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 save_static_function(sysn32_rt_sigreturn);
  85 __attribute_used__ noinline static void
  86 _sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
  87 {
  88         struct rt_sigframe_n32 __user *frame;
  89         sigset_t set;
  90         stack_t st;
  91         s32 sp;
  92
  93         frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
  94         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  95                 goto badframe;
  96         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
  97                 goto badframe;
  98
  99         sigdelsetmask(&set, ~_BLOCKABLE);
 100         spin_lock_irq(&current->sighand->siglock);
 101         current->blocked = set;
 102         recalc_sigpending();
 103         spin_unlock_irq(&current->sighand->siglock);
 104
 105         if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
 106                 goto badframe;
 107
 108         /* The ucontext contains a stack32_t, so we must convert!  */
 109         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 110                 goto badframe;
 111         st.ss_size = (long) sp;
 112         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 113                 goto badframe;
 114         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 115                 goto badframe;
 116
 117         /* It is more difficult to avoid calling this function than to
 118            call it and ignore errors.  */
 119         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 120
 121         /*
 122          * Don't let your children do this ...
 123          */
 124         __asm__ __volatile__(
 125                 "move\t$29, %0\n\t"
 126                 "j\tsyscall_exit"
 127                 :/* no outputs */
 128                 :"r" (&regs));
 129         /* Unreached */
 130
 131 badframe:
 132         force_sig(SIGSEGV, current);
 133 }
 134
 135 int setup_rt_frame_n32(struct k_sigaction * ka,
 136         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 137 {
 138         struct rt_sigframe_n32 __user *frame;
 139         int err = 0;
 140         s32 sp;
 141
 142         frame = get_sigframe(ka, regs, sizeof(*frame));
 143         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 144                 goto give_sigsegv;
 145
 146         install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
 147
 148         /* Create siginfo.  */
 149         err |= copy_siginfo_to_user(&frame->rs_info, info);
 150
 151         /* Create the ucontext.  */
 152         err |= __put_user(0, &frame->rs_uc.uc_flags);
 153         err |= __put_user(0, &frame->rs_uc.uc_link);
 154         sp = (int) (long) current->sas_ss_sp;
 155         err |= __put_user(sp,
 156                           &frame->rs_uc.uc_stack.ss_sp);
 157         err |= __put_user(sas_ss_flags(regs->regs[29]),
 158                           &frame->rs_uc.uc_stack.ss_flags);
 159         err |= __put_user(current->sas_ss_size,
 160                           &frame->rs_uc.uc_stack.ss_size);
 161         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 162         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 163
 164         if (err)
 165                 goto give_sigsegv;
 166
 167         /*
 168          * Arguments to signal handler:
 169          *
 170          *   a0 = signal number
 171          *   a1 = 0 (should be cause)
 172          *   a2 = pointer to ucontext
 173          *
 174          * $25 and c0_epc point to the signal handler, $29 points to
 175          * the struct rt_sigframe.
 176          */
 177         regs->regs[ 4] = signr;
 178         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 179         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 180         regs->regs[29] = (unsigned long) frame;
 181         regs->regs[31] = (unsigned long) frame->rs_code;
 182         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 183
 184 #if DEBUG_SIG
 185         printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
 186                current->comm, current->pid,
 187                frame, regs->cp0_epc, regs->regs[31]);
 188 #endif
 189         return 0;
 190
 191 give_sigsegv:
 192         force_sigsegv(signr, current);
 193         return -EFAULT;
 194 }