| 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 | #include "vdso-asmoffset.h" |
| 25 | #include "target_ptrace.h" |
| 26 | |
| 27 | #define __NUM_GPRS 16 |
| 28 | #define __NUM_FPRS 16 |
| 29 | #define __NUM_ACRS 16 |
| 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[STACK_FRAME_OVERHEAD]; |
| 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[STACK_FRAME_OVERHEAD]; |
| 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 | __put_user(env->fpc, &sregs->fpregs.fpc); |
| 150 | for (i = 0; i < 16; i++) { |
| 151 | __put_user(*get_freg(env, i), &sregs->fpregs.fprs[i]); |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | static void save_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext) |
| 156 | { |
| 157 | int i; |
| 158 | |
| 159 | /* |
| 160 | * if (MACHINE_HAS_VX) ... |
| 161 | * That said, we always allocate the stack storage and the |
| 162 | * space is always available in env. |
| 163 | */ |
| 164 | for (i = 0; i < 16; ++i) { |
| 165 | __put_user(env->vregs[i][1], &ext->vxrs_low[i]); |
| 166 | } |
| 167 | for (i = 0; i < 16; ++i) { |
| 168 | __put_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]); |
| 169 | __put_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | void setup_frame(int sig, struct target_sigaction *ka, |
| 174 | target_sigset_t *set, CPUS390XState *env) |
| 175 | { |
| 176 | sigframe *frame; |
| 177 | abi_ulong frame_addr; |
| 178 | abi_ulong restorer; |
| 179 | |
| 180 | frame_addr = get_sigframe(ka, env, sizeof(*frame)); |
| 181 | trace_user_setup_frame(env, frame_addr); |
| 182 | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { |
| 183 | force_sigsegv(sig); |
| 184 | return; |
| 185 | } |
| 186 | |
| 187 | /* Set up backchain. */ |
| 188 | __put_user(env->regs[15], (abi_ulong *) frame); |
| 189 | |
| 190 | /* Create struct sigcontext on the signal stack. */ |
| 191 | /* Make sure that we're initializing all of oldmask. */ |
| 192 | QEMU_BUILD_BUG_ON(ARRAY_SIZE(frame->sc.oldmask) != 1); |
| 193 | __put_user(set->sig[0], &frame->sc.oldmask[0]); |
| 194 | __put_user(frame_addr + offsetof(sigframe, sregs), &frame->sc.sregs); |
| 195 | |
| 196 | /* Create _sigregs on the signal stack */ |
| 197 | save_sigregs(env, &frame->sregs); |
| 198 | |
| 199 | /* |
| 200 | * ??? The kernel uses regs->gprs[2] here, which is not yet the signo. |
| 201 | * Moreover the comment talks about allowing backtrace, which is really |
| 202 | * done by the r15 copy above. |
| 203 | */ |
| 204 | __put_user(sig, &frame->signo); |
| 205 | |
| 206 | /* Create sigregs_ext on the signal stack. */ |
| 207 | save_sigregs_ext(env, &frame->sregs_ext); |
| 208 | |
| 209 | /* |
| 210 | * Set up to return from userspace. |
| 211 | * If provided, use a stub already in userspace. |
| 212 | */ |
| 213 | if (ka->sa_flags & TARGET_SA_RESTORER) { |
| 214 | restorer = ka->sa_restorer; |
| 215 | } else { |
| 216 | restorer = default_sigreturn; |
| 217 | } |
| 218 | |
| 219 | /* Set up registers for signal handler */ |
| 220 | env->regs[14] = restorer; |
| 221 | env->regs[15] = frame_addr; |
| 222 | /* Force default amode and default user address space control. */ |
| 223 | env->psw.mask = PSW_MASK_64 | PSW_MASK_32 | PSW_ASC_PRIMARY |
| 224 | | (env->psw.mask & ~PSW_MASK_ASC); |
| 225 | env->psw.addr = ka->_sa_handler; |
| 226 | |
| 227 | env->regs[2] = sig; |
| 228 | env->regs[3] = frame_addr + offsetof(typeof(*frame), sc); |
| 229 | |
| 230 | /* |
| 231 | * We forgot to include these in the sigcontext. |
| 232 | * To avoid breaking binary compatibility, they are passed as args. |
| 233 | */ |
| 234 | env->regs[4] = 0; /* FIXME: regs->int_code & 127 */ |
| 235 | env->regs[5] = 0; /* FIXME: regs->int_parm_long */ |
| 236 | env->regs[6] = 0; /* FIXME: current->thread.last_break */ |
| 237 | |
| 238 | unlock_user_struct(frame, frame_addr, 1); |
| 239 | } |
| 240 | |
| 241 | void setup_rt_frame(int sig, struct target_sigaction *ka, |
| 242 | target_siginfo_t *info, |
| 243 | target_sigset_t *set, CPUS390XState *env) |
| 244 | { |
| 245 | rt_sigframe *frame; |
| 246 | abi_ulong frame_addr; |
| 247 | abi_ulong restorer; |
| 248 | abi_ulong uc_flags; |
| 249 | |
| 250 | frame_addr = get_sigframe(ka, env, sizeof *frame); |
| 251 | trace_user_setup_rt_frame(env, frame_addr); |
| 252 | if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { |
| 253 | force_sigsegv(sig); |
| 254 | return; |
| 255 | } |
| 256 | |
| 257 | /* Set up backchain. */ |
| 258 | __put_user(env->regs[15], (abi_ulong *) frame); |
| 259 | |
| 260 | /* |
| 261 | * Set up to return from userspace. |
| 262 | * If provided, use a stub already in userspace. |
| 263 | */ |
| 264 | if (ka->sa_flags & TARGET_SA_RESTORER) { |
| 265 | restorer = ka->sa_restorer; |
| 266 | } else { |
| 267 | restorer = default_rt_sigreturn; |
| 268 | } |
| 269 | |
| 270 | /* Create siginfo on the signal stack. */ |
| 271 | 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 | { |
| 336 | uint32_t fpc; |
| 337 | __get_user(fpc, &sc->fpregs.fpc); |
| 338 | cpu_s390x_load_fpc(env, fpc); |
| 339 | } |
| 340 | for (i = 0; i < 16; i++) { |
| 341 | __get_user(*get_freg(env, i), &sc->fpregs.fprs[i]); |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | static void restore_sigregs_ext(CPUS390XState *env, target_sigregs_ext *ext) |
| 346 | { |
| 347 | int i; |
| 348 | |
| 349 | /* |
| 350 | * if (MACHINE_HAS_VX) ... |
| 351 | * That said, we always allocate the stack storage and the |
| 352 | * space is always available in env. |
| 353 | */ |
| 354 | for (i = 0; i < 16; ++i) { |
| 355 | __get_user(env->vregs[i][1], &ext->vxrs_low[i]); |
| 356 | } |
| 357 | for (i = 0; i < 16; ++i) { |
| 358 | __get_user(env->vregs[i + 16][0], &ext->vxrs_high[i][0]); |
| 359 | __get_user(env->vregs[i + 16][1], &ext->vxrs_high[i][1]); |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | long do_sigreturn(CPUS390XState *env) |
| 364 | { |
| 365 | sigframe *frame; |
| 366 | abi_ulong frame_addr = env->regs[15]; |
| 367 | target_sigset_t target_set; |
| 368 | sigset_t set; |
| 369 | |
| 370 | trace_user_do_sigreturn(env, frame_addr); |
| 371 | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { |
| 372 | force_sig(TARGET_SIGSEGV); |
| 373 | return -QEMU_ESIGRETURN; |
| 374 | } |
| 375 | |
| 376 | /* Make sure that we're initializing all of target_set. */ |
| 377 | QEMU_BUILD_BUG_ON(ARRAY_SIZE(target_set.sig) != 1); |
| 378 | __get_user(target_set.sig[0], &frame->sc.oldmask[0]); |
| 379 | |
| 380 | target_to_host_sigset_internal(&set, &target_set); |
| 381 | set_sigmask(&set); /* ~_BLOCKABLE? */ |
| 382 | |
| 383 | restore_sigregs(env, &frame->sregs); |
| 384 | restore_sigregs_ext(env, &frame->sregs_ext); |
| 385 | |
| 386 | unlock_user_struct(frame, frame_addr, 0); |
| 387 | return -QEMU_ESIGRETURN; |
| 388 | } |
| 389 | |
| 390 | long do_rt_sigreturn(CPUS390XState *env) |
| 391 | { |
| 392 | rt_sigframe *frame; |
| 393 | abi_ulong frame_addr = env->regs[15]; |
| 394 | sigset_t set; |
| 395 | |
| 396 | trace_user_do_rt_sigreturn(env, frame_addr); |
| 397 | if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { |
| 398 | force_sig(TARGET_SIGSEGV); |
| 399 | return -QEMU_ESIGRETURN; |
| 400 | } |
| 401 | target_to_host_sigset(&set, &frame->uc.tuc_sigmask); |
| 402 | |
| 403 | set_sigmask(&set); /* ~_BLOCKABLE? */ |
| 404 | |
| 405 | restore_sigregs(env, &frame->uc.tuc_mcontext); |
| 406 | restore_sigregs_ext(env, &frame->uc.tuc_mcontext_ext); |
| 407 | |
| 408 | target_restore_altstack(&frame->uc.tuc_stack, env); |
| 409 | |
| 410 | unlock_user_struct(frame, frame_addr, 0); |
| 411 | return -QEMU_ESIGRETURN; |
| 412 | } |
| 413 | |
| 414 | void setup_sigtramp(abi_ulong sigtramp_page) |
| 415 | { |
| 416 | uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 + 2, 0); |
| 417 | assert(tramp != NULL); |
| 418 | |
| 419 | default_sigreturn = sigtramp_page; |
| 420 | __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn, &tramp[0]); |
| 421 | |
| 422 | default_rt_sigreturn = sigtramp_page + 2; |
| 423 | __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn, &tramp[1]); |
| 424 | |
| 425 | unlock_user(tramp, sigtramp_page, 2 + 2); |
| 426 | } |