| 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 | #ifdef CONFIG_X86_32 |
| 20 | |
| 21 | /* |
| 22 | * FPU tag word conversions. |
| 23 | */ |
| 24 | |
| 25 | static inline unsigned short twd_i387_to_fxsr(unsigned short twd) |
| 26 | { |
| 27 | unsigned int tmp; /* to avoid 16 bit prefixes in the code */ |
| 28 | |
| 29 | /* Transform each pair of bits into 01 (valid) or 00 (empty) */ |
| 30 | tmp = ~twd; |
| 31 | tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */ |
| 32 | /* and move the valid bits to the lower byte. */ |
| 33 | tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */ |
| 34 | tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */ |
| 35 | tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */ |
| 36 | return tmp; |
| 37 | } |
| 38 | |
| 39 | static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave) |
| 40 | { |
| 41 | struct _fpxreg *st = NULL; |
| 42 | unsigned long twd = (unsigned long) fxsave->twd; |
| 43 | unsigned long tag; |
| 44 | unsigned long ret = 0xffff0000; |
| 45 | int i; |
| 46 | |
| 47 | #define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16) |
| 48 | |
| 49 | for (i = 0; i < 8; i++) { |
| 50 | if (twd & 0x1) { |
| 51 | st = (struct _fpxreg *) FPREG_ADDR(fxsave, i); |
| 52 | |
| 53 | switch (st->exponent & 0x7fff) { |
| 54 | case 0x7fff: |
| 55 | tag = 2; /* Special */ |
| 56 | break; |
| 57 | case 0x0000: |
| 58 | if ( !st->significand[0] && |
| 59 | !st->significand[1] && |
| 60 | !st->significand[2] && |
| 61 | !st->significand[3] ) { |
| 62 | tag = 1; /* Zero */ |
| 63 | } else { |
| 64 | tag = 2; /* Special */ |
| 65 | } |
| 66 | break; |
| 67 | default: |
| 68 | if (st->significand[3] & 0x8000) { |
| 69 | tag = 0; /* Valid */ |
| 70 | } else { |
| 71 | tag = 2; /* Special */ |
| 72 | } |
| 73 | break; |
| 74 | } |
| 75 | } else { |
| 76 | tag = 3; /* Empty */ |
| 77 | } |
| 78 | ret |= (tag << (2 * i)); |
| 79 | twd = twd >> 1; |
| 80 | } |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | static int convert_fxsr_to_user(struct _fpstate __user *buf, |
| 85 | struct user_fxsr_struct *fxsave) |
| 86 | { |
| 87 | unsigned long env[7]; |
| 88 | struct _fpreg __user *to; |
| 89 | struct _fpxreg *from; |
| 90 | int i; |
| 91 | |
| 92 | env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul; |
| 93 | env[1] = (unsigned long)fxsave->swd | 0xffff0000ul; |
| 94 | env[2] = twd_fxsr_to_i387(fxsave); |
| 95 | env[3] = fxsave->fip; |
| 96 | env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16); |
| 97 | env[5] = fxsave->foo; |
| 98 | env[6] = fxsave->fos; |
| 99 | |
| 100 | if (__copy_to_user(buf, env, 7 * sizeof(unsigned long))) |
| 101 | return 1; |
| 102 | |
| 103 | to = &buf->_st[0]; |
| 104 | from = (struct _fpxreg *) &fxsave->st_space[0]; |
| 105 | for (i = 0; i < 8; i++, to++, from++) { |
| 106 | unsigned long __user *t = (unsigned long __user *)to; |
| 107 | unsigned long *f = (unsigned long *)from; |
| 108 | |
| 109 | if (__put_user(*f, t) || |
| 110 | __put_user(*(f + 1), t + 1) || |
| 111 | __put_user(from->exponent, &to->exponent)) |
| 112 | return 1; |
| 113 | } |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave, |
| 118 | struct _fpstate __user *buf) |
| 119 | { |
| 120 | unsigned long env[7]; |
| 121 | struct _fpxreg *to; |
| 122 | struct _fpreg __user *from; |
| 123 | int i; |
| 124 | |
| 125 | if (copy_from_user( env, buf, 7 * sizeof(long))) |
| 126 | return 1; |
| 127 | |
| 128 | fxsave->cwd = (unsigned short)(env[0] & 0xffff); |
| 129 | fxsave->swd = (unsigned short)(env[1] & 0xffff); |
| 130 | fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff)); |
| 131 | fxsave->fip = env[3]; |
| 132 | fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16); |
| 133 | fxsave->fcs = (env[4] & 0xffff); |
| 134 | fxsave->foo = env[5]; |
| 135 | fxsave->fos = env[6]; |
| 136 | |
| 137 | to = (struct _fpxreg *) &fxsave->st_space[0]; |
| 138 | from = &buf->_st[0]; |
| 139 | for (i = 0; i < 8; i++, to++, from++) { |
| 140 | unsigned long *t = (unsigned long *)to; |
| 141 | unsigned long __user *f = (unsigned long __user *)from; |
| 142 | |
| 143 | if (__get_user(*t, f) || |
| 144 | __get_user(*(t + 1), f + 1) || |
| 145 | __get_user(to->exponent, &from->exponent)) |
| 146 | return 1; |
| 147 | } |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | extern int have_fpx_regs; |
| 152 | |
| 153 | #endif |
| 154 | |
| 155 | static int copy_sc_from_user(struct pt_regs *regs, |
| 156 | struct sigcontext __user *from) |
| 157 | { |
| 158 | struct sigcontext sc; |
| 159 | int err; |
| 160 | |
| 161 | /* Always make any pending restarted system calls return -EINTR */ |
| 162 | current->restart_block.fn = do_no_restart_syscall; |
| 163 | |
| 164 | err = copy_from_user(&sc, from, sizeof(sc)); |
| 165 | if (err) |
| 166 | return err; |
| 167 | |
| 168 | #define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname |
| 169 | |
| 170 | #ifdef CONFIG_X86_32 |
| 171 | GETREG(GS, gs); |
| 172 | GETREG(FS, fs); |
| 173 | GETREG(ES, es); |
| 174 | GETREG(DS, ds); |
| 175 | #endif |
| 176 | GETREG(DI, di); |
| 177 | GETREG(SI, si); |
| 178 | GETREG(BP, bp); |
| 179 | GETREG(SP, sp); |
| 180 | GETREG(BX, bx); |
| 181 | GETREG(DX, dx); |
| 182 | GETREG(CX, cx); |
| 183 | GETREG(AX, ax); |
| 184 | GETREG(IP, ip); |
| 185 | |
| 186 | #ifdef CONFIG_X86_64 |
| 187 | GETREG(R8, r8); |
| 188 | GETREG(R9, r9); |
| 189 | GETREG(R10, r10); |
| 190 | GETREG(R11, r11); |
| 191 | GETREG(R12, r12); |
| 192 | GETREG(R13, r13); |
| 193 | GETREG(R14, r14); |
| 194 | GETREG(R15, r15); |
| 195 | #endif |
| 196 | |
| 197 | GETREG(CS, cs); |
| 198 | GETREG(EFLAGS, flags); |
| 199 | #ifdef CONFIG_X86_32 |
| 200 | GETREG(SS, ss); |
| 201 | #endif |
| 202 | |
| 203 | #undef GETREG |
| 204 | |
| 205 | #ifdef CONFIG_X86_32 |
| 206 | if (have_fpx_regs) { |
| 207 | struct user_fxsr_struct fpx; |
| 208 | int pid = userspace_pid[current_thread_info()->cpu]; |
| 209 | |
| 210 | err = copy_from_user(&fpx, |
| 211 | &((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0], |
| 212 | sizeof(struct user_fxsr_struct)); |
| 213 | if (err) |
| 214 | return 1; |
| 215 | |
| 216 | err = convert_fxsr_from_user(&fpx, (void *)sc.fpstate); |
| 217 | if (err) |
| 218 | return 1; |
| 219 | |
| 220 | err = restore_fpx_registers(pid, (unsigned long *) &fpx); |
| 221 | if (err < 0) { |
| 222 | printk(KERN_ERR "copy_sc_from_user - " |
| 223 | "restore_fpx_registers failed, errno = %d\n", |
| 224 | -err); |
| 225 | return 1; |
| 226 | } |
| 227 | } else |
| 228 | #endif |
| 229 | { |
| 230 | err = copy_from_user(regs->regs.fp, (void *)sc.fpstate, |
| 231 | sizeof(struct _xstate)); |
| 232 | if (err) |
| 233 | return 1; |
| 234 | } |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | static int copy_sc_to_user(struct sigcontext __user *to, |
| 239 | struct _xstate __user *to_fp, struct pt_regs *regs, |
| 240 | unsigned long mask) |
| 241 | { |
| 242 | struct sigcontext sc; |
| 243 | struct faultinfo * fi = ¤t->thread.arch.faultinfo; |
| 244 | int err; |
| 245 | memset(&sc, 0, sizeof(struct sigcontext)); |
| 246 | |
| 247 | #define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno] |
| 248 | |
| 249 | #ifdef CONFIG_X86_32 |
| 250 | PUTREG(GS, gs); |
| 251 | PUTREG(FS, fs); |
| 252 | PUTREG(ES, es); |
| 253 | PUTREG(DS, ds); |
| 254 | #endif |
| 255 | PUTREG(DI, di); |
| 256 | PUTREG(SI, si); |
| 257 | PUTREG(BP, bp); |
| 258 | PUTREG(SP, sp); |
| 259 | PUTREG(BX, bx); |
| 260 | PUTREG(DX, dx); |
| 261 | PUTREG(CX, cx); |
| 262 | PUTREG(AX, ax); |
| 263 | #ifdef CONFIG_X86_64 |
| 264 | PUTREG(R8, r8); |
| 265 | PUTREG(R9, r9); |
| 266 | PUTREG(R10, r10); |
| 267 | PUTREG(R11, r11); |
| 268 | PUTREG(R12, r12); |
| 269 | PUTREG(R13, r13); |
| 270 | PUTREG(R14, r14); |
| 271 | PUTREG(R15, r15); |
| 272 | #endif |
| 273 | |
| 274 | sc.cr2 = fi->cr2; |
| 275 | sc.err = fi->error_code; |
| 276 | sc.trapno = fi->trap_no; |
| 277 | PUTREG(IP, ip); |
| 278 | PUTREG(CS, cs); |
| 279 | PUTREG(EFLAGS, flags); |
| 280 | #ifdef CONFIG_X86_32 |
| 281 | PUTREG(SP, sp_at_signal); |
| 282 | PUTREG(SS, ss); |
| 283 | #endif |
| 284 | #undef PUTREG |
| 285 | sc.oldmask = mask; |
| 286 | sc.fpstate = (unsigned long)to_fp; |
| 287 | |
| 288 | err = copy_to_user(to, &sc, sizeof(struct sigcontext)); |
| 289 | if (err) |
| 290 | return 1; |
| 291 | |
| 292 | #ifdef CONFIG_X86_32 |
| 293 | if (have_fpx_regs) { |
| 294 | int pid = userspace_pid[current_thread_info()->cpu]; |
| 295 | struct user_fxsr_struct fpx; |
| 296 | |
| 297 | err = save_fpx_registers(pid, (unsigned long *) &fpx); |
| 298 | if (err < 0){ |
| 299 | printk(KERN_ERR "copy_sc_to_user - save_fpx_registers " |
| 300 | "failed, errno = %d\n", err); |
| 301 | return 1; |
| 302 | } |
| 303 | |
| 304 | err = convert_fxsr_to_user(&to_fp->fpstate, &fpx); |
| 305 | if (err) |
| 306 | return 1; |
| 307 | |
| 308 | err |= __put_user(fpx.swd, &to_fp->fpstate.status); |
| 309 | err |= __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic); |
| 310 | if (err) |
| 311 | return 1; |
| 312 | |
| 313 | if (copy_to_user(&to_fp->fpstate._fxsr_env[0], &fpx, |
| 314 | sizeof(struct user_fxsr_struct))) |
| 315 | return 1; |
| 316 | } else |
| 317 | #endif |
| 318 | { |
| 319 | if (copy_to_user(to_fp, regs->regs.fp, sizeof(struct _xstate))) |
| 320 | return 1; |
| 321 | } |
| 322 | |
| 323 | return 0; |
| 324 | } |
| 325 | |
| 326 | #ifdef CONFIG_X86_32 |
| 327 | static int copy_ucontext_to_user(struct ucontext __user *uc, |
| 328 | struct _xstate __user *fp, sigset_t *set, |
| 329 | unsigned long sp) |
| 330 | { |
| 331 | int err = 0; |
| 332 | |
| 333 | err |= __save_altstack(&uc->uc_stack, sp); |
| 334 | err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, 0); |
| 335 | err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set)); |
| 336 | return err; |
| 337 | } |
| 338 | |
| 339 | struct sigframe |
| 340 | { |
| 341 | char __user *pretcode; |
| 342 | int sig; |
| 343 | struct sigcontext sc; |
| 344 | struct _xstate fpstate; |
| 345 | unsigned long extramask[_NSIG_WORDS-1]; |
| 346 | char retcode[8]; |
| 347 | }; |
| 348 | |
| 349 | struct rt_sigframe |
| 350 | { |
| 351 | char __user *pretcode; |
| 352 | int sig; |
| 353 | struct siginfo __user *pinfo; |
| 354 | void __user *puc; |
| 355 | struct siginfo info; |
| 356 | struct ucontext uc; |
| 357 | struct _xstate fpstate; |
| 358 | char retcode[8]; |
| 359 | }; |
| 360 | |
| 361 | int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig, |
| 362 | struct pt_regs *regs, sigset_t *mask) |
| 363 | { |
| 364 | struct sigframe __user *frame; |
| 365 | void __user *restorer; |
| 366 | int err = 0, sig = ksig->sig; |
| 367 | |
| 368 | /* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */ |
| 369 | stack_top = ((stack_top + 4) & -16UL) - 4; |
| 370 | frame = (struct sigframe __user *) stack_top - 1; |
| 371 | if (!access_ok(frame, sizeof(*frame))) |
| 372 | return 1; |
| 373 | |
| 374 | restorer = frame->retcode; |
| 375 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 376 | restorer = ksig->ka.sa.sa_restorer; |
| 377 | |
| 378 | err |= __put_user(restorer, &frame->pretcode); |
| 379 | err |= __put_user(sig, &frame->sig); |
| 380 | err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]); |
| 381 | if (_NSIG_WORDS > 1) |
| 382 | err |= __copy_to_user(&frame->extramask, &mask->sig[1], |
| 383 | sizeof(frame->extramask)); |
| 384 | |
| 385 | /* |
| 386 | * This is popl %eax ; movl $,%eax ; int $0x80 |
| 387 | * |
| 388 | * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| 389 | * reasons and because gdb uses it as a signature to notice |
| 390 | * signal handler stack frames. |
| 391 | */ |
| 392 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); |
| 393 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); |
| 394 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); |
| 395 | |
| 396 | if (err) |
| 397 | return err; |
| 398 | |
| 399 | PT_REGS_SP(regs) = (unsigned long) frame; |
| 400 | PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler; |
| 401 | PT_REGS_AX(regs) = (unsigned long) sig; |
| 402 | PT_REGS_DX(regs) = (unsigned long) 0; |
| 403 | PT_REGS_CX(regs) = (unsigned long) 0; |
| 404 | return 0; |
| 405 | } |
| 406 | |
| 407 | int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig, |
| 408 | struct pt_regs *regs, sigset_t *mask) |
| 409 | { |
| 410 | struct rt_sigframe __user *frame; |
| 411 | void __user *restorer; |
| 412 | int err = 0, sig = ksig->sig; |
| 413 | |
| 414 | stack_top &= -8UL; |
| 415 | frame = (struct rt_sigframe __user *) stack_top - 1; |
| 416 | if (!access_ok(frame, sizeof(*frame))) |
| 417 | return 1; |
| 418 | |
| 419 | restorer = frame->retcode; |
| 420 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 421 | restorer = ksig->ka.sa.sa_restorer; |
| 422 | |
| 423 | err |= __put_user(restorer, &frame->pretcode); |
| 424 | err |= __put_user(sig, &frame->sig); |
| 425 | err |= __put_user(&frame->info, &frame->pinfo); |
| 426 | err |= __put_user(&frame->uc, &frame->puc); |
| 427 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| 428 | err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask, |
| 429 | PT_REGS_SP(regs)); |
| 430 | |
| 431 | /* |
| 432 | * This is movl $,%eax ; int $0x80 |
| 433 | * |
| 434 | * WE DO NOT USE IT ANY MORE! It's only left here for historical |
| 435 | * reasons and because gdb uses it as a signature to notice |
| 436 | * signal handler stack frames. |
| 437 | */ |
| 438 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); |
| 439 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); |
| 440 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); |
| 441 | |
| 442 | if (err) |
| 443 | return err; |
| 444 | |
| 445 | PT_REGS_SP(regs) = (unsigned long) frame; |
| 446 | PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler; |
| 447 | PT_REGS_AX(regs) = (unsigned long) sig; |
| 448 | PT_REGS_DX(regs) = (unsigned long) &frame->info; |
| 449 | PT_REGS_CX(regs) = (unsigned long) &frame->uc; |
| 450 | return 0; |
| 451 | } |
| 452 | |
| 453 | SYSCALL_DEFINE0(sigreturn) |
| 454 | { |
| 455 | unsigned long sp = PT_REGS_SP(¤t->thread.regs); |
| 456 | struct sigframe __user *frame = (struct sigframe __user *)(sp - 8); |
| 457 | sigset_t set; |
| 458 | struct sigcontext __user *sc = &frame->sc; |
| 459 | int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long); |
| 460 | |
| 461 | if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) || |
| 462 | copy_from_user(&set.sig[1], frame->extramask, sig_size)) |
| 463 | goto segfault; |
| 464 | |
| 465 | set_current_blocked(&set); |
| 466 | |
| 467 | if (copy_sc_from_user(¤t->thread.regs, sc)) |
| 468 | goto segfault; |
| 469 | |
| 470 | /* Avoid ERESTART handling */ |
| 471 | PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; |
| 472 | return PT_REGS_SYSCALL_RET(¤t->thread.regs); |
| 473 | |
| 474 | segfault: |
| 475 | force_sig(SIGSEGV); |
| 476 | return 0; |
| 477 | } |
| 478 | |
| 479 | #else |
| 480 | |
| 481 | struct rt_sigframe |
| 482 | { |
| 483 | char __user *pretcode; |
| 484 | struct ucontext uc; |
| 485 | struct siginfo info; |
| 486 | struct _xstate fpstate; |
| 487 | }; |
| 488 | |
| 489 | int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig, |
| 490 | struct pt_regs *regs, sigset_t *set) |
| 491 | { |
| 492 | struct rt_sigframe __user *frame; |
| 493 | int err = 0, sig = ksig->sig; |
| 494 | unsigned long fp_to; |
| 495 | |
| 496 | frame = (struct rt_sigframe __user *) |
| 497 | round_down(stack_top - sizeof(struct rt_sigframe), 16); |
| 498 | /* Subtract 128 for a red zone and 8 for proper alignment */ |
| 499 | frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8); |
| 500 | |
| 501 | if (!access_ok(frame, sizeof(*frame))) |
| 502 | goto out; |
| 503 | |
| 504 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
| 505 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| 506 | if (err) |
| 507 | goto out; |
| 508 | } |
| 509 | |
| 510 | /* Create the ucontext. */ |
| 511 | err |= __put_user(0, &frame->uc.uc_flags); |
| 512 | err |= __put_user(0, &frame->uc.uc_link); |
| 513 | err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs)); |
| 514 | err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs, |
| 515 | set->sig[0]); |
| 516 | |
| 517 | fp_to = (unsigned long)&frame->fpstate; |
| 518 | |
| 519 | err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate); |
| 520 | if (sizeof(*set) == 16) { |
| 521 | err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); |
| 522 | err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); |
| 523 | } |
| 524 | else |
| 525 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, |
| 526 | sizeof(*set)); |
| 527 | |
| 528 | /* |
| 529 | * Set up to return from userspace. If provided, use a stub |
| 530 | * already in userspace. |
| 531 | */ |
| 532 | /* x86-64 should always use SA_RESTORER. */ |
| 533 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
| 534 | err |= __put_user((void *)ksig->ka.sa.sa_restorer, |
| 535 | &frame->pretcode); |
| 536 | else |
| 537 | /* could use a vstub here */ |
| 538 | return err; |
| 539 | |
| 540 | if (err) |
| 541 | return err; |
| 542 | |
| 543 | PT_REGS_SP(regs) = (unsigned long) frame; |
| 544 | PT_REGS_DI(regs) = sig; |
| 545 | /* In case the signal handler was declared without prototypes */ |
| 546 | PT_REGS_AX(regs) = 0; |
| 547 | |
| 548 | /* |
| 549 | * This also works for non SA_SIGINFO handlers because they expect the |
| 550 | * next argument after the signal number on the stack. |
| 551 | */ |
| 552 | PT_REGS_SI(regs) = (unsigned long) &frame->info; |
| 553 | PT_REGS_DX(regs) = (unsigned long) &frame->uc; |
| 554 | PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler; |
| 555 | out: |
| 556 | return err; |
| 557 | } |
| 558 | #endif |
| 559 | |
| 560 | SYSCALL_DEFINE0(rt_sigreturn) |
| 561 | { |
| 562 | unsigned long sp = PT_REGS_SP(¤t->thread.regs); |
| 563 | struct rt_sigframe __user *frame = |
| 564 | (struct rt_sigframe __user *)(sp - sizeof(long)); |
| 565 | struct ucontext __user *uc = &frame->uc; |
| 566 | sigset_t set; |
| 567 | |
| 568 | if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) |
| 569 | goto segfault; |
| 570 | |
| 571 | set_current_blocked(&set); |
| 572 | |
| 573 | if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext)) |
| 574 | goto segfault; |
| 575 | |
| 576 | /* Avoid ERESTART handling */ |
| 577 | PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; |
| 578 | return PT_REGS_SYSCALL_RET(¤t->thread.regs); |
| 579 | |
| 580 | segfault: |
| 581 | force_sig(SIGSEGV); |
| 582 | return 0; |
| 583 | } |