1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1991, 1992 Linus Torvalds 7 * Copyright (C) 1994 - 2000, 2006 Ralf Baechle 8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc. 9 */ 10 #include <linux/cache.h> 11 #include <linux/compat.h> 12 #include <linux/sched.h> 13 #include <linux/mm.h> 14 #include <linux/smp.h> 15 #include <linux/kernel.h> 16 #include <linux/signal.h> 17 #include <linux/syscalls.h> 18 #include <linux/errno.h> 19 #include <linux/wait.h> 20 #include <linux/ptrace.h> 21 #include <linux/suspend.h> 22 #include <linux/compiler.h> 23 #include <linux/uaccess.h> 24 25 #include <asm/abi.h> 26 #include <asm/asm.h> 27 #include <asm/compat-signal.h> 28 #include <linux/bitops.h> 29 #include <asm/cacheflush.h> 30 #include <asm/sim.h> 31 #include <asm/ucontext.h> 32 #include <asm/fpu.h> 33 #include <asm/war.h> 34 #include <asm/dsp.h> 35 36 #include "signal-common.h" 37 38 /* 39 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... 40 */ 41 #define __NR_O32_restart_syscall 4253 42 43 /* 32-bit compatibility types */ 44 45 typedef unsigned int __sighandler32_t; 46 typedef void (*vfptr_t)(void); 47 48 struct ucontext32 { 49 u32 uc_flags; 50 s32 uc_link; 51 compat_stack_t uc_stack; 52 struct sigcontext32 uc_mcontext; 53 compat_sigset_t uc_sigmask; /* mask last for extensibility */ 54 }; 55 56 struct sigframe32 { 57 u32 sf_ass[4]; /* argument save space for o32 */ 58 u32 sf_pad[2]; /* Was: signal trampoline */ 59 struct sigcontext32 sf_sc; 60 compat_sigset_t sf_mask; 61 }; 62 63 struct rt_sigframe32 { 64 u32 rs_ass[4]; /* argument save space for o32 */ 65 u32 rs_pad[2]; /* Was: signal trampoline */ 66 compat_siginfo_t rs_info; 67 struct ucontext32 rs_uc; 68 }; 69 70 static int setup_sigcontext32(struct pt_regs *regs, 71 struct sigcontext32 __user *sc) 72 { 73 int err = 0; 74 int i; 75 76 err |= __put_user(regs->cp0_epc, &sc->sc_pc); 77 78 err |= __put_user(0, &sc->sc_regs[0]); 79 for (i = 1; i < 32; i++) 80 err |= __put_user(regs->regs[i], &sc->sc_regs[i]); 81 82 err |= __put_user(regs->hi, &sc->sc_mdhi); 83 err |= __put_user(regs->lo, &sc->sc_mdlo); 84 if (cpu_has_dsp) { 85 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); 86 err |= __put_user(mfhi1(), &sc->sc_hi1); 87 err |= __put_user(mflo1(), &sc->sc_lo1); 88 err |= __put_user(mfhi2(), &sc->sc_hi2); 89 err |= __put_user(mflo2(), &sc->sc_lo2); 90 err |= __put_user(mfhi3(), &sc->sc_hi3); 91 err |= __put_user(mflo3(), &sc->sc_lo3); 92 } 93 94 /* 95 * Save FPU state to signal context. Signal handler 96 * will "inherit" current FPU state. 97 */ 98 err |= protected_save_fp_context(sc); 99 100 return err; 101 } 102 103 static int restore_sigcontext32(struct pt_regs *regs, 104 struct sigcontext32 __user *sc) 105 { 106 int err = 0; 107 s32 treg; 108 int i; 109 110 /* Always make any pending restarted system calls return -EINTR */ 111 current->restart_block.fn = do_no_restart_syscall; 112 113 err |= __get_user(regs->cp0_epc, &sc->sc_pc); 114 err |= __get_user(regs->hi, &sc->sc_mdhi); 115 err |= __get_user(regs->lo, &sc->sc_mdlo); 116 if (cpu_has_dsp) { 117 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg); 118 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg); 119 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg); 120 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg); 121 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg); 122 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg); 123 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK); 124 } 125 126 for (i = 1; i < 32; i++) 127 err |= __get_user(regs->regs[i], &sc->sc_regs[i]); 128 129 return err ?: protected_restore_fp_context(sc); 130 } 131 132 /* 133 * Atomically swap in the new signal mask, and wait for a signal. 134 */ 135 136 asmlinkage int sys32_sigsuspend(compat_sigset_t __user *uset) 137 { 138 return compat_sys_rt_sigsuspend(uset, sizeof(compat_sigset_t)); 139 } 140 141 SYSCALL_DEFINE3(32_sigaction, long, sig, const struct compat_sigaction __user *, act, 142 struct compat_sigaction __user *, oact) 143 { 144 struct k_sigaction new_ka, old_ka; 145 int ret; 146 int err = 0; 147 148 if (act) { 149 old_sigset_t mask; 150 s32 handler; 151 152 if (!access_ok(VERIFY_READ, act, sizeof(*act))) 153 return -EFAULT; 154 err |= __get_user(handler, &act->sa_handler); 155 new_ka.sa.sa_handler = (void __user *)(s64)handler; 156 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); 157 err |= __get_user(mask, &act->sa_mask.sig[0]); 158 if (err) 159 return -EFAULT; 160 161 siginitset(&new_ka.sa.sa_mask, mask); 162 } 163 164 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); 165 166 if (!ret && oact) { 167 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact))) 168 return -EFAULT; 169 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); 170 err |= __put_user((u32)(u64)old_ka.sa.sa_handler, 171 &oact->sa_handler); 172 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig); 173 err |= __put_user(0, &oact->sa_mask.sig[1]); 174 err |= __put_user(0, &oact->sa_mask.sig[2]); 175 err |= __put_user(0, &oact->sa_mask.sig[3]); 176 if (err) 177 return -EFAULT; 178 } 179 180 return ret; 181 } 182 183 int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) 184 { 185 int err; 186 187 if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t))) 188 return -EFAULT; 189 190 /* If you change siginfo_t structure, please be sure 191 this code is fixed accordingly. 192 It should never copy any pad contained in the structure 193 to avoid security leaks, but must copy the generic 194 3 ints plus the relevant union member. 195 This routine must convert siginfo from 64bit to 32bit as well 196 at the same time. */ 197 err = __put_user(from->si_signo, &to->si_signo); 198 err |= __put_user(from->si_errno, &to->si_errno); 199 err |= __put_user((short)from->si_code, &to->si_code); 200 if (from->si_code < 0) 201 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE); 202 else { 203 switch (from->si_code >> 16) { 204 case __SI_TIMER >> 16: 205 err |= __put_user(from->si_tid, &to->si_tid); 206 err |= __put_user(from->si_overrun, &to->si_overrun); 207 err |= __put_user(from->si_int, &to->si_int); 208 break; 209 case __SI_CHLD >> 16: 210 err |= __put_user(from->si_utime, &to->si_utime); 211 err |= __put_user(from->si_stime, &to->si_stime); 212 err |= __put_user(from->si_status, &to->si_status); 213 default: 214 err |= __put_user(from->si_pid, &to->si_pid); 215 err |= __put_user(from->si_uid, &to->si_uid); 216 break; 217 case __SI_FAULT >> 16: 218 err |= __put_user((unsigned long)from->si_addr, &to->si_addr); 219 break; 220 case __SI_POLL >> 16: 221 err |= __put_user(from->si_band, &to->si_band); 222 err |= __put_user(from->si_fd, &to->si_fd); 223 break; 224 case __SI_RT >> 16: /* This is not generated by the kernel as of now. */ 225 case __SI_MESGQ >> 16: 226 err |= __put_user(from->si_pid, &to->si_pid); 227 err |= __put_user(from->si_uid, &to->si_uid); 228 err |= __put_user(from->si_int, &to->si_int); 229 break; 230 } 231 } 232 return err; 233 } 234 235 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) 236 { 237 if (copy_from_user(to, from, 3*sizeof(int)) || 238 copy_from_user(to->_sifields._pad, 239 from->_sifields._pad, SI_PAD_SIZE32)) 240 return -EFAULT; 241 242 return 0; 243 } 244 245 asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs) 246 { 247 struct sigframe32 __user *frame; 248 sigset_t blocked; 249 int sig; 250 251 frame = (struct sigframe32 __user *) regs.regs[29]; 252 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 253 goto badframe; 254 if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask)) 255 goto badframe; 256 257 set_current_blocked(&blocked); 258 259 sig = restore_sigcontext32(®s, &frame->sf_sc); 260 if (sig < 0) 261 goto badframe; 262 else if (sig) 263 force_sig(sig, current); 264 265 /* 266 * Don't let your children do this ... 267 */ 268 __asm__ __volatile__( 269 "move\t$29, %0\n\t" 270 "j\tsyscall_exit" 271 :/* no outputs */ 272 :"r" (®s)); 273 /* Unreached */ 274 275 badframe: 276 force_sig(SIGSEGV, current); 277 } 278 279 asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) 280 { 281 struct rt_sigframe32 __user *frame; 282 sigset_t set; 283 int sig; 284 285 frame = (struct rt_sigframe32 __user *) regs.regs[29]; 286 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 287 goto badframe; 288 if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) 289 goto badframe; 290 291 set_current_blocked(&set); 292 293 sig = restore_sigcontext32(®s, &frame->rs_uc.uc_mcontext); 294 if (sig < 0) 295 goto badframe; 296 else if (sig) 297 force_sig(sig, current); 298 299 if (compat_restore_altstack(&frame->rs_uc.uc_stack)) 300 goto badframe; 301 302 /* 303 * Don't let your children do this ... 304 */ 305 __asm__ __volatile__( 306 "move\t$29, %0\n\t" 307 "j\tsyscall_exit" 308 :/* no outputs */ 309 :"r" (®s)); 310 /* Unreached */ 311 312 badframe: 313 force_sig(SIGSEGV, current); 314 } 315 316 static int setup_frame_32(void *sig_return, struct ksignal *ksig, 317 struct pt_regs *regs, sigset_t *set) 318 { 319 struct sigframe32 __user *frame; 320 int err = 0; 321 322 frame = get_sigframe(ksig, regs, sizeof(*frame)); 323 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) 324 return -EFAULT; 325 326 err |= setup_sigcontext32(regs, &frame->sf_sc); 327 err |= __copy_conv_sigset_to_user(&frame->sf_mask, set); 328 329 if (err) 330 return -EFAULT; 331 332 /* 333 * Arguments to signal handler: 334 * 335 * a0 = signal number 336 * a1 = 0 (should be cause) 337 * a2 = pointer to struct sigcontext 338 * 339 * $25 and c0_epc point to the signal handler, $29 points to the 340 * struct sigframe. 341 */ 342 regs->regs[ 4] = ksig->sig; 343 regs->regs[ 5] = 0; 344 regs->regs[ 6] = (unsigned long) &frame->sf_sc; 345 regs->regs[29] = (unsigned long) frame; 346 regs->regs[31] = (unsigned long) sig_return; 347 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 348 349 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 350 current->comm, current->pid, 351 frame, regs->cp0_epc, regs->regs[31]); 352 353 return 0; 354 } 355 356 static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig, 357 struct pt_regs *regs, sigset_t *set) 358 { 359 struct rt_sigframe32 __user *frame; 360 int err = 0; 361 362 frame = get_sigframe(ksig, regs, sizeof(*frame)); 363 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) 364 return -EFAULT; 365 366 /* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */ 367 err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info); 368 369 /* Create the ucontext. */ 370 err |= __put_user(0, &frame->rs_uc.uc_flags); 371 err |= __put_user(0, &frame->rs_uc.uc_link); 372 err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); 373 err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext); 374 err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); 375 376 if (err) 377 return -EFAULT; 378 379 /* 380 * Arguments to signal handler: 381 * 382 * a0 = signal number 383 * a1 = 0 (should be cause) 384 * a2 = pointer to ucontext 385 * 386 * $25 and c0_epc point to the signal handler, $29 points to 387 * the struct rt_sigframe32. 388 */ 389 regs->regs[ 4] = ksig->sig; 390 regs->regs[ 5] = (unsigned long) &frame->rs_info; 391 regs->regs[ 6] = (unsigned long) &frame->rs_uc; 392 regs->regs[29] = (unsigned long) frame; 393 regs->regs[31] = (unsigned long) sig_return; 394 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 395 396 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 397 current->comm, current->pid, 398 frame, regs->cp0_epc, regs->regs[31]); 399 400 return 0; 401 } 402 403 /* 404 * o32 compatibility on 64-bit kernels, without DSP ASE 405 */ 406 struct mips_abi mips_abi_32 = { 407 .setup_frame = setup_frame_32, 408 .setup_rt_frame = setup_rt_frame_32, 409 .restart = __NR_O32_restart_syscall, 410 411 .off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs), 412 .off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr), 413 .off_sc_used_math = offsetof(struct sigcontext32, sc_used_math), 414 415 .vdso = &vdso_image_o32, 416 }; 417