1 2 /*--------------------------------------------------------------------*/ 3 /*--- A minimal setjmp/longjmp implementation. m_libcsetjmp.c ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2010-2011 Mozilla Inc 11 12 This program is free software; you can redistribute it and/or 13 modify it under the terms of the GNU General Public License as 14 published by the Free Software Foundation; either version 2 of the 15 License, or (at your option) any later version. 16 17 This program is distributed in the hope that it will be useful, but 18 WITHOUT ANY WARRANTY; without even the implied warranty of 19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 General Public License for more details. 21 22 You should have received a copy of the GNU General Public License 23 along with this program; if not, write to the Free Software 24 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 25 02111-1307, USA. 26 27 The GNU General Public License is contained in the file COPYING. 28 */ 29 30 /* Contributed by Julian Seward <jseward@acm.org> */ 31 32 33 #include "pub_core_basics.h" 34 #include "pub_core_libcsetjmp.h" /* self */ 35 36 37 /* See include/pub_tool_libcsetjmp.h for background and rationale. */ 38 39 /* The alternative implementations are for ppc{32,64}-linux and 40 {amd64,x86}-{linux,darwin}. See #259977. That leaves only 41 {arm,s390x}-linux using the gcc builtins now. 42 */ 43 44 /* ------------ ppc32-linux ------------ */ 45 46 #if defined(VGP_ppc32_linux) 47 48 __asm__( 49 ".text" "\n" 50 "" "\n" 51 ".global VG_MINIMAL_SETJMP" "\n" // r3 = jmp_buf 52 "VG_MINIMAL_SETJMP:" "\n" 53 " stw 0, 0(3)" "\n" 54 " stw 1, 4(3)" "\n" 55 " stw 2, 8(3)" "\n" 56 " stw 3, 12(3)" "\n" 57 " stw 4, 16(3)" "\n" 58 " stw 5, 20(3)" "\n" 59 " stw 6, 24(3)" "\n" 60 " stw 7, 28(3)" "\n" 61 " stw 8, 32(3)" "\n" 62 " stw 9, 36(3)" "\n" 63 " stw 10, 40(3)" "\n" 64 " stw 11, 44(3)" "\n" 65 " stw 12, 48(3)" "\n" 66 " stw 13, 52(3)" "\n" 67 " stw 14, 56(3)" "\n" 68 " stw 15, 60(3)" "\n" 69 " stw 16, 64(3)" "\n" 70 " stw 17, 68(3)" "\n" 71 " stw 18, 72(3)" "\n" 72 " stw 19, 76(3)" "\n" 73 " stw 20, 80(3)" "\n" 74 " stw 21, 84(3)" "\n" 75 " stw 22, 88(3)" "\n" 76 " stw 23, 92(3)" "\n" 77 " stw 24, 96(3)" "\n" 78 " stw 25, 100(3)" "\n" 79 " stw 26, 104(3)" "\n" 80 " stw 27, 108(3)" "\n" 81 " stw 28, 112(3)" "\n" 82 " stw 29, 116(3)" "\n" 83 " stw 30, 120(3)" "\n" 84 " stw 31, 124(3)" "\n" 85 // must use a caller-save register here as scratch, hence r4 86 " mflr 4" "\n" 87 " stw 4, 128(3)" "\n" 88 " mfcr 4" "\n" 89 " stw 4, 132(3)" "\n" 90 " li 3, 0" "\n" 91 " blr" "\n" 92 "" "\n" 93 94 95 ".global VG_MINIMAL_LONGJMP" "\n" 96 "VG_MINIMAL_LONGJMP:" "\n" // r3 = jmp_buf 97 // do r4 = 1 98 // and park it in the restore slot for r3 (the ret reg) 99 " li 4, 1" "\n" 100 " stw 4, 12(3)" "\n" 101 // restore everything except r3 102 // then r3 last of all 103 // then blr 104 " lwz 0, 128(3)" "\n" 105 " mtlr 0" "\n" 106 " lwz 0, 132(3)" "\n" 107 " mtcr 0" "\n" 108 " lwz 0, 0(3)" "\n" 109 " lwz 1, 4(3)" "\n" 110 " lwz 2, 8(3)" "\n" 111 // r3 is done at the end 112 " lwz 4, 16(3)" "\n" 113 " lwz 5, 20(3)" "\n" 114 " lwz 6, 24(3)" "\n" 115 " lwz 7, 28(3)" "\n" 116 " lwz 8, 32(3)" "\n" 117 " lwz 9, 36(3)" "\n" 118 " lwz 10, 40(3)" "\n" 119 " lwz 11, 44(3)" "\n" 120 " lwz 12, 48(3)" "\n" 121 " lwz 13, 52(3)" "\n" 122 " lwz 14, 56(3)" "\n" 123 " lwz 15, 60(3)" "\n" 124 " lwz 16, 64(3)" "\n" 125 " lwz 17, 68(3)" "\n" 126 " lwz 18, 72(3)" "\n" 127 " lwz 19, 76(3)" "\n" 128 " lwz 20, 80(3)" "\n" 129 " lwz 21, 84(3)" "\n" 130 " lwz 22, 88(3)" "\n" 131 " lwz 23, 92(3)" "\n" 132 " lwz 24, 96(3)" "\n" 133 " lwz 25, 100(3)" "\n" 134 " lwz 26, 104(3)" "\n" 135 " lwz 27, 108(3)" "\n" 136 " lwz 28, 112(3)" "\n" 137 " lwz 29, 116(3)" "\n" 138 " lwz 30, 120(3)" "\n" 139 " lwz 31, 124(3)" "\n" 140 " lwz 3, 12(3)" "\n" 141 " blr" "\n" 142 "" "\n" 143 144 ".previous" "\n" 145 ); 146 147 #endif /* VGP_ppc32_linux */ 148 149 150 /* ------------ ppc64-linux ------------ */ 151 152 #if defined(VGP_ppc64_linux) 153 154 __asm__( 155 ".section \".toc\",\"aw\"" "\n" 156 157 ".section \".text\"" "\n" 158 ".align 2" "\n" 159 ".p2align 4,,15" "\n" 160 ".globl VG_MINIMAL_SETJMP" "\n" 161 162 ".section \".opd\",\"aw\"" "\n" 163 ".align 3" "\n" 164 "VG_MINIMAL_SETJMP:" "\n" 165 ".quad .L.VG_MINIMAL_SETJMP,.TOC.@tocbase,0" "\n" 166 ".previous" "\n" 167 168 ".type VG_MINIMAL_SETJMP, @function" "\n" 169 ".L.VG_MINIMAL_SETJMP:" "\n" 170 " std 0, 0(3)" "\n" 171 " std 1, 8(3)" "\n" 172 " std 2, 16(3)" "\n" 173 " std 3, 24(3)" "\n" 174 " std 4, 32(3)" "\n" 175 " std 5, 40(3)" "\n" 176 " std 6, 48(3)" "\n" 177 " std 7, 56(3)" "\n" 178 " std 8, 64(3)" "\n" 179 " std 9, 72(3)" "\n" 180 " std 10, 80(3)" "\n" 181 " std 11, 88(3)" "\n" 182 " std 12, 96(3)" "\n" 183 " std 13, 104(3)" "\n" 184 " std 14, 112(3)" "\n" 185 " std 15, 120(3)" "\n" 186 " std 16, 128(3)" "\n" 187 " std 17, 136(3)" "\n" 188 " std 18, 144(3)" "\n" 189 " std 19, 152(3)" "\n" 190 " std 20, 160(3)" "\n" 191 " std 21, 168(3)" "\n" 192 " std 22, 176(3)" "\n" 193 " std 23, 184(3)" "\n" 194 " std 24, 192(3)" "\n" 195 " std 25, 200(3)" "\n" 196 " std 26, 208(3)" "\n" 197 " std 27, 216(3)" "\n" 198 " std 28, 224(3)" "\n" 199 " std 29, 232(3)" "\n" 200 " std 30, 240(3)" "\n" 201 " std 31, 248(3)" "\n" 202 // must use a caller-save register here as scratch, hence r4 203 " mflr 4" "\n" 204 " std 4, 256(3)" "\n" 205 " mfcr 4" "\n" 206 " std 4, 264(3)" "\n" 207 " li 3, 0" "\n" 208 " blr" "\n" 209 "" "\n" 210 211 212 ".globl VG_MINIMAL_LONGJMP" "\n" 213 214 ".section \".opd\",\"aw\"" "\n" 215 ".align 3" "\n" 216 "VG_MINIMAL_LONGJMP:" "\n" 217 ".quad .L.VG_MINIMAL_LONGJMP,.TOC.@tocbase,0" "\n" 218 ".previous" "\n" 219 220 ".type VG_MINIMAL_LONGJMP, @function" "\n" 221 ".L.VG_MINIMAL_LONGJMP:" "\n" 222 // do r4 = 1 223 // and park it in the restore slot for r3 (the ret reg) 224 " li 4, 1" "\n" 225 " std 4, 24(3)" "\n" 226 // restore everything except r3 227 // then r3 last of all 228 // then blr 229 " ld 0, 256(3)" "\n" 230 " mtlr 0" "\n" 231 " ld 0, 264(3)" "\n" 232 " mtcr 0" "\n" 233 " ld 0, 0(3)" "\n" 234 " ld 1, 8(3)" "\n" 235 " ld 2, 16(3)" "\n" 236 // r3 is done at the end 237 " ld 4, 32(3)" "\n" 238 " ld 5, 40(3)" "\n" 239 " ld 6, 48(3)" "\n" 240 " ld 7, 56(3)" "\n" 241 " ld 8, 64(3)" "\n" 242 " ld 9, 72(3)" "\n" 243 " ld 10, 80(3)" "\n" 244 " ld 11, 88(3)" "\n" 245 " ld 12, 96(3)" "\n" 246 " ld 13, 104(3)" "\n" 247 " ld 14, 112(3)" "\n" 248 " ld 15, 120(3)" "\n" 249 " ld 16, 128(3)" "\n" 250 " ld 17, 136(3)" "\n" 251 " ld 18, 144(3)" "\n" 252 " ld 19, 152(3)" "\n" 253 " ld 20, 160(3)" "\n" 254 " ld 21, 168(3)" "\n" 255 " ld 22, 176(3)" "\n" 256 " ld 23, 184(3)" "\n" 257 " ld 24, 192(3)" "\n" 258 " ld 25, 200(3)" "\n" 259 " ld 26, 208(3)" "\n" 260 " ld 27, 216(3)" "\n" 261 " ld 28, 224(3)" "\n" 262 " ld 29, 232(3)" "\n" 263 " ld 30, 240(3)" "\n" 264 " ld 31, 248(3)" "\n" 265 " ld 3, 24(3)" "\n" 266 " blr" "\n" 267 "" "\n" 268 269 ".previous" "\n" 270 ".previous" "\n" 271 ); 272 273 #endif /* VGP_ppc64_linux */ 274 275 276 /* ------------ amd64-{linux,darwin} ------------ */ 277 278 #if defined(VGP_amd64_linux) || defined(VGP_amd64_darwin) 279 280 __asm__( 281 ".text" "\n" 282 "" "\n" 283 284 #if defined(VGP_amd64_linux) 285 ".global VG_MINIMAL_SETJMP" "\n" // rdi = jmp_buf 286 "VG_MINIMAL_SETJMP:" "\n" 287 288 #elif defined(VGP_amd64_darwin) 289 ".globl _VG_MINIMAL_SETJMP" "\n" // rdi = jmp_buf 290 "_VG_MINIMAL_SETJMP:" "\n" 291 292 #else 293 # error "Huh?" 294 #endif 295 296 " movq %rax, 0(%rdi)" "\n" 297 " movq %rbx, 8(%rdi)" "\n" 298 " movq %rcx, 16(%rdi)" "\n" 299 " movq %rdx, 24(%rdi)" "\n" 300 " movq %rdi, 32(%rdi)" "\n" 301 " movq %rsi, 40(%rdi)" "\n" 302 " movq %rbp, 48(%rdi)" "\n" 303 " movq %rsp, 56(%rdi)" "\n" 304 " movq %r8, 64(%rdi)" "\n" 305 " movq %r9, 72(%rdi)" "\n" 306 " movq %r10, 80(%rdi)" "\n" 307 " movq %r11, 88(%rdi)" "\n" 308 " movq %r12, 96(%rdi)" "\n" 309 " movq %r13, 104(%rdi)" "\n" 310 " movq %r14, 112(%rdi)" "\n" 311 " movq %r15, 120(%rdi)" "\n" 312 // store the return address 313 " movq 0(%rsp), %rax" "\n" 314 " movq %rax, 128(%rdi)" "\n" 315 // and return zero 316 " movq $0, %rax" "\n" 317 " ret" "\n" 318 "" "\n" 319 320 321 #if defined(VGP_amd64_linux) 322 ".global VG_MINIMAL_LONGJMP" "\n" 323 "VG_MINIMAL_LONGJMP:" "\n" // rdi = jmp_buf 324 325 #elif defined(VGP_amd64_darwin) 326 ".globl _VG_MINIMAL_LONGJMP" "\n" 327 "_VG_MINIMAL_LONGJMP:" "\n" // rdi = jmp_buf 328 329 #else 330 # error "Huh?" 331 #endif 332 // skip restoring rax; it's pointless 333 " movq 8(%rdi), %rbx" "\n" 334 " movq 16(%rdi), %rcx" "\n" 335 " movq 24(%rdi), %rdx" "\n" 336 // defer restoring rdi; we still need it 337 " movq 40(%rdi), %rsi" "\n" 338 " movq 48(%rdi), %rbp" "\n" 339 " movq 56(%rdi), %rsp" "\n" 340 " movq 64(%rdi), %r8" "\n" 341 " movq 72(%rdi), %r9" "\n" 342 " movq 80(%rdi), %r10" "\n" 343 " movq 88(%rdi), %r11" "\n" 344 " movq 96(%rdi), %r12" "\n" 345 " movq 104(%rdi), %r13" "\n" 346 " movq 112(%rdi), %r14" "\n" 347 " movq 120(%rdi), %r15" "\n" 348 // restore the return address 349 " movq 128(%rdi), %rax" "\n" 350 // restore rdi; this is the last use 351 " movq 32(%rdi), %rdi" "\n" 352 // make %rsp look like we really did a return 353 " addq $8, %rsp" "\n" 354 // continue at RA of original call. Note: this is a 355 // nasty trick. We assume that %rax is nonzero, and so the 356 // caller can differentiate this case from the normal _SETJMP 357 // return case. If the return address ever is zero, then 358 // we're hosed; but that seems pretty unlikely given that it 359 // would mean we'd be executing at the wraparound point of the 360 // address space. 361 " jmp *%rax" "\n" 362 "" "\n" 363 364 #if !defined(VGP_amd64_darwin) 365 ".previous" "\n" 366 #endif 367 ); 368 369 #endif /* VGP_amd64_linux || VGP_amd64_darwin */ 370 371 372 /* ------------ x86-{linux,darwin} ------------ */ 373 374 #if defined(VGP_x86_linux) || defined(VGP_x86_darwin) 375 376 __asm__( 377 ".text" "\n" 378 "" "\n" 379 380 #if defined(VGP_x86_linux) 381 ".global VG_MINIMAL_SETJMP" "\n" // eax = jmp_buf 382 "VG_MINIMAL_SETJMP:" "\n" 383 384 #elif defined(VGP_x86_darwin) 385 ".globl _VG_MINIMAL_SETJMP" "\n" // eax = jmp_buf 386 "_VG_MINIMAL_SETJMP:" "\n" 387 388 #else 389 # error "Huh?" 390 #endif 391 392 " movl %eax, 0(%eax)" "\n" 393 " movl %ebx, 4(%eax)" "\n" 394 " movl %ecx, 8(%eax)" "\n" 395 " movl %edx, 12(%eax)" "\n" 396 " movl %edi, 16(%eax)" "\n" 397 " movl %esi, 20(%eax)" "\n" 398 " movl %ebp, 24(%eax)" "\n" 399 " movl %esp, 28(%eax)" "\n" 400 // store the return address 401 " movl 0(%esp), %ebx" "\n" 402 " movl %ebx, 32(%eax)" "\n" 403 // un-trash ebx (necessary? i don't know) 404 " movl 4(%eax), %ebx" "\n" 405 // and return zero 406 " movl $0, %eax" "\n" 407 " ret" "\n" 408 "" "\n" 409 410 411 #if defined(VGP_x86_linux) 412 ".global VG_MINIMAL_LONGJMP" "\n" 413 "VG_MINIMAL_LONGJMP:" "\n" // eax = jmp_buf 414 415 #elif defined(VGP_x86_darwin) 416 ".globl _VG_MINIMAL_LONGJMP" "\n" 417 "_VG_MINIMAL_LONGJMP:" "\n" // eax = jmp_buf 418 419 #else 420 # error "Huh?" 421 #endif 422 423 // skip restoring eax; it's pointless 424 " movl 4(%eax), %ebx" "\n" 425 " movl 8(%eax), %ecx" "\n" 426 " movl 12(%eax), %edx" "\n" 427 " movl 16(%eax), %edi" "\n" 428 " movl 20(%eax), %esi" "\n" 429 " movl 24(%eax), %ebp" "\n" 430 " movl 28(%eax), %esp" "\n" 431 // restore the return address 432 " movl 32(%eax), %eax" "\n" 433 // make %esp look like we really did a return 434 " addl $4, %esp" "\n" 435 // continue at RA of original call. Same zero-vs-nonzero 436 // trick/assumption as documented for the amd64-linux case. 437 " jmp *%eax" "\n" 438 "" "\n" 439 440 #if !defined(VGP_x86_darwin) 441 ".previous" "\n" 442 #endif 443 ); 444 445 #endif /* VGP_x86_linux || VGP_x86_darwin */ 446 447 /*--------------------------------------------------------------------*/ 448 /*--- end ---*/ 449 /*--------------------------------------------------------------------*/ 450