf->types[type_id];
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}
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__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
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const char *fmt, ...)
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{
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va_list args;
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va_start(args, fmt);
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bpf_verifier_vlog(log, fmt, args);
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va_end(args);
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}
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__printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
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const char *fmt, ...)
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{
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struct bpf_verifier_log *log = &env->log;
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va_list args;
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if (!bpf_verifier_log_needed(log))
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return;
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va_start(args, fmt);
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bpf_verifier_vlog(log, fmt, args);
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va_end(args);
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}
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__printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
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const struct btf_type *t,
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bool log_details,
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const char *fmt, ...)
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{
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struct bpf_verifier_log *log = &env->log;
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u8 kind = BTF_INFO_KIND(t->info);
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struct btf *btf = env->btf;
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va_list args;
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if (!bpf_verifier_log_needed(log))
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return;
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__btf_verifier_log(log, "[%u] %s %s%s",
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env->log_type_id,
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btf_kind_str[kind],
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btf_name_by_offset(btf, t->name),
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log_details ? " " : "");
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if (log_details)
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btf_type_ops(t)->log_details(env, t);
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if (fmt && *fmt) {
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__btf_verifier_log(log, " ");
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va_start(args, fmt);
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bpf_verifier_vlog(log, fmt, args);
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va_end(args);
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}
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__btf_verifier_log(log, "\n");
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}
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#define btf_verifier_log_type(env, t, ...) \
|
|
__btf_verifier_log_type((env), (t), true, __VA_ARGS__)
|
|
#define btf_verifier_log_basic(env, t, ...) \
|
|
__btf_verifier_log_type((env), (t), false, __VA_ARGS__)
|
|
|
|
__printf(4, 5)
|
|
static void btf_verifier_log_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const char *fmt, ...)
|
|
{
|
|
struct bpf_verifier_log *log = &env->log;
|
|
struct btf *btf = env->btf;
|
|
va_list args;
|
|
|
|
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);
|
|
|
|
if (fmt && *fmt) {
|
|
__btf_verifier_log(log, " ");
|
|
va_start(args, fmt);
|
|
bpf_verifier_vlog(log, fmt, args);
|
|
va_end(args);
|
|
}
|
|
|
|
__btf_verifier_log(log, "\n");
|
|
}
|
|
|
|
static void btf_verifier_log_hdr(struct btf_verifier_env *env)
|
|
{
|
|
struct bpf_verifier_log *log = &env->log;
|
|
const struct btf *btf = env->btf;
|
|
const struct btf_header *hdr;
|
|
|
|
if (!bpf_verifier_log_needed(log))
|
|
return;
|
|
|
|
hdr = btf->hdr;
|
|
__btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
|
|
__btf_verifier_log(log, "version: %u\n", hdr->version);
|
|
__btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
|
|
__btf_verifier_log(log, "parent_label: %u\n", hdr->parent_label);
|
|
__btf_verifier_log(log, "parent_name: %u\n", hdr->parent_name);
|
|
__btf_verifier_log(log, "label_off: %u\n", hdr->label_off);
|
|
__btf_verifier_log(log, "object_off: %u\n", hdr->object_off);
|
|
__btf_verifier_log(log, "func_off: %u\n", hdr->func_off);
|
|
__btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
|
|
__btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
|
|
__btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
|
|
__btf_verifier_log(log, "btf_total_size: %u\n", btf->data_size);
|
|
}
|
|
|
|
static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
|
|
{
|
|
struct btf *btf = env->btf;
|
|
|
|
/* < 2 because +1 for btf_void which is always in btf->types[0].
|
|
* btf_void is not accounted in btf->nr_types because btf_void
|
|
* does not come from the BTF file.
|
|
*/
|
|
if (btf->types_size - btf->nr_types < 2) {
|
|
/* Expand 'types' array */
|
|
|
|
struct btf_type **new_types;
|
|
u32 expand_by, new_size;
|
|
|
|
if (btf->types_size == BTF_MAX_NR_TYPES) {
|
|
btf_verifier_log(env, "Exceeded max num of types");
|
|
return -E2BIG;
|
|
}
|
|
|
|
expand_by = max_t(u32, btf->types_size >> 2, 16);
|
|
new_size = min_t(u32, BTF_MAX_NR_TYPES,
|
|
btf->types_size + expand_by);
|
|
|
|
new_types = kvzalloc(new_size * sizeof(*new_types),
|
|
GFP_KERNEL | __GFP_NOWARN);
|
|
if (!new_types)
|
|
return -ENOMEM;
|
|
|
|
if (btf->nr_types == 0)
|
|
new_types[0] = &btf_void;
|
|
else
|
|
memcpy(new_types, btf->types,
|
|
sizeof(*btf->types) * (btf->nr_types + 1));
|
|
|
|
kvfree(btf->types);
|
|
btf->types = new_types;
|
|
btf->types_size = new_size;
|
|
}
|
|
|
|
btf->types[++(btf->nr_types)] = t;
|
|
|
|
return 0;
|
|
}
|
|
|
|
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_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
btf_verifier_log_basic(env, struct_type,
|
|
"Unsupported check_member");
|
|
return -EINVAL;
|
|
}
|
|
|
|
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 int btf_int_check_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
u32 int_data = btf_type_int(member_type);
|
|
u32 struct_bits_off = member->offset;
|
|
u32 struct_size = struct_type->size;
|
|
u32 nr_copy_bits;
|
|
u32 bytes_offset;
|
|
|
|
if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"bits_offset exceeds U32_MAX");
|
|
return -EINVAL;
|
|
}
|
|
|
|
struct_bits_off += BTF_INT_OFFSET(int_data);
|
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
|
|
nr_copy_bits = BTF_INT_BITS(int_data) +
|
|
BITS_PER_BYTE_MASKED(struct_bits_off);
|
|
|
|
if (nr_copy_bits > BITS_PER_U64) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"nr_copy_bits exceeds 64");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (struct_size < bytes_offset ||
|
|
struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member exceeds struct_size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static s32 btf_int_check_meta(struct btf_verifier_env *env,
|
|
const struct btf_type *t,
|
|
u32 meta_left)
|
|
{
|
|
u32 int_data, nr_bits, meta_needed = sizeof(int_data);
|
|
u16 encoding;
|
|
|
|
if (meta_left < meta_needed) {
|
|
btf_verifier_log_basic(env, t,
|
|
"meta_left:%u meta_needed:%u",
|
|
meta_left, meta_needed);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (btf_type_vlen(t)) {
|
|
btf_verifier_log_type(env, t, "vlen != 0");
|
|
return -EINVAL;
|
|
}
|
|
|
|
int_data = btf_type_int(t);
|
|
nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
|
|
|
|
if (nr_bits > BITS_PER_U64) {
|
|
btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
|
|
BITS_PER_U64);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
|
|
btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
encoding = BTF_INT_ENCODING(int_data);
|
|
if (encoding &&
|
|
encoding != BTF_INT_SIGNED &&
|
|
encoding != BTF_INT_CHAR &&
|
|
encoding != BTF_INT_BOOL &&
|
|
encoding != BTF_INT_VARARGS) {
|
|
btf_verifier_log_type(env, t, "Unsupported encoding");
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
btf_verifier_log_type(env, t, NULL);
|
|
|
|
return meta_needed;
|
|
}
|
|
|
|
static void btf_int_log(struct btf_verifier_env *env,
|
|
const struct btf_type *t)
|
|
{
|
|
int int_data = btf_type_int(t);
|
|
|
|
btf_verifier_log(env,
|
|
"size=%u bits_offset=%u nr_bits=%u encoding=%s",
|
|
t->size, BTF_INT_OFFSET(int_data),
|
|
BTF_INT_BITS(int_data),
|
|
btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
|
|
}
|
|
|
|
static const struct btf_kind_operations int_ops = {
|
|
.check_meta = btf_int_check_meta,
|
|
.resolve = btf_df_resolve,
|
|
.check_member = btf_int_check_member,
|
|
.log_details = btf_int_log,
|
|
};
|
|
|
|
static int btf_modifier_check_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
const struct btf_type *resolved_type;
|
|
u32 resolved_type_id = member->type;
|
|
struct btf_member resolved_member;
|
|
struct btf *btf = env->btf;
|
|
|
|
resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
|
|
if (!resolved_type) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Invalid member");
|
|
return -EINVAL;
|
|
}
|
|
|
|
resolved_member = *member;
|
|
resolved_member.type = resolved_type_id;
|
|
|
|
return btf_type_ops(resolved_type)->check_member(env, struct_type,
|
|
&resolved_member,
|
|
resolved_type);
|
|
}
|
|
|
|
static int btf_ptr_check_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
u32 struct_size, struct_bits_off, bytes_offset;
|
|
|
|
struct_size = struct_type->size;
|
|
struct_bits_off = member->offset;
|
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
|
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member is not byte aligned");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (struct_size - bytes_offset < sizeof(void *)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member exceeds struct_size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int btf_ref_type_check_meta(struct btf_verifier_env *env,
|
|
const struct btf_type *t,
|
|
u32 meta_left)
|
|
{
|
|
if (btf_type_vlen(t)) {
|
|
btf_verifier_log_type(env, t, "vlen != 0");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (BTF_TYPE_PARENT(t->type)) {
|
|
btf_verifier_log_type(env, t, "Invalid type_id");
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log_type(env, t, NULL);
|
|
|
|
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)
|
|
{
|
|
btf_verifier_log(env, "type_id=%u", t->type);
|
|
}
|
|
|
|
static struct btf_kind_operations modifier_ops = {
|
|
.check_meta = btf_ref_type_check_meta,
|
|
.resolve = btf_modifier_resolve,
|
|
.check_member = btf_modifier_check_member,
|
|
.log_details = btf_ref_type_log,
|
|
};
|
|
|
|
static struct btf_kind_operations ptr_ops = {
|
|
.check_meta = btf_ref_type_check_meta,
|
|
.resolve = btf_ptr_resolve,
|
|
.check_member = btf_ptr_check_member,
|
|
.log_details = btf_ref_type_log,
|
|
};
|
|
|
|
static struct btf_kind_operations fwd_ops = {
|
|
.check_meta = btf_ref_type_check_meta,
|
|
.resolve = btf_df_resolve,
|
|
.check_member = btf_df_check_member,
|
|
.log_details = btf_ref_type_log,
|
|
};
|
|
|
|
static int btf_array_check_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
u32 struct_bits_off = member->offset;
|
|
u32 struct_size, bytes_offset;
|
|
u32 array_type_id, array_size;
|
|
struct btf *btf = env->btf;
|
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member is not byte aligned");
|
|
return -EINVAL;
|
|
}
|
|
|
|
array_type_id = member->type;
|
|
btf_type_id_size(btf, &array_type_id, &array_size);
|
|
struct_size = struct_type->size;
|
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
|
|
if (struct_size - bytes_offset < array_size) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member exceeds struct_size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static s32 btf_array_check_meta(struct btf_verifier_env *env,
|
|
const struct btf_type *t,
|
|
u32 meta_left)
|
|
{
|
|
const struct btf_array *array = btf_type_array(t);
|
|
u32 meta_needed = sizeof(*array);
|
|
|
|
if (meta_left < meta_needed) {
|
|
btf_verifier_log_basic(env, t,
|
|
"meta_left:%u meta_needed:%u",
|
|
meta_left, meta_needed);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (btf_type_vlen(t)) {
|
|
btf_verifier_log_type(env, t, "vlen != 0");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* We are a little forgiving on array->index_type since
|
|
* the kernel is not using it.
|
|
*/
|
|
/* Array elem cannot be in type void,
|
|
* so !array->type is not allowed.
|
|
*/
|
|
if (!array->type || BTF_TYPE_PARENT(array->type)) {
|
|
btf_verifier_log_type(env, t, "Invalid type_id");
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log_type(env, t, NULL);
|
|
|
|
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)
|
|
{
|
|
const struct btf_array *array = btf_type_array(t);
|
|
|
|
btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
|
|
array->type, array->index_type, array->nelems);
|
|
}
|
|
|
|
static struct btf_kind_operations array_ops = {
|
|
.check_meta = btf_array_check_meta,
|
|
.resolve = btf_array_resolve,
|
|
.check_member = btf_array_check_member,
|
|
.log_details = btf_array_log,
|
|
};
|
|
|
|
static int btf_struct_check_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
u32 struct_bits_off = member->offset;
|
|
u32 struct_size, bytes_offset;
|
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member is not byte aligned");
|
|
return -EINVAL;
|
|
}
|
|
|
|
struct_size = struct_type->size;
|
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
|
|
if (struct_size - bytes_offset < member_type->size) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member exceeds struct_size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static s32 btf_struct_check_meta(struct btf_verifier_env *env,
|
|
const struct btf_type *t,
|
|
u32 meta_left)
|
|
{
|
|
bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
|
|
const struct btf_member *member;
|
|
struct btf *btf = env->btf;
|
|
u32 struct_size = t->size;
|
|
u32 meta_needed;
|
|
u16 i;
|
|
|
|
meta_needed = btf_type_vlen(t) * sizeof(*member);
|
|
if (meta_left < meta_needed) {
|
|
btf_verifier_log_basic(env, t,
|
|
"meta_left:%u meta_needed:%u",
|
|
meta_left, meta_needed);
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log_type(env, t, NULL);
|
|
|
|
for_each_member(i, t, member) {
|
|
if (!btf_name_offset_valid(btf, member->name)) {
|
|
btf_verifier_log_member(env, t, member,
|
|
"Invalid member name_offset:%u",
|
|
member->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* A member cannot be in type void */
|
|
if (!member->type || BTF_TYPE_PARENT(member->type)) {
|
|
btf_verifier_log_member(env, t, member,
|
|
"Invalid type_id");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (is_union && member->offset) {
|
|
btf_verifier_log_member(env, t, member,
|
|
"Invalid member bits_offset");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (BITS_ROUNDUP_BYTES(member->offset) > struct_size) {
|
|
btf_verifier_log_member(env, t, member,
|
|
"Memmber bits_offset exceeds its struct size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log_member(env, t, member, NULL);
|
|
}
|
|
|
|
return meta_needed;
|
|
}
|
|
|
|
static int btf_struct_resolve(struct btf_verifier_env *env,
|
|
const struct resolve_vertex *v)
|
|
{
|
|
const struct btf_member *member;
|
|
int err;
|
|
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_type *last_member_type;
|
|
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;
|
|
|
|
last_member_type = btf_type_by_id(env->btf,
|
|
last_member_type_id);
|
|
err = btf_type_ops(last_member_type)->check_member(env, v->t,
|
|
last_member,
|
|
last_member_type);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
err = btf_type_ops(member_type)->check_member(env, v->t,
|
|
member,
|
|
member_type);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
env_stack_pop_resolved(env, 0, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void btf_struct_log(struct btf_verifier_env *env,
|
|
const struct btf_type *t)
|
|
{
|
|
btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
|
|
}
|
|
|
|
static struct btf_kind_operations struct_ops = {
|
|
.check_meta = btf_struct_check_meta,
|
|
.resolve = btf_struct_resolve,
|
|
.check_member = btf_struct_check_member,
|
|
.log_details = btf_struct_log,
|
|
};
|
|
|
|
static int btf_enum_check_member(struct btf_verifier_env *env,
|
|
const struct btf_type *struct_type,
|
|
const struct btf_member *member,
|
|
const struct btf_type *member_type)
|
|
{
|
|
u32 struct_bits_off = member->offset;
|
|
u32 struct_size, bytes_offset;
|
|
|
|
if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member is not byte aligned");
|
|
return -EINVAL;
|
|
}
|
|
|
|
struct_size = struct_type->size;
|
|
bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
|
|
if (struct_size - bytes_offset < sizeof(int)) {
|
|
btf_verifier_log_member(env, struct_type, member,
|
|
"Member exceeds struct_size");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static s32 btf_enum_check_meta(struct btf_verifier_env *env,
|
|
const struct btf_type *t,
|
|
u32 meta_left)
|
|
{
|
|
const struct btf_enum *enums = btf_type_enum(t);
|
|
struct btf *btf = env->btf;
|
|
u16 i, nr_enums;
|
|
u32 meta_needed;
|
|
|
|
nr_enums = btf_type_vlen(t);
|
|
meta_needed = nr_enums * sizeof(*enums);
|
|
|
|
if (meta_left < meta_needed) {
|
|
btf_verifier_log_basic(env, t,
|
|
"meta_left:%u meta_needed:%u",
|
|
meta_left, meta_needed);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (t->size != sizeof(int)) {
|
|
btf_verifier_log_type(env, t, "Expected size:%zu",
|
|
sizeof(int));
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log_type(env, t, NULL);
|
|
|
|
for (i = 0; i < nr_enums; i++) {
|
|
if (!btf_name_offset_valid(btf, enums[i].name)) {
|
|
btf_verifier_log(env, "\tInvalid name_offset:%u",
|
|
enums[i].name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log(env, "\t%s val=%d\n",
|
|
btf_name_by_offset(btf, enums[i].name),
|
|
enums[i].val);
|
|
}
|
|
|
|
return meta_needed;
|
|
}
|
|
|
|
static void btf_enum_log(struct btf_verifier_env *env,
|
|
const struct btf_type *t)
|
|
{
|
|
btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
|
|
}
|
|
|
|
static struct btf_kind_operations enum_ops = {
|
|
.check_meta = btf_enum_check_meta,
|
|
.resolve = btf_df_resolve,
|
|
.check_member = btf_enum_check_member,
|
|
.log_details = btf_enum_log,
|
|
};
|
|
|
|
static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
|
|
[BTF_KIND_INT] = &int_ops,
|
|
[BTF_KIND_PTR] = &ptr_ops,
|
|
[BTF_KIND_ARRAY] = &array_ops,
|
|
[BTF_KIND_STRUCT] = &struct_ops,
|
|
[BTF_KIND_UNION] = &struct_ops,
|
|
[BTF_KIND_ENUM] = &enum_ops,
|
|
[BTF_KIND_FWD] = &fwd_ops,
|
|
[BTF_KIND_TYPEDEF] = &modifier_ops,
|
|
[BTF_KIND_VOLATILE] = &modifier_ops,
|
|
[BTF_KIND_CONST] = &modifier_ops,
|
|
[BTF_KIND_RESTRICT] = &modifier_ops,
|
|
};
|
|
|
|
static s32 btf_check_meta(struct btf_verifier_env *env,
|
|
const struct btf_type *t,
|
|
u32 meta_left)
|
|
{
|
|
u32 saved_meta_left = meta_left;
|
|
s32 var_meta_size;
|
|
|
|
if (meta_left < sizeof(*t)) {
|
|
btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
|
|
env->log_type_id, meta_left, sizeof(*t));
|
|
return -EINVAL;
|
|
}
|
|
meta_left -= sizeof(*t);
|
|
|
|
if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
|
|
BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
|
|
btf_verifier_log(env, "[%u] Invalid kind:%u",
|
|
env->log_type_id, BTF_INFO_KIND(t->info));
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!btf_name_offset_valid(env->btf, t->name)) {
|
|
btf_verifier_log(env, "[%u] Invalid name_offset:%u",
|
|
env->log_type_id, t->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
|
|
if (var_meta_size < 0)
|
|
return var_meta_size;
|
|
|
|
meta_left -= var_meta_size;
|
|
|
|
return saved_meta_left - meta_left;
|
|
}
|
|
|
|
static int btf_check_all_metas(struct btf_verifier_env *env)
|
|
{
|
|
struct btf *btf = env->btf;
|
|
struct btf_header *hdr;
|
|
void *cur, *end;
|
|
|
|
hdr = btf->hdr;
|
|
cur = btf->nohdr_data + hdr->type_off;
|
|
end = btf->nohdr_data + hdr->str_off;
|
|
|
|
env->log_type_id = 1;
|
|
while (cur < end) {
|
|
struct btf_type *t = cur;
|
|
s32 meta_size;
|
|
|
|
meta_size = btf_check_meta(env, t, end - cur);
|
|
if (meta_size < 0)
|
|
return meta_size;
|
|
|
|
btf_add_type(env, t);
|
|
cur += meta_size;
|
|
env->log_type_id++;
|
|
}
|
|
|
|
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)
|
|
{
|
|
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)
|
|
{
|
|
const struct btf_header *hdr;
|
|
struct btf *btf = env->btf;
|
|
const char *start, *end;
|
|
|
|
hdr = btf->hdr;
|
|
start = btf->nohdr_data + hdr->str_off;
|
|
end = start + hdr->str_len;
|
|
|
|
if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
|
|
start[0] || end[-1]) {
|
|
btf_verifier_log(env, "Invalid string section");
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf->strings = start;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int btf_parse_hdr(struct btf_verifier_env *env)
|
|
{
|
|
const struct btf_header *hdr;
|
|
struct btf *btf = env->btf;
|
|
u32 meta_left;
|
|
|
|
if (btf->data_size < sizeof(*hdr)) {
|
|
btf_verifier_log(env, "btf_header not found");
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf_verifier_log_hdr(env);
|
|
|
|
hdr = btf->hdr;
|
|
if (hdr->magic != BTF_MAGIC) {
|
|
btf_verifier_log(env, "Invalid magic");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (hdr->version != BTF_VERSION) {
|
|
btf_verifier_log(env, "Unsupported version");
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
if (hdr->flags) {
|
|
btf_verifier_log(env, "Unsupported flags");
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
meta_left = btf->data_size - sizeof(*hdr);
|
|
if (!meta_left) {
|
|
btf_verifier_log(env, "No data");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (meta_left < hdr->type_off || hdr->str_off <= hdr->type_off ||
|
|
/* Type section must align to 4 bytes */
|
|
hdr->type_off & (sizeof(u32) - 1)) {
|
|
btf_verifier_log(env, "Invalid type_off");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (meta_left < hdr->str_off ||
|
|
meta_left - hdr->str_off < hdr->str_len) {
|
|
btf_verifier_log(env, "Invalid str_off or str_len");
|
|
return -EINVAL;
|
|
}
|
|
|
|
btf->nohdr_data = btf->hdr + 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
|
|
u32 log_level, char __user *log_ubuf, u32 log_size)
|
|
{
|
|
struct btf_verifier_env *env = NULL;
|
|
struct bpf_verifier_log *log;
|
|
struct btf *btf = NULL;
|
|
u8 *data;
|
|
int err;
|
|
|
|
if (btf_data_size > BTF_MAX_SIZE)
|
|
return ERR_PTR(-E2BIG);
|
|
|
|
env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
|
|
if (!env)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
log = &env->log;
|
|
if (log_level || log_ubuf || log_size) {
|
|
/* user requested verbose verifier output
|
|
* and supplied buffer to store the verification trace
|
|
*/
|
|
log->level = log_level;
|
|
log->ubuf = log_ubuf;
|
|
log->len_total = log_size;
|
|
|
|
/* log attributes have to be sane */
|
|
if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
|
|
!log->level || !log->ubuf) {
|
|
err = -EINVAL;
|
|
goto errout;
|
|
}
|
|
}
|
|
|
|
btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
|
|
if (!btf) {
|
|
err = -ENOMEM;
|
|
goto errout;
|
|
}
|
|
|
|
data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
|
|
if (!data) {
|
|
err = -ENOMEM;
|
|
goto errout;
|
|
}
|
|
|
|
btf->data = data;
|
|
btf->data_size = btf_data_size;
|
|
|
|
if (copy_from_user(data, btf_data, btf_data_size)) {
|
|
err = -EFAULT;
|
|
goto errout;
|
|
}
|
|
|
|
env->btf = btf;
|
|
|
|
err = btf_parse_hdr(env);
|
|
if (err)
|
|
goto errout;
|
|
|
|
err = btf_parse_str_sec(env);
|
|
if (err)
|
|
goto errout;
|
|
|
|
err = btf_parse_type_sec(env);
|
|
if (err)
|
|
goto errout;
|
|
|
|
if (!err && log->level && bpf_verifier_log_full(log)) {
|
|
err = -ENOSPC;
|
|
goto errout;
|
|
}
|
|
|
|
if (!err) {
|
|
btf_verifier_env_free(env);
|
|
return btf;
|
|
}
|
|
|
|
errout:
|
|
btf_verifier_env_free(env);
|
|
if (btf)
|
|
btf_free(btf);
|
|
return ERR_PTR(err);
|
|
}
|