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 <linux/uaccess.h>
  37 #include <asm/ucontext.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_restart_syscall        6214
  48
  49 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  50 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  51
  52 struct ucontextn32 {
  53         u32                 uc_flags;
  54         s32                 uc_link;
  55         compat_stack_t      uc_stack;
  56         struct sigcontext   uc_mcontext;
  57         compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
  58 };
  59
  60 struct rt_sigframe_n32 {
  61         u32 rs_ass[4];                  /* argument save space for o32 */
  62         u32 rs_pad[2];                  /* Was: signal trampoline */
  63         struct compat_siginfo rs_info;
  64         struct ucontextn32 rs_uc;
  65 };
  66
  67 asmlinkage void sysn32_rt_sigreturn(void)
  68 {
  69         struct rt_sigframe_n32 __user *frame;
  70         struct pt_regs *regs;
  71         sigset_t set;
  72         int sig;
  73
  74         regs = current_pt_regs();
  75         frame = (struct rt_sigframe_n32 __user *)regs->regs[29];
  76         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  77                 goto badframe;
  78         if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
  79                 goto badframe;
  80
  81         set_current_blocked(&set);
  82
  83         sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
  84         if (sig < 0)
  85                 goto badframe;
  86         else if (sig)
  87                 force_sig(sig, current);
  88
  89         if (compat_restore_altstack(&frame->rs_uc.uc_stack))
  90                 goto badframe;
  91
  92         /*
  93          * Don't let your children do this ...
  94          */
  95         __asm__ __volatile__(
  96                 "move\t$29, %0\n\t"
  97                 "j\tsyscall_exit"
  98                 : /* no outputs */
  99                 : "r" (regs));
 100         /* Unreached */
 101
 102 badframe:
 103         force_sig(SIGSEGV, current);
 104 }
 105
 106 static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
 107                               struct pt_regs *regs, sigset_t *set)
 108 {
 109         struct rt_sigframe_n32 __user *frame;
 110         int err = 0;
 111
 112         frame = get_sigframe(ksig, regs, sizeof(*frame));
 113         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 114                 return -EFAULT;
 115
 116         /* Create siginfo.  */
 117         err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info);
 118
 119         /* Create the ucontext.  */
 120         err |= __put_user(0, &frame->rs_uc.uc_flags);
 121         err |= __put_user(0, &frame->rs_uc.uc_link);
 122         err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
 123         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 124         err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 125
 126         if (err)
 127                 return -EFAULT;
 128
 129         /*
 130          * Arguments to signal handler:
 131          *
 132          *   a0 = signal number
 133          *   a1 = 0 (should be cause)
 134          *   a2 = pointer to ucontext
 135          *
 136          * $25 and c0_epc point to the signal handler, $29 points to
 137          * the struct rt_sigframe.
 138          */
 139         regs->regs[ 4] = ksig->sig;
 140         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 141         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 142         regs->regs[29] = (unsigned long) frame;
 143         regs->regs[31] = (unsigned long) sig_return;
 144         regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
 145
 146         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 147                current->comm, current->pid,
 148                frame, regs->cp0_epc, regs->regs[31]);
 149
 150         return 0;
 151 }
 152
 153 struct mips_abi mips_abi_n32 = {
 154         .setup_rt_frame = setup_rt_frame_n32,
 155         .restart        = __NR_N32_restart_syscall,
 156
 157         .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
 158         .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
 159         .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
 160
 161         .vdso           = &vdso_image_n32,
 162 };