X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-elf.c;h=663699b7ce91a5d9febf0d9903b64d042a580782;hb=3fbec7dc3645facd9e809cf161ba3435a377ce56;hp=026d65cec362ce757994d2d500a295d6839ba44b;hpb=5a26ac5496892ae6faa6192074264b2f9adcd589;p=lttng-ust.git diff --git a/liblttng-ust/lttng-ust-elf.c b/liblttng-ust/lttng-ust-elf.c index 026d65ce..663699b7 100644 --- a/liblttng-ust/lttng-ust-elf.c +++ b/liblttng-ust/lttng-ust-elf.c @@ -16,6 +16,8 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#define _GNU_SOURCE +#define _LGPL_SOURCE #include #include #include @@ -24,6 +26,7 @@ #include #include #include +#include #include "lttng-tracer-core.h" #define BUF_LEN 4096 @@ -315,6 +318,18 @@ error: 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. */ @@ -341,7 +356,7 @@ 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; @@ -349,7 +364,6 @@ 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) { @@ -364,27 +378,19 @@ 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; @@ -405,11 +411,10 @@ error: static int lttng_ust_elf_get_build_id_from_segment( struct lttng_ust_elf *elf, uint8_t **build_id, size_t *length, - off_t offset, off_t segment_end, int *found) + off_t offset, off_t segment_end) { uint8_t *_build_id = NULL; /* Silence old gcc warning. */ size_t _length = 0; /* Silence old gcc warning. */ - int _found = 0; while (offset < segment_end) { struct lttng_ust_elf_nhdr nhdr; @@ -466,18 +471,17 @@ int lttng_ust_elf_get_build_id_from_segment( 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; } @@ -500,7 +504,6 @@ int lttng_ust_elf_get_build_id(struct lttng_ust_elf *elf, uint8_t **build_id, uint16_t i; uint8_t *_build_id = NULL; /* Silence old gcc warning. */ size_t _length = 0; /* Silence old gcc warning. */ - int _found = 0; if (!elf || !build_id || !length || !found) { goto error; @@ -524,26 +527,28 @@ 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; } @@ -559,16 +564,14 @@ error: */ 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 = NULL; /* Silence old gcc warning. */ size_t filename_len; char *section_name = NULL; uint32_t _crc = 0; /* Silence old gcc warning. */ - if (!elf || !filename || !crc || !found || !shdr) { + if (!elf || !filename || !crc || !shdr) { goto error; } @@ -611,23 +614,18 @@ int lttng_ust_elf_get_debug_link_from_section(struct lttng_ust_elf *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; } @@ -646,7 +644,6 @@ int lttng_ust_elf_get_debug_link(struct lttng_ust_elf *elf, char **filename, { int ret; uint16_t i; - int _found = 0; char *_filename = NULL; /* Silence old gcc warning. */ uint32_t _crc = 0; /* Silence old gcc warning. */ @@ -663,24 +660,28 @@ 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; }