arch/score/kernel/signal.c

   1 /*
   2  * arch/score/kernel/signal.c
   3  *
   4  * Score Processor version.
   5  *
   6  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
   7  *  Chen Liqin <liqin.chen@sunplusct.com>
   8  *  Lennox Wu <lennox.wu@sunplusct.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, see the file COPYING, or write
  22  * to the Free Software Foundation, Inc.,
  23  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  24  */
  25
  26 #include <linux/errno.h>
  27 #include <linux/signal.h>
  28 #include <linux/unistd.h>
  29 #include <linux/uaccess.h>
  30 #include <asm-generic/ucontext.h>
  31
  32 #include <asm/cacheflush.h>
  33
  34 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  35
  36 struct rt_sigframe {
  37         u32 rs_ass[4];          /* argument save space */
  38         u32 rs_code[2];         /* signal trampoline */
  39         struct siginfo rs_info;
  40         struct ucontext rs_uc;
  41 };
  42
  43 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
  44 {
  45         int err = 0;
  46         unsigned long reg;
  47
  48         reg = regs->cp0_epc; err |= __put_user(reg, &sc->sc_pc);
  49         err |= __put_user(regs->cp0_psr, &sc->sc_psr);
  50         err |= __put_user(regs->cp0_condition, &sc->sc_condition);
  51
  52
  53 #define save_gp_reg(i) {                                \
  54         reg = regs->regs[i];                            \
  55         err |= __put_user(reg, &sc->sc_regs[i]);        \
  56 } while (0)
  57         save_gp_reg(0); save_gp_reg(1); save_gp_reg(2);
  58         save_gp_reg(3); save_gp_reg(4); save_gp_reg(5);
  59         save_gp_reg(6); save_gp_reg(7); save_gp_reg(8);
  60         save_gp_reg(9); save_gp_reg(10); save_gp_reg(11);
  61         save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
  62         save_gp_reg(15); save_gp_reg(16); save_gp_reg(17);
  63         save_gp_reg(18); save_gp_reg(19); save_gp_reg(20);
  64         save_gp_reg(21); save_gp_reg(22); save_gp_reg(23);
  65         save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
  66         save_gp_reg(27); save_gp_reg(28); save_gp_reg(29);
  67 #undef save_gp_reg
  68
  69         reg = regs->ceh; err |= __put_user(reg, &sc->sc_mdceh);
  70         reg = regs->cel; err |= __put_user(reg, &sc->sc_mdcel);
  71         err |= __put_user(regs->cp0_ecr, &sc->sc_ecr);
  72         err |= __put_user(regs->cp0_ema, &sc->sc_ema);
  73
  74         return err;
  75 }
  76
  77 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
  78 {
  79         int err = 0;
  80         u32 reg;
  81
  82         err |= __get_user(regs->cp0_epc, &sc->sc_pc);
  83         err |= __get_user(regs->cp0_condition, &sc->sc_condition);
  84
  85         err |= __get_user(reg, &sc->sc_mdceh);
  86         regs->ceh = (int) reg;
  87         err |= __get_user(reg, &sc->sc_mdcel);
  88         regs->cel = (int) reg;
  89
  90         err |= __get_user(reg, &sc->sc_psr);
  91         regs->cp0_psr = (int) reg;
  92         err |= __get_user(reg, &sc->sc_ecr);
  93         regs->cp0_ecr = (int) reg;
  94         err |= __get_user(reg, &sc->sc_ema);
  95         regs->cp0_ema = (int) reg;
  96
  97 #define restore_gp_reg(i) do {                          \
  98         err |= __get_user(reg, &sc->sc_regs[i]);        \
  99         regs->regs[i] = reg;                            \
 100 } while (0)
 101         restore_gp_reg(0); restore_gp_reg(1); restore_gp_reg(2);
 102         restore_gp_reg(3); restore_gp_reg(4); restore_gp_reg(5);
 103         restore_gp_reg(6); restore_gp_reg(7); restore_gp_reg(8);
 104         restore_gp_reg(9); restore_gp_reg(10); restore_gp_reg(11);
 105         restore_gp_reg(12); restore_gp_reg(13); restore_gp_reg(14);
 106         restore_gp_reg(15); restore_gp_reg(16); restore_gp_reg(17);
 107         restore_gp_reg(18); restore_gp_reg(19); restore_gp_reg(20);
 108         restore_gp_reg(21); restore_gp_reg(22); restore_gp_reg(23);
 109         restore_gp_reg(24); restore_gp_reg(25); restore_gp_reg(26);
 110         restore_gp_reg(27); restore_gp_reg(28); restore_gp_reg(29);
 111 #undef restore_gp_reg
 112
 113         return err;
 114 }
 115
 116 /*
 117  * Determine which stack to use..
 118  */
 119 void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
 120                         size_t frame_size)
 121 {
 122         unsigned long sp;
 123
 124         /* Default to using normal stack */
 125         sp = regs->regs[0];
 126         sp -= 32;
 127
 128         /* This is the X/Open sanctioned signal stack switching.  */
 129         if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp)))
 130                 sp = current->sas_ss_sp + current->sas_ss_size;
 131
 132         return (void *)((sp - frame_size) & ~7);
 133 }
 134
 135 asmlinkage int score_sigaltstack(struct pt_regs *regs)
 136 {
 137         const stack_t *uss = (const stack_t *) regs->regs[4];
 138         stack_t *uoss = (stack_t *) regs->regs[5];
 139         unsigned long usp = regs->regs[0];
 140
 141         return do_sigaltstack(uss, uoss, usp);
 142 }
 143
 144 asmlinkage void score_rt_sigreturn(struct pt_regs *regs)
 145 {
 146         struct rt_sigframe __user *frame;
 147         sigset_t set;
 148         stack_t st;
 149         int sig;
 150
 151         frame = (struct rt_sigframe __user *) regs->regs[0];
 152         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 153                 goto badframe;
 154         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
 155                 goto badframe;
 156
 157         sigdelsetmask(&set, ~_BLOCKABLE);
 158         spin_lock_irq(&current->sighand->siglock);
 159         current->blocked = set;
 160         recalc_sigpending();
 161         spin_unlock_irq(&current->sighand->siglock);
 162
 163         sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 164         if (sig < 0)
 165                 goto badframe;
 166         else if (sig)
 167                 force_sig(sig, current);
 168
 169         if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
 170                 goto badframe;
 171
 172         /* It is more difficult to avoid calling this function than to
 173            call it and ignore errors.  */
 174         do_sigaltstack((stack_t __user *)&st, NULL, regs->regs[0]);
 175
 176         __asm__ __volatile__(
 177                 "mv\tr0, %0\n\t"
 178                 "la\tr8, syscall_exit\n\t"
 179                 "br\tr8\n\t"
 180                 : : "r" (regs) : "r8");
 181
 182 badframe:
 183         force_sig(SIGSEGV, current);
 184 }
 185
 186 int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 187                 int signr, sigset_t *set, siginfo_t *info)
 188 {
 189         struct rt_sigframe *frame;
 190         int err = 0;
 191
 192         frame = get_sigframe(ka, regs, sizeof(*frame));
 193         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 194                 goto give_sigsegv;
 195
 196         /*
 197          * Set up the return code ...
 198          *
 199          *         li      v0, __NR_rt_sigreturn
 200          *         syscall
 201          */
 202         err |= __put_user(0x87788000 + __NR_rt_sigreturn*2,
 203                         frame->rs_code + 0);
 204         err |= __put_user(0x80008002, frame->rs_code + 1);
 205         flush_cache_sigtramp((unsigned long) frame->rs_code);
 206
 207         err |= copy_siginfo_to_user(&frame->rs_info, info);
 208         err |= __put_user(0, &frame->rs_uc.uc_flags);
 209         err |= __put_user(0, &frame->rs_uc.uc_link);
 210         err |= __put_user((void *)current->sas_ss_sp,
 211                                 &frame->rs_uc.uc_stack.ss_sp);
 212         err |= __put_user(sas_ss_flags(regs->regs[0]),
 213                                 &frame->rs_uc.uc_stack.ss_flags);
 214         err |= __put_user(current->sas_ss_size,
 215                                 &frame->rs_uc.uc_stack.ss_size);
 216         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 217         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 218
 219         if (err)
 220                 goto give_sigsegv;
 221
 222         regs->regs[0] = (unsigned long) frame;
 223         regs->regs[3] = (unsigned long) frame->rs_code;
 224         regs->regs[4] = signr;
 225         regs->regs[5] = (unsigned long) &frame->rs_info;
 226         regs->regs[6] = (unsigned long) &frame->rs_uc;
 227         regs->regs[29] = (unsigned long) ka->sa.sa_handler;
 228         regs->cp0_epc = (unsigned long) ka->sa.sa_handler;
 229
 230         return 0;
 231
 232 give_sigsegv:
 233         if (signr == SIGSEGV)
 234                 ka->sa.sa_handler = SIG_DFL;
 235         force_sig(SIGSEGV, current);
 236         return -EFAULT;
 237 }
 238
 239 int handle_signal(unsigned long sig, siginfo_t *info,
 240         struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
 241 {
 242         int ret;
 243
 244         if (regs->is_syscall) {
 245                 switch (regs->regs[4]) {
 246                 case ERESTART_RESTARTBLOCK:
 247                 case ERESTARTNOHAND:
 248                         regs->regs[4] = EINTR;
 249                         break;
 250                 case ERESTARTSYS:
 251                         if (!(ka->sa.sa_flags & SA_RESTART)) {
 252                                 regs->regs[4] = EINTR;
 253                                 break;
 254                         }
 255                 case ERESTARTNOINTR:
 256                         regs->regs[4] = regs->orig_r4;
 257                         regs->regs[7] = regs->orig_r7;
 258                         regs->cp0_epc -= 8;
 259                 }
 260
 261                 regs->is_syscall = 0;
 262         }
 263
 264         /*
 265          * Set up the stack frame
 266          */
 267         ret = setup_rt_frame(ka, regs, sig, oldset, info);
 268
 269         spin_lock_irq(&current->sighand->siglock);
 270         sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
 271         if (!(ka->sa.sa_flags & SA_NODEFER))
 272                 sigaddset(&current->blocked, sig);
 273         recalc_sigpending();
 274         spin_unlock_irq(&current->sighand->siglock);
 275
 276         return ret;
 277 }
 278
 279 asmlinkage void do_signal(struct pt_regs *regs)
 280 {
 281         struct k_sigaction ka;
 282         sigset_t *oldset;
 283         siginfo_t info;
 284         int signr;
 285
 286         /*
 287          * We want the common case to go fast, which is why we may in certain
 288          * cases get here from kernel mode. Just return without doing anything
 289          * if so.
 290          */
 291         if (!user_mode(regs))
 292                 return;
 293
 294         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 295                 oldset = &current->saved_sigmask;
 296         else
 297                 oldset = &current->blocked;
 298
 299         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 300         if (signr > 0) {
 301                 /* Actually deliver the signal.  */
 302                 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
 303                         /*
 304                          * A signal was successfully delivered; the saved
 305                          * sigmask will have been stored in the signal frame,
 306                          * and will be restored by sigreturn, so we can simply
 307                          * clear the TIF_RESTORE_SIGMASK flag.
 308                          */
 309                         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 310                                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 311                 }
 312
 313                 return;
 314         }
 315
 316         if (regs->is_syscall) {
 317                 if (regs->regs[4] == ERESTARTNOHAND ||
 318                     regs->regs[4] == ERESTARTSYS ||
 319                     regs->regs[4] == ERESTARTNOINTR) {
 320                         regs->regs[4] = regs->orig_r4;
 321                         regs->regs[7] = regs->orig_r7;
 322                         regs->cp0_epc -= 8;
 323                 }
 324
 325                 if (regs->regs[4] == ERESTART_RESTARTBLOCK) {
 326                         regs->regs[27] = __NR_restart_syscall;
 327                         regs->regs[4] = regs->orig_r4;
 328                         regs->regs[7] = regs->orig_r7;
 329                         regs->cp0_epc -= 8;
 330                 }
 331
 332                 regs->is_syscall = 0;   /* Don't deal with this again.  */
 333         }
 334
 335         /*
 336          * If there's no signal to deliver, we just put the saved sigmask
 337          * back
 338          */
 339         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 340                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 341                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 342         }
 343 }
 344
 345 /*
 346  * notification of userspace execution resumption
 347  * - triggered by the TIF_WORK_MASK flags
 348  */
 349 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 350                                 __u32 thread_info_flags)
 351 {
 352         /* deal with pending signal delivery */
 353         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 354                 do_signal(regs);
 355 }