1 // Copyright (c) 2012, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above 11 // copyright notice, this list of conditions and the following disclaimer 12 // in the documentation and/or other materials provided with the 13 // distribution. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 16 // this software without specific prior written permission. 17 // 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 // A minimalistic implementation of getcontext() to be used by 31 // Google Breakpad on Android. 32 33 #include "common/android/ucontext_constants.h" 34 35 /* int getcontext (ucontext_t *ucp) */ 36 37 #if defined(__arm__) 38 39 .text 40 .global breakpad_getcontext 41 .hidden breakpad_getcontext 42 .type breakpad_getcontext, #function 43 .align 0 44 .fnstart 45 breakpad_getcontext: 46 47 /* First, save r4-r11 */ 48 add r1, r0, #(MCONTEXT_GREGS_OFFSET + 4*4) 49 stm r1, {r4-r11} 50 51 /* r12 is a scratch register, don't save it */ 52 53 /* Save sp and lr explicitly. */ 54 /* - sp can't be stored with stmia in Thumb-2 */ 55 /* - STM instructions that store sp and pc are deprecated in ARM */ 56 str sp, [r0, #(MCONTEXT_GREGS_OFFSET + 13*4)] 57 str lr, [r0, #(MCONTEXT_GREGS_OFFSET + 14*4)] 58 59 /* Save the caller's address in 'pc' */ 60 str lr, [r0, #(MCONTEXT_GREGS_OFFSET + 15*4)] 61 62 /* Save ucontext_t* pointer across next call */ 63 mov r4, r0 64 65 /* Call sigprocmask(SIG_BLOCK, NULL, &(ucontext->uc_sigmask)) */ 66 mov r0, #0 /* SIG_BLOCK */ 67 mov r1, #0 /* NULL */ 68 add r2, r4, #UCONTEXT_SIGMASK_OFFSET 69 bl sigprocmask(PLT) 70 71 /* Intentionally do not save the FPU state here. This is because on 72 * Linux/ARM, one should instead use ptrace(PTRACE_GETFPREGS) or 73 * ptrace(PTRACE_GETVFPREGS) to get it. 74 * 75 * Note that a real implementation of getcontext() would need to save 76 * this here to allow setcontext()/swapcontext() to work correctly. 77 */ 78 79 /* Restore the values of r4 and lr */ 80 mov r0, r4 81 ldr lr, [r0, #(MCONTEXT_GREGS_OFFSET + 14*4)] 82 ldr r4, [r0, #(MCONTEXT_GREGS_OFFSET + 4*4)] 83 84 /* Return 0 */ 85 mov r0, #0 86 bx lr 87 88 .fnend 89 .size breakpad_getcontext, . - breakpad_getcontext 90 91 #elif defined(__aarch64__) 92 93 #define _NSIG 64 94 #define __NR_rt_sigprocmask 135 95 96 .text 97 .global breakpad_getcontext 98 .hidden breakpad_getcontext 99 .type breakpad_getcontext, #function 100 .align 4 101 .cfi_startproc 102 breakpad_getcontext: 103 104 /* The saved context will return to the getcontext() call point 105 with a return value of 0 */ 106 str xzr, [x0, MCONTEXT_GREGS_OFFSET + 0 * REGISTER_SIZE] 107 108 stp x18, x19, [x0, MCONTEXT_GREGS_OFFSET + 18 * REGISTER_SIZE] 109 stp x20, x21, [x0, MCONTEXT_GREGS_OFFSET + 20 * REGISTER_SIZE] 110 stp x22, x23, [x0, MCONTEXT_GREGS_OFFSET + 22 * REGISTER_SIZE] 111 stp x24, x25, [x0, MCONTEXT_GREGS_OFFSET + 24 * REGISTER_SIZE] 112 stp x26, x27, [x0, MCONTEXT_GREGS_OFFSET + 26 * REGISTER_SIZE] 113 stp x28, x29, [x0, MCONTEXT_GREGS_OFFSET + 28 * REGISTER_SIZE] 114 str x30, [x0, MCONTEXT_GREGS_OFFSET + 30 * REGISTER_SIZE] 115 116 /* Place LR into the saved PC, this will ensure that when 117 switching to this saved context with setcontext() control 118 will pass back to the caller of getcontext(), we have 119 already arranged to return the appropriate return value in x0 120 above. */ 121 str x30, [x0, MCONTEXT_PC_OFFSET] 122 123 /* Save the current SP */ 124 mov x2, sp 125 str x2, [x0, MCONTEXT_SP_OFFSET] 126 127 /* Initialize the pstate. */ 128 str xzr, [x0, MCONTEXT_PSTATE_OFFSET] 129 130 /* Figure out where to place the first context extension 131 block. */ 132 add x2, x0, #MCONTEXT_EXTENSION_OFFSET 133 134 /* Write the context extension fpsimd header. */ 135 mov w3, #(FPSIMD_MAGIC & 0xffff) 136 movk w3, #(FPSIMD_MAGIC >> 16), lsl #16 137 str w3, [x2, #FPSIMD_CONTEXT_MAGIC_OFFSET] 138 mov w3, #FPSIMD_CONTEXT_SIZE 139 str w3, [x2, #FPSIMD_CONTEXT_SIZE_OFFSET] 140 141 /* Fill in the FP SIMD context. */ 142 add x3, x2, #(FPSIMD_CONTEXT_VREGS_OFFSET + 8 * SIMD_REGISTER_SIZE) 143 stp d8, d9, [x3], #(2 * SIMD_REGISTER_SIZE) 144 stp d10, d11, [x3], #(2 * SIMD_REGISTER_SIZE) 145 stp d12, d13, [x3], #(2 * SIMD_REGISTER_SIZE) 146 stp d14, d15, [x3], #(2 * SIMD_REGISTER_SIZE) 147 148 add x3, x2, FPSIMD_CONTEXT_FPSR_OFFSET 149 150 mrs x4, fpsr 151 str w4, [x3] 152 153 mrs x4, fpcr 154 str w4, [x3, FPSIMD_CONTEXT_FPCR_OFFSET - FPSIMD_CONTEXT_FPSR_OFFSET] 155 156 /* Write the termination context extension header. */ 157 add x2, x2, #FPSIMD_CONTEXT_SIZE 158 159 str xzr, [x2, #FPSIMD_CONTEXT_MAGIC_OFFSET] 160 str xzr, [x2, #FPSIMD_CONTEXT_SIZE_OFFSET] 161 162 /* Grab the signal mask */ 163 /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */ 164 add x2, x0, #UCONTEXT_SIGMASK_OFFSET 165 mov x0, #0 /* SIG_BLOCK */ 166 mov x1, #0 /* NULL */ 167 mov x3, #(_NSIG / 8) 168 mov x8, #__NR_rt_sigprocmask 169 svc 0 170 171 /* Return x0 for success */ 172 mov x0, 0 173 ret 174 175 .cfi_endproc 176 .size breakpad_getcontext, . - breakpad_getcontext 177 178 #elif defined(__i386__) 179 180 .text 181 .global breakpad_getcontext 182 .hidden breakpad_getcontext 183 .align 4 184 .type breakpad_getcontext, @function 185 186 breakpad_getcontext: 187 188 movl 4(%esp), %eax /* eax = uc */ 189 190 /* Save register values */ 191 movl %ecx, MCONTEXT_ECX_OFFSET(%eax) 192 movl %edx, MCONTEXT_EDX_OFFSET(%eax) 193 movl %ebx, MCONTEXT_EBX_OFFSET(%eax) 194 movl %edi, MCONTEXT_EDI_OFFSET(%eax) 195 movl %esi, MCONTEXT_ESI_OFFSET(%eax) 196 movl %ebp, MCONTEXT_EBP_OFFSET(%eax) 197 198 movl (%esp), %edx /* return address */ 199 lea 4(%esp), %ecx /* exclude return address from stack */ 200 mov %edx, MCONTEXT_EIP_OFFSET(%eax) 201 mov %ecx, MCONTEXT_ESP_OFFSET(%eax) 202 203 xorl %ecx, %ecx 204 movw %fs, %cx 205 mov %ecx, MCONTEXT_FS_OFFSET(%eax) 206 207 movl $0, MCONTEXT_EAX_OFFSET(%eax) 208 209 /* Save floating point state to fpregstate, then update 210 * the fpregs pointer to point to it */ 211 leal UCONTEXT_FPREGS_MEM_OFFSET(%eax), %ecx 212 fnstenv (%ecx) 213 fldenv (%ecx) 214 mov %ecx, UCONTEXT_FPREGS_OFFSET(%eax) 215 216 /* Save signal mask: sigprocmask(SIGBLOCK, NULL, &uc->uc_sigmask) */ 217 leal UCONTEXT_SIGMASK_OFFSET(%eax), %edx 218 xorl %ecx, %ecx 219 push %edx /* &uc->uc_sigmask */ 220 push %ecx /* NULL */ 221 push %ecx /* SIGBLOCK == 0 on i386 */ 222 call sigprocmask@PLT 223 addl $12, %esp 224 225 movl $0, %eax 226 ret 227 228 .size breakpad_getcontext, . - breakpad_getcontext 229 230 #elif defined(__mips__) 231 232 // This implementation is inspired by implementation of getcontext in glibc. 233 #if _MIPS_SIM == _ABIO32 234 #include <asm/asm.h> 235 #include <asm/regdef.h> 236 #include <asm/fpregdef.h> 237 #else 238 #include <machine/asm.h> 239 #include <machine/regdef.h> 240 #endif 241 242 // from asm/asm.h 243 #if _MIPS_SIM == _ABIO32 244 #define ALSZ 7 245 #define ALMASK ~7 246 #define SZREG 4 247 #else // _MIPS_SIM != _ABIO32 248 #define ALSZ 15 249 #define ALMASK ~15 250 #define SZREG 8 251 #endif 252 253 #include <asm/unistd.h> // for __NR_rt_sigprocmask 254 255 #define _NSIG8 128 / 8 256 #define SIG_BLOCK 1 257 258 259 .text 260 LOCALS_NUM = 1 // save gp on stack 261 FRAME_SIZE = ((LOCALS_NUM * SZREG) + ALSZ) & ALMASK 262 263 GP_FRAME_OFFSET = FRAME_SIZE - (1 * SZREG) 264 MCONTEXT_REG_SIZE = 8 265 266 #if _MIPS_SIM == _ABIO32 267 268 NESTED (breakpad_getcontext, FRAME_SIZE, ra) 269 .mask 0x00000000, 0 270 .fmask 0x00000000, 0 271 272 .set noreorder 273 .cpload t9 274 .set reorder 275 276 move a2, sp 277 #define _SP a2 278 279 addiu sp, -FRAME_SIZE 280 .cprestore GP_FRAME_OFFSET 281 282 sw s0, (16 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 283 sw s1, (17 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 284 sw s2, (18 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 285 sw s3, (19 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 286 sw s4, (20 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 287 sw s5, (21 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 288 sw s6, (22 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 289 sw s7, (23 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 290 sw _SP, (29 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 291 sw fp, (30 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 292 sw ra, (31 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 293 sw ra, MCONTEXT_PC_OFFSET(a0) 294 295 #ifdef __mips_hard_float 296 s.d fs0, (20 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 297 s.d fs1, (22 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 298 s.d fs2, (24 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 299 s.d fs3, (26 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 300 s.d fs4, (28 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 301 s.d fs5, (30 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 302 303 cfc1 v1, fcr31 304 sw v1, MCONTEXT_FPC_CSR(a0) 305 #endif // __mips_hard_float 306 307 /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */ 308 li a3, _NSIG8 309 addu a2, a0, UCONTEXT_SIGMASK_OFFSET 310 move a1, zero 311 li a0, SIG_BLOCK 312 li v0, __NR_rt_sigprocmask 313 syscall 314 315 addiu sp, FRAME_SIZE 316 jr ra 317 318 END (breakpad_getcontext) 319 #else 320 321 #ifndef NESTED 322 /* 323 * NESTED - declare nested routine entry point 324 */ 325 #define NESTED(symbol, framesize, rpc) \ 326 .globl symbol; \ 327 .align 2; \ 328 .type symbol,@function; \ 329 .ent symbol,0; \ 330 symbol: .frame sp, framesize, rpc; 331 #endif 332 333 /* 334 * END - mark end of function 335 */ 336 #ifndef END 337 # define END(function) \ 338 .end function; \ 339 .size function,.-function 340 #endif 341 342 /* int getcontext (ucontext_t *ucp) */ 343 344 NESTED (breakpad_getcontext, FRAME_SIZE, ra) 345 .mask 0x10000000, 0 346 .fmask 0x00000000, 0 347 348 move a2, sp 349 #define _SP a2 350 move a3, gp 351 #define _GP a3 352 353 daddiu sp, -FRAME_SIZE 354 .cpsetup $25, GP_FRAME_OFFSET, breakpad_getcontext 355 356 /* Store a magic flag. */ 357 li v1, 1 358 sd v1, (0 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) /* zero */ 359 360 sd s0, (16 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 361 sd s1, (17 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 362 sd s2, (18 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 363 sd s3, (19 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 364 sd s4, (20 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 365 sd s5, (21 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 366 sd s6, (22 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 367 sd s7, (23 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 368 sd _GP, (28 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 369 sd _SP, (29 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 370 sd s8, (30 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 371 sd ra, (31 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) 372 sd ra, MCONTEXT_PC_OFFSET(a0) 373 374 #ifdef __mips_hard_float 375 s.d $f24, (24 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 376 s.d $f25, (25 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 377 s.d $f26, (26 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 378 s.d $f27, (27 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 379 s.d $f28, (28 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 380 s.d $f29, (29 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 381 s.d $f30, (30 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 382 s.d $f31, (31 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0) 383 384 cfc1 v1, $31 385 sw v1, MCONTEXT_FPC_CSR(a0) 386 #endif /* __mips_hard_float */ 387 388 /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */ 389 li a3, _NSIG8 390 daddu a2, a0, UCONTEXT_SIGMASK_OFFSET 391 move a1, zero 392 li a0, SIG_BLOCK 393 394 li v0, __NR_rt_sigprocmask 395 syscall 396 397 .cpreturn 398 daddiu sp, FRAME_SIZE 399 move v0, zero 400 jr ra 401 402 END (breakpad_getcontext) 403 #endif // _MIPS_SIM == _ABIO32 404 405 #elif defined(__x86_64__) 406 /* The x64 implementation of breakpad_getcontext was derived in part 407 from the implementation of libunwind which requires the following 408 notice. */ 409 /* libunwind - a platform-independent unwind library 410 Copyright (C) 2008 Google, Inc 411 Contributed by Paul Pluzhnikov <ppluzhnikov (at) google.com> 412 Copyright (C) 2010 Konstantin Belousov <kib (at) freebsd.org> 413 414 This file is part of libunwind. 415 416 Permission is hereby granted, free of charge, to any person obtaining 417 a copy of this software and associated documentation files (the 418 "Software"), to deal in the Software without restriction, including 419 without limitation the rights to use, copy, modify, merge, publish, 420 distribute, sublicense, and/or sell copies of the Software, and to 421 permit persons to whom the Software is furnished to do so, subject to 422 the following conditions: 423 424 The above copyright notice and this permission notice shall be 425 included in all copies or substantial portions of the Software. 426 427 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 428 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 429 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 430 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 431 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 432 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 433 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 434 435 .text 436 .global breakpad_getcontext 437 .hidden breakpad_getcontext 438 .align 4 439 .type breakpad_getcontext, @function 440 441 breakpad_getcontext: 442 .cfi_startproc 443 444 /* Callee saved: RBX, RBP, R12-R15 */ 445 movq %r12, MCONTEXT_GREGS_R12(%rdi) 446 movq %r13, MCONTEXT_GREGS_R13(%rdi) 447 movq %r14, MCONTEXT_GREGS_R14(%rdi) 448 movq %r15, MCONTEXT_GREGS_R15(%rdi) 449 movq %rbp, MCONTEXT_GREGS_RBP(%rdi) 450 movq %rbx, MCONTEXT_GREGS_RBX(%rdi) 451 452 /* Save argument registers (not strictly needed, but setcontext 453 restores them, so don't restore garbage). */ 454 movq %r8, MCONTEXT_GREGS_R8(%rdi) 455 movq %r9, MCONTEXT_GREGS_R9(%rdi) 456 movq %rdi, MCONTEXT_GREGS_RDI(%rdi) 457 movq %rsi, MCONTEXT_GREGS_RSI(%rdi) 458 movq %rdx, MCONTEXT_GREGS_RDX(%rdi) 459 movq %rax, MCONTEXT_GREGS_RAX(%rdi) 460 movq %rcx, MCONTEXT_GREGS_RCX(%rdi) 461 462 /* Save fp state (not needed, except for setcontext not 463 restoring garbage). */ 464 leaq MCONTEXT_FPREGS_MEM(%rdi),%r8 465 movq %r8, MCONTEXT_FPREGS_PTR(%rdi) 466 fnstenv (%r8) 467 stmxcsr FPREGS_OFFSET_MXCSR(%r8) 468 469 leaq 8(%rsp), %rax /* exclude this call. */ 470 movq %rax, MCONTEXT_GREGS_RSP(%rdi) 471 472 movq 0(%rsp), %rax 473 movq %rax, MCONTEXT_GREGS_RIP(%rdi) 474 475 /* Save signal mask: sigprocmask(SIGBLOCK, NULL, &uc->uc_sigmask) */ 476 leaq UCONTEXT_SIGMASK_OFFSET(%rdi), %rdx // arg3 477 xorq %rsi, %rsi // arg2 NULL 478 xorq %rdi, %rdi // arg1 SIGBLOCK == 0 479 call sigprocmask@PLT 480 481 /* Always return 0 for success, even if sigprocmask failed. */ 482 xorl %eax, %eax 483 ret 484 .cfi_endproc 485 .size breakpad_getcontext, . - breakpad_getcontext 486 487 #else 488 #error "This file has not been ported for your CPU!" 489 #endif 490
