| 1 | /* |
| 2 | * Copyright (C) 2003 PathScale, Inc. |
| 3 | * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| 4 | * Licensed under the GPL |
| 5 | */ |
| 6 | |
| 7 | |
| 8 | #include <linux/personality.h> |
| 9 | #include <linux/ptrace.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/syscalls.h> |
| 12 | #include <asm/unistd.h> |
| 13 | #include <linux/uaccess.h> |
| 14 | #include <asm/ucontext.h> |
| 15 | #include <frame_kern.h> |
| 16 | #include <registers.h> |
| 17 | #include <skas.h> |
| 18 | |
| 19 | #include <linux/regset.h> |
| 20 | #include <asm/sigframe.h> |
| 21 | |
| 22 | #ifdef CONFIG_X86_32 |
| 23 | struct _xstate_64 { |
| 24 | struct _fpstate_64 fpstate; |
| 25 | struct _header xstate_hdr; |
| 26 | struct _ymmh_state ymmh; |
| 27 | /* New processor state extensions go here: */ |
| 28 | }; |
| 29 | #else |
| 30 | #define _xstate_64 _xstate |
| 31 | #endif |
| 32 | |
| 33 | static int copy_sc_from_user(struct pt_regs *regs, |
| 34 | struct sigcontext __user *from) |
| 35 | { |
| 36 | struct _xstate_64 __user *from_fp64; |
| 37 | struct sigcontext sc; |
| 38 | int err; |
| 39 | |
| 40 | /* Always make any pending restarted system calls return -EINTR */ |
| 41 | current->restart_block.fn = do_no_restart_syscall; |
| 42 | |
| 43 | err = copy_from_user(&sc, from, sizeof(sc)); |
| 44 | if (err) |
| 45 | return err; |
| 46 | |
| 47 | #define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname |
| 48 | |
| 49 | #ifdef CONFIG_X86_32 |
| 50 | GETREG(GS, gs); |
| 51 | GETREG(FS, fs); |
| 52 | GETREG(ES, es); |
| 53 | GETREG(DS, ds); |
| 54 | #endif |
| 55 | GETREG(DI, di); |
| 56 | GETREG(SI, si); |
| 57 | GETREG(BP, bp); |
| 58 | GETREG(SP, sp); |
| 59 | GETREG(BX, bx); |
| 60 | GETREG(DX, dx); |
| 61 | GETREG(CX, cx); |
| 62 | GETREG(AX, ax); |
| 63 | GETREG(IP, ip); |
| 64 | |
| 65 | #ifdef CONFIG_X86_64 |
| 66 | GETREG(R8, r8); |
| 67 | GETREG(R9, r9); |
| 68 | GETREG(R10, r10); |
| 69 | GETREG(R11, r11); |
| 70 | GETREG(R12, r12); |
| 71 | GETREG(R13, r13); |
| 72 | GETREG(R14, r14); |
| 73 | GETREG(R15, r15); |
| 74 | #endif |
| 75 | |
| 76 | GETREG(CS, cs); |
| 77 | GETREG(EFLAGS, flags); |
| 78 | #ifdef CONFIG_X86_32 |
| 79 | GETREG(SS, ss); |
| 80 | #endif |
| 81 | |
| 82 | #undef GETREG |
| 83 | |
| 84 | #ifdef CONFIG_X86_32 |
| 85 | from_fp64 = ((void __user *)sc.fpstate) + |
| 86 | offsetof(struct _fpstate_32, _fxsr_env); |
| 87 | #else |
| 88 | from_fp64 = (void __user *)sc.fpstate; |
| 89 | #endif |
| 90 | |
| 91 | err = copy_from_user(regs->regs.fp, from_fp64, host_fp_size); |
| 92 | if (err) |
| 93 | return 1; |
| 94 | |
| 95 | #ifdef CONFIG_X86_32 |
| 96 | /* Data is duplicated and this copy is the important one */ |
| 97 | err = copy_regset_from_user(current, |
| 98 | task_user_regset_view(current), |
| 99 | REGSET_FP_LEGACY, 0, |
| 100 | sizeof(struct user_i387_struct), |
| 101 | (void __user *)sc.fpstate); |
| 102 | if (err < 0) |
| 103 | return err; |
| 104 | #endif |
| 105 | |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int copy_sc_to_user(struct sigcontext __user *to, |
| 110 | struct _xstate __user *to_fp, struct pt_regs *regs, |
| 111 | unsigned long mask) |
| 112 | { |
| 113 | struct _xstate_64 __user *to_fp64; |
| 114 | struct sigcontext sc; |
| 115 | struct faultinfo * fi = ¤t->thread.arch.faultinfo; |
| 116 | int err; |
| 117 | memset(&sc, 0, sizeof(struct sigcontext)); |
| 118 | |
| 119 | #define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno] |
| 120 | |
| 121 | #ifdef CONFIG_X86_32 |
| 122 | PUTREG(GS, gs); |
| 123 | PUTREG(FS, fs); |
| 124 | PUTREG(ES, es); |
| 125 | PUTREG(DS, ds); |
| 126 | #endif |
| 127 | PUTREG(DI, di); |
| 128 | PUTREG(SI, si); |
| 129 | PUTREG(BP, bp); |
| 130 | PUTREG(SP, sp); |
| 131 | PUTREG(BX, bx); |
| 132 | PUTREG(DX, dx); |
| 133 | PUTREG(CX, cx); |
| 134 | PUTREG(AX, ax); |
| 135 | #ifdef CONFIG_X86_64 |
| 136 | PUTREG(R8, r8); |
| 137 | PUTREG(R9, r9); |
| 138 | PUTREG(R10, r10); |
| 139 | PUTREG(R11, r11); |
| 140 | PUTREG(R12, r12); |
| 141 | PUTREG(R13, r13); |
| 142 | PUTREG(R14, r14); |
| 143 | PUTREG(R15, r15); |
| 144 | #endif |
| 145 | |
| 146 | sc.cr2 = fi->cr2; |
| 147 | sc.err = fi->error_code; |
| 148 | sc.trapno = fi->trap_no; |
| 149 | PUTREG(IP, ip); |
| 150 | PUTREG(CS, cs); |
| 151 | PUTREG(EFLAGS, flags); |
| 152 | #ifdef CONFIG_X86_32 |
| 153 | PUTREG(SP, sp_at_signal); |
| 154 | PUTREG(SS, ss); |
| 155 | #endif |
| 156 | #undef PUTREG |
| 157 | sc.oldmask = mask; |
| 158 | sc.fpstate = (unsigned long)to_fp; |
| 159 | |
| 160 | err = copy_to_user(to, &sc, sizeof(struct sigcontext)); |
| 161 | if (err) |
| 162 | return 1; |
| 163 | |
| 164 | #ifdef CONFIG_X86_32 |
| 165 | err = copy_regset_to_user(current, |
| 166 | task_user_regset_view(current), |
| 167 | REGSET_FP_LEGACY, 0, |
| 168 | sizeof(struct _fpstate_32), to_fp); |
| 169 | if (err < 0) |
| 170 | return err; |
| 171 | |
| 172 | __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic); |
| 173 | |
| 174 | BUILD_BUG_ON(offsetof(struct _xstate, xstate_hdr) != |
| 175 | offsetof(struct _xstate_64, xstate_hdr) + |
| 176 | offsetof(struct _fpstate_32, _fxsr_env)); |
| 177 | to_fp64 = (void __user *)to_fp + |
| 178 | offsetof(struct _fpstate_32, _fxsr_env); |
| 179 | #else |
| 180 | to_fp64 = to_fp; |
| 181 | #endif /* CONFIG_X86_32 */ |
| 182 | |
| 183 | if (copy_to_user(to_fp64, regs->regs.fp, host_fp_size)) |
| 184 | return 1; |
| 185 | |
| 186 | /* |
| 187 | * Put magic/size values for userspace. We do not bother to verify them |
| 188 | * later on, however, userspace needs them should it try to read the |
| 189 | * XSTATE data. And ptrace does not fill in these parts. |
| 190 | * |
| 191 | * Skip this if we do not have an XSTATE frame. |
| 192 | */ |
| 193 | if (host_fp_size <= sizeof(to_fp64->fpstate)) |
| 194 | return 0; |
| 195 | |
| 196 | BUILD_BUG_ON(sizeof(int) != FP_XSTATE_MAGIC2_SIZE); |
| 197 | #ifdef CONFIG_X86_32 |
| 198 | __put_user(offsetof(struct _fpstate_32, _fxsr_env) + |
| 199 | host_fp_size + FP_XSTATE_MAGIC2_SIZE, |
| 200 | &to_fp64->fpstate.sw_reserved.extended_size); |
| 201 | #else |
| 202 | __put_user(host_fp_size + FP_XSTATE_MAGIC2_SIZE, |
| 203 | &to_fp64->fpstate.sw_reserved.extended_size); |
| 204 | #endif |
| 205 | __put_user(host_fp_size, &to_fp64->fpstate.sw_reserved.xstate_size); |
| 206 | |
| 207 | __put_user(FP_XSTATE_MAGIC1, &to_fp64->fpstate.sw_reserved.magic1); |
| 208 | __put_user(FP_XSTATE_MAGIC2, |
| 209 | (int __user *)((void __user *)to_fp64 + host_fp_size)); |
| 210 | |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | #ifdef CONFIG_X86_32 |
| 215 | static int copy_ucontext_to_user(struct ucontext __user *uc, |
| 216 | struct _xstate __user *fp, sigset_t *set, |
| 217 | unsigned long sp) |
| 218 | { |
| 219 | int err = 0; |
| 220 | |
| 221 | err |= __save_altstack(&uc->uc_stack, sp); |
| 222 | err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, 0); |
| 223 | err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set)); |
| 224 | return err; |
| 225 | } |
| 226 | |
| 227 | int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig, |
| 228 | struct pt_regs *regs, sigset_t *mask) |
| 229 | { |
| 230 | size_t math_size = offsetof(struct _fpstate_32, _fxsr_env) + |
| 231 | host_fp_size + FP_XSTATE_MAGIC2_SIZE; |
| 232 | struct sigframe __user *frame; |
| 233 | void __user *restorer; |
| 234 | int err = 0, sig = ksig->sig; |
| 235 | unsigned long fp_to; |
| 236 | |
| 237 | /* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */ |
| 238 | stack_top = ((stack_top + 4) & -16UL) - 4; |
| 239 | frame = (struct sigframe __user *) stack_top - 1; |
| 240 | if (!access_ok(frame, sizeof(*frame))) |
| 241 | return 1; |
| 242 | |
| 243 | /* Add required space for math frame */ |
| 244 | frame = (struct sigframe __user *)((unsigned long)frame - math_size); |
| 245 | |
| 246 | restorer = frame->retcode; |
| 247 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 248 | restorer = ksig->ka.sa.sa_restorer; |
| 249 | |
| 250 | err |= __put_user(restorer, (void __user * __user *)&frame->pretcode); |
| 251 | err |= __put_user(sig, &frame->sig); |
| 252 | |
| 253 | fp_to = (unsigned long)frame + sizeof(*frame); |
| 254 | |
| 255 | err |= copy_sc_to_user(&frame->sc, |
| 256 | (struct _xstate __user *)fp_to, |
| 257 | regs, mask->sig[0]); |
| 258 | if (_NSIG_WORDS > 1) |
| 259 | err |= __copy_to_user(&frame->extramask, &mask->sig[1], |
| 260 | sizeof(frame->extramask)); |
| 261 | |
| 262 | /* |
| 263 | * This is popl %eax ; movl $,%eax ; int $0x80 |
| 264 | * |
| 265 | * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| 266 | * reasons and because gdb uses it as a signature to notice |
| 267 | * signal handler stack frames. |
| 268 | */ |
| 269 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); |
| 270 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); |
| 271 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); |
| 272 | |
| 273 | if (err) |
| 274 | return err; |
| 275 | |
| 276 | PT_REGS_SP(regs) = (unsigned long) frame; |
| 277 | PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler; |
| 278 | PT_REGS_AX(regs) = (unsigned long) sig; |
| 279 | PT_REGS_DX(regs) = (unsigned long) 0; |
| 280 | PT_REGS_CX(regs) = (unsigned long) 0; |
| 281 | return 0; |
| 282 | } |
| 283 | |
| 284 | int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig, |
| 285 | struct pt_regs *regs, sigset_t *mask) |
| 286 | { |
| 287 | size_t math_size = offsetof(struct _fpstate_32, _fxsr_env) + |
| 288 | host_fp_size + FP_XSTATE_MAGIC2_SIZE; |
| 289 | struct rt_sigframe __user *frame; |
| 290 | void __user *restorer; |
| 291 | int err = 0, sig = ksig->sig; |
| 292 | unsigned long fp_to; |
| 293 | |
| 294 | stack_top &= -8UL; |
| 295 | frame = (struct rt_sigframe __user *) stack_top - 1; |
| 296 | if (!access_ok(frame, sizeof(*frame))) |
| 297 | return 1; |
| 298 | |
| 299 | /* Add required space for math frame */ |
| 300 | frame = (struct rt_sigframe __user *)((unsigned long)frame - math_size); |
| 301 | |
| 302 | restorer = frame->retcode; |
| 303 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 304 | restorer = ksig->ka.sa.sa_restorer; |
| 305 | |
| 306 | err |= __put_user(restorer, (void __user * __user *)&frame->pretcode); |
| 307 | err |= __put_user(sig, &frame->sig); |
| 308 | err |= __put_user(&frame->info, (void __user * __user *)&frame->pinfo); |
| 309 | err |= __put_user(&frame->uc, (void __user * __user *)&frame->puc); |
| 310 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| 311 | |
| 312 | fp_to = (unsigned long)frame + sizeof(*frame); |
| 313 | |
| 314 | err |= copy_ucontext_to_user(&frame->uc, (struct _xstate __user *)fp_to, |
| 315 | mask, PT_REGS_SP(regs)); |
| 316 | |
| 317 | /* |
| 318 | * This is movl $,%eax ; int $0x80 |
| 319 | * |
| 320 | * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| 321 | * reasons and because gdb uses it as a signature to notice |
| 322 | * signal handler stack frames. |
| 323 | */ |
| 324 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); |
| 325 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); |
| 326 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); |
| 327 | |
| 328 | if (err) |
| 329 | return err; |
| 330 | |
| 331 | PT_REGS_SP(regs) = (unsigned long) frame; |
| 332 | PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler; |
| 333 | PT_REGS_AX(regs) = (unsigned long) sig; |
| 334 | PT_REGS_DX(regs) = (unsigned long) &frame->info; |
| 335 | PT_REGS_CX(regs) = (unsigned long) &frame->uc; |
| 336 | return 0; |
| 337 | } |
| 338 | |
| 339 | SYSCALL_DEFINE0(sigreturn) |
| 340 | { |
| 341 | unsigned long sp = PT_REGS_SP(¤t->thread.regs); |
| 342 | struct sigframe __user *frame = (struct sigframe __user *)(sp - 8); |
| 343 | sigset_t set; |
| 344 | struct sigcontext __user *sc = &frame->sc; |
| 345 | int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long); |
| 346 | |
| 347 | if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) || |
| 348 | copy_from_user(&set.sig[1], frame->extramask, sig_size)) |
| 349 | goto segfault; |
| 350 | |
| 351 | set_current_blocked(&set); |
| 352 | |
| 353 | if (copy_sc_from_user(¤t->thread.regs, sc)) |
| 354 | goto segfault; |
| 355 | |
| 356 | /* Avoid ERESTART handling */ |
| 357 | PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; |
| 358 | return PT_REGS_SYSCALL_RET(¤t->thread.regs); |
| 359 | |
| 360 | segfault: |
| 361 | force_sig(SIGSEGV); |
| 362 | return 0; |
| 363 | } |
| 364 | |
| 365 | #else |
| 366 | |
| 367 | int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig, |
| 368 | struct pt_regs *regs, sigset_t *set) |
| 369 | { |
| 370 | unsigned long math_size = host_fp_size + FP_XSTATE_MAGIC2_SIZE; |
| 371 | struct rt_sigframe __user *frame; |
| 372 | int err = 0, sig = ksig->sig; |
| 373 | unsigned long fp_to; |
| 374 | |
| 375 | frame = (void __user *)stack_top - sizeof(struct rt_sigframe); |
| 376 | |
| 377 | /* Add required space for math frame */ |
| 378 | frame = (void __user *)((unsigned long)frame - math_size); |
| 379 | |
| 380 | /* ABI requires 16 byte boundary alignment */ |
| 381 | frame = (void __user *)round_down((unsigned long)frame, 16); |
| 382 | |
| 383 | /* Subtract 128 for a red zone and 8 for proper alignment */ |
| 384 | frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8); |
| 385 | |
| 386 | if (!access_ok(frame, sizeof(*frame) + math_size)) |
| 387 | goto out; |
| 388 | |
| 389 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
| 390 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| 391 | if (err) |
| 392 | goto out; |
| 393 | } |
| 394 | |
| 395 | /* Create the ucontext. */ |
| 396 | err |= __put_user(0, &frame->uc.uc_flags); |
| 397 | err |= __put_user(NULL, &frame->uc.uc_link); |
| 398 | err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs)); |
| 399 | |
| 400 | fp_to = (unsigned long)frame + sizeof(*frame); |
| 401 | |
| 402 | err |= copy_sc_to_user(&frame->uc.uc_mcontext, |
| 403 | (struct _xstate __user *)fp_to, |
| 404 | regs, set->sig[0]); |
| 405 | |
| 406 | err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate); |
| 407 | if (sizeof(*set) == 16) { |
| 408 | err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); |
| 409 | err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); |
| 410 | } |
| 411 | else |
| 412 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, |
| 413 | sizeof(*set)); |
| 414 | |
| 415 | /* |
| 416 | * Set up to return from userspace. If provided, use a stub |
| 417 | * already in userspace. |
| 418 | */ |
| 419 | /* x86-64 should always use SA_RESTORER. */ |
| 420 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 421 | err |= __put_user((void __user *)ksig->ka.sa.sa_restorer, |
| 422 | &frame->pretcode); |
| 423 | else |
| 424 | /* could use a vstub here */ |
| 425 | return err; |
| 426 | |
| 427 | if (err) |
| 428 | return err; |
| 429 | |
| 430 | PT_REGS_SP(regs) = (unsigned long) frame; |
| 431 | PT_REGS_DI(regs) = sig; |
| 432 | /* In case the signal handler was declared without prototypes */ |
| 433 | PT_REGS_AX(regs) = 0; |
| 434 | |
| 435 | /* |
| 436 | * This also works for non SA_SIGINFO handlers because they expect the |
| 437 | * next argument after the signal number on the stack. |
| 438 | */ |
| 439 | PT_REGS_SI(regs) = (unsigned long) &frame->info; |
| 440 | PT_REGS_DX(regs) = (unsigned long) &frame->uc; |
| 441 | PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler; |
| 442 | out: |
| 443 | return err; |
| 444 | } |
| 445 | #endif |
| 446 | |
| 447 | SYSCALL_DEFINE0(rt_sigreturn) |
| 448 | { |
| 449 | unsigned long sp = PT_REGS_SP(¤t->thread.regs); |
| 450 | struct rt_sigframe __user *frame = |
| 451 | (struct rt_sigframe __user *)(sp - sizeof(long)); |
| 452 | struct ucontext __user *uc = &frame->uc; |
| 453 | sigset_t set; |
| 454 | |
| 455 | if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) |
| 456 | goto segfault; |
| 457 | |
| 458 | set_current_blocked(&set); |
| 459 | |
| 460 | if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext)) |
| 461 | goto segfault; |
| 462 | |
| 463 | /* Avoid ERESTART handling */ |
| 464 | PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; |
| 465 | return PT_REGS_SYSCALL_RET(¤t->thread.regs); |
| 466 | |
| 467 | segfault: |
| 468 | force_sig(SIGSEGV); |
| 469 | return 0; |
| 470 | } |