Mike Dodd | 8cfa702 | 2010-11-17 11:12:26 -0800 | [diff] [blame^] | 1 | /** |
| 2 | * @file create_bfd.c |
| 3 | * Routine to handle elf file creation |
| 4 | * |
| 5 | * @remark Copyright 2007 OProfile authors |
| 6 | * @remark Read the file COPYING |
| 7 | * |
| 8 | * @author Jens Wilke |
| 9 | * @Modifications Maynard Johnson |
| 10 | * @Modifications Philippe Elie |
| 11 | * @Modifications Daniel Hansel |
| 12 | * |
| 13 | * Copyright IBM Corporation 2007 |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | #include "opjitconv.h" |
| 18 | #include "opd_printf.h" |
| 19 | #include "op_libiberty.h" |
| 20 | |
| 21 | #include <bfd.h> |
| 22 | #include <stdint.h> |
| 23 | #include <stdio.h> |
| 24 | |
| 25 | /* Create the symbols and fill the syms array for all functions |
| 26 | * from start_idx to end_idx pointing into entries_address_ascending array */ |
| 27 | static int fill_symtab(void) |
| 28 | { |
| 29 | int rc = OP_JIT_CONV_OK; |
| 30 | u32 i; |
| 31 | int r; |
| 32 | struct jitentry const * e; |
| 33 | asymbol * s; |
| 34 | asection * section = NULL; |
| 35 | |
| 36 | /* Check for valid value of entry_count to avoid integer overflow. */ |
| 37 | if (entry_count > UINT32_MAX - 1) { |
| 38 | bfd_perror("invalid entry_count value"); |
| 39 | rc = OP_JIT_CONV_FAIL; |
| 40 | goto out; |
| 41 | } |
| 42 | |
| 43 | syms = xmalloc(sizeof(asymbol *) * (entry_count+1)); |
| 44 | syms[entry_count] = NULL; |
| 45 | for (i = 0; i < entry_count; i++) { |
| 46 | e = entries_address_ascending[i]; |
| 47 | if (e->section) |
| 48 | section = e->section; |
| 49 | s = bfd_make_empty_symbol(cur_bfd); |
| 50 | if (!s) { |
| 51 | bfd_perror("bfd_make_empty_symbol"); |
| 52 | rc = OP_JIT_CONV_FAIL; |
| 53 | goto out; |
| 54 | } |
| 55 | s->name = e->symbol_name; |
| 56 | s->section = section; |
| 57 | s->flags = BSF_GLOBAL | BSF_FUNCTION; |
| 58 | s->value = e->vma - section->vma; |
| 59 | verbprintf(debug,"add sym: name=%s, value=%llx\n", s->name, |
| 60 | (unsigned long long)s->value); |
| 61 | syms[i] = s; |
| 62 | } |
| 63 | r = bfd_set_symtab(cur_bfd, syms, entry_count); |
| 64 | if (r == FALSE) { |
| 65 | bfd_perror("bfd_set_symtab"); |
| 66 | rc = OP_JIT_CONV_FAIL; |
| 67 | } |
| 68 | out: |
| 69 | return rc; |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * create a new section. |
| 74 | */ |
| 75 | asection * create_section(bfd * abfd, char const * section_name, |
| 76 | size_t size, bfd_vma vma, flagword flags) |
| 77 | { |
| 78 | asection * section; |
| 79 | |
| 80 | verbprintf(debug, "create_section() %s\n", section_name); |
| 81 | section = bfd_make_section(abfd, section_name); |
| 82 | if (section == NULL) { |
| 83 | bfd_perror("bfd_make_section"); |
| 84 | goto error; |
| 85 | } |
| 86 | if (bfd_set_section_vma(abfd, section, vma) == FALSE) { |
| 87 | bfd_perror("bfd_set_section_vma"); |
| 88 | goto error; |
| 89 | } |
| 90 | if (bfd_set_section_size(abfd, section, size) == FALSE) { |
| 91 | bfd_perror("bfd_set_section_size"); |
| 92 | goto error; |
| 93 | } |
| 94 | if (bfd_set_section_flags(abfd, section, flags) == FALSE) { |
| 95 | bfd_perror("bfd_set_section_flags"); |
| 96 | goto error; |
| 97 | } |
| 98 | return section; |
| 99 | error: |
| 100 | return NULL; |
| 101 | } |
| 102 | |
| 103 | |
| 104 | /* create a .text section. end_idx: index last jitentry (inclusive!) */ |
| 105 | static int create_text_section(int start_idx, int end_idx) |
| 106 | { |
| 107 | int rc = OP_JIT_CONV_OK; |
| 108 | |
| 109 | asection * section; |
| 110 | char const * section_name; |
| 111 | int idx = start_idx; |
| 112 | unsigned long long vma_start = |
| 113 | entries_address_ascending[start_idx]->vma; |
| 114 | struct jitentry * ee = entries_address_ascending[end_idx]; |
| 115 | unsigned long long vma_end = ee->vma + ee->code_size; |
| 116 | int size = vma_end - vma_start; |
| 117 | |
| 118 | section_name = bfd_get_unique_section_name(cur_bfd, ".text", &idx); |
| 119 | verbprintf(debug, "section idx=%i, name=%s, vma_start=%llx, size=%i\n", |
| 120 | idx, section_name, vma_start, size); |
| 121 | |
| 122 | section = create_section(cur_bfd, section_name, size, vma_start, |
| 123 | SEC_ALLOC|SEC_LOAD|SEC_READONLY|SEC_CODE|SEC_HAS_CONTENTS); |
| 124 | if (section) |
| 125 | entries_address_ascending[start_idx]->section = section; |
| 126 | else |
| 127 | rc = OP_JIT_CONV_FAIL; |
| 128 | |
| 129 | return rc; |
| 130 | } |
| 131 | |
| 132 | /* fill a section contents at a given offset from the start of the section */ |
| 133 | int fill_section_content(bfd * abfd, asection * section, |
| 134 | void const * b, file_ptr offset, size_t sz) |
| 135 | { |
| 136 | if (bfd_set_section_contents(abfd, section, b, offset, sz) == FALSE) { |
| 137 | bfd_perror("bfd_set_section_contents"); |
| 138 | return OP_JIT_CONV_FAIL; |
| 139 | } |
| 140 | return OP_JIT_CONV_OK; |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * Copy all code of the functions that are within start_idx and end_idx to |
| 145 | * the section. |
| 146 | */ |
| 147 | static int fill_text_section_content(asection * section, int start_idx, |
| 148 | int end_idx) |
| 149 | { |
| 150 | int rc = OP_JIT_CONV_OK; |
| 151 | unsigned long long vma_start = |
| 152 | entries_address_ascending[start_idx]->vma; |
| 153 | struct jitentry const * e; |
| 154 | int i; |
| 155 | |
| 156 | for (i = start_idx; i <= end_idx; i++) { |
| 157 | e = entries_address_ascending[i]; |
| 158 | verbprintf(debug, "section = %s, i = %i, code = %llx," |
| 159 | " vma = %llx, offset = %llx," |
| 160 | "size = %i, name = %s\n", |
| 161 | section->name, i, |
| 162 | (unsigned long long) (uintptr_t) e->code, |
| 163 | e->vma, e->vma - vma_start, |
| 164 | e->code_size, e->symbol_name); |
| 165 | /* the right part that is created by split_entry may |
| 166 | * have no code; also, the agent may have passed NULL |
| 167 | * for the code location. |
| 168 | */ |
| 169 | if (e->code) { |
| 170 | rc = fill_section_content(cur_bfd, section, |
| 171 | e->code, (file_ptr) (e->vma - vma_start), |
| 172 | (bfd_size_type)e->code_size); |
| 173 | if (rc != OP_JIT_CONV_OK) |
| 174 | break; |
| 175 | } |
| 176 | } |
| 177 | return rc; |
| 178 | } |
| 179 | |
| 180 | |
| 181 | /* Walk over the symbols sorted by address and create ELF sections. Whenever we |
| 182 | * have a gap greater or equal to 4096 make a new section. |
| 183 | */ |
| 184 | int partition_sections(void) |
| 185 | { |
| 186 | int rc = OP_JIT_CONV_OK; |
| 187 | u32 i, j; |
| 188 | struct jitentry const * pred; |
| 189 | struct jitentry const * entry; |
| 190 | unsigned long long end_addr; |
| 191 | |
| 192 | // i: start index of the section |
| 193 | i = 0; |
| 194 | for (j = 1; j < entry_count; j++) { |
| 195 | entry = entries_address_ascending[j]; |
| 196 | pred = entries_address_ascending[j - 1]; |
| 197 | end_addr = pred->vma + pred->code_size; |
| 198 | // calculate gap between code, if it is more than one page |
| 199 | // create an additional section |
| 200 | if ((entry->vma - end_addr) >= 4096) { |
| 201 | rc = create_text_section(i, j - 1); |
| 202 | if (rc == OP_JIT_CONV_FAIL) |
| 203 | goto out; |
| 204 | i = j; |
| 205 | } |
| 206 | } |
| 207 | // this holds always if we have at least one jitentry |
| 208 | if (i < entry_count) |
| 209 | rc = create_text_section(i, entry_count - 1); |
| 210 | out: |
| 211 | return rc; |
| 212 | } |
| 213 | |
| 214 | |
| 215 | /* Fill the code content into the sections created by partition_sections() */ |
| 216 | int fill_sections(void) |
| 217 | { |
| 218 | int rc = OP_JIT_CONV_OK; |
| 219 | u32 i, j; |
| 220 | asection * section; |
| 221 | |
| 222 | rc = fill_symtab(); |
| 223 | if (rc == OP_JIT_CONV_FAIL) |
| 224 | goto out; |
| 225 | |
| 226 | verbprintf(debug, "opjitconv: fill_sections\n"); |
| 227 | i = 0; |
| 228 | for (j = 1; j < entry_count; j++) { |
| 229 | if (entries_address_ascending[j]->section) { |
| 230 | section = entries_address_ascending[i]->section; |
| 231 | rc = fill_text_section_content(section, i, |
| 232 | j - 1); |
| 233 | if (rc == OP_JIT_CONV_FAIL) |
| 234 | goto out; |
| 235 | i = j; |
| 236 | } |
| 237 | } |
| 238 | // this holds always if we have at least one jitentry |
| 239 | if (i < entry_count) { |
| 240 | section = entries_address_ascending[i]->section; |
| 241 | rc = fill_text_section_content(section, |
| 242 | i, entry_count - 1); |
| 243 | } |
| 244 | out: |
| 245 | return rc; |
| 246 | } |
| 247 | |
| 248 | |
| 249 | /* create the elf file */ |
| 250 | bfd * open_elf(char const * filename) |
| 251 | { |
| 252 | bfd * abfd; |
| 253 | |
| 254 | abfd = bfd_openw(filename, dump_bfd_target_name); |
| 255 | if (!abfd) { |
| 256 | bfd_perror("bfd_openw"); |
| 257 | goto error1; |
| 258 | } |
| 259 | if (bfd_set_format(abfd, bfd_object) == FALSE) { |
| 260 | bfd_perror("bfd_set_format"); |
| 261 | goto error; |
| 262 | } |
| 263 | if (bfd_set_arch_mach(abfd, dump_bfd_arch, dump_bfd_mach) == FALSE) { |
| 264 | bfd_perror("bfd_set_format"); |
| 265 | goto error; |
| 266 | } |
| 267 | return abfd; |
| 268 | error: |
| 269 | bfd_close(abfd); |
| 270 | error1: |
| 271 | return NULL; |
| 272 | } |