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         current->saved_sigmask = current->blocked;
  98         set_current_blocked(&newset);
  99
 100         current->state = TASK_INTERRUPTIBLE;
 101         schedule();
 102         set_thread_flag(TIF_RESTORE_SIGMASK);
 103         return -ERESTARTNOHAND;
 104 }
 105
 106 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 107 {
 108         struct rt_sigframe_n32 __user *frame;
 109         mm_segment_t old_fs;
 110         sigset_t set;
 111         stack_t st;
 112         s32 sp;
 113         int sig;
 114
 115         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 116         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 117                 goto badframe;
 118         if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
 119                 goto badframe;
 120
 121         sigdelsetmask(&set, ~_BLOCKABLE);
 122         set_current_blocked(&set);
 123
 124         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 125         if (sig < 0)
 126                 goto badframe;
 127         else if (sig)
 128                 force_sig(sig, current);
 129
 130         /* The ucontext contains a stack32_t, so we must convert!  */
 131         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 132                 goto badframe;
 133         st.ss_sp = (void __user *)(long) sp;
 134         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 135                 goto badframe;
 136         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 137                 goto badframe;
 138
 139         /* It is more difficult to avoid calling this function than to
 140            call it and ignore errors.  */
 141         old_fs = get_fs();
 142         set_fs(KERNEL_DS);
 143         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 144         set_fs(old_fs);
 145
 146
 147         /*
 148          * Don't let your children do this ...
 149          */
 150         __asm__ __volatile__(
 151                 "move\t$29, %0\n\t"
 152                 "j\tsyscall_exit"
 153                 :/* no outputs */
 154                 :"r" (&regs));
 155         /* Unreached */
 156
 157 badframe:
 158         force_sig(SIGSEGV, current);
 159 }
 160
 161 static int setup_rt_frame_n32(void *sig_return, struct k_sigaction *ka,
 162         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 163 {
 164         struct rt_sigframe_n32 __user *frame;
 165         int err = 0;
 166         s32 sp;
 167
 168         frame = get_sigframe(ka, regs, sizeof(*frame));
 169         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 170                 goto give_sigsegv;
 171
 172         /* Create siginfo.  */
 173         err |= copy_siginfo_to_user32(&frame->rs_info, info);
 174
 175         /* Create the ucontext.  */
 176         err |= __put_user(0, &frame->rs_uc.uc_flags);
 177         err |= __put_user(0, &frame->rs_uc.uc_link);
 178         sp = (int) (long) current->sas_ss_sp;
 179         err |= __put_user(sp,
 180                           &frame->rs_uc.uc_stack.ss_sp);
 181         err |= __put_user(sas_ss_flags(regs->regs[29]),
 182                           &frame->rs_uc.uc_stack.ss_flags);
 183         err |= __put_user(current->sas_ss_size,
 184                           &frame->rs_uc.uc_stack.ss_size);
 185         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 186         err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 187
 188         if (err)
 189                 goto give_sigsegv;
 190
 191         /*
 192          * Arguments to signal handler:
 193          *
 194          *   a0 = signal number
 195          *   a1 = 0 (should be cause)
 196          *   a2 = pointer to ucontext
 197          *
 198          * $25 and c0_epc point to the signal handler, $29 points to
 199          * the struct rt_sigframe.
 200          */
 201         regs->regs[ 4] = signr;
 202         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 203         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 204         regs->regs[29] = (unsigned long) frame;
 205         regs->regs[31] = (unsigned long) sig_return;
 206         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 207
 208         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 209                current->comm, current->pid,
 210                frame, regs->cp0_epc, regs->regs[31]);
 211
 212         return 0;
 213
 214 give_sigsegv:
 215         force_sigsegv(signr, current);
 216         return -EFAULT;
 217 }
 218
 219 struct mips_abi mips_abi_n32 = {
 220         .setup_rt_frame = setup_rt_frame_n32,
 221         .rt_signal_return_offset =
 222                 offsetof(struct mips_vdso, n32_rt_signal_trampoline),
 223         .restart        = __NR_N32_restart_syscall
 224 };