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 #include <asm/vdso.h>
  43
  44 #include "signal-common.h"
  45
  46 /*
  47  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
  48  */
  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 struct rt_sigframe_n32 {
  71         u32 rs_ass[4];                  /* argument save space for o32 */
  72         u32 rs_pad[2];                  /* Was: signal trampoline */
  73         struct compat_siginfo rs_info;
  74         struct ucontextn32 rs_uc;
  75 };
  76
  77 extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
  78
  79 asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  80 {
  81         compat_sigset_t __user *unewset;
  82         compat_sigset_t uset;
  83         size_t sigsetsize;
  84         sigset_t newset;
  85
  86         /* XXX Don't preclude handling different sized sigset_t's.  */
  87         sigsetsize = regs.regs[5];
  88         if (sigsetsize != sizeof(sigset_t))
  89                 return -EINVAL;
  90
  91         unewset = (compat_sigset_t __user *) regs.regs[4];
  92         if (copy_from_user(&uset, unewset, sizeof(uset)))
  93                 return -EFAULT;
  94         sigset_from_compat(&newset, &uset);
  95         sigdelsetmask(&newset, ~_BLOCKABLE);
  96
  97         spin_lock_irq(&current->sighand->siglock);
  98         current->saved_sigmask = current->blocked;
  99         current->blocked = newset;
 100         recalc_sigpending();
 101         spin_unlock_irq(&current->sighand->siglock);
 102
 103         current->state = TASK_INTERRUPTIBLE;
 104         schedule();
 105         set_thread_flag(TIF_RESTORE_SIGMASK);
 106         return -ERESTARTNOHAND;
 107 }
 108
 109 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 110 {
 111         struct rt_sigframe_n32 __user *frame;
 112         mm_segment_t old_fs;
 113         sigset_t set;
 114         stack_t st;
 115         s32 sp;
 116         int sig;
 117
 118         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 119         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 120                 goto badframe;
 121         if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
 122                 goto badframe;
 123
 124         sigdelsetmask(&set, ~_BLOCKABLE);
 125         spin_lock_irq(&current->sighand->siglock);
 126         current->blocked = set;
 127         recalc_sigpending();
 128         spin_unlock_irq(&current->sighand->siglock);
 129
 130         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 131         if (sig < 0)
 132                 goto badframe;
 133         else if (sig)
 134                 force_sig(sig, current);
 135
 136         /* The ucontext contains a stack32_t, so we must convert!  */
 137         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 138                 goto badframe;
 139         st.ss_sp = (void __user *)(long) sp;
 140         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 141                 goto badframe;
 142         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 143                 goto badframe;
 144
 145         /* It is more difficult to avoid calling this function than to
 146            call it and ignore errors.  */
 147         old_fs = get_fs();
 148         set_fs(KERNEL_DS);
 149         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 150         set_fs(old_fs);
 151
 152
 153         /*
 154          * Don't let your children do this ...
 155          */
 156         __asm__ __volatile__(
 157                 "move\t$29, %0\n\t"
 158                 "j\tsyscall_exit"
 159                 :/* no outputs */
 160                 :"r" (&regs));
 161         /* Unreached */
 162
 163 badframe:
 164         force_sig(SIGSEGV, current);
 165 }
 166
 167 static int setup_rt_frame_n32(void *sig_return, struct k_sigaction *ka,
 168         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 169 {
 170         struct rt_sigframe_n32 __user *frame;
 171         int err = 0;
 172         s32 sp;
 173
 174         frame = get_sigframe(ka, regs, sizeof(*frame));
 175         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 176                 goto give_sigsegv;
 177
 178         /* Create siginfo.  */
 179         err |= copy_siginfo_to_user32(&frame->rs_info, info);
 180
 181         /* Create the ucontext.  */
 182         err |= __put_user(0, &frame->rs_uc.uc_flags);
 183         err |= __put_user(0, &frame->rs_uc.uc_link);
 184         sp = (int) (long) current->sas_ss_sp;
 185         err |= __put_user(sp,
 186                           &frame->rs_uc.uc_stack.ss_sp);
 187         err |= __put_user(sas_ss_flags(regs->regs[29]),
 188                           &frame->rs_uc.uc_stack.ss_flags);
 189         err |= __put_user(current->sas_ss_size,
 190                           &frame->rs_uc.uc_stack.ss_size);
 191         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 192         err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 193
 194         if (err)
 195                 goto give_sigsegv;
 196
 197         /*
 198          * Arguments to signal handler:
 199          *
 200          *   a0 = signal number
 201          *   a1 = 0 (should be cause)
 202          *   a2 = pointer to ucontext
 203          *
 204          * $25 and c0_epc point to the signal handler, $29 points to
 205          * the struct rt_sigframe.
 206          */
 207         regs->regs[ 4] = signr;
 208         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 209         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 210         regs->regs[29] = (unsigned long) frame;
 211         regs->regs[31] = (unsigned long) sig_return;
 212         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 213
 214         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 215                current->comm, current->pid,
 216                frame, regs->cp0_epc, regs->regs[31]);
 217
 218         return 0;
 219
 220 give_sigsegv:
 221         force_sigsegv(signr, current);
 222         return -EFAULT;
 223 }
 224
 225 struct mips_abi mips_abi_n32 = {
 226         .setup_rt_frame = setup_rt_frame_n32,
 227         .rt_signal_return_offset =
 228                 offsetof(struct mips_vdso, n32_rt_signal_trampoline),
 229         .restart        = __NR_N32_restart_syscall
 230 };