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