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/smp_lock.h>
  23 #include <linux/kernel.h>
  24 #include <linux/signal.h>
  25 #include <linux/errno.h>
  26 #include <linux/wait.h>
  27 #include <linux/ptrace.h>
  28 #include <linux/unistd.h>
  29 #include <linux/compat.h>
  30 #include <linux/bitops.h>
  31
  32 #include <asm/abi.h>
  33 #include <asm/asm.h>
  34 #include <asm/cacheflush.h>
  35 #include <asm/compat-signal.h>
  36 #include <asm/sim.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/ucontext.h>
  39 #include <asm/system.h>
  40 #include <asm/fpu.h>
  41 #include <asm/cpu-features.h>
  42 #include <asm/war.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_rt_sigreturn           6211
  50 #define __NR_N32_restart_syscall        6214
  51
  52 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  53 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  54
  55
  56 /* IRIX compatible stack_t  */
  57 typedef struct sigaltstack32 {
  58         s32 ss_sp;
  59         compat_size_t ss_size;
  60         int ss_flags;
  61 } stack32_t;
  62
  63 struct ucontextn32 {
  64         u32                 uc_flags;
  65         s32                 uc_link;
  66         stack32_t           uc_stack;
  67         struct sigcontext   uc_mcontext;
  68         compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
  69 };
  70
  71 #if ICACHE_REFILLS_WORKAROUND_WAR == 0
  72
  73 struct rt_sigframe_n32 {
  74         u32 rs_ass[4];                  /* argument save space for o32 */
  75         u32 rs_code[2];                 /* signal trampoline */
  76         struct siginfo rs_info;
  77         struct ucontextn32 rs_uc;
  78 };
  79
  80 #else  /* ICACHE_REFILLS_WORKAROUND_WAR */
  81
  82 struct rt_sigframe_n32 {
  83         u32 rs_ass[4];                  /* argument save space for o32 */
  84         u32 rs_pad[2];
  85         struct siginfo rs_info;
  86         struct ucontextn32 rs_uc;
  87         u32 rs_code[8] ____cacheline_aligned;           /* signal trampoline */
  88 };
  89
  90 #endif  /* !ICACHE_REFILLS_WORKAROUND_WAR */
  91
  92 extern void sigset_from_compat (sigset_t *set, compat_sigset_t *compat);
  93
  94 asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  95 {
  96         compat_sigset_t __user *unewset;
  97         compat_sigset_t uset;
  98         size_t sigsetsize;
  99         sigset_t newset;
 100
 101         /* XXX Don't preclude handling different sized sigset_t's.  */
 102         sigsetsize = regs.regs[5];
 103         if (sigsetsize != sizeof(sigset_t))
 104                 return -EINVAL;
 105
 106         unewset = (compat_sigset_t __user *) regs.regs[4];
 107         if (copy_from_user(&uset, unewset, sizeof(uset)))
 108                 return -EFAULT;
 109         sigset_from_compat (&newset, &uset);
 110         sigdelsetmask(&newset, ~_BLOCKABLE);
 111
 112         spin_lock_irq(&current->sighand->siglock);
 113         current->saved_sigmask = current->blocked;
 114         current->blocked = newset;
 115         recalc_sigpending();
 116         spin_unlock_irq(&current->sighand->siglock);
 117
 118         current->state = TASK_INTERRUPTIBLE;
 119         schedule();
 120         set_thread_flag(TIF_RESTORE_SIGMASK);
 121         return -ERESTARTNOHAND;
 122 }
 123
 124 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 125 {
 126         struct rt_sigframe_n32 __user *frame;
 127         sigset_t set;
 128         stack_t st;
 129         s32 sp;
 130         int sig;
 131
 132         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 133         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 134                 goto badframe;
 135         if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
 136                 goto badframe;
 137
 138         sigdelsetmask(&set, ~_BLOCKABLE);
 139         spin_lock_irq(&current->sighand->siglock);
 140         current->blocked = set;
 141         recalc_sigpending();
 142         spin_unlock_irq(&current->sighand->siglock);
 143
 144         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 145         if (sig < 0)
 146                 goto badframe;
 147         else if (sig)
 148                 force_sig(sig, current);
 149
 150         /* The ucontext contains a stack32_t, so we must convert!  */
 151         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 152                 goto badframe;
 153         st.ss_sp = (void __user *)(long) sp;
 154         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 155                 goto badframe;
 156         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 157                 goto badframe;
 158
 159         /* It is more difficult to avoid calling this function than to
 160            call it and ignore errors.  */
 161         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 162
 163         /*
 164          * Don't let your children do this ...
 165          */
 166         __asm__ __volatile__(
 167                 "move\t$29, %0\n\t"
 168                 "j\tsyscall_exit"
 169                 :/* no outputs */
 170                 :"r" (&regs));
 171         /* Unreached */
 172
 173 badframe:
 174         force_sig(SIGSEGV, current);
 175 }
 176
 177 static int setup_rt_frame_n32(struct k_sigaction * ka,
 178         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 179 {
 180         struct rt_sigframe_n32 __user *frame;
 181         int err = 0;
 182         s32 sp;
 183
 184         frame = get_sigframe(ka, regs, sizeof(*frame));
 185         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 186                 goto give_sigsegv;
 187
 188         install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
 189
 190         /* Create siginfo.  */
 191         err |= copy_siginfo_to_user(&frame->rs_info, info);
 192
 193         /* Create the ucontext.  */
 194         err |= __put_user(0, &frame->rs_uc.uc_flags);
 195         err |= __put_user(0, &frame->rs_uc.uc_link);
 196         sp = (int) (long) current->sas_ss_sp;
 197         err |= __put_user(sp,
 198                           &frame->rs_uc.uc_stack.ss_sp);
 199         err |= __put_user(sas_ss_flags(regs->regs[29]),
 200                           &frame->rs_uc.uc_stack.ss_flags);
 201         err |= __put_user(current->sas_ss_size,
 202                           &frame->rs_uc.uc_stack.ss_size);
 203         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 204         err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 205
 206         if (err)
 207                 goto give_sigsegv;
 208
 209         /*
 210          * Arguments to signal handler:
 211          *
 212          *   a0 = signal number
 213          *   a1 = 0 (should be cause)
 214          *   a2 = pointer to ucontext
 215          *
 216          * $25 and c0_epc point to the signal handler, $29 points to
 217          * the struct rt_sigframe.
 218          */
 219         regs->regs[ 4] = signr;
 220         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 221         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 222         regs->regs[29] = (unsigned long) frame;
 223         regs->regs[31] = (unsigned long) frame->rs_code;
 224         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 225
 226         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 227                current->comm, current->pid,
 228                frame, regs->cp0_epc, regs->regs[31]);
 229
 230         return 0;
 231
 232 give_sigsegv:
 233         force_sigsegv(signr, current);
 234         return -EFAULT;
 235 }
 236
 237 struct mips_abi mips_abi_n32 = {
 238         .setup_rt_frame = setup_rt_frame_n32,
 239         .restart        = __NR_N32_restart_syscall
 240 };