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/sched.h>
  21 #include <linux/mm.h>
  22 #include <linux/smp.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/kernel.h>
  25 #include <linux/signal.h>
  26 #include <linux/errno.h>
  27 #include <linux/wait.h>
  28 #include <linux/ptrace.h>
  29 #include <linux/unistd.h>
  30 #include <linux/compat.h>
  31 #include <linux/bitops.h>
  32
  33 #include <asm/asm.h>
  34 #include <asm/cacheflush.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 extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
  46
  47 /*
  48  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
  49  */
  50 #define __NR_N32_rt_sigreturn           6211
  51 #define __NR_N32_restart_syscall        6214
  52
  53 #define DEBUG_SIG 0
  54
  55 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  56
  57 /* IRIX compatible stack_t  */
  58 typedef struct sigaltstack32 {
  59         s32 ss_sp;
  60         compat_size_t ss_size;
  61         int ss_flags;
  62 } stack32_t;
  63
  64 struct ucontextn32 {
  65         u32                 uc_flags;
  66         s32                 uc_link;
  67         stack32_t           uc_stack;
  68         struct sigcontext   uc_mcontext;
  69         sigset_t            uc_sigmask;   /* mask last for extensibility */
  70 };
  71
  72 struct rt_sigframe_n32 {
  73         u32 rs_ass[4];                  /* argument save space for o32 */
  74 #if ICACHE_REFILLS_WORKAROUND_WAR
  75         u32 rs_pad[2];
  76 #else
  77         u32 rs_code[2];                 /* signal trampoline */
  78 #endif
  79         struct siginfo rs_info;
  80         struct ucontextn32 rs_uc;
  81 #if ICACHE_REFILLS_WORKAROUND_WAR
  82         u32 rs_code[8] ____cacheline_aligned;           /* signal trampoline */
  83 #endif
  84 };
  85
  86 save_static_function(sysn32_rt_sigsuspend);
  87 __attribute_used__ noinline static int
  88 _sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  89 {
  90         compat_sigset_t __user *unewset;
  91         compat_sigset_t uset;
  92         size_t sigsetsize;
  93         sigset_t newset;
  94
  95         /* XXX Don't preclude handling different sized sigset_t's.  */
  96         sigsetsize = regs.regs[5];
  97         if (sigsetsize != sizeof(sigset_t))
  98                 return -EINVAL;
  99
 100         unewset = (compat_sigset_t __user *) regs.regs[4];
 101         if (copy_from_user(&uset, unewset, sizeof(uset)))
 102                 return -EFAULT;
 103         sigset_from_compat (&newset, &uset);
 104         sigdelsetmask(&newset, ~_BLOCKABLE);
 105
 106         spin_lock_irq(&current->sighand->siglock);
 107         current->saved_sigmask = current->blocked;
 108         current->blocked = newset;
 109         recalc_sigpending();
 110         spin_unlock_irq(&current->sighand->siglock);
 111
 112         current->state = TASK_INTERRUPTIBLE;
 113         schedule();
 114         set_thread_flag(TIF_RESTORE_SIGMASK);
 115         return -ERESTARTNOHAND;
 116 }
 117
 118 save_static_function(sysn32_rt_sigreturn);
 119 __attribute_used__ noinline static void
 120 _sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 121 {
 122         struct rt_sigframe_n32 __user *frame;
 123         sigset_t set;
 124         stack_t st;
 125         s32 sp;
 126
 127         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 128         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 129                 goto badframe;
 130         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
 131                 goto badframe;
 132
 133         sigdelsetmask(&set, ~_BLOCKABLE);
 134         spin_lock_irq(&current->sighand->siglock);
 135         current->blocked = set;
 136         recalc_sigpending();
 137         spin_unlock_irq(&current->sighand->siglock);
 138
 139         if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
 140                 goto badframe;
 141
 142         /* The ucontext contains a stack32_t, so we must convert!  */
 143         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 144                 goto badframe;
 145         st.ss_sp = (void __user *)(long) sp;
 146         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 147                 goto badframe;
 148         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 149                 goto badframe;
 150
 151         /* It is more difficult to avoid calling this function than to
 152            call it and ignore errors.  */
 153         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 154
 155         /*
 156          * Don't let your children do this ...
 157          */
 158         __asm__ __volatile__(
 159                 "move\t$29, %0\n\t"
 160                 "j\tsyscall_exit"
 161                 :/* no outputs */
 162                 :"r" (&regs));
 163         /* Unreached */
 164
 165 badframe:
 166         force_sig(SIGSEGV, current);
 167 }
 168
 169 int setup_rt_frame_n32(struct k_sigaction * ka,
 170         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 171 {
 172         struct rt_sigframe_n32 __user *frame;
 173         int err = 0;
 174         s32 sp;
 175
 176         frame = get_sigframe(ka, regs, sizeof(*frame));
 177         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 178                 goto give_sigsegv;
 179
 180         install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
 181
 182         /* Create siginfo.  */
 183         err |= copy_siginfo_to_user(&frame->rs_info, info);
 184
 185         /* Create the ucontext.  */
 186         err |= __put_user(0, &frame->rs_uc.uc_flags);
 187         err |= __put_user(0, &frame->rs_uc.uc_link);
 188         sp = (int) (long) current->sas_ss_sp;
 189         err |= __put_user(sp,
 190                           &frame->rs_uc.uc_stack.ss_sp);
 191         err |= __put_user(sas_ss_flags(regs->regs[29]),
 192                           &frame->rs_uc.uc_stack.ss_flags);
 193         err |= __put_user(current->sas_ss_size,
 194                           &frame->rs_uc.uc_stack.ss_size);
 195         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 196         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 197
 198         if (err)
 199                 goto give_sigsegv;
 200
 201         /*
 202          * Arguments to signal handler:
 203          *
 204          *   a0 = signal number
 205          *   a1 = 0 (should be cause)
 206          *   a2 = pointer to ucontext
 207          *
 208          * $25 and c0_epc point to the signal handler, $29 points to
 209          * the struct rt_sigframe.
 210          */
 211         regs->regs[ 4] = signr;
 212         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 213         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 214         regs->regs[29] = (unsigned long) frame;
 215         regs->regs[31] = (unsigned long) frame->rs_code;
 216         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 217
 218 #if DEBUG_SIG
 219         printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
 220                current->comm, current->pid,
 221                frame, regs->cp0_epc, regs->regs[31]);
 222 #endif
 223         return 0;
 224
 225 give_sigsegv:
 226         force_sigsegv(signr, current);
 227         return -EFAULT;
 228 }