signal_o32.c (7524B)
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 23#include "signal-common.h" 24 25/* 26 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... 27 */ 28#define __NR_O32_restart_syscall 4253 29 30struct sigframe32 { 31 u32 sf_ass[4]; /* argument save space for o32 */ 32 u32 sf_pad[2]; /* Was: signal trampoline */ 33 struct sigcontext32 sf_sc; 34 compat_sigset_t sf_mask; 35}; 36 37struct ucontext32 { 38 u32 uc_flags; 39 s32 uc_link; 40 compat_stack_t uc_stack; 41 struct sigcontext32 uc_mcontext; 42 compat_sigset_t uc_sigmask; /* mask last for extensibility */ 43}; 44 45struct rt_sigframe32 { 46 u32 rs_ass[4]; /* argument save space for o32 */ 47 u32 rs_pad[2]; /* Was: signal trampoline */ 48 compat_siginfo_t rs_info; 49 struct ucontext32 rs_uc; 50}; 51 52static int setup_sigcontext32(struct pt_regs *regs, 53 struct sigcontext32 __user *sc) 54{ 55 int err = 0; 56 int i; 57 58 err |= __put_user(regs->cp0_epc, &sc->sc_pc); 59 60 err |= __put_user(0, &sc->sc_regs[0]); 61 for (i = 1; i < 32; i++) 62 err |= __put_user(regs->regs[i], &sc->sc_regs[i]); 63 64 err |= __put_user(regs->hi, &sc->sc_mdhi); 65 err |= __put_user(regs->lo, &sc->sc_mdlo); 66 if (cpu_has_dsp) { 67 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); 68 err |= __put_user(mfhi1(), &sc->sc_hi1); 69 err |= __put_user(mflo1(), &sc->sc_lo1); 70 err |= __put_user(mfhi2(), &sc->sc_hi2); 71 err |= __put_user(mflo2(), &sc->sc_lo2); 72 err |= __put_user(mfhi3(), &sc->sc_hi3); 73 err |= __put_user(mflo3(), &sc->sc_lo3); 74 } 75 76 /* 77 * Save FPU state to signal context. Signal handler 78 * will "inherit" current FPU state. 79 */ 80 err |= protected_save_fp_context(sc); 81 82 return err; 83} 84 85static int restore_sigcontext32(struct pt_regs *regs, 86 struct sigcontext32 __user *sc) 87{ 88 int err = 0; 89 s32 treg; 90 int i; 91 92 /* Always make any pending restarted system calls return -EINTR */ 93 current->restart_block.fn = do_no_restart_syscall; 94 95 err |= __get_user(regs->cp0_epc, &sc->sc_pc); 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 } 107 108 for (i = 1; i < 32; i++) 109 err |= __get_user(regs->regs[i], &sc->sc_regs[i]); 110 111 return err ?: protected_restore_fp_context(sc); 112} 113 114static int setup_frame_32(void *sig_return, struct ksignal *ksig, 115 struct pt_regs *regs, sigset_t *set) 116{ 117 struct sigframe32 __user *frame; 118 int err = 0; 119 120 frame = get_sigframe(ksig, regs, sizeof(*frame)); 121 if (!access_ok(frame, sizeof (*frame))) 122 return -EFAULT; 123 124 err |= setup_sigcontext32(regs, &frame->sf_sc); 125 err |= __copy_conv_sigset_to_user(&frame->sf_mask, set); 126 127 if (err) 128 return -EFAULT; 129 130 /* 131 * Arguments to signal handler: 132 * 133 * a0 = signal number 134 * a1 = 0 (should be cause) 135 * a2 = pointer to struct sigcontext 136 * 137 * $25 and c0_epc point to the signal handler, $29 points to the 138 * struct sigframe. 139 */ 140 regs->regs[ 4] = ksig->sig; 141 regs->regs[ 5] = 0; 142 regs->regs[ 6] = (unsigned long) &frame->sf_sc; 143 regs->regs[29] = (unsigned long) frame; 144 regs->regs[31] = (unsigned long) sig_return; 145 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 146 147 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 148 current->comm, current->pid, 149 frame, regs->cp0_epc, regs->regs[31]); 150 151 return 0; 152} 153 154asmlinkage void sys32_rt_sigreturn(void) 155{ 156 struct rt_sigframe32 __user *frame; 157 struct pt_regs *regs; 158 sigset_t set; 159 int sig; 160 161 regs = current_pt_regs(); 162 frame = (struct rt_sigframe32 __user *)regs->regs[29]; 163 if (!access_ok(frame, sizeof(*frame))) 164 goto badframe; 165 if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) 166 goto badframe; 167 168 set_current_blocked(&set); 169 170 sig = restore_sigcontext32(regs, &frame->rs_uc.uc_mcontext); 171 if (sig < 0) 172 goto badframe; 173 else if (sig) 174 force_sig(sig); 175 176 if (compat_restore_altstack(&frame->rs_uc.uc_stack)) 177 goto badframe; 178 179 /* 180 * Don't let your children do this ... 181 */ 182 __asm__ __volatile__( 183 "move\t$29, %0\n\t" 184 "j\tsyscall_exit" 185 : /* no outputs */ 186 : "r" (regs)); 187 /* Unreached */ 188 189badframe: 190 force_sig(SIGSEGV); 191} 192 193static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig, 194 struct pt_regs *regs, sigset_t *set) 195{ 196 struct rt_sigframe32 __user *frame; 197 int err = 0; 198 199 frame = get_sigframe(ksig, regs, sizeof(*frame)); 200 if (!access_ok(frame, sizeof (*frame))) 201 return -EFAULT; 202 203 /* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */ 204 err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info); 205 206 /* Create the ucontext. */ 207 err |= __put_user(0, &frame->rs_uc.uc_flags); 208 err |= __put_user(0, &frame->rs_uc.uc_link); 209 err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); 210 err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext); 211 err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); 212 213 if (err) 214 return -EFAULT; 215 216 /* 217 * Arguments to signal handler: 218 * 219 * a0 = signal number 220 * a1 = 0 (should be cause) 221 * a2 = pointer to ucontext 222 * 223 * $25 and c0_epc point to the signal handler, $29 points to 224 * the struct rt_sigframe32. 225 */ 226 regs->regs[ 4] = ksig->sig; 227 regs->regs[ 5] = (unsigned long) &frame->rs_info; 228 regs->regs[ 6] = (unsigned long) &frame->rs_uc; 229 regs->regs[29] = (unsigned long) frame; 230 regs->regs[31] = (unsigned long) sig_return; 231 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 232 233 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 234 current->comm, current->pid, 235 frame, regs->cp0_epc, regs->regs[31]); 236 237 return 0; 238} 239 240/* 241 * o32 compatibility on 64-bit kernels, without DSP ASE 242 */ 243struct mips_abi mips_abi_32 = { 244 .setup_frame = setup_frame_32, 245 .setup_rt_frame = setup_rt_frame_32, 246 .restart = __NR_O32_restart_syscall, 247 248 .off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs), 249 .off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr), 250 .off_sc_used_math = offsetof(struct sigcontext32, sc_used_math), 251 252 .vdso = &vdso_image_o32, 253}; 254 255 256asmlinkage void sys32_sigreturn(void) 257{ 258 struct sigframe32 __user *frame; 259 struct pt_regs *regs; 260 sigset_t blocked; 261 int sig; 262 263 regs = current_pt_regs(); 264 frame = (struct sigframe32 __user *)regs->regs[29]; 265 if (!access_ok(frame, sizeof(*frame))) 266 goto badframe; 267 if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask)) 268 goto badframe; 269 270 set_current_blocked(&blocked); 271 272 sig = restore_sigcontext32(regs, &frame->sf_sc); 273 if (sig < 0) 274 goto badframe; 275 else if (sig) 276 force_sig(sig); 277 278 /* 279 * Don't let your children do this ... 280 */ 281 __asm__ __volatile__( 282 "move\t$29, %0\n\t" 283 "j\tsyscall_exit" 284 : /* no outputs */ 285 : "r" (regs)); 286 /* Unreached */ 287 288badframe: 289 force_sig(SIGSEGV); 290}