Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 1 | // Copyright (c) 2017, Google Inc. |
| 2 | // |
| 3 | // Permission to use, copy, modify, and/or distribute this software for any |
| 4 | // purpose with or without fee is hereby granted, provided that the above |
| 5 | // copyright notice and this permission notice appear in all copies. |
| 6 | // |
| 7 | // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 8 | // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 9 | // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| 10 | // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 11 | // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| 12 | // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| 13 | // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ |
| 14 | |
| 15 | // delocate performs several transformations of textual assembly code. See |
| 16 | // FIPS.md in this directory for an overview. |
| 17 | package main |
| 18 | |
| 19 | import ( |
| 20 | "bufio" |
| 21 | "bytes" |
| 22 | "flag" |
| 23 | "fmt" |
| 24 | "os" |
| 25 | "path/filepath" |
| 26 | "sort" |
| 27 | "strconv" |
| 28 | "strings" |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 29 | "unicode" |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 30 | "unicode/utf8" |
| 31 | ) |
| 32 | |
| 33 | func main() { |
| 34 | // The .a file, if given, is expected to be an archive of textual |
| 35 | // assembly sources. That's odd, but CMake really wants to create |
| 36 | // archive files so it's the only way that we can make it work. |
| 37 | arInput := flag.String("a", "", "Path to a .a file containing assembly sources") |
| 38 | |
| 39 | outFile := flag.String("o", "", "Path to output assembly") |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 40 | |
| 41 | flag.Parse() |
| 42 | |
| 43 | var lines []string |
| 44 | var err error |
| 45 | if len(*arInput) > 0 { |
| 46 | if lines, err = arLines(lines, *arInput); err != nil { |
| 47 | panic(err) |
| 48 | } |
| 49 | } |
| 50 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 51 | for i, path := range flag.Args() { |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 52 | if len(path) == 0 { |
| 53 | continue |
| 54 | } |
| 55 | |
| 56 | if lines, err = asLines(lines, path, i); err != nil { |
| 57 | panic(err) |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | symbols := definedSymbols(lines) |
| 62 | lines = transform(lines, symbols) |
| 63 | |
| 64 | out, err := os.OpenFile(*outFile, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644) |
| 65 | if err != nil { |
| 66 | panic(err) |
| 67 | } |
| 68 | defer out.Close() |
| 69 | |
| 70 | for _, line := range lines { |
| 71 | out.WriteString(line) |
| 72 | out.WriteString("\n") |
| 73 | } |
| 74 | } |
| 75 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 76 | func removeComment(line string) string { |
| 77 | if i := strings.Index(line, "#"); i != -1 { |
| 78 | return line[:i] |
| 79 | } |
| 80 | return line |
| 81 | } |
| 82 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 83 | // isSymbolDef returns detects whether line contains a (non-local) symbol |
| 84 | // definition. If so, it returns the symbol and true. Otherwise it returns "" |
| 85 | // and false. |
| 86 | func isSymbolDef(line string) (string, bool) { |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 87 | line = strings.TrimSpace(removeComment(line)) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 88 | |
| 89 | if len(line) > 0 && line[len(line)-1] == ':' && line[0] != '.' { |
| 90 | symbol := line[:len(line)-1] |
| 91 | if validSymbolName(symbol) { |
| 92 | return symbol, true |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | return "", false |
| 97 | } |
| 98 | |
| 99 | // definedSymbols finds all (non-local) symbols from lines and returns a map |
| 100 | // from symbol name to whether or not that symbol is global. |
| 101 | func definedSymbols(lines []string) map[string]bool { |
| 102 | globalSymbols := make(map[string]struct{}) |
| 103 | symbols := make(map[string]bool) |
| 104 | |
| 105 | for _, line := range lines { |
| 106 | if len(line) == 0 { |
| 107 | continue |
| 108 | } |
| 109 | |
| 110 | if symbol, ok := isSymbolDef(line); ok { |
| 111 | _, isGlobal := globalSymbols[symbol] |
| 112 | symbols[symbol] = isGlobal |
| 113 | } |
| 114 | |
| 115 | parts := strings.Fields(strings.TrimSpace(line)) |
| 116 | if parts[0] == ".globl" { |
| 117 | globalSymbols[parts[1]] = struct{}{} |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | return symbols |
| 122 | } |
| 123 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 124 | // threadLocalOffsetFunc describes a function that fetches the offset to symbol |
| 125 | // in the thread-local space and writes it to the given target register. |
| 126 | type threadLocalOffsetFunc struct { |
| 127 | target string |
| 128 | symbol string |
| 129 | } |
| 130 | |
| 131 | type lineSource struct { |
| 132 | lines []string |
| 133 | lineNo int |
| 134 | } |
| 135 | |
| 136 | func (ls *lineSource) Next() (string, bool) { |
| 137 | if ls.lineNo == len(ls.lines) { |
| 138 | return "", false |
| 139 | } |
| 140 | |
| 141 | ret := ls.lines[ls.lineNo] |
| 142 | ls.lineNo++ |
| 143 | return ret, true |
| 144 | } |
| 145 | |
| 146 | func (ls *lineSource) Unread() { |
| 147 | ls.lineNo-- |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 148 | } |
| 149 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 150 | func parseInstruction(line string) (instr string, args []string) { |
| 151 | line = strings.TrimSpace(line) |
| 152 | if len(line) == 0 || line[0] == '#' { |
| 153 | return "", nil |
| 154 | } |
| 155 | |
| 156 | idx := strings.IndexFunc(line, unicode.IsSpace) |
| 157 | if idx < 0 { |
| 158 | return line, nil |
| 159 | } |
| 160 | |
| 161 | instr = strings.TrimSpace(line[:idx]) |
| 162 | line = strings.TrimSpace(line[idx:]) |
| 163 | for len(line) > 0 { |
| 164 | var inQuote bool |
| 165 | var parens int |
| 166 | Loop: |
| 167 | for idx = 0; idx < len(line); idx++ { |
| 168 | if inQuote { |
| 169 | if line[idx] == '\\' { |
| 170 | if idx == len(line)-1 { |
| 171 | panic(fmt.Sprintf("could not parse %q", line)) |
| 172 | } |
| 173 | idx++ |
| 174 | } else { |
| 175 | inQuote = line[idx] != '"' |
| 176 | } |
| 177 | continue |
| 178 | } |
| 179 | switch line[idx] { |
| 180 | case '"': |
| 181 | inQuote = true |
| 182 | case '(': |
| 183 | parens++ |
| 184 | case ')': |
| 185 | if parens == 0 { |
| 186 | panic(fmt.Sprintf("could not parse %q", line)) |
| 187 | } |
| 188 | parens-- |
| 189 | case ',': |
| 190 | if parens == 0 { |
| 191 | break Loop |
| 192 | } |
| 193 | case '#': |
| 194 | line = line[:idx] |
| 195 | break Loop |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | if inQuote || parens > 0 { |
| 200 | panic(fmt.Sprintf("could not parse %q", line)) |
| 201 | } |
| 202 | |
| 203 | args = append(args, strings.TrimSpace(line[:idx])) |
| 204 | if idx < len(line) { |
| 205 | // Skip the comma. |
| 206 | line = line[idx+1:] |
| 207 | } else { |
| 208 | line = line[idx:] |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | return |
| 213 | } |
| 214 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 215 | // transform performs a number of transformations on the given assembly code. |
| 216 | // See FIPS.md in the current directory for an overview. |
| 217 | func transform(lines []string, symbols map[string]bool) (ret []string) { |
| 218 | ret = append(ret, ".text", "BORINGSSL_bcm_text_start:") |
| 219 | |
| 220 | // redirectors maps from out-call symbol name to the name of a |
| 221 | // redirector function for that symbol. |
| 222 | redirectors := make(map[string]string) |
| 223 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 224 | // ia32capAddrDeltaNeeded is true iff OPENSSL_ia32cap_addr_delta has |
| 225 | // been referenced and thus needs to be emitted outside the module. |
| 226 | ia32capAddrDeltaNeeded := false |
| 227 | |
| 228 | // ia32capGetNeeded is true iff OPENSSL_ia32cap_get has been referenced |
| 229 | // and thus needs to be emitted outside the module. |
| 230 | ia32capGetNeeded := false |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 231 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 232 | // bssAccessorsNeeded maps the names of BSS variables for which |
| 233 | // accessor functions need to be emitted outside of the module, to the |
| 234 | // BSS symbols they point to. For example, “EVP_sha256_once” could map |
| 235 | // to “.LEVP_sha256_once_local_target” or “EVP_sha256_once” (if .comm |
| 236 | // was used). |
| 237 | bssAccessorsNeeded := make(map[string]string) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 238 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 239 | // threadLocalOffsets records the accessor functions needed for getting |
| 240 | // offsets in the thread-local storage. |
| 241 | threadLocalOffsets := make(map[string]threadLocalOffsetFunc) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 242 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 243 | source := &lineSource{lines: lines} |
| 244 | |
| 245 | for { |
| 246 | line, ok := source.Next() |
| 247 | if !ok { |
| 248 | break |
| 249 | } |
| 250 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 251 | if strings.Contains(line, "OPENSSL_ia32cap_get@PLT") { |
| 252 | ia32capGetNeeded = true |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 253 | } |
| 254 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 255 | line = strings.Replace(line, "@PLT", "", -1) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 256 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 257 | instr, args := parseInstruction(line) |
| 258 | if len(instr) == 0 { |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 259 | ret = append(ret, line) |
| 260 | continue |
| 261 | } |
| 262 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 263 | switch instr { |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 264 | case "call", "callq", "jmp", "jne", "jb", "jz", "jnz", "ja": |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 265 | target := args[0] |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 266 | // indirect via register or local label |
| 267 | if strings.HasPrefix(target, "*") || strings.HasPrefix(target, ".L") { |
| 268 | ret = append(ret, line) |
| 269 | continue |
| 270 | } |
| 271 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 272 | if strings.HasSuffix(target, "_bss_get") { |
| 273 | // reference to a synthesised function. Don't |
| 274 | // indirect it. |
| 275 | ret = append(ret, line) |
| 276 | continue |
| 277 | } |
| 278 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 279 | if isGlobal, ok := symbols[target]; ok { |
| 280 | newTarget := target |
| 281 | if isGlobal { |
| 282 | newTarget = localTargetName(target) |
| 283 | } |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 284 | ret = append(ret, fmt.Sprintf("\t%s %s", instr, newTarget)) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 285 | continue |
| 286 | } |
| 287 | |
| 288 | redirectorName := "bcm_redirector_" + target |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 289 | ret = append(ret, fmt.Sprintf("\t%s %s", instr, redirectorName)) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 290 | redirectors[redirectorName] = target |
| 291 | continue |
| 292 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 293 | case "pushq": |
| 294 | target := args[0] |
| 295 | if strings.HasSuffix(target, "@GOTPCREL(%rip)") { |
| 296 | target = target[:len(target)-15] |
| 297 | if !symbols[target] { |
| 298 | panic(fmt.Sprintf("Reference to unknown symbol on line %d: %s", source.lineNo, line)) |
| 299 | } |
| 300 | |
| 301 | ret = append(ret, "\tpushq %rax") |
| 302 | ret = append(ret, "\tleaq "+localTargetName(target)+"(%rip), %rax") |
| 303 | ret = append(ret, "\txchg %rax, (%rsp)") |
| 304 | continue |
| 305 | } |
| 306 | |
| 307 | ret = append(ret, line) |
| 308 | continue |
| 309 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 310 | case "leaq", "movq", "cmpq": |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 311 | if instr == "movq" && strings.Contains(line, "@GOTTPOFF(%rip)") { |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 312 | // GOTTPOFF are offsets into the thread-local |
| 313 | // storage that are stored in the GOT. We have |
| 314 | // to move these relocations out of the module, |
| 315 | // but do not know whether rax is live at this |
| 316 | // point. Thus a normal function call might |
| 317 | // clobber a register and so we synthesize |
| 318 | // different functions for writing to each |
| 319 | // target register. |
| 320 | // |
| 321 | // (BoringSSL itself does not use __thread |
| 322 | // variables, but ASAN and MSAN may add these |
| 323 | // references for their bookkeeping.) |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 324 | targetRegister := args[1][1:] |
| 325 | symbol := strings.SplitN(args[0], "@", 2)[0] |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 326 | functionName := fmt.Sprintf("BORINGSSL_bcm_tpoff_to_%s_for_%s", targetRegister, symbol) |
| 327 | threadLocalOffsets[functionName] = threadLocalOffsetFunc{target: targetRegister, symbol: symbol} |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 328 | ret = append(ret, "leaq -128(%rsp), %rsp") // Clear the red zone. |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 329 | ret = append(ret, "\tcallq "+functionName+"\n") |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 330 | ret = append(ret, "leaq 128(%rsp), %rsp") |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 331 | continue |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 332 | } |
| 333 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 334 | target := args[0] |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 335 | if strings.HasSuffix(target, "(%rip)") { |
| 336 | target = target[:len(target)-6] |
| 337 | if isGlobal := symbols[target]; isGlobal { |
| 338 | line = strings.Replace(line, target, localTargetName(target), 1) |
| 339 | } |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 340 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 341 | if strings.Contains(line, "@GOTPCREL") && instr == "movq" { |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 342 | line = strings.Replace(line, "@GOTPCREL", "", -1) |
| 343 | target = strings.Replace(target, "@GOTPCREL", "", -1) |
| 344 | |
| 345 | if isGlobal := symbols[target]; isGlobal { |
| 346 | line = strings.Replace(line, target, localTargetName(target), 1) |
| 347 | } |
| 348 | |
| 349 | // Nobody actually wants to read the |
| 350 | // code of a function. This is a load |
| 351 | // from the GOT which, now that we're |
| 352 | // referencing the symbol directly, |
| 353 | // needs to be transformed into an LEA. |
| 354 | line = strings.Replace(line, "movq", "leaq", 1) |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 355 | instr = "leaq" |
| 356 | } |
| 357 | |
| 358 | if target == "OPENSSL_ia32cap_P" { |
| 359 | if instr != "leaq" { |
| 360 | panic("reference to OPENSSL_ia32cap_P needs to be changed to go through leaq or GOTPCREL") |
| 361 | } |
| 362 | if args[1][0] != '%' { |
| 363 | panic("reference to OPENSSL_ia32cap_P must target a register.") |
| 364 | } |
| 365 | |
| 366 | // We assume pushfq is safe, after |
| 367 | // clearing the red zone, because any |
| 368 | // signals will be delivered using |
| 369 | // %rsp. Thus perlasm and |
| 370 | // compiler-generated code must not use |
| 371 | // %rsp as a general-purpose register. |
| 372 | // |
| 373 | // TODO(davidben): This messes up CFI |
| 374 | // for a small window if %rsp is the CFI |
| 375 | // register. |
| 376 | ia32capAddrDeltaNeeded = true |
| 377 | ret = append(ret, "leaq -128(%rsp), %rsp") // Clear the red zone. |
| 378 | ret = append(ret, "pushfq") |
| 379 | ret = append(ret, fmt.Sprintf("leaq OPENSSL_ia32cap_addr_delta(%%rip), %s", args[1])) |
| 380 | ret = append(ret, fmt.Sprintf("addq OPENSSL_ia32cap_addr_delta(%%rip), %s", args[1])) |
| 381 | ret = append(ret, "popfq") |
| 382 | ret = append(ret, "leaq 128(%rsp), %rsp") |
| 383 | continue |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 384 | } |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 385 | } |
| 386 | |
| 387 | ret = append(ret, line) |
| 388 | continue |
| 389 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 390 | case ".comm": |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 391 | name := args[0] |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 392 | bssAccessorsNeeded[name] = name |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 393 | ret = append(ret, line) |
| 394 | |
| 395 | case ".section": |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 396 | section := strings.Trim(args[0], "\"") |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 397 | if section == ".data.rel.ro" { |
| 398 | // In a normal build, this is an indication of |
| 399 | // a problem but any references from the module |
| 400 | // to this section will result in a relocation |
| 401 | // and thus will break the integrity check. |
| 402 | // However, ASAN can generate these sections |
| 403 | // and so we cannot forbid them. |
| 404 | ret = append(ret, line) |
| 405 | continue |
| 406 | } |
| 407 | |
| 408 | sectionType, ok := sectionType(section) |
| 409 | if !ok { |
| 410 | panic(fmt.Sprintf("unknown section %q on line %d", section, source.lineNo)) |
| 411 | } |
| 412 | |
| 413 | switch sectionType { |
| 414 | case ".rodata", ".text": |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 415 | // Move .rodata to .text so it may be accessed |
| 416 | // without a relocation. GCC with |
| 417 | // -fmerge-constants will place strings into |
| 418 | // separate sections, so we move all sections |
| 419 | // named like .rodata. Also move .text.startup |
| 420 | // so the self-test function is also in the |
| 421 | // module. |
| 422 | ret = append(ret, ".text # "+section) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 423 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 424 | case ".data": |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 425 | panic(fmt.Sprintf("bad section %q on line %d", args[0], source.lineNo)) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 426 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 427 | case ".init_array", ".fini_array", ".ctors", ".dtors": |
| 428 | // init_array/ctors/dtors contains function |
| 429 | // pointers to constructor/destructor |
| 430 | // functions. These contain relocations, but |
| 431 | // they're in a different section anyway. |
| 432 | ret = append(ret, line) |
| 433 | |
| 434 | case ".debug", ".note": |
| 435 | ret = append(ret, line) |
| 436 | |
| 437 | case ".bss": |
| 438 | ret = append(ret, line) |
| 439 | |
| 440 | var accessors map[string]string |
| 441 | accessors, ret = handleBSSSection(ret, source) |
| 442 | for accessor, name := range accessors { |
| 443 | bssAccessorsNeeded[accessor] = name |
| 444 | } |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 445 | |
| 446 | default: |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 447 | panic(fmt.Sprintf("unknown section %q on line %d", section, source.lineNo)) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 448 | } |
| 449 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 450 | default: |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 451 | if symbol, ok := isSymbolDef(line); ok { |
| 452 | if isGlobal := symbols[symbol]; isGlobal { |
| 453 | ret = append(ret, localTargetName(symbol)+":") |
| 454 | } |
| 455 | } |
| 456 | |
| 457 | ret = append(ret, line) |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | ret = append(ret, ".text") |
| 462 | ret = append(ret, "BORINGSSL_bcm_text_end:") |
| 463 | |
| 464 | // Emit redirector functions. Each is a single JMP instruction. |
| 465 | var redirectorNames []string |
| 466 | for name := range redirectors { |
| 467 | redirectorNames = append(redirectorNames, name) |
| 468 | } |
| 469 | sort.Strings(redirectorNames) |
| 470 | |
| 471 | for _, name := range redirectorNames { |
| 472 | ret = append(ret, ".type "+name+", @function") |
| 473 | ret = append(ret, name+":") |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 474 | ret = append(ret, "\tjmp "+redirectors[name]+"@PLT") |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 475 | } |
| 476 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 477 | var accessorNames []string |
| 478 | for accessor := range bssAccessorsNeeded { |
| 479 | accessorNames = append(accessorNames, accessor) |
| 480 | } |
| 481 | sort.Strings(accessorNames) |
| 482 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 483 | // Emit BSS accessor functions. Each is a single LEA followed by RET. |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 484 | for _, name := range accessorNames { |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 485 | funcName := accessorName(name) |
| 486 | ret = append(ret, ".type "+funcName+", @function") |
| 487 | ret = append(ret, funcName+":") |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 488 | ret = append(ret, "\tleaq "+bssAccessorsNeeded[name]+"(%rip), %rax") |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 489 | ret = append(ret, "\tret") |
| 490 | } |
| 491 | |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 492 | // Emit an OPENSSL_ia32cap_get accessor. |
| 493 | if ia32capGetNeeded { |
| 494 | ret = append(ret, ".type OPENSSL_ia32cap_get, @function") |
| 495 | ret = append(ret, "OPENSSL_ia32cap_get:") |
| 496 | ret = append(ret, "\tleaq OPENSSL_ia32cap_P(%rip), %rax") |
| 497 | ret = append(ret, "\tret") |
| 498 | } |
| 499 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 500 | // Emit an indirect reference to OPENSSL_ia32cap_P. |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 501 | if ia32capAddrDeltaNeeded { |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 502 | ret = append(ret, ".extern OPENSSL_ia32cap_P") |
Robert Sloan | 2424d84 | 2017-05-01 07:46:28 -0700 | [diff] [blame] | 503 | ret = append(ret, ".type OPENSSL_ia32cap_addr_delta,@object") |
| 504 | ret = append(ret, ".size OPENSSL_ia32cap_addr_delta,8") |
| 505 | ret = append(ret, "OPENSSL_ia32cap_addr_delta:") |
| 506 | ret = append(ret, "\t.quad OPENSSL_ia32cap_P-OPENSSL_ia32cap_addr_delta") |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 507 | } |
| 508 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 509 | // Emit accessors for thread-local offsets. |
| 510 | var threadAccessorNames []string |
| 511 | for name := range threadLocalOffsets { |
| 512 | threadAccessorNames = append(threadAccessorNames, name) |
| 513 | } |
| 514 | sort.Strings(threadAccessorNames) |
| 515 | |
| 516 | for _, name := range threadAccessorNames { |
| 517 | f := threadLocalOffsets[name] |
| 518 | |
| 519 | ret = append(ret, ".type "+name+",@function") |
| 520 | ret = append(ret, name+":") |
| 521 | ret = append(ret, "\tmovq "+f.symbol+"@GOTTPOFF(%rip), %"+f.target) |
| 522 | ret = append(ret, "\tret") |
| 523 | } |
| 524 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 525 | // Emit an array for storing the module hash. |
| 526 | ret = append(ret, ".type BORINGSSL_bcm_text_hash,@object") |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 527 | ret = append(ret, ".size BORINGSSL_bcm_text_hash,32") |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 528 | ret = append(ret, "BORINGSSL_bcm_text_hash:") |
| 529 | for _, b := range uninitHashValue { |
| 530 | ret = append(ret, ".byte 0x"+strconv.FormatUint(uint64(b), 16)) |
| 531 | } |
| 532 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 533 | return ret |
| 534 | } |
| 535 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 536 | // handleBSSSection reads lines from source until the next section and adds a |
| 537 | // local symbol for each BSS symbol found. |
| 538 | func handleBSSSection(lines []string, source *lineSource) (map[string]string, []string) { |
| 539 | accessors := make(map[string]string) |
| 540 | |
| 541 | for { |
| 542 | line, ok := source.Next() |
| 543 | if !ok { |
| 544 | return accessors, lines |
| 545 | } |
| 546 | |
| 547 | parts := strings.Fields(strings.TrimSpace(line)) |
| 548 | if len(parts) == 0 { |
| 549 | lines = append(lines, line) |
| 550 | continue |
| 551 | } |
| 552 | |
| 553 | if strings.HasSuffix(parts[0], ":") { |
| 554 | symbol := parts[0][:len(parts[0])-1] |
| 555 | localSymbol := ".L" + symbol + "_local_target" |
| 556 | |
| 557 | lines = append(lines, line) |
| 558 | lines = append(lines, localSymbol+":") |
| 559 | |
| 560 | accessors[symbol] = localSymbol |
| 561 | continue |
| 562 | } |
| 563 | |
| 564 | switch parts[0] { |
| 565 | case ".text", ".section": |
| 566 | source.Unread() |
| 567 | return accessors, lines |
| 568 | |
| 569 | default: |
| 570 | lines = append(lines, line) |
| 571 | } |
| 572 | } |
| 573 | } |
| 574 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 575 | // accessorName returns the name of the accessor function for a BSS symbol |
| 576 | // named name. |
| 577 | func accessorName(name string) string { |
| 578 | return name + "_bss_get" |
| 579 | } |
| 580 | |
| 581 | // localTargetName returns the name of the local target label for a global |
| 582 | // symbol named name. |
| 583 | func localTargetName(name string) string { |
| 584 | return ".L" + name + "_local_target" |
| 585 | } |
| 586 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 587 | // sectionType returns the type of a section. I.e. a section called “.text.foo” |
| 588 | // is a “.text” section. |
| 589 | func sectionType(section string) (string, bool) { |
| 590 | if len(section) == 0 || section[0] != '.' { |
| 591 | return "", false |
| 592 | } |
| 593 | |
| 594 | i := strings.Index(section[1:], ".") |
| 595 | if i != -1 { |
| 596 | section = section[:i+1] |
| 597 | } |
| 598 | |
| 599 | if strings.HasPrefix(section, ".debug_") { |
| 600 | return ".debug", true |
| 601 | } |
| 602 | |
| 603 | return section, true |
| 604 | } |
| 605 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 606 | // asLines appends the contents of path to lines. Local symbols are renamed |
| 607 | // using uniqueId to avoid collisions. |
| 608 | func asLines(lines []string, path string, uniqueId int) ([]string, error) { |
| 609 | basename := symbolRuneOrUnderscore(filepath.Base(path)) |
| 610 | |
| 611 | asFile, err := os.Open(path) |
| 612 | if err != nil { |
| 613 | return nil, err |
| 614 | } |
| 615 | defer asFile.Close() |
| 616 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 617 | // localSymbols maps from the symbol name used in the input, to a |
| 618 | // unique symbol name. |
| 619 | localSymbols := make(map[string]string) |
| 620 | |
| 621 | scanner := bufio.NewScanner(asFile) |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 622 | var contents []string |
| 623 | |
| 624 | if len(lines) == 0 { |
| 625 | // If this is the first assembly file, don't rewrite symbols. |
| 626 | // Only all-but-one file needs to be rewritten and so time can |
| 627 | // be saved by putting the (large) bcm.s first. |
| 628 | for scanner.Scan() { |
| 629 | lines = append(lines, scanner.Text()) |
| 630 | } |
| 631 | |
| 632 | if err := scanner.Err(); err != nil { |
| 633 | return nil, err |
| 634 | } |
| 635 | |
| 636 | return lines, nil |
| 637 | } |
| 638 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 639 | for scanner.Scan() { |
| 640 | line := scanner.Text() |
| 641 | trimmed := strings.TrimSpace(line) |
| 642 | if strings.HasPrefix(trimmed, ".L") && strings.HasSuffix(trimmed, ":") { |
| 643 | symbol := trimmed[:len(trimmed)-1] |
| 644 | mappedSymbol := fmt.Sprintf(".L%s_%d_%s", basename, uniqueId, symbol[2:]) |
| 645 | localSymbols[symbol] = mappedSymbol |
| 646 | contents = append(contents, mappedSymbol+":") |
| 647 | continue |
| 648 | } |
| 649 | |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 650 | contents = append(contents, line) |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 651 | } |
| 652 | if err := scanner.Err(); err != nil { |
| 653 | return nil, err |
| 654 | } |
| 655 | |
| 656 | for _, line := range contents { |
| 657 | for symbol, mappedSymbol := range localSymbols { |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 658 | i := 0 |
| 659 | for match := strings.Index(line, symbol); match >= 0; match = strings.Index(line[i:], symbol) { |
| 660 | i += match |
| 661 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 662 | before := ' ' |
| 663 | if i > 0 { |
| 664 | before, _ = utf8.DecodeLastRuneInString(line[:i]) |
| 665 | } |
| 666 | |
| 667 | after, _ := utf8.DecodeRuneInString(line[i+len(symbol):]) |
| 668 | |
| 669 | if !symbolRune(before) && !symbolRune(after) { |
| 670 | line = strings.Replace(line, symbol, mappedSymbol, 1) |
| 671 | i += len(mappedSymbol) |
| 672 | } else { |
| 673 | i += len(symbol) |
| 674 | } |
| 675 | } |
| 676 | } |
| 677 | |
| 678 | lines = append(lines, line) |
| 679 | } |
| 680 | |
| 681 | return lines, nil |
| 682 | } |
| 683 | |
| 684 | func arLines(lines []string, arPath string) ([]string, error) { |
| 685 | arFile, err := os.Open(arPath) |
| 686 | if err != nil { |
| 687 | return nil, err |
| 688 | } |
| 689 | defer arFile.Close() |
| 690 | |
| 691 | ar, err := ParseAR(arFile) |
| 692 | if err != nil { |
| 693 | return nil, err |
| 694 | } |
| 695 | |
| 696 | if len(ar) != 1 { |
| 697 | return nil, fmt.Errorf("expected one file in archive, but found %d", len(ar)) |
| 698 | } |
| 699 | |
| 700 | for _, contents := range ar { |
| 701 | scanner := bufio.NewScanner(bytes.NewBuffer(contents)) |
| 702 | for scanner.Scan() { |
| 703 | lines = append(lines, scanner.Text()) |
| 704 | } |
| 705 | if err := scanner.Err(); err != nil { |
| 706 | return nil, err |
| 707 | } |
| 708 | } |
| 709 | |
| 710 | return lines, nil |
| 711 | } |
| 712 | |
| 713 | // validSymbolName returns true if s is a valid (non-local) name for a symbol. |
| 714 | func validSymbolName(s string) bool { |
| 715 | if len(s) == 0 { |
| 716 | return false |
| 717 | } |
| 718 | |
| 719 | r, n := utf8.DecodeRuneInString(s) |
| 720 | // symbols don't start with a digit. |
| 721 | if r == utf8.RuneError || !symbolRune(r) || ('0' <= s[0] && s[0] <= '9') { |
| 722 | return false |
| 723 | } |
| 724 | |
| 725 | return strings.IndexFunc(s[n:], func(r rune) bool { |
| 726 | return !symbolRune(r) |
| 727 | }) == -1 |
| 728 | } |
| 729 | |
| 730 | // symbolRune returns true if r is valid in a symbol name. |
| 731 | func symbolRune(r rune) bool { |
| 732 | return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '$' || r == '_' |
| 733 | } |
| 734 | |
| 735 | // symbolRuneOrUnderscore maps s where runes valid in a symbol name map to |
| 736 | // themselves and all other runs map to underscore. |
| 737 | func symbolRuneOrUnderscore(s string) string { |
| 738 | runes := make([]rune, 0, len(s)) |
| 739 | |
| 740 | for _, r := range s { |
| 741 | if symbolRune(r) { |
| 742 | runes = append(runes, r) |
| 743 | } else { |
| 744 | runes = append(runes, '_') |
| 745 | } |
| 746 | } |
| 747 | |
| 748 | return string(runes) |
| 749 | } |