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 } 178