| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ART_COMPILER_LINKER_LINKER_PATCH_H_ |
| #define ART_COMPILER_LINKER_LINKER_PATCH_H_ |
| |
| #include <iosfwd> |
| #include <stdint.h> |
| |
| #include <android-base/logging.h> |
| |
| #include "base/bit_utils.h" |
| #include "dex/method_reference.h" |
| |
| namespace art { |
| |
| class DexFile; |
| |
| namespace linker { |
| |
| class LinkerPatch { |
| public: |
| // Note: We explicitly specify the underlying type of the enum because GCC |
| // would otherwise select a bigger underlying type and then complain that |
| // 'art::LinkerPatch::patch_type_' is too small to hold all |
| // values of 'enum class art::LinkerPatch::Type' |
| // which is ridiculous given we have only a handful of values here. If we |
| // choose to squeeze the Type into fewer than 8 bits, we'll have to declare |
| // patch_type_ as an uintN_t and do explicit static_cast<>s. |
| enum class Type : uint8_t { |
| kDataBimgRelRo, // NOTE: Actual patching is instruction_set-dependent. |
| kMethodRelative, // NOTE: Actual patching is instruction_set-dependent. |
| kMethodBssEntry, // NOTE: Actual patching is instruction_set-dependent. |
| kCall, |
| kCallRelative, // NOTE: Actual patching is instruction_set-dependent. |
| kTypeRelative, // NOTE: Actual patching is instruction_set-dependent. |
| kTypeBssEntry, // NOTE: Actual patching is instruction_set-dependent. |
| kStringRelative, // NOTE: Actual patching is instruction_set-dependent. |
| kStringBssEntry, // NOTE: Actual patching is instruction_set-dependent. |
| kBakerReadBarrierBranch, // NOTE: Actual patching is instruction_set-dependent. |
| }; |
| |
| static LinkerPatch DataBimgRelRoPatch(size_t literal_offset, |
| uint32_t pc_insn_offset, |
| uint32_t boot_image_offset) { |
| LinkerPatch patch(literal_offset, Type::kDataBimgRelRo, /* target_dex_file */ nullptr); |
| patch.boot_image_offset_ = boot_image_offset; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch RelativeMethodPatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t pc_insn_offset, |
| uint32_t target_method_idx) { |
| LinkerPatch patch(literal_offset, Type::kMethodRelative, target_dex_file); |
| patch.method_idx_ = target_method_idx; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch MethodBssEntryPatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t pc_insn_offset, |
| uint32_t target_method_idx) { |
| LinkerPatch patch(literal_offset, Type::kMethodBssEntry, target_dex_file); |
| patch.method_idx_ = target_method_idx; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch CodePatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t target_method_idx) { |
| LinkerPatch patch(literal_offset, Type::kCall, target_dex_file); |
| patch.method_idx_ = target_method_idx; |
| return patch; |
| } |
| |
| static LinkerPatch RelativeCodePatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t target_method_idx) { |
| LinkerPatch patch(literal_offset, Type::kCallRelative, target_dex_file); |
| patch.method_idx_ = target_method_idx; |
| return patch; |
| } |
| |
| static LinkerPatch RelativeTypePatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t pc_insn_offset, |
| uint32_t target_type_idx) { |
| LinkerPatch patch(literal_offset, Type::kTypeRelative, target_dex_file); |
| patch.type_idx_ = target_type_idx; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch TypeBssEntryPatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t pc_insn_offset, |
| uint32_t target_type_idx) { |
| LinkerPatch patch(literal_offset, Type::kTypeBssEntry, target_dex_file); |
| patch.type_idx_ = target_type_idx; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch RelativeStringPatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t pc_insn_offset, |
| uint32_t target_string_idx) { |
| LinkerPatch patch(literal_offset, Type::kStringRelative, target_dex_file); |
| patch.string_idx_ = target_string_idx; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch StringBssEntryPatch(size_t literal_offset, |
| const DexFile* target_dex_file, |
| uint32_t pc_insn_offset, |
| uint32_t target_string_idx) { |
| LinkerPatch patch(literal_offset, Type::kStringBssEntry, target_dex_file); |
| patch.string_idx_ = target_string_idx; |
| patch.pc_insn_offset_ = pc_insn_offset; |
| return patch; |
| } |
| |
| static LinkerPatch BakerReadBarrierBranchPatch(size_t literal_offset, |
| uint32_t custom_value1 = 0u, |
| uint32_t custom_value2 = 0u) { |
| LinkerPatch patch(literal_offset, Type::kBakerReadBarrierBranch, /* target_dex_file */ nullptr); |
| patch.baker_custom_value1_ = custom_value1; |
| patch.baker_custom_value2_ = custom_value2; |
| return patch; |
| } |
| |
| LinkerPatch(const LinkerPatch& other) = default; |
| LinkerPatch& operator=(const LinkerPatch& other) = default; |
| |
| size_t LiteralOffset() const { |
| return literal_offset_; |
| } |
| |
| Type GetType() const { |
| return patch_type_; |
| } |
| |
| bool IsPcRelative() const { |
| switch (GetType()) { |
| case Type::kDataBimgRelRo: |
| case Type::kMethodRelative: |
| case Type::kMethodBssEntry: |
| case Type::kCallRelative: |
| case Type::kTypeRelative: |
| case Type::kTypeBssEntry: |
| case Type::kStringRelative: |
| case Type::kStringBssEntry: |
| case Type::kBakerReadBarrierBranch: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| uint32_t BootImageOffset() const { |
| DCHECK(patch_type_ == Type::kDataBimgRelRo); |
| return boot_image_offset_; |
| } |
| |
| MethodReference TargetMethod() const { |
| DCHECK(patch_type_ == Type::kMethodRelative || |
| patch_type_ == Type::kMethodBssEntry || |
| patch_type_ == Type::kCall || |
| patch_type_ == Type::kCallRelative); |
| return MethodReference(target_dex_file_, method_idx_); |
| } |
| |
| const DexFile* TargetTypeDexFile() const { |
| DCHECK(patch_type_ == Type::kTypeRelative || |
| patch_type_ == Type::kTypeBssEntry); |
| return target_dex_file_; |
| } |
| |
| dex::TypeIndex TargetTypeIndex() const { |
| DCHECK(patch_type_ == Type::kTypeRelative || |
| patch_type_ == Type::kTypeBssEntry); |
| return dex::TypeIndex(type_idx_); |
| } |
| |
| const DexFile* TargetStringDexFile() const { |
| DCHECK(patch_type_ == Type::kStringRelative || |
| patch_type_ == Type::kStringBssEntry); |
| return target_dex_file_; |
| } |
| |
| dex::StringIndex TargetStringIndex() const { |
| DCHECK(patch_type_ == Type::kStringRelative || |
| patch_type_ == Type::kStringBssEntry); |
| return dex::StringIndex(string_idx_); |
| } |
| |
| uint32_t PcInsnOffset() const { |
| DCHECK(patch_type_ == Type::kDataBimgRelRo || |
| patch_type_ == Type::kMethodRelative || |
| patch_type_ == Type::kMethodBssEntry || |
| patch_type_ == Type::kTypeRelative || |
| patch_type_ == Type::kTypeBssEntry || |
| patch_type_ == Type::kStringRelative || |
| patch_type_ == Type::kStringBssEntry); |
| return pc_insn_offset_; |
| } |
| |
| uint32_t GetBakerCustomValue1() const { |
| DCHECK(patch_type_ == Type::kBakerReadBarrierBranch); |
| return baker_custom_value1_; |
| } |
| |
| uint32_t GetBakerCustomValue2() const { |
| DCHECK(patch_type_ == Type::kBakerReadBarrierBranch); |
| return baker_custom_value2_; |
| } |
| |
| private: |
| LinkerPatch(size_t literal_offset, Type patch_type, const DexFile* target_dex_file) |
| : target_dex_file_(target_dex_file), |
| literal_offset_(literal_offset), |
| patch_type_(patch_type) { |
| cmp1_ = 0u; |
| cmp2_ = 0u; |
| // The compiler rejects methods that are too big, so the compiled code |
| // of a single method really shouln't be anywhere close to 16MiB. |
| DCHECK(IsUint<24>(literal_offset)); |
| } |
| |
| const DexFile* target_dex_file_; |
| // TODO: Clean up naming. Some patched locations are literals but others are not. |
| uint32_t literal_offset_ : 24; // Method code size up to 16MiB. |
| Type patch_type_ : 8; |
| union { |
| uint32_t cmp1_; // Used for relational operators. |
| uint32_t boot_image_offset_; // Data to write to the .data.bimg.rel.ro entry. |
| uint32_t method_idx_; // Method index for Call/Method patches. |
| uint32_t type_idx_; // Type index for Type patches. |
| uint32_t string_idx_; // String index for String patches. |
| uint32_t baker_custom_value1_; |
| static_assert(sizeof(method_idx_) == sizeof(cmp1_), "needed by relational operators"); |
| static_assert(sizeof(type_idx_) == sizeof(cmp1_), "needed by relational operators"); |
| static_assert(sizeof(string_idx_) == sizeof(cmp1_), "needed by relational operators"); |
| static_assert(sizeof(baker_custom_value1_) == sizeof(cmp1_), "needed by relational operators"); |
| }; |
| union { |
| // Note: To avoid uninitialized padding on 64-bit systems, we use `size_t` for `cmp2_`. |
| // This allows a hashing function to treat an array of linker patches as raw memory. |
| size_t cmp2_; // Used for relational operators. |
| // Literal offset of the insn loading PC (same as literal_offset if it's the same insn, |
| // may be different if the PC-relative addressing needs multiple insns). |
| uint32_t pc_insn_offset_; |
| uint32_t baker_custom_value2_; |
| static_assert(sizeof(pc_insn_offset_) <= sizeof(cmp2_), "needed by relational operators"); |
| static_assert(sizeof(baker_custom_value2_) <= sizeof(cmp2_), "needed by relational operators"); |
| }; |
| |
| friend bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs); |
| friend bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs); |
| }; |
| std::ostream& operator<<(std::ostream& os, const LinkerPatch::Type& type); |
| |
| inline bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs) { |
| return lhs.literal_offset_ == rhs.literal_offset_ && |
| lhs.patch_type_ == rhs.patch_type_ && |
| lhs.target_dex_file_ == rhs.target_dex_file_ && |
| lhs.cmp1_ == rhs.cmp1_ && |
| lhs.cmp2_ == rhs.cmp2_; |
| } |
| |
| inline bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs) { |
| return (lhs.literal_offset_ != rhs.literal_offset_) ? lhs.literal_offset_ < rhs.literal_offset_ |
| : (lhs.patch_type_ != rhs.patch_type_) ? lhs.patch_type_ < rhs.patch_type_ |
| : (lhs.target_dex_file_ != rhs.target_dex_file_) ? lhs.target_dex_file_ < rhs.target_dex_file_ |
| : (lhs.cmp1_ != rhs.cmp1_) ? lhs.cmp1_ < rhs.cmp1_ |
| : lhs.cmp2_ < rhs.cmp2_; |
| } |
| |
| } // namespace linker |
| } // namespace art |
| |
| #endif // ART_COMPILER_LINKER_LINKER_PATCH_H_ |