| // Copyright 2018 The Crashpad Authors. All rights reserved. |
| // |
| // 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. |
| |
| // This note section is used on ELF platforms to give ElfImageReader a method |
| // of finding the instance of CrashpadInfo g_crashpad_info without requiring |
| // that symbol to be in the dynamic symbol table. |
| |
| #include "util/misc/elf_note_types.h" |
| |
| // namespace crashpad { |
| // CrashpadInfo g_crashpad_info; |
| // } // namespace crashpad |
| #define CRASHPAD_INFO_SYMBOL _ZN8crashpad15g_crashpad_infoE |
| |
| #define NOTE_ALIGN 4 |
| |
| // This section must be "a"llocated so that it appears in the final binary at |
| // runtime. The reference to CRASHPAD_INFO_SYMBOL uses an offset relative to |
| // this note to avoid making this note writable, which triggers a bug in GNU |
| // ld, or adding text relocations which require the target system to allow |
| // making text segments writable. https://crbug.com/crashpad/260. |
| .section .note.crashpad.info,"a",%note |
| .balign NOTE_ALIGN |
| CRASHPAD_NOTE: |
| .long name_end - name // namesz |
| .long desc_end - desc // descsz |
| .long CRASHPAD_ELF_NOTE_TYPE_CRASHPAD_INFO // type |
| name: |
| .asciz CRASHPAD_ELF_NOTE_NAME |
| name_end: |
| .balign NOTE_ALIGN |
| desc: |
| #if defined(__LP64__) |
| .quad CRASHPAD_INFO_SYMBOL - desc |
| #else |
| .long CRASHPAD_INFO_SYMBOL - desc |
| #endif // __LP64__ |
| desc_end: |
| .size CRASHPAD_NOTE, .-CRASHPAD_NOTE |
| |
| // CRASHPAD_NOTE can't be referenced directly by GetCrashpadInfo() because the |
| // relocation used to make the reference may require that the address be |
| // 8-byte aligned and notes must have 4-byte alignment. |
| .section .rodata,"a",%progbits |
| .balign 8 |
| # .globl indicates that it's available to link against other .o files. .hidden |
| # indicates that it will not appear in the executable's symbol table. |
| .globl CRASHPAD_NOTE_REFERENCE |
| .hidden CRASHPAD_NOTE_REFERENCE |
| .type CRASHPAD_NOTE_REFERENCE, %object |
| CRASHPAD_NOTE_REFERENCE: |
| // The value of this quad isn't important. It exists to reference |
| // CRASHPAD_NOTE, causing the linker to include the note into the binary |
| // linking Crashpad. The subtraction from |name| is a convenience to allow the |
| // value to be computed statically. |
| .quad name - CRASHPAD_NOTE |
