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