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, 2006 Ralf Baechle 8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc. 9 * Copyright (C) 2016, Imagination Technologies Ltd. 10 */ 11 #include <linux/compiler.h> 12 #include <linux/errno.h> 13 #include <linux/signal.h> 14 #include <linux/sched/signal.h> 15 #include <linux/uaccess.h> 16 17 #include <asm/abi.h> 18 #include <asm/compat-signal.h> 19 #include <asm/dsp.h> 20 #include <asm/sim.h> 21 #include <asm/unistd.h> 22 #include <asm/syscalls.h> 23 24 #include "signal-common.h" 25 26 /* 27 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... 28 */ 29 #define __NR_O32_restart_syscall 4253 30 31 struct sigframe32 { 32 u32 sf_ass[4]; /* argument save space for o32 */ 33 u32 sf_pad[2]; /* Was: signal trampoline */ 34 struct sigcontext32 sf_sc; 35 compat_sigset_t sf_mask; 36 }; 37 38 struct ucontext32 { 39 u32 uc_flags; 40 s32 uc_link; 41 compat_stack_t uc_stack; 42 struct sigcontext32 uc_mcontext; 43 compat_sigset_t uc_sigmask; /* mask last for extensibility */ 44 }; 45 46 struct rt_sigframe32 { 47 u32 rs_ass[4]; /* argument save space for o32 */ 48 u32 rs_pad[2]; /* Was: signal trampoline */ 49 compat_siginfo_t rs_info; 50 struct ucontext32 rs_uc; 51 }; 52 53 static int setup_sigcontext32(struct pt_regs *regs, 54 struct sigcontext32 __user *sc) 55 { 56 int err = 0; 57 int i; 58 59 err |= __put_user(regs->cp0_epc, &sc->sc_pc); 60 61 err |= __put_user(0, &sc->sc_regs[0]); 62 for (i = 1; i < 32; i++) 63 err |= __put_user(regs->regs[i], &sc->sc_regs[i]); 64 65 err |= __put_user(regs->hi, &sc->sc_mdhi); 66 err |= __put_user(regs->lo, &sc->sc_mdlo); 67 if (cpu_has_dsp) { 68 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); 69 err |= __put_user(mfhi1(), &sc->sc_hi1); 70 err |= __put_user(mflo1(), &sc->sc_lo1); 71 err |= __put_user(mfhi2(), &sc->sc_hi2); 72 err |= __put_user(mflo2(), &sc->sc_lo2); 73 err |= __put_user(mfhi3(), &sc->sc_hi3); 74 err |= __put_user(mflo3(), &sc->sc_lo3); 75 } 76 77 /* 78 * Save FPU state to signal context. Signal handler 79 * will "inherit" current FPU state. 80 */ 81 err |= protected_save_fp_context(sc); 82 83 return err; 84 } 85 86 static int restore_sigcontext32(struct pt_regs *regs, 87 struct sigcontext32 __user *sc) 88 { 89 int err = 0; 90 s32 treg; 91 int i; 92 93 /* Always make any pending restarted system calls return -EINTR */ 94 current->restart_block.fn = do_no_restart_syscall; 95 96 err |= __get_user(regs->cp0_epc, &sc->sc_pc); 97 err |= __get_user(regs->hi, &sc->sc_mdhi); 98 err |= __get_user(regs->lo, &sc->sc_mdlo); 99 if (cpu_has_dsp) { 100 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg); 101 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg); 102 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg); 103 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg); 104 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg); 105 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg); 106 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK); 107 } 108 109 for (i = 1; i < 32; i++) 110 err |= __get_user(regs->regs[i], &sc->sc_regs[i]); 111 112 return err ?: protected_restore_fp_context(sc); 113 } 114 115 static int setup_frame_32(void *sig_return, struct ksignal *ksig, 116 struct pt_regs *regs, sigset_t *set) 117 { 118 struct sigframe32 __user *frame; 119 int err = 0; 120 121 frame = get_sigframe(ksig, regs, sizeof(*frame)); 122 if (!access_ok(frame, sizeof (*frame))) 123 return -EFAULT; 124 125 err |= setup_sigcontext32(regs, &frame->sf_sc); 126 err |= __copy_conv_sigset_to_user(&frame->sf_mask, set); 127 128 if (err) 129 return -EFAULT; 130 131 /* 132 * Arguments to signal handler: 133 * 134 * a0 = signal number 135 * a1 = 0 (should be cause) 136 * a2 = pointer to struct sigcontext 137 * 138 * $25 and c0_epc point to the signal handler, $29 points to the 139 * struct sigframe. 140 */ 141 regs->regs[ 4] = ksig->sig; 142 regs->regs[ 5] = 0; 143 regs->regs[ 6] = (unsigned long) &frame->sf_sc; 144 regs->regs[29] = (unsigned long) frame; 145 regs->regs[31] = (unsigned long) sig_return; 146 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 147 148 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 149 current->comm, current->pid, 150 frame, regs->cp0_epc, regs->regs[31]); 151 152 return 0; 153 } 154 155 asmlinkage void sys32_rt_sigreturn(void) 156 { 157 struct rt_sigframe32 __user *frame; 158 struct pt_regs *regs; 159 sigset_t set; 160 int sig; 161 162 regs = current_pt_regs(); 163 frame = (struct rt_sigframe32 __user *)regs->regs[29]; 164 if (!access_ok(frame, sizeof(*frame))) 165 goto badframe; 166 if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) 167 goto badframe; 168 169 set_current_blocked(&set); 170 171 sig = restore_sigcontext32(regs, &frame->rs_uc.uc_mcontext); 172 if (sig < 0) 173 goto badframe; 174 else if (sig) 175 force_sig(sig); 176 177 if (compat_restore_altstack(&frame->rs_uc.uc_stack)) 178 goto badframe; 179 180 /* 181 * Don't let your children do this ... 182 */ 183 __asm__ __volatile__( 184 "move\t$29, %0\n\t" 185 "j\tsyscall_exit" 186 : /* no outputs */ 187 : "r" (regs)); 188 /* Unreached */ 189 190 badframe: 191 force_sig(SIGSEGV); 192 } 193 194 static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig, 195 struct pt_regs *regs, sigset_t *set) 196 { 197 struct rt_sigframe32 __user *frame; 198 int err = 0; 199 200 frame = get_sigframe(ksig, regs, sizeof(*frame)); 201 if (!access_ok(frame, sizeof (*frame))) 202 return -EFAULT; 203 204 /* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */ 205 err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info); 206 207 /* Create the ucontext. */ 208 err |= __put_user(0, &frame->rs_uc.uc_flags); 209 err |= __put_user(0, &frame->rs_uc.uc_link); 210 err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); 211 err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext); 212 err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); 213 214 if (err) 215 return -EFAULT; 216 217 /* 218 * Arguments to signal handler: 219 * 220 * a0 = signal number 221 * a1 = 0 (should be cause) 222 * a2 = pointer to ucontext 223 * 224 * $25 and c0_epc point to the signal handler, $29 points to 225 * the struct rt_sigframe32. 226 */ 227 regs->regs[ 4] = ksig->sig; 228 regs->regs[ 5] = (unsigned long) &frame->rs_info; 229 regs->regs[ 6] = (unsigned long) &frame->rs_uc; 230 regs->regs[29] = (unsigned long) frame; 231 regs->regs[31] = (unsigned long) sig_return; 232 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 233 234 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 235 current->comm, current->pid, 236 frame, regs->cp0_epc, regs->regs[31]); 237 238 return 0; 239 } 240 241 /* 242 * o32 compatibility on 64-bit kernels, without DSP ASE 243 */ 244 struct mips_abi mips_abi_32 = { 245 .setup_frame = setup_frame_32, 246 .setup_rt_frame = setup_rt_frame_32, 247 .restart = __NR_O32_restart_syscall, 248 249 .off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs), 250 .off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr), 251 .off_sc_used_math = offsetof(struct sigcontext32, sc_used_math), 252 253 .vdso = &vdso_image_o32, 254 }; 255 256 257 asmlinkage void sys32_sigreturn(void) 258 { 259 struct sigframe32 __user *frame; 260 struct pt_regs *regs; 261 sigset_t blocked; 262 int sig; 263 264 regs = current_pt_regs(); 265 frame = (struct sigframe32 __user *)regs->regs[29]; 266 if (!access_ok(frame, sizeof(*frame))) 267 goto badframe; 268 if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask)) 269 goto badframe; 270 271 set_current_blocked(&blocked); 272 273 sig = restore_sigcontext32(regs, &frame->sf_sc); 274 if (sig < 0) 275 goto badframe; 276 else if (sig) 277 force_sig(sig); 278 279 /* 280 * Don't let your children do this ... 281 */ 282 __asm__ __volatile__( 283 "move\t$29, %0\n\t" 284 "j\tsyscall_exit" 285 : /* no outputs */ 286 : "r" (regs)); 287 /* Unreached */ 288 289 badframe: 290 force_sig(SIGSEGV); 291 } 292