| /* |
| * Copyright (C) 2024 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include"platform/bionic/macros.h" |
| #include"private/elf_note.h" |
| |
| #include<string.h> |
| |
| bool __get_elf_note(unsigned note_type,constchar* note_name,constElfW(Addr) note_addr, |
| constElfW(Phdr)* phdr_note,constElfW(Nhdr)** note_hdr, |
| constchar** note_desc){ |
| if(phdr_note->p_type!= PT_NOTE||!note_name||!note_addr){ |
| returnfalse; |
| } |
| |
| size_t note_name_len= strlen(note_name)+1; |
| |
| ElfW(Addr) p= note_addr; |
| ElfW(Addr) note_end= p+ phdr_note->p_memsz; |
| while(p< note_end){ |
| // Parse the note and check it's structurally valid. |
| constElfW(Nhdr)* note=reinterpret_cast<constElfW(Nhdr)*>(p); |
| if(__builtin_add_overflow(p,sizeof(ElfW(Nhdr)),&p)|| p>= note_end){ |
| returnfalse; |
| } |
| constchar* name=reinterpret_cast<constchar*>(p); |
| if(__builtin_add_overflow(p, __builtin_align_up(note->n_namesz,4),&p)){ |
| returnfalse; |
| } |
| constchar* desc=reinterpret_cast<constchar*>(p); |
| if(__builtin_add_overflow(p, __builtin_align_up(note->n_descsz,4),&p)){ |
| returnfalse; |
| } |
| if(p> note_end){ |
| returnfalse; |
| } |
| |
| // Is this the note we're looking for? |
| if(note->n_type== note_type&& |
| note->n_namesz== note_name_len&& |
| strncmp(note_name, name, note_name_len)==0){ |
| *note_hdr= note; |
| *note_desc= desc; |
| returntrue; |
| } |
| } |
| returnfalse; |
| } |
| |
| bool __find_elf_note(unsignedint note_type,constchar* note_name,constElfW(Phdr)* phdr_start, |
| size_t phdr_ct,constElfW(Nhdr)** note_hdr,constchar** note_desc, |
| constElfW(Addr) load_bias){ |
| for(size_t i=0; i< phdr_ct;++i){ |
| constElfW(Phdr)* phdr=&phdr_start[i]; |
| |
| ElfW(Addr) note_addr= load_bias+ phdr->p_vaddr; |
| if(__get_elf_note(note_type, note_name, note_addr, phdr, note_hdr, note_desc)){ |
| returntrue; |
| } |
| } |
| |
| returnfalse; |
| } |
