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