arch/mips/kernel/signal-common.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1991, 1992  Linus Torvalds
   7  * Copyright (C) 1994 - 2000  Ralf Baechle
   8  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   9  */
  10
  11 #include <linux/config.h>
  12
  13 static inline int
  14 setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
  15 {
  16         int err = 0;
  17
  18         err |= __put_user(regs->cp0_epc, &sc->sc_pc);
  19
  20 #define save_gp_reg(i) do {                                             \
  21         err |= __put_user(regs->regs[i], &sc->sc_regs[i]);              \
  22 } while(0)
  23         __put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
  24         save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
  25         save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
  26         save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
  27         save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
  28         save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
  29         save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
  30         save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
  31         save_gp_reg(31);
  32 #undef save_gp_reg
  33
  34 #ifdef CONFIG_32BIT
  35         err |= __put_user(regs->hi, &sc->sc_mdhi);
  36         err |= __put_user(regs->lo, &sc->sc_mdlo);
  37         if (cpu_has_dsp) {
  38                 err |= __put_user(mfhi1(), &sc->sc_hi1);
  39                 err |= __put_user(mflo1(), &sc->sc_lo1);
  40                 err |= __put_user(mfhi2(), &sc->sc_hi2);
  41                 err |= __put_user(mflo2(), &sc->sc_lo2);
  42                 err |= __put_user(mfhi3(), &sc->sc_hi3);
  43                 err |= __put_user(mflo3(), &sc->sc_lo3);
  44                 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
  45         }
  46 #endif
  47 #ifdef CONFIG_64BIT
  48         err |= __put_user(regs->hi, &sc->sc_hi[0]);
  49         err |= __put_user(regs->lo, &sc->sc_lo[0]);
  50         if (cpu_has_dsp) {
  51                 err |= __put_user(mfhi1(), &sc->sc_hi[1]);
  52                 err |= __put_user(mflo1(), &sc->sc_lo[1]);
  53                 err |= __put_user(mfhi2(), &sc->sc_hi[2]);
  54                 err |= __put_user(mflo2(), &sc->sc_lo[2]);
  55                 err |= __put_user(mfhi3(), &sc->sc_hi[3]);
  56                 err |= __put_user(mflo3(), &sc->sc_lo[3]);
  57                 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
  58         }
  59 #endif
  60
  61         err |= __put_user(!!used_math(), &sc->sc_used_math);
  62
  63         if (!used_math())
  64                 goto out;
  65
  66         /*
  67          * Save FPU state to signal context.  Signal handler will "inherit"
  68          * current FPU state.
  69          */
  70         preempt_disable();
  71
  72         if (!is_fpu_owner()) {
  73                 own_fpu();
  74                 restore_fp(current);
  75         }
  76         err |= save_fp_context(sc);
  77
  78         preempt_enable();
  79
  80 out:
  81         return err;
  82 }
  83
  84 static inline int
  85 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
  86 {
  87         unsigned int used_math;
  88         unsigned long treg;
  89         int err = 0;
  90
  91         /* Always make any pending restarted system calls return -EINTR */
  92         current_thread_info()->restart_block.fn = do_no_restart_syscall;
  93
  94         err |= __get_user(regs->cp0_epc, &sc->sc_pc);
  95 #ifdef CONFIG_32BIT
  96         err |= __get_user(regs->hi, &sc->sc_mdhi);
  97         err |= __get_user(regs->lo, &sc->sc_mdlo);
  98         if (cpu_has_dsp) {
  99                 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
 100                 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
 101                 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
 102                 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
 103                 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
 104                 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
 105                 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
 106         }
 107 #endif
 108 #ifdef CONFIG_64BIT
 109         err |= __get_user(regs->hi, &sc->sc_hi[0]);
 110         err |= __get_user(regs->lo, &sc->sc_lo[0]);
 111         if (cpu_has_dsp) {
 112                 err |= __get_user(treg, &sc->sc_hi[1]); mthi1(treg);
 113                 err |= __get_user(treg, &sc->sc_lo[1]); mthi1(treg);
 114                 err |= __get_user(treg, &sc->sc_hi[2]); mthi2(treg);
 115                 err |= __get_user(treg, &sc->sc_lo[2]); mthi2(treg);
 116                 err |= __get_user(treg, &sc->sc_hi[3]); mthi3(treg);
 117                 err |= __get_user(treg, &sc->sc_lo[3]); mthi3(treg);
 118                 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
 119         }
 120 #endif
 121
 122 #define restore_gp_reg(i) do {                                          \
 123         err |= __get_user(regs->regs[i], &sc->sc_regs[i]);              \
 124 } while(0)
 125         restore_gp_reg( 1); restore_gp_reg( 2); restore_gp_reg( 3);
 126         restore_gp_reg( 4); restore_gp_reg( 5); restore_gp_reg( 6);
 127         restore_gp_reg( 7); restore_gp_reg( 8); restore_gp_reg( 9);
 128         restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
 129         restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
 130         restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
 131         restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
 132         restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
 133         restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
 134         restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
 135         restore_gp_reg(31);
 136 #undef restore_gp_reg
 137
 138         err |= __get_user(used_math, &sc->sc_used_math);
 139         conditional_used_math(used_math);
 140
 141         preempt_disable();
 142
 143         if (used_math()) {
 144                 /* restore fpu context if we have used it before */
 145                 own_fpu();
 146                 err |= restore_fp_context(sc);
 147         } else {
 148                 /* signal handler may have used FPU.  Give it up. */
 149                 lose_fpu();
 150         }
 151
 152         preempt_enable();
 153
 154         return err;
 155 }
 156
 157 /*
 158  * Determine which stack to use..
 159  */
 160 static inline void __user *
 161 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 162 {
 163         unsigned long sp;
 164
 165         /* Default to using normal stack */
 166         sp = regs->regs[29];
 167
 168         /*
 169          * FPU emulator may have it's own trampoline active just
 170          * above the user stack, 16-bytes before the next lowest
 171          * 16 byte boundary.  Try to avoid trashing it.
 172          */
 173         sp -= 32;
 174
 175         /* This is the X/Open sanctioned signal stack switching.  */
 176         if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
 177                 sp = current->sas_ss_sp + current->sas_ss_size;
 178
 179         return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
 180 }
 181
 182 static inline int install_sigtramp(unsigned int __user *tramp,
 183         unsigned int syscall)
 184 {
 185         int err;
 186
 187         /*
 188          * Set up the return code ...
 189          *
 190          *         li      v0, __NR__foo_sigreturn
 191          *         syscall
 192          */
 193
 194         err = __put_user(0x24020000 + syscall, tramp + 0);
 195         err |= __put_user(0x0000000c          , tramp + 1);
 196         if (ICACHE_REFILLS_WORKAROUND_WAR) {
 197                 err |= __put_user(0, tramp + 2);
 198                 err |= __put_user(0, tramp + 3);
 199                 err |= __put_user(0, tramp + 4);
 200                 err |= __put_user(0, tramp + 5);
 201                 err |= __put_user(0, tramp + 6);
 202                 err |= __put_user(0, tramp + 7);
 203         }
 204         flush_cache_sigtramp((unsigned long) tramp);
 205
 206         return err;
 207 }