arch/mips/kernel/signal_n32.c

   1 /*
   2  * Copyright (C) 2003 Broadcom Corporation
   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; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18 #include <linux/cache.h>
  19 #include <linux/sched.h>
  20 #include <linux/mm.h>
  21 #include <linux/smp.h>
  22 #include <linux/kernel.h>
  23 #include <linux/signal.h>
  24 #include <linux/errno.h>
  25 #include <linux/wait.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/unistd.h>
  28 #include <linux/compat.h>
  29 #include <linux/bitops.h>
  30
  31 #include <asm/abi.h>
  32 #include <asm/asm.h>
  33 #include <asm/cacheflush.h>
  34 #include <asm/compat-signal.h>
  35 #include <asm/sim.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/ucontext.h>
  38 #include <asm/system.h>
  39 #include <asm/fpu.h>
  40 #include <asm/cpu-features.h>
  41 #include <asm/war.h>
  42
  43 #include "signal-common.h"
  44
  45 /*
  46  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
  47  */
  48 #define __NR_N32_rt_sigreturn           6211
  49 #define __NR_N32_restart_syscall        6214
  50
  51 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  52 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  53
  54
  55 /* IRIX compatible stack_t  */
  56 typedef struct sigaltstack32 {
  57         s32 ss_sp;
  58         compat_size_t ss_size;
  59         int ss_flags;
  60 } stack32_t;
  61
  62 struct ucontextn32 {
  63         u32                 uc_flags;
  64         s32                 uc_link;
  65         stack32_t           uc_stack;
  66         struct sigcontext   uc_mcontext;
  67         compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
  68 };
  69
  70 #if ICACHE_REFILLS_WORKAROUND_WAR == 0
  71
  72 struct rt_sigframe_n32 {
  73         u32 rs_ass[4];                  /* argument save space for o32 */
  74         u32 rs_code[2];                 /* signal trampoline */
  75         struct compat_siginfo rs_info;
  76         struct ucontextn32 rs_uc;
  77 };
  78
  79 #else  /* ICACHE_REFILLS_WORKAROUND_WAR */
  80
  81 struct rt_sigframe_n32 {
  82         u32 rs_ass[4];                  /* argument save space for o32 */
  83         u32 rs_pad[2];
  84         struct compat_siginfo rs_info;
  85         struct ucontextn32 rs_uc;
  86         u32 rs_code[8] ____cacheline_aligned;           /* signal trampoline */
  87 };
  88
  89 #endif  /* !ICACHE_REFILLS_WORKAROUND_WAR */
  90
  91 extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
  92
  93 asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  94 {
  95         compat_sigset_t __user *unewset;
  96         compat_sigset_t uset;
  97         size_t sigsetsize;
  98         sigset_t newset;
  99
 100         /* XXX Don't preclude handling different sized sigset_t's.  */
 101         sigsetsize = regs.regs[5];
 102         if (sigsetsize != sizeof(sigset_t))
 103                 return -EINVAL;
 104
 105         unewset = (compat_sigset_t __user *) regs.regs[4];
 106         if (copy_from_user(&uset, unewset, sizeof(uset)))
 107                 return -EFAULT;
 108         sigset_from_compat(&newset, &uset);
 109         sigdelsetmask(&newset, ~_BLOCKABLE);
 110
 111         spin_lock_irq(&current->sighand->siglock);
 112         current->saved_sigmask = current->blocked;
 113         current->blocked = newset;
 114         recalc_sigpending();
 115         spin_unlock_irq(&current->sighand->siglock);
 116
 117         current->state = TASK_INTERRUPTIBLE;
 118         schedule();
 119         set_thread_flag(TIF_RESTORE_SIGMASK);
 120         return -ERESTARTNOHAND;
 121 }
 122
 123 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 124 {
 125         struct rt_sigframe_n32 __user *frame;
 126         sigset_t set;
 127         stack_t st;
 128         s32 sp;
 129         int sig;
 130
 131         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 132         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 133                 goto badframe;
 134         if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
 135                 goto badframe;
 136
 137         sigdelsetmask(&set, ~_BLOCKABLE);
 138         spin_lock_irq(&current->sighand->siglock);
 139         current->blocked = set;
 140         recalc_sigpending();
 141         spin_unlock_irq(&current->sighand->siglock);
 142
 143         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 144         if (sig < 0)
 145                 goto badframe;
 146         else if (sig)
 147                 force_sig(sig, current);
 148
 149         /* The ucontext contains a stack32_t, so we must convert!  */
 150         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 151                 goto badframe;
 152         st.ss_sp = (void __user *)(long) sp;
 153         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 154                 goto badframe;
 155         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 156                 goto badframe;
 157
 158         /* It is more difficult to avoid calling this function than to
 159            call it and ignore errors.  */
 160         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 161
 162         /*
 163          * Don't let your children do this ...
 164          */
 165         __asm__ __volatile__(
 166                 "move\t$29, %0\n\t"
 167                 "j\tsyscall_exit"
 168                 :/* no outputs */
 169                 :"r" (&regs));
 170         /* Unreached */
 171
 172 badframe:
 173         force_sig(SIGSEGV, current);
 174 }
 175
 176 static int setup_rt_frame_n32(struct k_sigaction * ka,
 177         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 178 {
 179         struct rt_sigframe_n32 __user *frame;
 180         int err = 0;
 181         s32 sp;
 182
 183         frame = get_sigframe(ka, regs, sizeof(*frame));
 184         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 185                 goto give_sigsegv;
 186
 187         install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
 188
 189         /* Create siginfo.  */
 190         err |= copy_siginfo_to_user32(&frame->rs_info, info);
 191
 192         /* Create the ucontext.  */
 193         err |= __put_user(0, &frame->rs_uc.uc_flags);
 194         err |= __put_user(0, &frame->rs_uc.uc_link);
 195         sp = (int) (long) current->sas_ss_sp;
 196         err |= __put_user(sp,
 197                           &frame->rs_uc.uc_stack.ss_sp);
 198         err |= __put_user(sas_ss_flags(regs->regs[29]),
 199                           &frame->rs_uc.uc_stack.ss_flags);
 200         err |= __put_user(current->sas_ss_size,
 201                           &frame->rs_uc.uc_stack.ss_size);
 202         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 203         err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 204
 205         if (err)
 206                 goto give_sigsegv;
 207
 208         /*
 209          * Arguments to signal handler:
 210          *
 211          *   a0 = signal number
 212          *   a1 = 0 (should be cause)
 213          *   a2 = pointer to ucontext
 214          *
 215          * $25 and c0_epc point to the signal handler, $29 points to
 216          * the struct rt_sigframe.
 217          */
 218         regs->regs[ 4] = signr;
 219         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 220         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 221         regs->regs[29] = (unsigned long) frame;
 222         regs->regs[31] = (unsigned long) frame->rs_code;
 223         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 224
 225         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 226                current->comm, current->pid,
 227                frame, regs->cp0_epc, regs->regs[31]);
 228
 229         return 0;
 230
 231 give_sigsegv:
 232         force_sigsegv(signr, current);
 233         return -EFAULT;
 234 }
 235
 236 struct mips_abi mips_abi_n32 = {
 237         .setup_rt_frame = setup_rt_frame_n32,
 238         .restart        = __NR_N32_restart_syscall
 239 };