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 static inline int
  12 setup_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
  13 {
  14         int err = 0;
  15
  16         err |= __put_user(regs->cp0_epc, &sc->sc_pc);
  17         err |= __put_user(regs->cp0_status, &sc->sc_status);
  18
  19 #define save_gp_reg(i) do {                                             \
  20         err |= __put_user(regs->regs[i], &sc->sc_regs[i]);              \
  21 } while(0)
  22         __put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
  23         save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
  24         save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
  25         save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
  26         save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
  27         save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
  28         save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
  29         save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
  30         save_gp_reg(31);
  31 #undef save_gp_reg
  32
  33         err |= __put_user(regs->hi, &sc->sc_mdhi);
  34         err |= __put_user(regs->lo, &sc->sc_mdlo);
  35         err |= __put_user(regs->cp0_cause, &sc->sc_cause);
  36         err |= __put_user(regs->cp0_badvaddr, &sc->sc_badvaddr);
  37
  38         err |= __put_user(!!used_math(), &sc->sc_used_math);
  39
  40         if (!used_math())
  41                 goto out;
  42
  43         /*
  44          * Save FPU state to signal context.  Signal handler will "inherit"
  45          * current FPU state.
  46          */
  47         preempt_disable();
  48
  49         if (!is_fpu_owner()) {
  50                 own_fpu();
  51                 restore_fp(current);
  52         }
  53         err |= save_fp_context(sc);
  54
  55         preempt_enable();
  56
  57 out:
  58         return err;
  59 }
  60
  61 static inline int
  62 restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
  63 {
  64         int err = 0;
  65         unsigned int used_math;
  66
  67         /* Always make any pending restarted system calls return -EINTR */
  68         current_thread_info()->restart_block.fn = do_no_restart_syscall;
  69
  70         err |= __get_user(regs->cp0_epc, &sc->sc_pc);
  71         err |= __get_user(regs->hi, &sc->sc_mdhi);
  72         err |= __get_user(regs->lo, &sc->sc_mdlo);
  73
  74 #define restore_gp_reg(i) do {                                          \
  75         err |= __get_user(regs->regs[i], &sc->sc_regs[i]);              \
  76 } while(0)
  77         restore_gp_reg( 1); restore_gp_reg( 2); restore_gp_reg( 3);
  78         restore_gp_reg( 4); restore_gp_reg( 5); restore_gp_reg( 6);
  79         restore_gp_reg( 7); restore_gp_reg( 8); restore_gp_reg( 9);
  80         restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
  81         restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
  82         restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
  83         restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
  84         restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
  85         restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
  86         restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
  87         restore_gp_reg(31);
  88 #undef restore_gp_reg
  89
  90         err |= __get_user(used_math, &sc->sc_used_math);
  91         conditional_used_math(used_math);
  92
  93         preempt_disable();
  94
  95         if (used_math()) {
  96                 /* restore fpu context if we have used it before */
  97                 own_fpu();
  98                 err |= restore_fp_context(sc);
  99         } else {
 100                 /* signal handler may have used FPU.  Give it up. */
 101                 lose_fpu();
 102         }
 103
 104         preempt_enable();
 105
 106         return err;
 107 }
 108
 109 /*
 110  * Determine which stack to use..
 111  */
 112 static inline void *
 113 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 114 {
 115         unsigned long sp, almask;
 116
 117         /* Default to using normal stack */
 118         sp = regs->regs[29];
 119
 120         /*
 121          * FPU emulator may have it's own trampoline active just
 122          * above the user stack, 16-bytes before the next lowest
 123          * 16 byte boundary.  Try to avoid trashing it.
 124          */
 125         sp -= 32;
 126
 127         /* This is the X/Open sanctioned signal stack switching.  */
 128         if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
 129                 sp = current->sas_ss_sp + current->sas_ss_size;
 130
 131         if (PLAT_TRAMPOLINE_STUFF_LINE)
 132                 almask = ~(PLAT_TRAMPOLINE_STUFF_LINE - 1);
 133         else
 134                 almask = ALMASK;
 135
 136         return (void *)((sp - frame_size) & almask);
 137 }