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 } sigframe; 72 73 #define TARGET_UC_VXRS 2 74 75 struct target_ucontext { 76 abi_ulong tuc_flags; 77 abi_ulong tuc_link; 78 target_stack_t tuc_stack; 79 target_sigregs tuc_mcontext; 80 target_sigset_t tuc_sigmask; 81 uint8_t reserved[128 - sizeof(target_sigset_t)]; 82 target_sigregs_ext tuc_mcontext_ext; 83 }; 84 85 typedef struct { 86 uint8_t callee_used_stack[__SIGNAL_FRAMESIZE]; 87 /* 88 * This field is no longer initialized by the kernel, but it's still a part 89 * of the ABI. 90 */ 91 uint16_t svc_insn; 92 struct target_siginfo info; 93 struct target_ucontext uc; 94 } rt_sigframe; 95 96 static inline abi_ulong 97 get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size) 98 { 99 abi_ulong sp; 100 101 /* Default to using normal stack */ 102 sp = get_sp_from_cpustate(env); 103 104 /* This is the X/Open sanctioned signal stack switching. */ 105 if (ka->sa_flags & TARGET_SA_ONSTACK) { 106 sp = target_sigsp(sp, ka); 107 } 108 109 /* This is the legacy signal stack switching. */ 110 else if (/* FIXME !user_mode(regs) */ 0 && 111 !(ka->sa_flags & TARGET_SA_RESTORER) && 112 ka->sa_restorer) { 113 sp = (abi_ulong) ka->sa_restorer; 114 } 115 116 return (sp - frame_size) & -8ul; 117 } 118 119 #define PSW_USER_BITS (PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | \ 120 PSW_MASK_MCHECK | PSW_MASK_PSTATE | PSW_ASC_PRIMARY) 121 #define PSW_MASK_USER (PSW_MASK_ASC | PSW_MASK_CC | PSW_MASK_PM | \ 122 PSW_MASK_64 | PSW_MASK_32) 123 124 static void save_sigregs(CPUS390XState *env, target_sigregs *sregs) 125 { 126 uint64_t psw_mask = s390_cpu_get_psw_mask(env); 127 int i; 128 129 /* 130 * Copy a 'clean' PSW mask to the user to avoid leaking 131 * information about whether PER is currently on. 132 * TODO: qemu does not support PSW_MASK_RI; it will never be set. 133 */ 134 psw_mask = PSW_USER_BITS | (psw_mask & PSW_MASK_USER); 135 __put_user(psw_mask, &sregs->regs.psw.mask); 136 __put_user(env->psw.addr, &sregs->regs.psw.addr); 137 138 for (i = 0; i < 16; i++) { 139 __put_user(env->regs[i], &sregs->regs.gprs[i]); 140 } 141 for (i = 0; i < 16; i++) { 142 __put_user(env->aregs[i], &sregs->regs.acrs[i]); 143 } 144 145 /* 146 * We have to store the fp registers to current->thread.fp_regs 147 * to merge them with the emulated registers. 148 */ 149 for (i = 0; i < 16; i++) { 150 __put_user(*get_freg(env, i), &sregs->fpregs.fprs[i]); 151 } 152 } 153 154 static void save_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext) 155 { 156 int i; 157 158 /* 159 * if (MACHINE_HAS_VX) ... 160 * That said, we always allocate the stack storage and the 161 * space is always available in env. 162 */ 163 for (i = 0; i < 16; ++i) { 164 __put_user(env->vregs[i][1], &ext->vxrs_low[i]); 165 } 166 for (i = 0; i < 16; ++i) { 167 __put_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]); 168 __put_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]); 169 } 170 } 171 172 void setup_frame(int sig, struct target_sigaction *ka, 173 target_sigset_t *set, CPUS390XState *env) 174 { 175 sigframe *frame; 176 abi_ulong frame_addr; 177 abi_ulong restorer; 178 179 frame_addr = get_sigframe(ka, env, sizeof(*frame)); 180 trace_user_setup_frame(env, frame_addr); 181 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 182 force_sigsegv(sig); 183 return; 184 } 185 186 /* Set up backchain. */ 187 __put_user(env->regs[15], (abi_ulong *) frame); 188 189 /* Create struct sigcontext on the signal stack. */ 190 /* Make sure that we're initializing all of oldmask. */ 191 QEMU_BUILD_BUG_ON(ARRAY_SIZE(frame->sc.oldmask) != 1); 192 __put_user(set->sig[0], &frame->sc.oldmask[0]); 193 __put_user(frame_addr + offsetof(sigframe, sregs), &frame->sc.sregs); 194 195 /* Create _sigregs on the signal stack */ 196 save_sigregs(env, &frame->sregs); 197 198 /* 199 * ??? The kernel uses regs->gprs[2] here, which is not yet the signo. 200 * Moreover the comment talks about allowing backtrace, which is really 201 * done by the r15 copy above. 202 */ 203 __put_user(sig, &frame->signo); 204 205 /* Create sigregs_ext on the signal stack. */ 206 save_sigregs_ext(env, &frame->sregs_ext); 207 208 /* 209 * Set up to return from userspace. 210 * If provided, use a stub already in userspace. 211 */ 212 if (ka->sa_flags & TARGET_SA_RESTORER) { 213 restorer = ka->sa_restorer; 214 } else { 215 restorer = default_sigreturn; 216 } 217 218 /* Set up registers for signal handler */ 219 env->regs[14] = restorer; 220 env->regs[15] = frame_addr; 221 /* Force default amode and default user address space control. */ 222 env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY 223 | (env->psw.mask & ~PSW_MASK_ASC); 224 env->psw.addr = ka->_sa_handler; 225 226 env->regs[2] = sig; 227 env->regs[3] = frame_addr + offsetof(typeof(*frame), sc); 228 229 /* 230 * We forgot to include these in the sigcontext. 231 * To avoid breaking binary compatibility, they are passed as args. 232 */ 233 env->regs[4] = 0; /* FIXME: regs->int_code & 127 */ 234 env->regs[5] = 0; /* FIXME: regs->int_parm_long */ 235 env->regs[6] = 0; /* FIXME: current->thread.last_break */ 236 237 unlock_user_struct(frame, frame_addr, 1); 238 } 239 240 void setup_rt_frame(int sig, struct target_sigaction *ka, 241 target_siginfo_t *info, 242 target_sigset_t *set, CPUS390XState *env) 243 { 244 rt_sigframe *frame; 245 abi_ulong frame_addr; 246 abi_ulong restorer; 247 abi_ulong uc_flags; 248 249 frame_addr = get_sigframe(ka, env, sizeof *frame); 250 trace_user_setup_rt_frame(env, frame_addr); 251 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { 252 force_sigsegv(sig); 253 return; 254 } 255 256 /* Set up backchain. */ 257 __put_user(env->regs[15], (abi_ulong *) frame); 258 259 /* 260 * Set up to return from userspace. 261 * If provided, use a stub already in userspace. 262 */ 263 if (ka->sa_flags & TARGET_SA_RESTORER) { 264 restorer = ka->sa_restorer; 265 } else { 266 restorer = default_rt_sigreturn; 267 } 268 269 /* Create siginfo on the signal stack. */ 270 tswap_siginfo(&frame->info, info); 271 272 /* Create ucontext on the signal stack. */ 273 uc_flags = 0; 274 if (s390_has_feat(S390_FEAT_VECTOR)) { 275 uc_flags |= TARGET_UC_VXRS; 276 } 277 __put_user(uc_flags, &frame->uc.tuc_flags); 278 __put_user(0, &frame->uc.tuc_link); 279 target_save_altstack(&frame->uc.tuc_stack, env); 280 save_sigregs(env, &frame->uc.tuc_mcontext); 281 save_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); 282 tswap_sigset(&frame->uc.tuc_sigmask, set); 283 284 /* Set up registers for signal handler */ 285 env->regs[14] = restorer; 286 env->regs[15] = frame_addr; 287 /* Force default amode and default user address space control. */ 288 env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY 289 | (env->psw.mask & ~PSW_MASK_ASC); 290 env->psw.addr = ka->_sa_handler; 291 292 env->regs[2] = sig; 293 env->regs[3] = frame_addr + offsetof(typeof(*frame), info); 294 env->regs[4] = frame_addr + offsetof(typeof(*frame), uc); 295 env->regs[5] = 0; /* FIXME: current->thread.last_break */ 296 } 297 298 static void restore_sigregs(CPUS390XState *env, target_sigregs *sc) 299 { 300 uint64_t prev_addr, prev_mask, mask, addr; 301 int i; 302 303 for (i = 0; i < 16; i++) { 304 __get_user(env->regs[i], &sc->regs.gprs[i]); 305 } 306 307 prev_addr = env->psw.addr; 308 __get_user(mask, &sc->regs.psw.mask); 309 __get_user(addr, &sc->regs.psw.addr); 310 trace_user_s390x_restore_sigregs(env, addr, prev_addr); 311 312 /* 313 * Use current psw.mask to preserve PER bit. 314 * TODO: 315 * if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI)) 316 * return -EINVAL; 317 * Simply do not allow it to be set in mask. 318 */ 319 prev_mask = s390_cpu_get_psw_mask(env); 320 mask = (prev_mask & ~PSW_MASK_USER) | (mask & PSW_MASK_USER); 321 /* Check for invalid user address space control. */ 322 if ((mask & PSW_MASK_ASC) == PSW_ASC_HOME) { 323 mask = (mask & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY; 324 } 325 /* Check for invalid amode. */ 326 if (mask & PSW_MASK_64) { 327 mask |= PSW_MASK_32; 328 } 329 s390_cpu_set_psw(env, mask, addr); 330 331 for (i = 0; i < 16; i++) { 332 __get_user(env->aregs[i], &sc->regs.acrs[i]); 333 } 334 for (i = 0; i < 16; i++) { 335 __get_user(*get_freg(env, i), &sc->fpregs.fprs[i]); 336 } 337 } 338 339 static void restore_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext) 340 { 341 int i; 342 343 /* 344 * if (MACHINE_HAS_VX) ... 345 * That said, we always allocate the stack storage and the 346 * space is always available in env. 347 */ 348 for (i = 0; i < 16; ++i) { 349 __get_user(env->vregs[i][1], &ext->vxrs_low[i]); 350 } 351 for (i = 0; i < 16; ++i) { 352 __get_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]); 353 __get_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]); 354 } 355 } 356 357 long do_sigreturn(CPUS390XState *env) 358 { 359 sigframe *frame; 360 abi_ulong frame_addr = env->regs[15]; 361 target_sigset_t target_set; 362 sigset_t set; 363 364 trace_user_do_sigreturn(env, frame_addr); 365 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 366 force_sig(TARGET_SIGSEGV); 367 return -QEMU_ESIGRETURN; 368 } 369 370 /* Make sure that we're initializing all of target_set. */ 371 QEMU_BUILD_BUG_ON(ARRAY_SIZE(target_set.sig) != 1); 372 __get_user(target_set.sig[0], &frame->sc.oldmask[0]); 373 374 target_to_host_sigset_internal(&set, &target_set); 375 set_sigmask(&set); /* ~_BLOCKABLE? */ 376 377 restore_sigregs(env, &frame->sregs); 378 restore_sigregs_ext(env, &frame->sregs_ext); 379 380 unlock_user_struct(frame, frame_addr, 0); 381 return -QEMU_ESIGRETURN; 382 } 383 384 long do_rt_sigreturn(CPUS390XState *env) 385 { 386 rt_sigframe *frame; 387 abi_ulong frame_addr = env->regs[15]; 388 sigset_t set; 389 390 trace_user_do_rt_sigreturn(env, frame_addr); 391 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { 392 force_sig(TARGET_SIGSEGV); 393 return -QEMU_ESIGRETURN; 394 } 395 target_to_host_sigset(&set, &frame->uc.tuc_sigmask); 396 397 set_sigmask(&set); /* ~_BLOCKABLE? */ 398 399 restore_sigregs(env, &frame->uc.tuc_mcontext); 400 restore_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); 401 402 target_restore_altstack(&frame->uc.tuc_stack, env); 403 404 unlock_user_struct(frame, frame_addr, 0); 405 return -QEMU_ESIGRETURN; 406 } 407 408 void setup_sigtramp(abi_ulong sigtramp_page) 409 { 410 uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 + 2, 0); 411 assert(tramp != NULL); 412 413 default_sigreturn = sigtramp_page; 414 __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn, &tramp[0]); 415 416 default_rt_sigreturn = sigtramp_page + 2; 417 __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn, &tramp[1]); 418 419 unlock_user(tramp, sigtramp_page, 2 + 2); 420 } 421