1 /* 2 * Emulation of Linux signals 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 #include "qemu/osdep.h" 20 #include "qemu.h" 21 #include "user-internals.h" 22 #include "signal-common.h" 23 #include "linux-user/trace.h" 24 25 #define __NUM_GPRS 16 26 #define __NUM_FPRS 16 27 #define __NUM_ACRS 16 28 29 #define __SIGNAL_FRAMESIZE 160 /* FIXME: 31-bit mode -> 96 */ 30 31 #define _SIGCONTEXT_NSIG 64 32 #define _SIGCONTEXT_NSIG_BPW 64 /* FIXME: 31-bit mode -> 32 */ 33 #define _SIGCONTEXT_NSIG_WORDS (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW) 34 #define _SIGMASK_COPY_SIZE (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS) 35 #define S390_SYSCALL_OPCODE ((uint16_t)0x0a00) 36 37 typedef struct { 38 target_psw_t psw; 39 abi_ulong gprs[__NUM_GPRS]; 40 abi_uint acrs[__NUM_ACRS]; 41 } target_s390_regs_common; 42 43 typedef struct { 44 uint32_t fpc; 45 uint32_t pad; 46 uint64_t fprs[__NUM_FPRS]; 47 } target_s390_fp_regs; 48 49 typedef struct { 50 target_s390_regs_common regs; 51 target_s390_fp_regs fpregs; 52 } target_sigregs; 53 54 typedef struct { 55 uint64_t vxrs_low[16]; 56 uint64_t vxrs_high[16][2]; 57 uint8_t reserved[128]; 58 } target_sigregs_ext; 59 60 typedef struct { 61 abi_ulong oldmask[_SIGCONTEXT_NSIG_WORDS]; 62 abi_ulong sregs; 63 } target_sigcontext; 64 65 typedef struct { 66 uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; 67 target_sigcontext sc; 68 target_sigregs sregs; 69 int signo; 70 target_sigregs_ext sregs_ext; 71 uint16_t retcode; 72 } sigframe; 73 74 #define TARGET_UC_VXRS 2 75 76 struct target_ucontext { 77 abi_ulong tuc_flags; 78 abi_ulong tuc_link; 79 target_stack_t tuc_stack; 80 target_sigregs tuc_mcontext; 81 target_sigset_t tuc_sigmask; 82 uint8_t reserved[128 - sizeof(target_sigset_t)]; 83 target_sigregs_ext tuc_mcontext_ext; 84 }; 85 86 typedef struct { 87 uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; 88 uint16_t retcode; 89 struct target_siginfo info; 90 struct target_ucontext uc; 91 } rt_sigframe; 92 93 static inline abi_ulong 94 get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size) 95 { 96 abi_ulong sp; 97 98 /* Default to using normal stack */ 99 sp = get_sp_from_cpustate(env); 100 101 /* This is the X/Open sanctioned signal stack switching. */ 102 if (ka->sa_flags & TARGET_SA_ONSTACK) { 103 sp = target_sigsp(sp, ka); 104 } 105 106 /* This is the legacy signal stack switching. */ 107 else if (/* FIXME !user_mode(regs) */ 0 && 108 !(ka->sa_flags & TARGET_SA_RESTORER) && 109 ka->sa_restorer) { 110 sp = (abi_ulong) ka->sa_restorer; 111 } 112 113 return (sp - frame_size) & -8ul; 114 } 115 116 #define PSW_USER_BITS (PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | \ 117 PSW_MASK_MCHECK | PSW_MASK_PSTATE | PSW_ASC_PRIMARY) 118 #define PSW_MASK_USER (PSW_MASK_ASC | PSW_MASK_CC | PSW_MASK_PM | \ 119 PSW_MASK_64 | PSW_MASK_32) 120 121 static void save_sigregs(CPUS390XState *env, target_sigregs *sregs) 122 { 123 uint64_t psw_mask = s390_cpu_get_psw_mask(env); 124 int i; 125 126 /* 127 * Copy a 'clean' PSW mask to the user to avoid leaking 128 * information about whether PER is currently on. 129 * TODO: qemu does not support PSW_MASK_RI; it will never be set. 130 */ 131 psw_mask = PSW_USER_BITS | (psw_mask & PSW_MASK_USER); 132 __put_user(psw_mask, &sregs->regs.psw.mask); 133 __put_user(env->psw.addr, &sregs->regs.psw.addr); 134 135 for (i = 0; i < 16; i++) { 136 __put_user(env->regs[i], &sregs->regs.gprs[i]); 137 } 138 for (i = 0; i < 16; i++) { 139 __put_user(env->aregs[i], &sregs->regs.acrs[i]); 140 } 141 142 /* 143 * We have to store the fp registers to current->thread.fp_regs 144 * to merge them with the emulated registers. 145 */ 146 for (i = 0; i < 16; i++) { 147 __put_user(*get_freg(env, i), &sregs->fpregs.fprs[i]); 148 } 149 } 150 151 static void save_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext) 152 { 153 int i; 154 155 /* 156 * if (MACHINE_HAS_VX) ... 157 * That said, we always allocate the stack storage and the 158 * space is always available in env. 159 */ 160 for (i = 0; i < 16; ++i) { 161 __put_user(env->vregs[i][1], &ext->vxrs_low[i]); 162 } 163 for (i = 0; i < 16; ++i) { 164 __put_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]); 165 __put_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]); 166 } 167 } 168 169 void setup_frame(int sig, struct target_sigaction *ka, 170 target_sigset_t *set, CPUS390XState *env) 171 { 172 sigframe *frame; 173 abi_ulong frame_addr; 174 abi_ulong restorer; 175 176 frame_addr = get_sigframe(ka, env, sizeof(*frame)); 177 trace_user_setup_frame(env, frame_addr); 178 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 179 force_sigsegv(sig); 180 return; 181 } 182 183 /* Set up backchain. */ 184 __put_user(env->regs[15], (abi_ulong *) frame); 185 186 /* Create struct sigcontext on the signal stack. */ 187 /* Make sure that we're initializing all of oldmask. */ 188 QEMU_BUILD_BUG_ON(ARRAY_SIZE(frame->sc.oldmask) != 1); 189 __put_user(set->sig[0], &frame->sc.oldmask[0]); 190 __put_user(frame_addr + offsetof(sigframe, sregs), &frame->sc.sregs); 191 192 /* Create _sigregs on the signal stack */ 193 save_sigregs(env, &frame->sregs); 194 195 /* 196 * ??? The kernel uses regs->gprs[2] here, which is not yet the signo. 197 * Moreover the comment talks about allowing backtrace, which is really 198 * done by the r15 copy above. 199 */ 200 __put_user(sig, &frame->signo); 201 202 /* Create sigregs_ext on the signal stack. */ 203 save_sigregs_ext(env, &frame->sregs_ext); 204 205 /* 206 * Set up to return from userspace. 207 * If provided, use a stub already in userspace. 208 */ 209 if (ka->sa_flags & TARGET_SA_RESTORER) { 210 restorer = ka->sa_restorer; 211 } else { 212 restorer = frame_addr + offsetof(sigframe, retcode); 213 __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn, 214 &frame->retcode); 215 } 216 217 /* Set up registers for signal handler */ 218 env->regs[14] = restorer; 219 env->regs[15] = frame_addr; 220 /* Force default amode and default user address space control. */ 221 env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY 222 | (env->psw.mask & ~PSW_MASK_ASC); 223 env->psw.addr = ka->_sa_handler; 224 225 env->regs[2] = sig; 226 env->regs[3] = frame_addr + offsetof(typeof(*frame), sc); 227 228 /* 229 * We forgot to include these in the sigcontext. 230 * To avoid breaking binary compatibility, they are passed as args. 231 */ 232 env->regs[4] = 0; /* FIXME: regs->int_code & 127 */ 233 env->regs[5] = 0; /* FIXME: regs->int_parm_long */ 234 env->regs[6] = 0; /* FIXME: current->thread.last_break */ 235 236 unlock_user_struct(frame, frame_addr, 1); 237 } 238 239 void setup_rt_frame(int sig, struct target_sigaction *ka, 240 target_siginfo_t *info, 241 target_sigset_t *set, CPUS390XState *env) 242 { 243 rt_sigframe *frame; 244 abi_ulong frame_addr; 245 abi_ulong restorer; 246 abi_ulong uc_flags; 247 248 frame_addr = get_sigframe(ka, env, sizeof *frame); 249 trace_user_setup_rt_frame(env, frame_addr); 250 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 251 force_sigsegv(sig); 252 return; 253 } 254 255 /* Set up backchain. */ 256 __put_user(env->regs[15], (abi_ulong *) frame); 257 258 /* 259 * Set up to return from userspace. 260 * If provided, use a stub already in userspace. 261 */ 262 if (ka->sa_flags & TARGET_SA_RESTORER) { 263 restorer = ka->sa_restorer; 264 } else { 265 restorer = frame_addr + offsetof(typeof(*frame), retcode); 266 __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn, 267 &frame->retcode); 268 } 269 270 /* Create siginfo on the signal stack. */ 271 tswap_siginfo(&frame->info, info); 272 273 /* Create ucontext on the signal stack. */ 274 uc_flags = 0; 275 if (s390_has_feat(S390_FEAT_VECTOR)) { 276 uc_flags |= TARGET_UC_VXRS; 277 } 278 __put_user(uc_flags, &frame->uc.tuc_flags); 279 __put_user(0, &frame->uc.tuc_link); 280 target_save_altstack(&frame->uc.tuc_stack, env); 281 save_sigregs(env, &frame->uc.tuc_mcontext); 282 save_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); 283 tswap_sigset(&frame->uc.tuc_sigmask, set); 284 285 /* Set up registers for signal handler */ 286 env->regs[14] = restorer; 287 env->regs[15] = frame_addr; 288 /* Force default amode and default user address space control. */ 289 env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY 290 | (env->psw.mask & ~PSW_MASK_ASC); 291 env->psw.addr = ka->_sa_handler; 292 293 env->regs[2] = sig; 294 env->regs[3] = frame_addr + offsetof(typeof(*frame), info); 295 env->regs[4] = frame_addr + offsetof(typeof(*frame), uc); 296 env->regs[5] = 0; /* FIXME: current->thread.last_break */ 297 } 298 299 static void restore_sigregs(CPUS390XState *env, target_sigregs *sc) 300 { 301 uint64_t prev_addr, prev_mask, mask, addr; 302 int i; 303 304 for (i = 0; i < 16; i++) { 305 __get_user(env->regs[i], &sc->regs.gprs[i]); 306 } 307 308 prev_addr = env->psw.addr; 309 __get_user(mask, &sc->regs.psw.mask); 310 __get_user(addr, &sc->regs.psw.addr); 311 trace_user_s390x_restore_sigregs(env, addr, prev_addr); 312 313 /* 314 * Use current psw.mask to preserve PER bit. 315 * TODO: 316 * if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI)) 317 * return -EINVAL; 318 * Simply do not allow it to be set in mask. 319 */ 320 prev_mask = s390_cpu_get_psw_mask(env); 321 mask = (prev_mask & ~PSW_MASK_USER) | (mask & PSW_MASK_USER); 322 /* Check for invalid user address space control. */ 323 if ((mask & PSW_MASK_ASC) == PSW_ASC_HOME) { 324 mask = (mask & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY; 325 } 326 /* Check for invalid amode. */ 327 if (mask & PSW_MASK_64) { 328 mask |= PSW_MASK_32; 329 } 330 s390_cpu_set_psw(env, mask, addr); 331 332 for (i = 0; i < 16; i++) { 333 __get_user(env->aregs[i], &sc->regs.acrs[i]); 334 } 335 for (i = 0; i < 16; i++) { 336 __get_user(*get_freg(env, i), &sc->fpregs.fprs[i]); 337 } 338 } 339 340 static void restore_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext) 341 { 342 int i; 343 344 /* 345 * if (MACHINE_HAS_VX) ... 346 * That said, we always allocate the stack storage and the 347 * space is always available in env. 348 */ 349 for (i = 0; i < 16; ++i) { 350 __get_user(env->vregs[i][1], &ext->vxrs_low[i]); 351 } 352 for (i = 0; i < 16; ++i) { 353 __get_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]); 354 __get_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]); 355 } 356 } 357 358 long do_sigreturn(CPUS390XState *env) 359 { 360 sigframe *frame; 361 abi_ulong frame_addr = env->regs[15]; 362 target_sigset_t target_set; 363 sigset_t set; 364 365 trace_user_do_sigreturn(env, frame_addr); 366 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 367 force_sig(TARGET_SIGSEGV); 368 return -TARGET_QEMU_ESIGRETURN; 369 } 370 371 /* Make sure that we're initializing all of target_set. */ 372 QEMU_BUILD_BUG_ON(ARRAY_SIZE(target_set.sig) != 1); 373 __get_user(target_set.sig[0], &frame->sc.oldmask[0]); 374 375 target_to_host_sigset_internal(&set, &target_set); 376 set_sigmask(&set); /* ~_BLOCKABLE? */ 377 378 restore_sigregs(env, &frame->sregs); 379 restore_sigregs_ext(env, &frame->sregs_ext); 380 381 unlock_user_struct(frame, frame_addr, 0); 382 return -TARGET_QEMU_ESIGRETURN; 383 } 384 385 long do_rt_sigreturn(CPUS390XState *env) 386 { 387 rt_sigframe *frame; 388 abi_ulong frame_addr = env->regs[15]; 389 sigset_t set; 390 391 trace_user_do_rt_sigreturn(env, frame_addr); 392 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 393 force_sig(TARGET_SIGSEGV); 394 return -TARGET_QEMU_ESIGRETURN; 395 } 396 target_to_host_sigset(&set, &frame->uc.tuc_sigmask); 397 398 set_sigmask(&set); /* ~_BLOCKABLE? */ 399 400 restore_sigregs(env, &frame->uc.tuc_mcontext); 401 restore_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); 402 403 target_restore_altstack(&frame->uc.tuc_stack, env); 404 405 unlock_user_struct(frame, frame_addr, 0); 406 return -TARGET_QEMU_ESIGRETURN; 407 } 408