X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-elf.c;h=52078d9629f34df177e88857ccd82690a6fb6c4e;hb=c0c0989ab70574e09b2f7e8b48c2da6af664a849;hp=f5c4f1a1c4988e2e323981e491071e2572f5f527;hpb=8e2aed3f18adc14ec586ef717e396bcac4473dd7;p=lttng-ust.git diff --git a/liblttng-ust/lttng-ust-elf.c b/liblttng-ust/lttng-ust-elf.c index f5c4f1a1..52078d96 100644 --- a/liblttng-ust/lttng-ust-elf.c +++ b/liblttng-ust/lttng-ust-elf.c @@ -1,25 +1,30 @@ /* - * Copyright (C) 2015 Antoine Busque + * SPDX-License-Identifier: LGPL-2.1-or-later * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * This library 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * Copyright (C) 2015 Antoine Busque */ +#define _LGPL_SOURCE +#include #include -#include #include #include +#include +#include +#include +#include +#include +#include + +#include + +#include "lttng-tracer-core.h" + +#define BUF_LEN 4096 + +#ifndef NT_GNU_BUILD_ID +# define NT_GNU_BUILD_ID 3 +#endif /* * Retrieve the nth (where n is the `index` argument) phdr (program @@ -32,7 +37,7 @@ struct lttng_ust_elf_phdr *lttng_ust_elf_get_phdr(struct lttng_ust_elf *elf, uint16_t index) { struct lttng_ust_elf_phdr *phdr = NULL; - long offset; + off_t offset; if (!elf) { goto error; @@ -47,15 +52,17 @@ struct lttng_ust_elf_phdr *lttng_ust_elf_get_phdr(struct lttng_ust_elf *elf, goto error; } - offset = elf->ehdr->e_phoff + index * elf->ehdr->e_phentsize; - if (fseek(elf->file, offset, SEEK_SET)) { + offset = (off_t) elf->ehdr->e_phoff + + (off_t) index * elf->ehdr->e_phentsize; + if (lseek(elf->fd, offset, SEEK_SET) < 0) { goto error; } if (is_elf_32_bit(elf)) { Elf32_Phdr elf_phdr; - if (!fread(&elf_phdr, sizeof(elf_phdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &elf_phdr, sizeof(elf_phdr)) + < sizeof(elf_phdr)) { goto error; } if (!is_elf_native_endian(elf)) { @@ -65,7 +72,8 @@ struct lttng_ust_elf_phdr *lttng_ust_elf_get_phdr(struct lttng_ust_elf *elf, } else { Elf64_Phdr elf_phdr; - if (!fread(&elf_phdr, sizeof(elf_phdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &elf_phdr, sizeof(elf_phdr)) + < sizeof(elf_phdr)) { goto error; } if (!is_elf_native_endian(elf)) { @@ -92,7 +100,7 @@ struct lttng_ust_elf_shdr *lttng_ust_elf_get_shdr(struct lttng_ust_elf *elf, uint16_t index) { struct lttng_ust_elf_shdr *shdr = NULL; - long offset; + off_t offset; if (!elf) { goto error; @@ -107,15 +115,17 @@ struct lttng_ust_elf_shdr *lttng_ust_elf_get_shdr(struct lttng_ust_elf *elf, goto error; } - offset = elf->ehdr->e_shoff + index * elf->ehdr->e_shentsize; - if (fseek(elf->file, offset, SEEK_SET)) { + offset = (off_t) elf->ehdr->e_shoff + + (off_t) index * elf->ehdr->e_shentsize; + if (lseek(elf->fd, offset, SEEK_SET) < 0) { goto error; } if (is_elf_32_bit(elf)) { Elf32_Shdr elf_shdr; - if (!fread(&elf_shdr, sizeof(elf_shdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &elf_shdr, sizeof(elf_shdr)) + < sizeof(elf_shdr)) { goto error; } if (!is_elf_native_endian(elf)) { @@ -125,7 +135,8 @@ struct lttng_ust_elf_shdr *lttng_ust_elf_get_shdr(struct lttng_ust_elf *elf, } else { Elf64_Shdr elf_shdr; - if (!fread(&elf_shdr, sizeof(elf_shdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &elf_shdr, sizeof(elf_shdr)) + < sizeof(elf_shdr)) { goto error; } if (!is_elf_native_endian(elf)) { @@ -149,10 +160,10 @@ error: * If no name is found, NULL is returned. */ static -char *lttng_ust_elf_get_section_name(struct lttng_ust_elf *elf, uint32_t offset) +char *lttng_ust_elf_get_section_name(struct lttng_ust_elf *elf, off_t offset) { char *name = NULL; - size_t len; + size_t len = 0, to_read; /* len does not include \0 */ if (!elf) { goto error; @@ -162,34 +173,45 @@ char *lttng_ust_elf_get_section_name(struct lttng_ust_elf *elf, uint32_t offset) goto error; } - if (fseek(elf->file, elf->section_names_offset + offset, SEEK_SET)) { + if (lseek(elf->fd, elf->section_names_offset + offset, SEEK_SET) < 0) { goto error; } - /* Note that len starts at 1, it is not an index. */ - for (len = 1; offset + len <= elf->section_names_size; ++len) { - switch (fgetc(elf->file)) { - case EOF: + + to_read = elf->section_names_size - offset; + + /* Find first \0 after or at current location, remember len. */ + for (;;) { + char buf[BUF_LEN]; + ssize_t read_len; + size_t i; + + if (!to_read) { + goto error; + } + read_len = lttng_ust_read(elf->fd, buf, + min_t(size_t, BUF_LEN, to_read)); + if (read_len <= 0) { goto error; - case '\0': - goto end; - default: - break; } + for (i = 0; i < read_len; i++) { + if (buf[i] == '\0') { + len += i; + goto end; + } + } + len += read_len; + to_read -= read_len; } - - /* No name was found before the end of the table. */ - goto error; - end: - name = zmalloc(sizeof(char) * len); + name = zmalloc(sizeof(char) * (len + 1)); /* + 1 for \0 */ if (!name) { goto error; } - if (fseek(elf->file, elf->section_names_offset + offset, - SEEK_SET)) { + if (lseek(elf->fd, elf->section_names_offset + offset, + SEEK_SET) < 0) { goto error; } - if (!fgets(name, len, elf->file)) { + if (lttng_ust_read(elf->fd, name, len + 1) < len + 1) { goto error; } @@ -210,29 +232,51 @@ struct lttng_ust_elf *lttng_ust_elf_create(const char *path) { uint8_t e_ident[EI_NIDENT]; struct lttng_ust_elf_shdr *section_names_shdr; - struct lttng_ust_elf *elf; + struct lttng_ust_elf *elf = NULL; + int ret, fd; elf = zmalloc(sizeof(struct lttng_ust_elf)); if (!elf) { goto error; } + /* Initialize fd field to -1. 0 is a valid fd number */ + elf->fd = -1; + elf->path = strdup(path); if (!elf->path) { goto error; } - elf->file = fopen(elf->path, "rb"); - if (!elf->file) { + lttng_ust_lock_fd_tracker(); + fd = open(elf->path, O_RDONLY | O_CLOEXEC); + if (fd < 0) { + lttng_ust_unlock_fd_tracker(); + goto error; + } + + ret = lttng_ust_add_fd_to_tracker(fd); + if (ret < 0) { + ret = close(fd); + if (ret) { + PERROR("close on elf->fd"); + } + ret = -1; + lttng_ust_unlock_fd_tracker(); goto error; } + elf->fd = ret; + lttng_ust_unlock_fd_tracker(); - if (!fread(e_ident, 1, EI_NIDENT, elf->file)) { + if (lttng_ust_read(elf->fd, e_ident, EI_NIDENT) < EI_NIDENT) { goto error; } elf->bitness = e_ident[EI_CLASS]; elf->endianness = e_ident[EI_DATA]; - rewind(elf->file); + + if (lseek(elf->fd, 0, SEEK_SET) < 0) { + goto error; + } elf->ehdr = zmalloc(sizeof(struct lttng_ust_elf_ehdr)); if (!elf->ehdr) { @@ -242,7 +286,8 @@ struct lttng_ust_elf *lttng_ust_elf_create(const char *path) if (is_elf_32_bit(elf)) { Elf32_Ehdr elf_ehdr; - if (!fread(&elf_ehdr, sizeof(elf_ehdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &elf_ehdr, sizeof(elf_ehdr)) + < sizeof(elf_ehdr)) { goto error; } if (!is_elf_native_endian(elf)) { @@ -252,7 +297,8 @@ struct lttng_ust_elf *lttng_ust_elf_create(const char *path) } else { Elf64_Ehdr elf_ehdr; - if (!fread(&elf_ehdr, sizeof(elf_ehdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &elf_ehdr, sizeof(elf_ehdr)) + < sizeof(elf_ehdr)) { goto error; } if (!is_elf_native_endian(elf)) { @@ -270,30 +316,49 @@ struct lttng_ust_elf *lttng_ust_elf_create(const char *path) elf->section_names_size = section_names_shdr->sh_size; free(section_names_shdr); - return elf; error: - if (elf) { - free(elf->ehdr); - fclose(elf->file); - free(elf->path); - } - free(elf); + lttng_ust_elf_destroy(elf); return NULL; } +/* + * Test whether the ELF file is position independent code (PIC) + */ +uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf) +{ + /* + * PIC has and e_type value of ET_DYN, see ELF specification + * version 1.1 p. 1-3. + */ + return elf->ehdr->e_type == ET_DYN; +} + /* * Destroy the given lttng_ust_elf instance. */ void lttng_ust_elf_destroy(struct lttng_ust_elf *elf) { + int ret; + if (!elf) { return; } + if (elf->fd >= 0) { + lttng_ust_lock_fd_tracker(); + ret = close(elf->fd); + if (!ret) { + lttng_ust_delete_fd_from_tracker(elf->fd); + } else { + PERROR("close"); + abort(); + } + lttng_ust_unlock_fd_tracker(); + } + free(elf->ehdr); - fclose(elf->file); free(elf->path); free(elf); } @@ -307,7 +372,7 @@ void lttng_ust_elf_destroy(struct lttng_ust_elf *elf) int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz) { uint16_t i; - uint64_t _memsz = 0; + uint64_t low_addr = UINT64_MAX, high_addr = 0; if (!elf || !memsz) { goto error; @@ -315,7 +380,6 @@ int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz) for (i = 0; i < elf->ehdr->e_phnum; ++i) { struct lttng_ust_elf_phdr *phdr; - uint64_t align; phdr = lttng_ust_elf_get_phdr(elf, i); if (!phdr) { @@ -330,27 +394,19 @@ int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz) goto next_loop; } - /* - * A p_align of 0 means no alignment, i.e. aligned to - * 1 byte. - */ - align = phdr->p_align == 0 ? 1 : phdr->p_align; - /* Align the start of the segment. */ - _memsz += offset_align(_memsz, align); - _memsz += phdr->p_memsz; - /* - * Add padding at the end of the segment, so it ends - * on a multiple of the align value (which usually - * means a page boundary). This makes the computation - * valid even in cases where p_align would change from - * one segment to the next. - */ - _memsz += offset_align(_memsz, align); + low_addr = min_t(uint64_t, low_addr, phdr->p_vaddr); + high_addr = max_t(uint64_t, high_addr, + phdr->p_vaddr + phdr->p_memsz); next_loop: free(phdr); } - *memsz = _memsz; + if (high_addr < low_addr) { + /* No PT_LOAD segments or corrupted data. */ + goto error; + } + + *memsz = high_addr - low_addr; return 0; error: return -1; @@ -371,17 +427,17 @@ error: static int lttng_ust_elf_get_build_id_from_segment( struct lttng_ust_elf *elf, uint8_t **build_id, size_t *length, - uint64_t offset, uint64_t segment_end, int *found) + off_t offset, off_t segment_end) { - uint8_t *_build_id; - size_t _length; - int _found = 0; + uint8_t *_build_id = NULL; /* Silence old gcc warning. */ + size_t _length = 0; /* Silence old gcc warning. */ while (offset < segment_end) { struct lttng_ust_elf_nhdr nhdr; + size_t read_len; /* Align start of note entry */ - offset += offset_align(offset, ELF_NOTE_ENTRY_ALIGN); + offset += lttng_ust_offset_align(offset, ELF_NOTE_ENTRY_ALIGN); if (offset >= segment_end) { break; } @@ -390,10 +446,11 @@ int lttng_ust_elf_get_build_id_from_segment( * build id the data following the header will not * have been read. */ - if (fseek(elf->file, offset, SEEK_SET)) { + if (lseek(elf->fd, offset, SEEK_SET) < 0) { goto error; } - if (!fread(&nhdr, sizeof(nhdr), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &nhdr, sizeof(nhdr)) + < sizeof(nhdr)) { goto error; } @@ -405,7 +462,7 @@ int lttng_ust_elf_get_build_id_from_segment( offset += sizeof(nhdr) + nhdr.n_namesz; /* Align start of desc entry */ - offset += offset_align(offset, ELF_NOTE_DESC_ALIGN); + offset += lttng_ust_offset_align(offset, ELF_NOTE_DESC_ALIGN); if (nhdr.n_type != NT_GNU_BUILD_ID) { /* @@ -418,29 +475,29 @@ int lttng_ust_elf_get_build_id_from_segment( _length = nhdr.n_descsz; _build_id = zmalloc(sizeof(uint8_t) * _length); - if (!build_id) { + if (!_build_id) { goto error; } - if (fseek(elf->file, offset, SEEK_SET)) { + if (lseek(elf->fd, offset, SEEK_SET) < 0) { goto error; } - if (!fread(_build_id, sizeof(*_build_id), _length, elf->file)) { + read_len = sizeof(*_build_id) * _length; + if (lttng_ust_read(elf->fd, _build_id, read_len) < read_len) { goto error; } - _found = 1; break; } - if (_found) { + if (_build_id) { *build_id = _build_id; *length = _length; } - *found = _found; return 0; error: + free(_build_id); return -1; } @@ -461,18 +518,17 @@ int lttng_ust_elf_get_build_id(struct lttng_ust_elf *elf, uint8_t **build_id, size_t *length, int *found) { uint16_t i; - uint8_t *_build_id; - size_t _length; - int _found = 0; + uint8_t *_build_id = NULL; /* Silence old gcc warning. */ + size_t _length = 0; /* Silence old gcc warning. */ if (!elf || !build_id || !length || !found) { goto error; } for (i = 0; i < elf->ehdr->e_phnum; ++i) { - uint64_t offset, segment_end; + off_t offset, segment_end; struct lttng_ust_elf_phdr *phdr; - int ret; + int ret = 0; phdr = lttng_ust_elf_get_phdr(elf, i); if (!phdr) { @@ -487,26 +543,28 @@ int lttng_ust_elf_get_build_id(struct lttng_ust_elf *elf, uint8_t **build_id, offset = phdr->p_offset; segment_end = offset + phdr->p_filesz; ret = lttng_ust_elf_get_build_id_from_segment( - elf, &_build_id, &_length, offset, segment_end, - &_found); + elf, &_build_id, &_length, offset, segment_end); next_loop: free(phdr); if (ret) { goto error; } - if (_found) { + if (_build_id) { break; } } - if (_found) { + if (_build_id) { *build_id = _build_id; *length = _length; + *found = 1; + } else { + *found = 0; } - *found = _found; return 0; error: + free(_build_id); return -1; } @@ -520,18 +578,16 @@ error: * * Returns 0 on success, -1 if an error occurred. */ -static int lttng_ust_elf_get_debug_link_from_section(struct lttng_ust_elf *elf, char **filename, uint32_t *crc, - int *found, struct lttng_ust_elf_shdr *shdr) { - int _found = 0; - char *_filename; + char *_filename = NULL; /* Silence old gcc warning. */ + size_t filename_len; char *section_name = NULL; - uint32_t _crc; + uint32_t _crc = 0; /* Silence old gcc warning. */ - if (!elf || !filename || !crc || !found || !shdr) { + if (!elf || !filename || !crc || !shdr) { goto error; } @@ -560,37 +616,32 @@ int lttng_ust_elf_get_debug_link_from_section(struct lttng_ust_elf *elf, if (!_filename) { goto error; } - if (fseek(elf->file, shdr->sh_offset, SEEK_SET)) { + if (lseek(elf->fd, shdr->sh_offset, SEEK_SET) < 0) { goto error; } - if (!fread(_filename, sizeof(*_filename), shdr->sh_size - ELF_CRC_SIZE, - elf->file)) { + filename_len = sizeof(*_filename) * (shdr->sh_size - ELF_CRC_SIZE); + if (lttng_ust_read(elf->fd, _filename, filename_len) < filename_len) { goto error; } - if (!fread(&_crc, sizeof(_crc), 1, elf->file)) { + if (lttng_ust_read(elf->fd, &_crc, sizeof(_crc)) < sizeof(_crc)) { goto error; } if (!is_elf_native_endian(elf)) { _crc = bswap_32(_crc); } - _found = 1; - end: free(section_name); - if (_found) { + if (_filename) { *filename = _filename; *crc = _crc; } - *found = _found; return 0; error: - if (section_name) { - free(section_name); - } - + free(_filename); + free(section_name); return -1; } @@ -609,9 +660,8 @@ int lttng_ust_elf_get_debug_link(struct lttng_ust_elf *elf, char **filename, { int ret; uint16_t i; - int _found = 0; - char *_filename; - uint32_t _crc; + char *_filename = NULL; /* Silence old gcc warning. */ + uint32_t _crc = 0; /* Silence old gcc warning. */ if (!elf || !filename || !crc || !found) { goto error; @@ -626,24 +676,28 @@ int lttng_ust_elf_get_debug_link(struct lttng_ust_elf *elf, char **filename, } ret = lttng_ust_elf_get_debug_link_from_section( - elf, &_filename, &_crc, &_found, shdr); + elf, &_filename, &_crc, shdr); free(shdr); if (ret) { goto error; } - if (_found) { + if (_filename) { break; } } - if (_found) { + if (_filename) { *filename = _filename; *crc = _crc; + *found = 1; + } else { + *found = 0; } - *found = _found; return 0; + error: + free(_filename); return -1; }