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/asm.h>
  33 #include <asm/cacheflush.h>
  34 #include <asm/sim.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/ucontext.h>
  37 #include <asm/system.h>
  38 #include <asm/fpu.h>
  39 #include <asm/cpu-features.h>
  40 #include <asm/war.h>
  41
  42 #include "signal-common.h"
  43
  44 /*
  45  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
  46  */
  47 #define __NR_N32_rt_sigreturn           6211
  48 #define __NR_N32_restart_syscall        6214
  49
  50 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  51 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  52
  53
  54 /* IRIX compatible stack_t  */
  55 typedef struct sigaltstack32 {
  56         s32 ss_sp;
  57         compat_size_t ss_size;
  58         int ss_flags;
  59 } stack32_t;
  60
  61 struct ucontextn32 {
  62         u32                 uc_flags;
  63         s32                 uc_link;
  64         stack32_t           uc_stack;
  65         struct sigcontext   uc_mcontext;
  66         sigset_t            uc_sigmask;   /* mask last for extensibility */
  67 };
  68
  69 #if ICACHE_REFILLS_WORKAROUND_WAR == 0
  70
  71 struct rt_sigframe_n32 {
  72         u32 rs_ass[4];                  /* argument save space for o32 */
  73         u32 rs_code[2];                 /* signal trampoline */
  74         struct siginfo rs_info;
  75         struct ucontextn32 rs_uc;
  76 };
  77
  78 #else  /* ICACHE_REFILLS_WORKAROUND_WAR */
  79
  80 struct rt_sigframe_n32 {
  81         u32 rs_ass[4];                  /* argument save space for o32 */
  82         u32 rs_pad[2];
  83         struct siginfo rs_info;
  84         struct ucontextn32 rs_uc;
  85         u32 rs_code[8] ____cacheline_aligned;           /* signal trampoline */
  86 };
  87
  88 #endif  /* !ICACHE_REFILLS_WORKAROUND_WAR */
  89
  90 extern void sigset_from_compat (sigset_t *set, compat_sigset_t *compat);
  91
  92 asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  93 {
  94         compat_sigset_t __user *unewset;
  95         compat_sigset_t uset;
  96         size_t sigsetsize;
  97         sigset_t newset;
  98
  99         /* XXX Don't preclude handling different sized sigset_t's.  */
 100         sigsetsize = regs.regs[5];
 101         if (sigsetsize != sizeof(sigset_t))
 102                 return -EINVAL;
 103
 104         unewset = (compat_sigset_t __user *) regs.regs[4];
 105         if (copy_from_user(&uset, unewset, sizeof(uset)))
 106                 return -EFAULT;
 107         sigset_from_compat (&newset, &uset);
 108         sigdelsetmask(&newset, ~_BLOCKABLE);
 109
 110         spin_lock_irq(&current->sighand->siglock);
 111         current->saved_sigmask = current->blocked;
 112         current->blocked = newset;
 113         recalc_sigpending();
 114         spin_unlock_irq(&current->sighand->siglock);
 115
 116         current->state = TASK_INTERRUPTIBLE;
 117         schedule();
 118         set_thread_flag(TIF_RESTORE_SIGMASK);
 119         return -ERESTARTNOHAND;
 120 }
 121
 122 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 123 {
 124         struct rt_sigframe_n32 __user *frame;
 125         sigset_t set;
 126         stack_t st;
 127         s32 sp;
 128
 129         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 130         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 131                 goto badframe;
 132         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
 133                 goto badframe;
 134
 135         sigdelsetmask(&set, ~_BLOCKABLE);
 136         spin_lock_irq(&current->sighand->siglock);
 137         current->blocked = set;
 138         recalc_sigpending();
 139         spin_unlock_irq(&current->sighand->siglock);
 140
 141         if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
 142                 goto badframe;
 143
 144         /* The ucontext contains a stack32_t, so we must convert!  */
 145         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 146                 goto badframe;
 147         st.ss_sp = (void __user *)(long) sp;
 148         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 149                 goto badframe;
 150         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 151                 goto badframe;
 152
 153         /* It is more difficult to avoid calling this function than to
 154            call it and ignore errors.  */
 155         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 156
 157         /*
 158          * Don't let your children do this ...
 159          */
 160         __asm__ __volatile__(
 161                 "move\t$29, %0\n\t"
 162                 "j\tsyscall_exit"
 163                 :/* no outputs */
 164                 :"r" (&regs));
 165         /* Unreached */
 166
 167 badframe:
 168         force_sig(SIGSEGV, current);
 169 }
 170
 171 int setup_rt_frame_n32(struct k_sigaction * ka,
 172         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 173 {
 174         struct rt_sigframe_n32 __user *frame;
 175         int err = 0;
 176         s32 sp;
 177
 178         frame = get_sigframe(ka, regs, sizeof(*frame));
 179         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 180                 goto give_sigsegv;
 181
 182         install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
 183
 184         /* Create siginfo.  */
 185         err |= copy_siginfo_to_user(&frame->rs_info, info);
 186
 187         /* Create the ucontext.  */
 188         err |= __put_user(0, &frame->rs_uc.uc_flags);
 189         err |= __put_user(0, &frame->rs_uc.uc_link);
 190         sp = (int) (long) current->sas_ss_sp;
 191         err |= __put_user(sp,
 192                           &frame->rs_uc.uc_stack.ss_sp);
 193         err |= __put_user(sas_ss_flags(regs->regs[29]),
 194                           &frame->rs_uc.uc_stack.ss_flags);
 195         err |= __put_user(current->sas_ss_size,
 196                           &frame->rs_uc.uc_stack.ss_size);
 197         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 198         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 199
 200         if (err)
 201                 goto give_sigsegv;
 202
 203         /*
 204          * Arguments to signal handler:
 205          *
 206          *   a0 = signal number
 207          *   a1 = 0 (should be cause)
 208          *   a2 = pointer to ucontext
 209          *
 210          * $25 and c0_epc point to the signal handler, $29 points to
 211          * the struct rt_sigframe.
 212          */
 213         regs->regs[ 4] = signr;
 214         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 215         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 216         regs->regs[29] = (unsigned long) frame;
 217         regs->regs[31] = (unsigned long) frame->rs_code;
 218         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 219
 220         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 221                current->comm, current->pid,
 222                frame, regs->cp0_epc, regs->regs[31]);
 223
 224         return 0;
 225
 226 give_sigsegv:
 227         force_sigsegv(signr, current);
 228         return -EFAULT;
 229 }