1/* 2 * Copyright 2010 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 */ 14 15#include <linux/sched.h> 16#include <linux/mm.h> 17#include <linux/smp.h> 18#include <linux/smp_lock.h> 19#include <linux/kernel.h> 20#include <linux/signal.h> 21#include <linux/errno.h> 22#include <linux/wait.h> 23#include <linux/unistd.h> 24#include <linux/stddef.h> 25#include <linux/personality.h> 26#include <linux/suspend.h> 27#include <linux/ptrace.h> 28#include <linux/elf.h> 29#include <linux/compat.h> 30#include <linux/syscalls.h> 31#include <linux/uaccess.h> 32#include <asm/processor.h> 33#include <asm/ucontext.h> 34#include <asm/sigframe.h> 35#include <asm/syscalls.h> 36#include <arch/interrupts.h> 37 38struct compat_sigaction { 39 compat_uptr_t sa_handler; 40 compat_ulong_t sa_flags; 41 compat_uptr_t sa_restorer; 42 sigset_t sa_mask __packed; 43}; 44 45struct compat_sigaltstack { 46 compat_uptr_t ss_sp; 47 int ss_flags; 48 compat_size_t ss_size; 49}; 50 51struct compat_ucontext { 52 compat_ulong_t uc_flags; 53 compat_uptr_t uc_link; 54 struct compat_sigaltstack uc_stack; 55 struct sigcontext uc_mcontext; 56 sigset_t uc_sigmask; /* mask last for extensibility */ 57}; 58 59#define COMPAT_SI_PAD_SIZE ((SI_MAX_SIZE - 3 * sizeof(int)) / sizeof(int)) 60 61struct compat_siginfo { 62 int si_signo; 63 int si_errno; 64 int si_code; 65 66 union { 67 int _pad[COMPAT_SI_PAD_SIZE]; 68 69 /* kill() */ 70 struct { 71 unsigned int _pid; /* sender's pid */ 72 unsigned int _uid; /* sender's uid */ 73 } _kill; 74 75 /* POSIX.1b timers */ 76 struct { 77 compat_timer_t _tid; /* timer id */ 78 int _overrun; /* overrun count */ 79 compat_sigval_t _sigval; /* same as below */ 80 int _sys_private; /* not to be passed to user */ 81 int _overrun_incr; /* amount to add to overrun */ 82 } _timer; 83 84 /* POSIX.1b signals */ 85 struct { 86 unsigned int _pid; /* sender's pid */ 87 unsigned int _uid; /* sender's uid */ 88 compat_sigval_t _sigval; 89 } _rt; 90 91 /* SIGCHLD */ 92 struct { 93 unsigned int _pid; /* which child */ 94 unsigned int _uid; /* sender's uid */ 95 int _status; /* exit code */ 96 compat_clock_t _utime; 97 compat_clock_t _stime; 98 } _sigchld; 99 100 /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */ 101 struct { 102 unsigned int _addr; /* faulting insn/memory ref. */ 103#ifdef __ARCH_SI_TRAPNO 104 int _trapno; /* TRAP # which caused the signal */ 105#endif 106 } _sigfault; 107 108 /* SIGPOLL */ 109 struct { 110 int _band; /* POLL_IN, POLL_OUT, POLL_MSG */ 111 int _fd; 112 } _sigpoll; 113 } _sifields; 114}; 115 116struct compat_rt_sigframe { 117 unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */ 118 struct compat_siginfo info; 119 struct compat_ucontext uc; 120}; 121 122#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) 123 124long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act, 125 struct compat_sigaction __user *oact, 126 size_t sigsetsize) 127{ 128 struct k_sigaction new_sa, old_sa; 129 int ret = -EINVAL; 130 131 if (sigsetsize != sizeof(sigset_t)) 132 goto out; 133 134 if (act) { 135 compat_uptr_t handler, restorer; 136 137 if (!access_ok(VERIFY_READ, act, sizeof(*act)) || 138 __get_user(handler, &act->sa_handler) || 139 __get_user(new_sa.sa.sa_flags, &act->sa_flags) || 140 __get_user(restorer, &act->sa_restorer) || 141 __copy_from_user(&new_sa.sa.sa_mask, &act->sa_mask, 142 sizeof(sigset_t))) 143 return -EFAULT; 144 new_sa.sa.sa_handler = compat_ptr(handler); 145 new_sa.sa.sa_restorer = compat_ptr(restorer); 146 } 147 148 ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); 149 150 if (!ret && oact) { 151 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || 152 __put_user(ptr_to_compat(old_sa.sa.sa_handler), 153 &oact->sa_handler) || 154 __put_user(ptr_to_compat(old_sa.sa.sa_restorer), 155 &oact->sa_restorer) || 156 __put_user(old_sa.sa.sa_flags, &oact->sa_flags) || 157 __copy_to_user(&oact->sa_mask, &old_sa.sa.sa_mask, 158 sizeof(sigset_t))) 159 return -EFAULT; 160 } 161out: 162 return ret; 163} 164 165long compat_sys_rt_sigqueueinfo(int pid, int sig, 166 struct compat_siginfo __user *uinfo) 167{ 168 siginfo_t info; 169 int ret; 170 mm_segment_t old_fs = get_fs(); 171 172 if (copy_siginfo_from_user32(&info, uinfo)) 173 return -EFAULT; 174 set_fs(KERNEL_DS); 175 ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *)&info); 176 set_fs(old_fs); 177 return ret; 178} 179 180int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from) 181{ 182 int err; 183 184 if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo))) 185 return -EFAULT; 186 187 /* If you change siginfo_t structure, please make sure that 188 this code is fixed accordingly. 189 It should never copy any pad contained in the structure 190 to avoid security leaks, but must copy the generic 191 3 ints plus the relevant union member. */ 192 err = __put_user(from->si_signo, &to->si_signo); 193 err |= __put_user(from->si_errno, &to->si_errno); 194 err |= __put_user((short)from->si_code, &to->si_code); 195 196 if (from->si_code < 0) { 197 err |= __put_user(from->si_pid, &to->si_pid); 198 err |= __put_user(from->si_uid, &to->si_uid); 199 err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr); 200 } else { 201 /* 202 * First 32bits of unions are always present: 203 * si_pid === si_band === si_tid === si_addr(LS half) 204 */ 205 err |= __put_user(from->_sifields._pad[0], 206 &to->_sifields._pad[0]); 207 switch (from->si_code >> 16) { 208 case __SI_FAULT >> 16: 209 break; 210 case __SI_CHLD >> 16: 211 err |= __put_user(from->si_utime, &to->si_utime); 212 err |= __put_user(from->si_stime, &to->si_stime); 213 err |= __put_user(from->si_status, &to->si_status); 214 /* FALL THROUGH */ 215 default: 216 case __SI_KILL >> 16: 217 err |= __put_user(from->si_uid, &to->si_uid); 218 break; 219 case __SI_POLL >> 16: 220 err |= __put_user(from->si_fd, &to->si_fd); 221 break; 222 case __SI_TIMER >> 16: 223 err |= __put_user(from->si_overrun, &to->si_overrun); 224 err |= __put_user(ptr_to_compat(from->si_ptr), 225 &to->si_ptr); 226 break; 227 /* This is not generated by the kernel as of now. */ 228 case __SI_RT >> 16: 229 case __SI_MESGQ >> 16: 230 err |= __put_user(from->si_uid, &to->si_uid); 231 err |= __put_user(from->si_int, &to->si_int); 232 break; 233 } 234 } 235 return err; 236} 237 238int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from) 239{ 240 int err; 241 u32 ptr32; 242 243 if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo))) 244 return -EFAULT; 245 246 err = __get_user(to->si_signo, &from->si_signo); 247 err |= __get_user(to->si_errno, &from->si_errno); 248 err |= __get_user(to->si_code, &from->si_code); 249 250 err |= __get_user(to->si_pid, &from->si_pid); 251 err |= __get_user(to->si_uid, &from->si_uid); 252 err |= __get_user(ptr32, &from->si_ptr); 253 to->si_ptr = compat_ptr(ptr32); 254 255 return err; 256} 257 258long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, 259 struct compat_sigaltstack __user *uoss_ptr, 260 struct pt_regs *regs) 261{ 262 stack_t uss, uoss; 263 int ret; 264 mm_segment_t seg; 265 266 if (uss_ptr) { 267 u32 ptr; 268 269 memset(&uss, 0, sizeof(stack_t)); 270 if (!access_ok(VERIFY_READ, uss_ptr, sizeof(*uss_ptr)) || 271 __get_user(ptr, &uss_ptr->ss_sp) || 272 __get_user(uss.ss_flags, &uss_ptr->ss_flags) || 273 __get_user(uss.ss_size, &uss_ptr->ss_size)) 274 return -EFAULT; 275 uss.ss_sp = compat_ptr(ptr); 276 } 277 seg = get_fs(); 278 set_fs(KERNEL_DS); 279 ret = do_sigaltstack(uss_ptr ? (stack_t __user __force *)&uss : NULL, 280 (stack_t __user __force *)&uoss, 281 (unsigned long)compat_ptr(regs->sp)); 282 set_fs(seg); 283 if (ret >= 0 && uoss_ptr) { 284 if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(*uoss_ptr)) || 285 __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) || 286 __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) || 287 __put_user(uoss.ss_size, &uoss_ptr->ss_size)) 288 ret = -EFAULT; 289 } 290 return ret; 291} 292 293long _compat_sys_rt_sigreturn(struct pt_regs *regs) 294{ 295 struct compat_rt_sigframe __user *frame = 296 (struct compat_rt_sigframe __user *) compat_ptr(regs->sp); 297 sigset_t set; 298 long r0; 299 300 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 301 goto badframe; 302 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) 303 goto badframe; 304 305 sigdelsetmask(&set, ~_BLOCKABLE); 306 spin_lock_irq(¤t->sighand->siglock); 307 current->blocked = set; 308 recalc_sigpending(); 309 spin_unlock_irq(¤t->sighand->siglock); 310 311 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) 312 goto badframe; 313 314 if (_compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0) 315 goto badframe; 316 317 return r0; 318 319badframe: 320 force_sig(SIGSEGV, current); 321 return 0; 322} 323 324/* 325 * Determine which stack to use.. 326 */ 327static inline void __user *compat_get_sigframe(struct k_sigaction *ka, 328 struct pt_regs *regs, 329 size_t frame_size) 330{ 331 unsigned long sp; 332 333 /* Default to using normal stack */ 334 sp = (unsigned long)compat_ptr(regs->sp); 335 336 /* 337 * If we are on the alternate signal stack and would overflow 338 * it, don't. Return an always-bogus address instead so we 339 * will die with SIGSEGV. 340 */ 341 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) 342 return (void __user __force *)-1UL; 343 344 /* This is the X/Open sanctioned signal stack switching. */ 345 if (ka->sa.sa_flags & SA_ONSTACK) { 346 if (sas_ss_flags(sp) == 0) 347 sp = current->sas_ss_sp + current->sas_ss_size; 348 } 349 350 sp -= frame_size; 351 /* 352 * Align the stack pointer according to the TILE ABI, 353 * i.e. so that on function entry (sp & 15) == 0. 354 */ 355 sp &= -16UL; 356 return (void __user *) sp; 357} 358 359int compat_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 360 sigset_t *set, struct pt_regs *regs) 361{ 362 unsigned long restorer; 363 struct compat_rt_sigframe __user *frame; 364 int err = 0; 365 int usig; 366 367 frame = compat_get_sigframe(ka, regs, sizeof(*frame)); 368 369 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 370 goto give_sigsegv; 371 372 usig = current_thread_info()->exec_domain 373 && current_thread_info()->exec_domain->signal_invmap 374 && sig < 32 375 ? current_thread_info()->exec_domain->signal_invmap[sig] 376 : sig; 377 378 /* Always write at least the signal number for the stack backtracer. */ 379 if (ka->sa.sa_flags & SA_SIGINFO) { 380 /* At sigreturn time, restore the callee-save registers too. */ 381 err |= copy_siginfo_to_user32(&frame->info, info); 382 regs->flags |= PT_FLAGS_RESTORE_REGS; 383 } else { 384 err |= __put_user(info->si_signo, &frame->info.si_signo); 385 } 386 387 /* Create the ucontext. */ 388 err |= __clear_user(&frame->save_area, sizeof(frame->save_area)); 389 err |= __put_user(0, &frame->uc.uc_flags); 390 err |= __put_user(0, &frame->uc.uc_link); 391 err |= __put_user(ptr_to_compat((void *)(current->sas_ss_sp)), 392 &frame->uc.uc_stack.ss_sp); 393 err |= __put_user(sas_ss_flags(regs->sp), 394 &frame->uc.uc_stack.ss_flags); 395 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); 396 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); 397 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 398 if (err) 399 goto give_sigsegv; 400 401 restorer = VDSO_BASE; 402 if (ka->sa.sa_flags & SA_RESTORER) 403 restorer = ptr_to_compat_reg(ka->sa.sa_restorer); 404 405 /* 406 * Set up registers for signal handler. 407 * Registers that we don't modify keep the value they had from 408 * user-space at the time we took the signal. 409 */ 410 regs->pc = ptr_to_compat_reg(ka->sa.sa_handler); 411 regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */ 412 regs->sp = ptr_to_compat_reg(frame); 413 regs->lr = restorer; 414 regs->regs[0] = (unsigned long) usig; 415 416 if (ka->sa.sa_flags & SA_SIGINFO) { 417 /* Need extra arguments, so mark to restore caller-saves. */ 418 regs->regs[1] = ptr_to_compat_reg(&frame->info); 419 regs->regs[2] = ptr_to_compat_reg(&frame->uc); 420 regs->flags |= PT_FLAGS_CALLER_SAVES; 421 } 422 423 /* 424 * Notify any tracer that was single-stepping it. 425 * The tracer may want to single-step inside the 426 * handler too. 427 */ 428 if (test_thread_flag(TIF_SINGLESTEP)) 429 ptrace_notify(SIGTRAP); 430 431 return 0; 432 433give_sigsegv: 434 force_sigsegv(sig, current); 435 return -EFAULT; 436} 437