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 _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  52
  53 /* IRIX compatible stack_t  */
  54 typedef struct sigaltstack32 {
  55         s32 ss_sp;
  56         compat_size_t ss_size;
  57         int ss_flags;
  58 } stack32_t;
  59
  60 struct ucontextn32 {
  61         u32                 uc_flags;
  62         s32                 uc_link;
  63         stack32_t           uc_stack;
  64         struct sigcontext   uc_mcontext;
  65         sigset_t            uc_sigmask;   /* mask last for extensibility */
  66 };
  67
  68 struct rt_sigframe_n32 {
  69         u32 rs_ass[4];                  /* argument save space for o32 */
  70 #if ICACHE_REFILLS_WORKAROUND_WAR
  71         u32 rs_pad[2];
  72 #else
  73         u32 rs_code[2];                 /* signal trampoline */
  74 #endif
  75         struct siginfo rs_info;
  76         struct ucontextn32 rs_uc;
  77 #if ICACHE_REFILLS_WORKAROUND_WAR
  78         u32 rs_code[8] ____cacheline_aligned;           /* signal trampoline */
  79 #endif
  80 };
  81
  82 save_static_function(sysn32_rt_sigreturn);
  83 __attribute_used__ noinline static void
  84 _sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
  85 {
  86         struct rt_sigframe_n32 *frame;
  87         sigset_t set;
  88         stack_t st;
  89         s32 sp;
  90
  91         frame = (struct rt_sigframe_n32 *) regs.regs[29];
  92         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  93                 goto badframe;
  94         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
  95                 goto badframe;
  96
  97         sigdelsetmask(&set, ~_BLOCKABLE);
  98         spin_lock_irq(&current->sighand->siglock);
  99         current->blocked = set;
 100         recalc_sigpending();
 101         spin_unlock_irq(&current->sighand->siglock);
 102
 103         if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
 104                 goto badframe;
 105
 106         /* The ucontext contains a stack32_t, so we must convert!  */
 107         if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 108                 goto badframe;
 109         st.ss_size = (long) sp;
 110         if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 111                 goto badframe;
 112         if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 113                 goto badframe;
 114
 115         /* It is more difficult to avoid calling this function than to
 116            call it and ignore errors.  */
 117         do_sigaltstack(&st, NULL, regs.regs[29]);
 118
 119         /*
 120          * Don't let your children do this ...
 121          */
 122         __asm__ __volatile__(
 123                 "move\t$29, %0\n\t"
 124                 "j\tsyscall_exit"
 125                 :/* no outputs */
 126                 :"r" (&regs));
 127         /* Unreached */
 128
 129 badframe:
 130         force_sig(SIGSEGV, current);
 131 }
 132
 133 int setup_rt_frame_n32(struct k_sigaction * ka,
 134         struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 135 {
 136         struct rt_sigframe_n32 *frame;
 137         int err = 0;
 138         s32 sp;
 139
 140         frame = get_sigframe(ka, regs, sizeof(*frame));
 141         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 142                 goto give_sigsegv;
 143
 144         install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
 145
 146         /* Create siginfo.  */
 147         err |= copy_siginfo_to_user(&frame->rs_info, info);
 148
 149         /* Create the ucontext.  */
 150         err |= __put_user(0, &frame->rs_uc.uc_flags);
 151         err |= __put_user(0, &frame->rs_uc.uc_link);
 152         sp = (int) (long) current->sas_ss_sp;
 153         err |= __put_user(sp,
 154                           &frame->rs_uc.uc_stack.ss_sp);
 155         err |= __put_user(sas_ss_flags(regs->regs[29]),
 156                           &frame->rs_uc.uc_stack.ss_flags);
 157         err |= __put_user(current->sas_ss_size,
 158                           &frame->rs_uc.uc_stack.ss_size);
 159         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 160         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 161
 162         if (err)
 163                 goto give_sigsegv;
 164
 165         /*
 166          * Arguments to signal handler:
 167          *
 168          *   a0 = signal number
 169          *   a1 = 0 (should be cause)
 170          *   a2 = pointer to ucontext
 171          *
 172          * $25 and c0_epc point to the signal handler, $29 points to
 173          * the struct rt_sigframe.
 174          */
 175         regs->regs[ 4] = signr;
 176         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 177         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 178         regs->regs[29] = (unsigned long) frame;
 179         regs->regs[31] = (unsigned long) frame->rs_code;
 180         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 181
 182 #if DEBUG_SIG
 183         printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
 184                current->comm, current->pid,
 185                frame, regs->cp0_epc, regs->regs[31]);
 186 #endif
 187         return 1;
 188
 189 give_sigsegv:
 190         force_sigsegv(signr, current);
 191         return 0;
 192 }