/* * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "jvm.h" #include "logging/log.hpp" #include "memory/allocation.hpp" #include "memory/resourceArea.hpp" #include "utilities/decoder_elf.hpp" #include "utilities/elfFile.hpp" #include bool ElfDecoder::demangle(const char* symbol, char *buf, int buflen) { int status; char* result; size_t size = (size_t)buflen; #ifdef PPC64 // On PPC64 ElfDecoder::decode() may return a dot (.) prefixed name // (see elfFuncDescTable.hpp for details) if (symbol && *symbol == '.') symbol += 1; #endif // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small, // __cxa_demangle will call system "realloc" for additional memory, which // may use different malloc/realloc mechanism that allocates 'buf'. if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) { jio_snprintf(buf, buflen, "%s", result); // call c library's free ::free(result); return true; } return false; } // Returns true if the elf file is marked NOT to require an executable stack, // or if the file could not be opened. // Returns false if the elf file requires an executable stack, the stack flag // is not set at all, or if the file can not be read. bool ElfFile::specifies_noexecstack(const char* filepath) { if (filepath == NULL) return true; FILE* file = fopen(filepath, "r"); if (file == NULL) return true; // AARCH64 defaults to noexecstack. All others default to execstack. bool result = AARCH64_ONLY(true) NOT_AARCH64(false); // Read file header Elf_Ehdr head; if (fread(&head, sizeof(Elf_Ehdr), 1, file) == 1 && is_elf_file(head) && fseek(file, head.e_phoff, SEEK_SET) == 0) { // Read program header table Elf_Phdr phdr; for (int index = 0; index < head.e_phnum; index ++) { if (fread((void*)&phdr, sizeof(Elf_Phdr), 1, file) != 1) { result = false; break; } if (phdr.p_type == PT_GNU_STACK) { result = (phdr.p_flags == (PF_R | PF_W)); break; } } } fclose(file); return result; } class LinuxElfDebugInfo : public ElfDebugInfo { private: ElfFile* _elf_file; public: LinuxElfDebugInfo(const char* filepath); ~LinuxElfDebugInfo() { if (_elf_file != NULL) delete _elf_file; } static LinuxElfDebugInfo* by_debug_link(const char* filepath, const char* debug_info_name, unsigned int crc); static LinuxElfDebugInfo* by_build_id(const char* filepath, unsigned char* build_id, size_t size); bool decode(address addr, char* const buf, size_t buflen, int* offset) { assert(_elf_file != NULL, "Debug info file not opened"); return _elf_file->decode(addr, buf, buflen, offset); } bool has_error() const { return NullDecoder::is_error(_elf_file->get_status()); } }; static const char* debug_link_section_name = ".gnu_debuglink"; static const char* gnu_build_id_section_name = ".note.gnu.build-id"; // Directory that contains global debuginfo files. In theory it // should be possible to change this, but in a Java environment there // is no obvious place to put a user interface to do it. Maybe this // could be set with an environment variable. static const char* debug_file_directory = "/usr/lib/debug"; static unsigned int gnu_debuglink_crc32 (unsigned int crc, unsigned char *buf, size_t len) { static const unsigned int crc32_table[256] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d }; unsigned char *end; crc = ~crc & 0xffffffff; for (end = buf + len; buf < end; ++buf) crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); return ~crc & 0xffffffff; } static bool verify_file_crc(const char* filepath, unsigned int crc) { unsigned int file_crc = 0; unsigned char buf[4 * K]; FILE* fd = fopen(filepath, "r"); if (fd == NULL) { return false; } FileReader reader(fd); int len; unsigned char *end; while (true) { len = reader.read_buffer(buf, sizeof(buf)); if (len <= 0) break; file_crc = gnu_debuglink_crc32(file_crc, buf, len); } fclose(fd); return (crc == file_crc); } LinuxElfDebugInfo::LinuxElfDebugInfo(const char* filepath) { _elf_file = new ElfFile(filepath, false /* load debug info */); } LinuxElfDebugInfo* LinuxElfDebugInfo::by_debug_link(const char* filepath, const char* debug_info_name, unsigned int crc) { size_t size = strlen(filepath) + strlen(debug_info_name) + 2; ResourceMark rm; char* debuginfo_pathname = NEW_RESOURCE_ARRAY(char, size); if (debuginfo_pathname == NULL) return NULL; strcpy(debuginfo_pathname, filepath); char *last_slash = strrchr(debuginfo_pathname, '/'); if (last_slash == NULL) { return NULL; } /* Look in the same directory as the object. */ strcpy(last_slash + 1, debug_info_name); if (!verify_file_crc(debuginfo_pathname, crc)) { return NULL; } LinuxElfDebugInfo* debug_info = new LinuxElfDebugInfo(debuginfo_pathname); if (debug_info->has_error()) { delete debug_info; return NULL; } log_debug(decoder)("Use %s for decoding symbols in %s", debuginfo_pathname, filepath); return debug_info; } LinuxElfDebugInfo* LinuxElfDebugInfo::by_build_id(const char* filepath, unsigned char* build_id, size_t size) { size_t filename_size = strlen(debug_file_directory) + (sizeof "/.build-id/" - 1) + 1 + 2 * size + (sizeof ".debug" - 1) + 1; ResourceMark rm; char* filename = NEW_RESOURCE_ARRAY(char, size); if (filename == NULL) return NULL; char* s = filename + sprintf(filename, "%s/.build-id/", debug_file_directory); if (size > 0) { size --; s += sprintf(s, "%02x", *build_id++); } if (size > 0) *s++ = '/'; while (size -- > 0) { s += sprintf(s, "%02x", *build_id++); } strcpy (s, ".debug"); LinuxElfDebugInfo* debug_info = new LinuxElfDebugInfo(filename); if (debug_info->has_error()) { delete debug_info; return NULL; } log_debug(decoder)("Use %s for decoding symbols in %s", filename, filepath); return debug_info; } ElfDebugInfo* ElfFile::load_debuginfo() { const char* file_path = filepath(); Elf_Shdr build_id_hdr; ElfDebugInfo* debuginfo = NULL; // try build id first Elf_Nhdr* nhdr; if (section_by_name(gnu_build_id_section_name, build_id_hdr) != -1) { ElfSection build_id_section(_file, build_id_hdr); nhdr = (Elf_Nhdr*)build_id_section.section_data(); if (nhdr != NULL) { debuginfo = LinuxElfDebugInfo::by_build_id(file_path, (unsigned char*)(nhdr + 1) + nhdr->n_namesz, nhdr->n_descsz); } else { Elf_Nhdr note_hdr; MarkedFileReader mfd(fd()); if (mfd.has_mark() && mfd.set_position(build_id_section.section_header()->sh_offset) && mfd.read((void*)¬e_hdr, sizeof(note_hdr))) { nhdr = ¬e_hdr; debuginfo = LinuxElfDebugInfo::by_build_id(file_path, (unsigned char*)(nhdr + 1) + nhdr->n_namesz, nhdr->n_descsz); } } } if (debuginfo != NULL) return debuginfo; // try debug link Elf_Shdr debug_link_hdr; if (section_by_name(debug_link_section_name, debug_link_hdr) != -1) { ElfSection debug_link_section(_file, debug_link_hdr); char* debug_info_file = (char* const)debug_link_section.section_data(); unsigned int crc = 0; if (debug_info_file != NULL) { int offset = (strlen(debug_info_file) + 4) >> 2; crc = ((unsigned int*)debug_link_section.section_data())[offset]; debuginfo = LinuxElfDebugInfo::by_debug_link(file_path, debug_info_file, crc); } else { size_t size = debug_link_section.section_header()->sh_size; ResourceMark rm; debug_info_file = NEW_RESOURCE_ARRAY(char, size); if (debug_info_file != NULL) { MarkedFileReader mfd(fd()); size_t sect_offset = debug_link_section.section_header()->sh_offset; if (mfd.has_mark() && mfd.set_position(sect_offset) && mfd.read(debug_info_file, size)) { int offset = ((strlen(debug_info_file) + 4) >> 2) * sizeof(unsigned int); if (mfd.set_position(sect_offset + size_t(offset)) && mfd.read((void*)&crc, sizeof(crc))) { debuginfo = LinuxElfDebugInfo::by_debug_link(file_path, debug_info_file, crc); } } } } } return debuginfo; }