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Diffstat (limited to 'gdb/coff-pe-read.c')
| -rw-r--r-- | gdb/coff-pe-read.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/gdb/coff-pe-read.c b/gdb/coff-pe-read.c new file mode 100644 index 0000000..2d1e854 --- /dev/null +++ b/gdb/coff-pe-read.c @@ -0,0 +1,346 @@ +/* Read the export table symbols from a portable executable and + convert to internal format, for GDB. Used as a last resort if no + debugging symbols recognized. + + Copyright 2003 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 of the License, 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, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. + + Contributed by Raoul M. Gough (RaoulGough@yahoo.co.uk). */ + +#include "coff-pe-read.h" + +#include "bfd.h" + +#include "defs.h" +#include "gdbtypes.h" + +#include "symtab.h" +#include "symfile.h" +#include "objfiles.h" + +/* Internal section information */ + +struct read_pe_section_data +{ + CORE_ADDR vma_offset; /* Offset to loaded address of section. */ + unsigned long rva_start; /* Start offset within the pe. */ + unsigned long rva_end; /* End offset within the pe. */ + enum minimal_symbol_type ms_type; /* Type to assign symbols in section. */ +}; + +#define PE_SECTION_INDEX_TEXT 0 +#define PE_SECTION_INDEX_DATA 1 +#define PE_SECTION_INDEX_BSS 2 +#define PE_SECTION_TABLE_SIZE 3 +#define PE_SECTION_INDEX_INVALID -1 + +/* Get the index of the named section in our own array, which contains + text, data and bss in that order. Return PE_SECTION_INDEX_INVALID + if passed an unrecognised section name. */ + +static int +read_pe_section_index (const char *section_name) +{ + if (strcmp (section_name, ".text") == 0) + { + return PE_SECTION_INDEX_TEXT; + } + + else if (strcmp (section_name, ".data") == 0) + { + return PE_SECTION_INDEX_DATA; + } + + else if (strcmp (section_name, ".bss") == 0) + { + return PE_SECTION_INDEX_BSS; + } + + else + { + return PE_SECTION_INDEX_INVALID; + } +} + +/* Record the virtual memory address of a section. */ + +static void +get_section_vmas (bfd *abfd, asection *sectp, void *context) +{ + struct read_pe_section_data *sections = context; + int sectix = read_pe_section_index (sectp->name); + + if (sectix != PE_SECTION_INDEX_INVALID) + { + /* Data within the section start at rva_start in the pe and at + bfd_get_section_vma() within memory. Store the offset. */ + + sections[sectix].vma_offset + = bfd_get_section_vma (abfd, sectp) - sections[sectix].rva_start; + } +} + +/* Create a minimal symbol entry for an exported symbol. */ + +static void +add_pe_exported_sym (char *sym_name, + unsigned long func_rva, + const struct read_pe_section_data *section_data, + const char *dll_name, struct objfile *objfile) +{ + /* Add the stored offset to get the loaded address of the symbol. */ + + CORE_ADDR vma = func_rva + section_data->vma_offset; + + char *qualified_name = 0; + int dll_name_len = strlen (dll_name); + int count; + + /* Generate a (hopefully unique) qualified name using the first part + of the dll name, e.g. KERNEL32!AddAtomA. This matches the style + used by windbg from the "Microsoft Debugging Tools for Windows". */ + + qualified_name = xmalloc (dll_name_len + strlen (sym_name) + 2); + + strncpy (qualified_name, dll_name, dll_name_len); + qualified_name[dll_name_len] = '!'; + strcpy (qualified_name + dll_name_len + 1, sym_name); + + prim_record_minimal_symbol (qualified_name, + vma, section_data->ms_type, objfile); + + xfree (qualified_name); + + /* Enter the plain name as well, which might not be unique. */ + prim_record_minimal_symbol (sym_name, vma, section_data->ms_type, objfile); +} + +/* Truncate a dll_name at the first dot character. */ + +static void +read_pe_truncate_name (char *dll_name) +{ + while (*dll_name) + { + if ((*dll_name) == '.') + { + *dll_name = '\0'; /* truncates and causes loop exit. */ + } + + else + { + ++dll_name; + } + } +} + +/* Low-level support functions, direct from the ld module pe-dll.c. */ +static unsigned int +pe_get16 (bfd *abfd, int where) +{ + unsigned char b[2]; + + bfd_seek (abfd, (file_ptr) where, SEEK_SET); + bfd_bread (b, (bfd_size_type) 2, abfd); + return b[0] + (b[1] << 8); +} + +static unsigned int +pe_get32 (bfd *abfd, int where) +{ + unsigned char b[4]; + + bfd_seek (abfd, (file_ptr) where, SEEK_SET); + bfd_bread (b, (bfd_size_type) 4, abfd); + return b[0] + (b[1] << 8) + (b[2] << 16) + (b[3] << 24); +} + +static unsigned int +pe_as32 (void *ptr) +{ + unsigned char *b = ptr; + + return b[0] + (b[1] << 8) + (b[2] << 16) + (b[3] << 24); +} + +/* Read the (non-debug) export symbol table from a portable + executable. Code originally lifted from the ld function + pe_implied_import_dll in pe-dll.c. */ + +void +read_pe_exported_syms (struct objfile *objfile) +{ + bfd *dll = objfile->obfd; + unsigned long pe_header_offset, opthdr_ofs, num_entries, i; + unsigned long export_rva, export_size, nsections, secptr, expptr; + unsigned long exp_funcbase; + unsigned char *expdata, *erva; + unsigned long name_rvas, ordinals, nexp, ordbase; + char *dll_name; + + /* Array elements are for text, data and bss in that order + Initialization with start_rva > end_rva guarantees that + unused sections won't be matched. */ + struct read_pe_section_data section_data[PE_SECTION_TABLE_SIZE] + = { {0, 1, 0, mst_text}, + {0, 1, 0, mst_data}, + {0, 1, 0, mst_bss} + }; + + struct cleanup *back_to = 0; + + char const *target = bfd_get_target (objfile->obfd); + + if ((strcmp (target, "pe-i386") != 0) && (strcmp (target, "pei-i386") != 0)) + { + /* This is not an i386 format file. Abort now, because the code + is untested on anything else. *FIXME* test on further + architectures and loosen or remove this test. */ + return; + } + + /* Get pe_header, optional header and numbers of export entries. */ + pe_header_offset = pe_get32 (dll, 0x3c); + opthdr_ofs = pe_header_offset + 4 + 20; + num_entries = pe_get32 (dll, opthdr_ofs + 92); + + if (num_entries < 1) /* No exports. */ + { + return; + } + + export_rva = pe_get32 (dll, opthdr_ofs + 96); + export_size = pe_get32 (dll, opthdr_ofs + 100); + nsections = pe_get16 (dll, pe_header_offset + 4 + 2); + secptr = (pe_header_offset + 4 + 20 + + pe_get16 (dll, pe_header_offset + 4 + 16)); + expptr = 0; + + /* Get the rva and size of the export section. */ + for (i = 0; i < nsections; i++) + { + char sname[8]; + unsigned long secptr1 = secptr + 40 * i; + unsigned long vaddr = pe_get32 (dll, secptr1 + 12); + unsigned long vsize = pe_get32 (dll, secptr1 + 16); + unsigned long fptr = pe_get32 (dll, secptr1 + 20); + + bfd_seek (dll, (file_ptr) secptr1, SEEK_SET); + bfd_bread (sname, (bfd_size_type) 8, dll); + + if (vaddr <= export_rva && vaddr + vsize > export_rva) + { + expptr = fptr + (export_rva - vaddr); + if (export_rva + export_size > vaddr + vsize) + export_size = vsize - (export_rva - vaddr); + break; + } + } + + if (export_size == 0) + { + /* Empty export table. */ + return; + } + + /* Scan sections and store the base and size of the relevant sections. */ + for (i = 0; i < nsections; i++) + { + unsigned long secptr1 = secptr + 40 * i; + unsigned long vsize = pe_get32 (dll, secptr1 + 8); + unsigned long vaddr = pe_get32 (dll, secptr1 + 12); + unsigned long flags = pe_get32 (dll, secptr1 + 36); + char sec_name[9]; + int sectix; + + sec_name[8] = '\0'; + bfd_seek (dll, (file_ptr) secptr1 + 0, SEEK_SET); + bfd_bread (sec_name, (bfd_size_type) 8, dll); + + sectix = read_pe_section_index (sec_name); + + if (sectix != PE_SECTION_INDEX_INVALID) + { + section_data[sectix].rva_start = vaddr; + section_data[sectix].rva_end = vaddr + vsize; + } + } + + expdata = (unsigned char *) xmalloc (export_size); + back_to = make_cleanup (xfree, expdata); + + bfd_seek (dll, (file_ptr) expptr, SEEK_SET); + bfd_bread (expdata, (bfd_size_type) export_size, dll); + erva = expdata - export_rva; + + nexp = pe_as32 (expdata + 24); + name_rvas = pe_as32 (expdata + 32); + ordinals = pe_as32 (expdata + 36); + ordbase = pe_as32 (expdata + 16); + exp_funcbase = pe_as32 (expdata + 28); + + /* Use internal dll name instead of full pathname. */ + dll_name = pe_as32 (expdata + 12) + erva; + + bfd_map_over_sections (dll, get_section_vmas, section_data); + + /* Adjust the vma_offsets in case this PE got relocated. This + assumes that *all* sections share the same relocation offset + as the text section. */ + for (i = 0; i < PE_SECTION_TABLE_SIZE; i++) + { + section_data[i].vma_offset + += ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile)); + } + + printf_filtered ("Minimal symbols from %s...", dll_name); + wrap_here (""); + + /* Truncate name at first dot. Should maybe also convert to all + lower case for convenience on Windows. */ + read_pe_truncate_name (dll_name); + + /* Iterate through the list of symbols. */ + for (i = 0; i < nexp; i++) + { + /* Pointer to the names vector. */ + unsigned long name_rva = pe_as32 (erva + name_rvas + i * 4); + + /* Pointer to the function address vector. */ + unsigned long func_rva = pe_as32 (erva + exp_funcbase + i * 4); + + /* Find this symbol's section in our own array. */ + int sectix = 0; + + for (sectix = 0; sectix < PE_SECTION_TABLE_SIZE; ++sectix) + { + if ((func_rva >= section_data[sectix].rva_start) + && (func_rva < section_data[sectix].rva_end)) + { + add_pe_exported_sym (erva + name_rva, + func_rva, + section_data + sectix, dll_name, objfile); + break; + } + } + } + + /* discard expdata. */ + do_cleanups (back_to); +} |