| /* simple-object.c -- simple routines to read and write object files. |
| Copyright (C) 2010-2024 Free Software Foundation, Inc. |
| Written by Ian Lance Taylor, Google. |
| |
| This program is free software; you can redistribute it and/or modify it |
| under the terms of the GNU General Public License as published by the |
| Free Software Foundation; either version 2, or (at your option) any |
| later version. |
| |
| This program 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, 51 Franklin Street - Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "config.h" |
| #include "libiberty.h" |
| #include "simple-object.h" |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| |
| #ifdef HAVE_STDLIB_H |
| #include <stdlib.h> |
| #endif |
| |
| #ifdef HAVE_STDINT_H |
| #include <stdint.h> |
| #endif |
| |
| #ifdef HAVE_STRING_H |
| #include <string.h> |
| #endif |
| |
| #ifdef HAVE_INTTYPES_H |
| #include <inttypes.h> |
| #endif |
| |
| #ifndef SEEK_SET |
| #define SEEK_SET 0 |
| #endif |
| |
| #ifndef O_BINARY |
| #define O_BINARY 0 |
| #endif |
| |
| #include "simple-object-common.h" |
| |
| /* The known object file formats. */ |
| |
| static const struct simple_object_functions * const format_functions[] = |
| { |
| &simple_object_elf_functions, |
| &simple_object_mach_o_functions, |
| &simple_object_coff_functions, |
| &simple_object_xcoff_functions |
| }; |
| |
| /* Read data from a file using the simple_object error reporting |
| conventions. */ |
| |
| int |
| simple_object_internal_read (int descriptor, off_t offset, |
| unsigned char *buffer, size_t size, |
| const char **errmsg, int *err) |
| { |
| if (lseek (descriptor, offset, SEEK_SET) < 0) |
| { |
| *errmsg = "lseek"; |
| *err = errno; |
| return 0; |
| } |
| |
| do |
| { |
| ssize_t got = read (descriptor, buffer, size); |
| if (got == 0) |
| break; |
| else if (got > 0) |
| { |
| buffer += got; |
| size -= got; |
| } |
| else if (errno != EINTR) |
| { |
| *errmsg = "read"; |
| *err = errno; |
| return 0; |
| } |
| } |
| while (size > 0); |
| |
| if (size > 0) |
| { |
| *errmsg = "file too short"; |
| *err = 0; |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* Write data to a file using the simple_object error reporting |
| conventions. */ |
| |
| int |
| simple_object_internal_write (int descriptor, off_t offset, |
| const unsigned char *buffer, size_t size, |
| const char **errmsg, int *err) |
| { |
| if (lseek (descriptor, offset, SEEK_SET) < 0) |
| { |
| *errmsg = "lseek"; |
| *err = errno; |
| return 0; |
| } |
| |
| do |
| { |
| ssize_t wrote = write (descriptor, buffer, size); |
| if (wrote == 0) |
| break; |
| else if (wrote > 0) |
| { |
| buffer += wrote; |
| size -= wrote; |
| } |
| else if (errno != EINTR) |
| { |
| *errmsg = "write"; |
| *err = errno; |
| return 0; |
| } |
| } |
| while (size > 0); |
| |
| if (size > 0) |
| { |
| *errmsg = "short write"; |
| *err = 0; |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* Open for read. */ |
| |
| simple_object_read * |
| simple_object_start_read (int descriptor, off_t offset, |
| const char *segment_name, const char **errmsg, |
| int *err) |
| { |
| unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN]; |
| size_t len, i; |
| |
| if (!simple_object_internal_read (descriptor, offset, header, |
| SIMPLE_OBJECT_MATCH_HEADER_LEN, |
| errmsg, err)) |
| return NULL; |
| |
| len = sizeof (format_functions) / sizeof (format_functions[0]); |
| for (i = 0; i < len; ++i) |
| { |
| void *data; |
| |
| data = format_functions[i]->match (header, descriptor, offset, |
| segment_name, errmsg, err); |
| if (data != NULL) |
| { |
| simple_object_read *ret; |
| |
| ret = XNEW (simple_object_read); |
| ret->descriptor = descriptor; |
| ret->offset = offset; |
| ret->functions = format_functions[i]; |
| ret->data = data; |
| return ret; |
| } |
| } |
| |
| *errmsg = "file not recognized"; |
| *err = 0; |
| return NULL; |
| } |
| |
| /* Find all sections. */ |
| |
| const char * |
| simple_object_find_sections (simple_object_read *sobj, |
| int (*pfn) (void *, const char *, off_t, off_t), |
| void *data, |
| int *err) |
| { |
| return sobj->functions->find_sections (sobj, pfn, data, err); |
| } |
| |
| /* Internal data passed to find_one_section. */ |
| |
| struct find_one_section_data |
| { |
| /* The section we are looking for. */ |
| const char *name; |
| /* Where to store the section offset. */ |
| off_t *offset; |
| /* Where to store the section length. */ |
| off_t *length; |
| /* Set if the name is found. */ |
| int found; |
| }; |
| |
| /* Internal function passed to find_sections. */ |
| |
| static int |
| find_one_section (void *data, const char *name, off_t offset, off_t length) |
| { |
| struct find_one_section_data *fosd = (struct find_one_section_data *) data; |
| |
| if (strcmp (name, fosd->name) != 0) |
| return 1; |
| |
| *fosd->offset = offset; |
| *fosd->length = length; |
| fosd->found = 1; |
| |
| /* Stop iteration. */ |
| return 0; |
| } |
| |
| /* Find a section. */ |
| |
| int |
| simple_object_find_section (simple_object_read *sobj, const char *name, |
| off_t *offset, off_t *length, |
| const char **errmsg, int *err) |
| { |
| struct find_one_section_data fosd; |
| |
| fosd.name = name; |
| fosd.offset = offset; |
| fosd.length = length; |
| fosd.found = 0; |
| |
| *errmsg = simple_object_find_sections (sobj, find_one_section, |
| (void *) &fosd, err); |
| if (*errmsg != NULL) |
| return 0; |
| if (!fosd.found) |
| return 0; |
| return 1; |
| } |
| |
| /* Callback to identify and rename LTO debug sections by name. |
| Returns non-NULL if NAME is a LTO debug section, NULL if not. |
| If RENAME is true it will rename LTO debug sections to non-LTO |
| ones. */ |
| |
| static char * |
| handle_lto_debug_sections (const char *name, int rename) |
| { |
| char *newname = rename ? XCNEWVEC (char, strlen (name) + 1) |
| : xstrdup (name); |
| |
| /* ??? So we can't use .gnu.lto_ prefixed sections as the assembler |
| complains about bogus section flags. Which means we need to arrange |
| for that to be fixed or .gnu.debuglto_ marked as SHF_EXCLUDE (to make |
| fat lto object tooling work for the fat part). */ |
| /* Also include corresponding reloc sections. */ |
| if (strncmp (name, ".rela", sizeof (".rela") - 1) == 0) |
| { |
| if (rename) |
| strncpy (newname, name, sizeof (".rela") - 1); |
| name += sizeof (".rela") - 1; |
| } |
| else if (strncmp (name, ".rel", sizeof (".rel") - 1) == 0) |
| { |
| if (rename) |
| strncpy (newname, name, sizeof (".rel") - 1); |
| name += sizeof (".rel") - 1; |
| } |
| /* ??? For now this handles both .gnu.lto_ and .gnu.debuglto_ prefixed |
| sections. */ |
| /* Copy LTO debug sections and rename them to their non-LTO name. */ |
| if (strncmp (name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0) |
| return rename ? strcat (newname, name + sizeof (".gnu.debuglto_") - 1) : newname; |
| else if (strncmp (name, ".gnu.lto_.debug_", |
| sizeof (".gnu.lto_.debug_") -1) == 0) |
| return rename ? strcat (newname, name + sizeof (".gnu.lto_") - 1) : newname; |
| /* Copy over .note.GNU-stack section under the same name if present. */ |
| else if (strcmp (name, ".note.GNU-stack") == 0) |
| return strcpy (newname, name); |
| /* Copy over .note.gnu.property section under the same name if present. */ |
| else if (strcmp (name, ".note.gnu.property") == 0) |
| return strcpy (newname, name); |
| /* Copy over .comment section under the same name if present. Solaris |
| ld uses them to relax its checking of ELF gABI access rules for |
| COMDAT sections in objects produced by GCC. */ |
| else if (strcmp (name, ".comment") == 0) |
| return strcpy (newname, name); |
| /* Copy over .GCC.command.line section under the same name if present. */ |
| else if (strcmp (name, ".GCC.command.line") == 0) |
| return strcpy (newname, name); |
| /* Copy over .ctf section under the same name if present. */ |
| else if (strcmp (name, ".ctf") == 0) |
| return strcpy (newname, name); |
| /* Copy over .BTF section under the same name if present. */ |
| else if (strcmp (name, ".BTF") == 0) |
| return strcpy (newname, name); |
| free (newname); |
| return NULL; |
| } |
| |
| /* Wrapper for handle_lto_debug_sections. */ |
| |
| static char * |
| handle_lto_debug_sections_rename (const char *name) |
| { |
| return handle_lto_debug_sections (name, 1); |
| } |
| |
| /* Wrapper for handle_lto_debug_sections. */ |
| |
| static char * |
| handle_lto_debug_sections_norename (const char *name) |
| { |
| return handle_lto_debug_sections (name, 0); |
| } |
| |
| /* Copy LTO debug sections. */ |
| |
| const char * |
| simple_object_copy_lto_debug_sections (simple_object_read *sobj, |
| const char *dest, int *err, int rename) |
| { |
| const char *errmsg; |
| simple_object_write *dest_sobj; |
| simple_object_attributes *attrs; |
| int outfd; |
| |
| if (! sobj->functions->copy_lto_debug_sections) |
| { |
| *err = EINVAL; |
| return "simple_object_copy_lto_debug_sections not implemented"; |
| } |
| |
| attrs = simple_object_fetch_attributes (sobj, &errmsg, err); |
| if (! attrs) |
| return errmsg; |
| dest_sobj = simple_object_start_write (attrs, NULL, &errmsg, err); |
| simple_object_release_attributes (attrs); |
| if (! dest_sobj) |
| return errmsg; |
| |
| errmsg = sobj->functions->copy_lto_debug_sections |
| (sobj, dest_sobj, |
| rename ? handle_lto_debug_sections_rename |
| : handle_lto_debug_sections_norename, err); |
| if (errmsg) |
| { |
| simple_object_release_write (dest_sobj); |
| return errmsg; |
| } |
| |
| outfd = open (dest, O_CREAT|O_WRONLY|O_TRUNC|O_BINARY, 00777); |
| if (outfd == -1) |
| { |
| *err = errno; |
| simple_object_release_write (dest_sobj); |
| return "open failed"; |
| } |
| |
| errmsg = simple_object_write_to_file (dest_sobj, outfd, err); |
| close (outfd); |
| if (errmsg) |
| { |
| simple_object_release_write (dest_sobj); |
| return errmsg; |
| } |
| |
| simple_object_release_write (dest_sobj); |
| return NULL; |
| } |
| |
| /* Fetch attributes. */ |
| |
| simple_object_attributes * |
| simple_object_fetch_attributes (simple_object_read *sobj, const char **errmsg, |
| int *err) |
| { |
| void *data; |
| simple_object_attributes *ret; |
| |
| data = sobj->functions->fetch_attributes (sobj, errmsg, err); |
| if (data == NULL) |
| return NULL; |
| ret = XNEW (simple_object_attributes); |
| ret->functions = sobj->functions; |
| ret->data = data; |
| return ret; |
| } |
| |
| /* Release an simple_object_read. */ |
| |
| void |
| simple_object_release_read (simple_object_read *sobj) |
| { |
| sobj->functions->release_read (sobj->data); |
| XDELETE (sobj); |
| } |
| |
| /* Merge attributes. */ |
| |
| const char * |
| simple_object_attributes_merge (simple_object_attributes *to, |
| simple_object_attributes *from, |
| int *err) |
| { |
| if (to->functions != from->functions) |
| { |
| *err = 0; |
| return "different object file format"; |
| } |
| return to->functions->attributes_merge (to->data, from->data, err); |
| } |
| |
| /* Release an attributes structure. */ |
| |
| void |
| simple_object_release_attributes (simple_object_attributes *attrs) |
| { |
| attrs->functions->release_attributes (attrs->data); |
| XDELETE (attrs); |
| } |
| |
| /* Start creating an object file. */ |
| |
| simple_object_write * |
| simple_object_start_write (simple_object_attributes *attrs, |
| const char *segment_name, const char **errmsg, |
| int *err) |
| { |
| void *data; |
| simple_object_write *ret; |
| |
| data = attrs->functions->start_write (attrs->data, errmsg, err); |
| if (data == NULL) |
| return NULL; |
| ret = XNEW (simple_object_write); |
| ret->functions = attrs->functions; |
| ret->segment_name = segment_name ? xstrdup (segment_name) : NULL; |
| ret->sections = NULL; |
| ret->last_section = NULL; |
| ret->data = data; |
| return ret; |
| } |
| |
| /* Start creating a section. */ |
| |
| simple_object_write_section * |
| simple_object_write_create_section (simple_object_write *sobj, const char *name, |
| unsigned int align, |
| const char **errmsg ATTRIBUTE_UNUSED, |
| int *err ATTRIBUTE_UNUSED) |
| { |
| simple_object_write_section *ret; |
| |
| ret = XNEW (simple_object_write_section); |
| ret->next = NULL; |
| ret->name = xstrdup (name); |
| ret->align = align; |
| ret->buffers = NULL; |
| ret->last_buffer = NULL; |
| |
| if (sobj->last_section == NULL) |
| { |
| sobj->sections = ret; |
| sobj->last_section = ret; |
| } |
| else |
| { |
| sobj->last_section->next = ret; |
| sobj->last_section = ret; |
| } |
| |
| return ret; |
| } |
| |
| /* Add data to a section. */ |
| |
| const char * |
| simple_object_write_add_data (simple_object_write *sobj ATTRIBUTE_UNUSED, |
| simple_object_write_section *section, |
| const void *buffer, |
| size_t size, int copy, |
| int *err ATTRIBUTE_UNUSED) |
| { |
| struct simple_object_write_section_buffer *wsb; |
| |
| wsb = XNEW (struct simple_object_write_section_buffer); |
| wsb->next = NULL; |
| wsb->size = size; |
| |
| if (!copy) |
| { |
| wsb->buffer = buffer; |
| wsb->free_buffer = NULL; |
| } |
| else |
| { |
| wsb->free_buffer = (void *) XNEWVEC (char, size); |
| memcpy (wsb->free_buffer, buffer, size); |
| wsb->buffer = wsb->free_buffer; |
| } |
| |
| if (section->last_buffer == NULL) |
| { |
| section->buffers = wsb; |
| section->last_buffer = wsb; |
| } |
| else |
| { |
| section->last_buffer->next = wsb; |
| section->last_buffer = wsb; |
| } |
| |
| return NULL; |
| } |
| |
| /* Write the complete object file. */ |
| |
| const char * |
| simple_object_write_to_file (simple_object_write *sobj, int descriptor, |
| int *err) |
| { |
| return sobj->functions->write_to_file (sobj, descriptor, err); |
| } |
| |
| /* Release an simple_object_write. */ |
| |
| void |
| simple_object_release_write (simple_object_write *sobj) |
| { |
| simple_object_write_section *section; |
| |
| free (sobj->segment_name); |
| |
| section = sobj->sections; |
| while (section != NULL) |
| { |
| struct simple_object_write_section_buffer *buffer; |
| simple_object_write_section *next_section; |
| |
| buffer = section->buffers; |
| while (buffer != NULL) |
| { |
| struct simple_object_write_section_buffer *next_buffer; |
| |
| if (buffer->free_buffer != NULL) |
| XDELETEVEC (buffer->free_buffer); |
| next_buffer = buffer->next; |
| XDELETE (buffer); |
| buffer = next_buffer; |
| } |
| |
| next_section = section->next; |
| free (section->name); |
| XDELETE (section); |
| section = next_section; |
| } |
| |
| sobj->functions->release_write (sobj->data); |
| XDELETE (sobj); |
| } |