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/fpu.h>
  39 #include <asm/cpu-features.h>
  40 #include <asm/war.h>
  41 #include <asm/vdso.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_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 struct ucontextn32 {
  54         u32                 uc_flags;
  55         s32                 uc_link;
  56         compat_stack_t      uc_stack;
  57         struct sigcontext   uc_mcontext;
  58         compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
  59 };
  60
  61 struct rt_sigframe_n32 {
  62         u32 rs_ass[4];                  /* argument save space for o32 */
  63         u32 rs_pad[2];                  /* Was: signal trampoline */
  64         struct compat_siginfo rs_info;
  65         struct ucontextn32 rs_uc;
  66 };
  67
  68 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
  69 {
  70         struct rt_sigframe_n32 __user *frame;
  71         sigset_t set;
  72         int sig;
  73
  74         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
  75         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  76                 goto badframe;
  77         if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
  78                 goto badframe;
  79
  80         set_current_blocked(&set);
  81
  82         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
  83         if (sig < 0)
  84                 goto badframe;
  85         else if (sig)
  86                 force_sig(sig, current);
  87
  88         if (compat_restore_altstack(&frame->rs_uc.uc_stack))
  89                 goto badframe;
  90
  91         /*
  92          * Don't let your children do this ...
  93          */
  94         __asm__ __volatile__(
  95                 "move\t$29, %0\n\t"
  96                 "j\tsyscall_exit"
  97                 :/* no outputs */
  98                 :"r" (&regs));
  99         /* Unreached */
 100
 101 badframe:
 102         force_sig(SIGSEGV, current);
 103 }
 104
 105 static int setup_rt_frame_n32(void *sig_return, struct k_sigaction *ka,
 106         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 107 {
 108         struct rt_sigframe_n32 __user *frame;
 109         int err = 0;
 110
 111         frame = get_sigframe(ka, regs, sizeof(*frame));
 112         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 113                 goto give_sigsegv;
 114
 115         /* Create siginfo.  */
 116         err |= copy_siginfo_to_user32(&frame->rs_info, info);
 117
 118         /* Create the ucontext.  */
 119         err |= __put_user(0, &frame->rs_uc.uc_flags);
 120         err |= __put_user(0, &frame->rs_uc.uc_link);
 121         err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
 122         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 123         err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 124
 125         if (err)
 126                 goto give_sigsegv;
 127
 128         /*
 129          * Arguments to signal handler:
 130          *
 131          *   a0 = signal number
 132          *   a1 = 0 (should be cause)
 133          *   a2 = pointer to ucontext
 134          *
 135          * $25 and c0_epc point to the signal handler, $29 points to
 136          * the struct rt_sigframe.
 137          */
 138         regs->regs[ 4] = signr;
 139         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 140         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 141         regs->regs[29] = (unsigned long) frame;
 142         regs->regs[31] = (unsigned long) sig_return;
 143         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 144
 145         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 146                current->comm, current->pid,
 147                frame, regs->cp0_epc, regs->regs[31]);
 148
 149         return 0;
 150
 151 give_sigsegv:
 152         force_sigsegv(signr, current);
 153         return -EFAULT;
 154 }
 155
 156 struct mips_abi mips_abi_n32 = {
 157         .setup_rt_frame = setup_rt_frame_n32,
 158         .rt_signal_return_offset =
 159                 offsetof(struct mips_vdso, n32_rt_signal_trampoline),
 160         .restart        = __NR_N32_restart_syscall
 161 };