arch/sparc/kernel/signal32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*  arch/sparc64/kernel/signal32.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   6  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
   7  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
   8  *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   9  */
  10
  11 #include <linux/sched.h>
  12 #include <linux/kernel.h>
  13 #include <linux/signal.h>
  14 #include <linux/errno.h>
  15 #include <linux/wait.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/unistd.h>
  18 #include <linux/mm.h>
  19 #include <linux/tty.h>
  20 #include <linux/binfmts.h>
  21 #include <linux/compat.h>
  22 #include <linux/bitops.h>
  23
  24 #include <linux/uaccess.h>
  25 #include <asm/ptrace.h>
  26 #include <asm/psrcompat.h>
  27 #include <asm/fpumacro.h>
  28 #include <asm/visasm.h>
  29 #include <asm/compat_signal.h>
  30 #include <asm/switch_to.h>
  31
  32 #include "sigutil.h"
  33 #include "kernel.h"
  34
  35 /* This magic should be in g_upper[0] for all upper parts
  36  * to be valid.
  37  */
  38 #define SIGINFO_EXTRA_V8PLUS_MAGIC      0x130e269
  39 typedef struct {
  40         unsigned int g_upper[8];
  41         unsigned int o_upper[8];
  42         unsigned int asi;
  43 } siginfo_extra_v8plus_t;
  44
  45 struct signal_frame32 {
  46         struct sparc_stackf32   ss;
  47         __siginfo32_t           info;
  48         /* __siginfo_fpu_t * */ u32 fpu_save;
  49         unsigned int            insns[2];
  50         unsigned int            extramask[_COMPAT_NSIG_WORDS - 1];
  51         unsigned int            extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
  52         /* Only valid if (info.si_regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
  53         siginfo_extra_v8plus_t  v8plus;
  54         /* __siginfo_rwin_t * */u32 rwin_save;
  55 } __attribute__((aligned(8)));
  56
  57 struct rt_signal_frame32 {
  58         struct sparc_stackf32   ss;
  59         compat_siginfo_t        info;
  60         struct pt_regs32        regs;
  61         compat_sigset_t         mask;
  62         /* __siginfo_fpu_t * */ u32 fpu_save;
  63         unsigned int            insns[2];
  64         compat_stack_t          stack;
  65         unsigned int            extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
  66         /* Only valid if (regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
  67         siginfo_extra_v8plus_t  v8plus;
  68         /* __siginfo_rwin_t * */u32 rwin_save;
  69 } __attribute__((aligned(8)));
  70
  71 /* Checks if the fp is valid.  We always build signal frames which are
  72  * 16-byte aligned, therefore we can always enforce that the restore
  73  * frame has that property as well.
  74  */
  75 static bool invalid_frame_pointer(void __user *fp, int fplen)
  76 {
  77         if ((((unsigned long) fp) & 15) ||
  78             ((unsigned long)fp) > 0x100000000ULL - fplen)
  79                 return true;
  80         return false;
  81 }
  82
  83 void do_sigreturn32(struct pt_regs *regs)
  84 {
  85         struct signal_frame32 __user *sf;
  86         compat_uptr_t fpu_save;
  87         compat_uptr_t rwin_save;
  88         unsigned int psr, ufp;
  89         unsigned int pc, npc;
  90         sigset_t set;
  91         compat_sigset_t seta;
  92         int err, i;
  93
  94         /* Always make any pending restarted system calls return -EINTR */
  95         current->restart_block.fn = do_no_restart_syscall;
  96
  97         synchronize_user_stack();
  98
  99         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 100         sf = (struct signal_frame32 __user *) regs->u_regs[UREG_FP];
 101
 102         /* 1. Make sure we are not getting garbage from the user */
 103         if (invalid_frame_pointer(sf, sizeof(*sf)))
 104                 goto segv;
 105
 106         if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
 107                 goto segv;
 108
 109         if (ufp & 0x7)
 110                 goto segv;
 111
 112         if (__get_user(pc, &sf->info.si_regs.pc) ||
 113             __get_user(npc, &sf->info.si_regs.npc))
 114                 goto segv;
 115
 116         if ((pc | npc) & 3)
 117                 goto segv;
 118
 119         if (test_thread_flag(TIF_32BIT)) {
 120                 pc &= 0xffffffff;
 121                 npc &= 0xffffffff;
 122         }
 123         regs->tpc = pc;
 124         regs->tnpc = npc;
 125
 126         /* 2. Restore the state */
 127         err = __get_user(regs->y, &sf->info.si_regs.y);
 128         err |= __get_user(psr, &sf->info.si_regs.psr);
 129
 130         for (i = UREG_G1; i <= UREG_I7; i++)
 131                 err |= __get_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
 132         if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
 133                 err |= __get_user(i, &sf->v8plus.g_upper[0]);
 134                 if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
 135                         unsigned long asi;
 136
 137                         for (i = UREG_G1; i <= UREG_I7; i++)
 138                                 err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
 139                         err |= __get_user(asi, &sf->v8plus.asi);
 140                         regs->tstate &= ~TSTATE_ASI;
 141                         regs->tstate |= ((asi & 0xffUL) << 24UL);
 142                 }
 143         }
 144
 145         /* User can only change condition codes in %tstate. */
 146         regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
 147         regs->tstate |= psr_to_tstate_icc(psr);
 148
 149         /* Prevent syscall restart.  */
 150         pt_regs_clear_syscall(regs);
 151
 152         err |= __get_user(fpu_save, &sf->fpu_save);
 153         if (!err && fpu_save)
 154                 err |= restore_fpu_state(regs, compat_ptr(fpu_save));
 155         err |= __get_user(rwin_save, &sf->rwin_save);
 156         if (!err && rwin_save) {
 157                 if (restore_rwin_state(compat_ptr(rwin_save)))
 158                         goto segv;
 159         }
 160         err |= __get_user(seta.sig[0], &sf->info.si_mask);
 161         err |= copy_from_user(&seta.sig[1], &sf->extramask,
 162                               (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
 163         if (err)
 164                 goto segv;
 165
 166         set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
 167         set_current_blocked(&set);
 168         return;
 169
 170 segv:
 171         force_sig(SIGSEGV);
 172 }
 173
 174 asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
 175 {
 176         struct rt_signal_frame32 __user *sf;
 177         unsigned int psr, pc, npc, ufp;
 178         compat_uptr_t fpu_save;
 179         compat_uptr_t rwin_save;
 180         sigset_t set;
 181         int err, i;
 182
 183         /* Always make any pending restarted system calls return -EINTR */
 184         current->restart_block.fn = do_no_restart_syscall;
 185
 186         synchronize_user_stack();
 187         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 188         sf = (struct rt_signal_frame32 __user *) regs->u_regs[UREG_FP];
 189
 190         /* 1. Make sure we are not getting garbage from the user */
 191         if (invalid_frame_pointer(sf, sizeof(*sf)))
 192                 goto segv;
 193
 194         if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
 195                 goto segv;
 196
 197         if (ufp & 0x7)
 198                 goto segv;
 199
 200         if (__get_user(pc, &sf->regs.pc) ||
 201             __get_user(npc, &sf->regs.npc))
 202                 goto segv;
 203
 204         if ((pc | npc) & 3)
 205                 goto segv;
 206
 207         if (test_thread_flag(TIF_32BIT)) {
 208                 pc &= 0xffffffff;
 209                 npc &= 0xffffffff;
 210         }
 211         regs->tpc = pc;
 212         regs->tnpc = npc;
 213
 214         /* 2. Restore the state */
 215         err = __get_user(regs->y, &sf->regs.y);
 216         err |= __get_user(psr, &sf->regs.psr);
 217
 218         for (i = UREG_G1; i <= UREG_I7; i++)
 219                 err |= __get_user(regs->u_regs[i], &sf->regs.u_regs[i]);
 220         if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
 221                 err |= __get_user(i, &sf->v8plus.g_upper[0]);
 222                 if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
 223                         unsigned long asi;
 224
 225                         for (i = UREG_G1; i <= UREG_I7; i++)
 226                                 err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
 227                         err |= __get_user(asi, &sf->v8plus.asi);
 228                         regs->tstate &= ~TSTATE_ASI;
 229                         regs->tstate |= ((asi & 0xffUL) << 24UL);
 230                 }
 231         }
 232
 233         /* User can only change condition codes in %tstate. */
 234         regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
 235         regs->tstate |= psr_to_tstate_icc(psr);
 236
 237         /* Prevent syscall restart.  */
 238         pt_regs_clear_syscall(regs);
 239
 240         err |= __get_user(fpu_save, &sf->fpu_save);
 241         if (!err && fpu_save)
 242                 err |= restore_fpu_state(regs, compat_ptr(fpu_save));
 243         err |= get_compat_sigset(&set, &sf->mask);
 244         err |= compat_restore_altstack(&sf->stack);
 245         if (err)
 246                 goto segv;
 247
 248         err |= __get_user(rwin_save, &sf->rwin_save);
 249         if (!err && rwin_save) {
 250                 if (restore_rwin_state(compat_ptr(rwin_save)))
 251                         goto segv;
 252         }
 253
 254         set_current_blocked(&set);
 255         return;
 256 segv:
 257         force_sig(SIGSEGV);
 258 }
 259
 260 static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
 261 {
 262         unsigned long sp;
 263
 264         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 265         sp = regs->u_regs[UREG_FP];
 266
 267         /*
 268          * If we are on the alternate signal stack and would overflow it, don't.
 269          * Return an always-bogus address instead so we will die with SIGSEGV.
 270          */
 271         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 272                 return (void __user *) -1L;
 273
 274         /* This is the X/Open sanctioned signal stack switching.  */
 275         sp = sigsp(sp, ksig) - framesize;
 276
 277         /* Always align the stack frame.  This handles two cases.  First,
 278          * sigaltstack need not be mindful of platform specific stack
 279          * alignment.  Second, if we took this signal because the stack
 280          * is not aligned properly, we'd like to take the signal cleanly
 281          * and report that.
 282          */
 283         sp &= ~15UL;
 284
 285         return (void __user *) sp;
 286 }
 287
 288 /* The I-cache flush instruction only works in the primary ASI, which
 289  * right now is the nucleus, aka. kernel space.
 290  *
 291  * Therefore we have to kick the instructions out using the kernel
 292  * side linear mapping of the physical address backing the user
 293  * instructions.
 294  */
 295 static void flush_signal_insns(unsigned long address)
 296 {
 297         unsigned long pstate, paddr;
 298         pte_t *ptep, pte;
 299         pgd_t *pgdp;
 300         p4d_t *p4dp;
 301         pud_t *pudp;
 302         pmd_t *pmdp;
 303
 304         /* Commit all stores of the instructions we are about to flush.  */
 305         wmb();
 306
 307         /* Disable cross-call reception.  In this way even a very wide
 308          * munmap() on another cpu can't tear down the page table
 309          * hierarchy from underneath us, since that can't complete
 310          * until the IPI tlb flush returns.
 311          */
 312
 313         __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
 314         __asm__ __volatile__("wrpr %0, %1, %%pstate"
 315                                 : : "r" (pstate), "i" (PSTATE_IE));
 316
 317         pgdp = pgd_offset(current->mm, address);
 318         if (pgd_none(*pgdp))
 319                 goto out_irqs_on;
 320         p4dp = p4d_offset(pgdp, address);
 321         if (p4d_none(*p4dp))
 322                 goto out_irqs_on;
 323         pudp = pud_offset(p4dp, address);
 324         if (pud_none(*pudp))
 325                 goto out_irqs_on;
 326         pmdp = pmd_offset(pudp, address);
 327         if (pmd_none(*pmdp))
 328                 goto out_irqs_on;
 329
 330         ptep = pte_offset_map(pmdp, address);
 331         pte = *ptep;
 332         if (!pte_present(pte))
 333                 goto out_unmap;
 334
 335         paddr = (unsigned long) page_address(pte_page(pte));
 336
 337         __asm__ __volatile__("flush     %0 + %1"
 338                              : /* no outputs */
 339                              : "r" (paddr),
 340                                "r" (address & (PAGE_SIZE - 1))
 341                              : "memory");
 342
 343 out_unmap:
 344         pte_unmap(ptep);
 345 out_irqs_on:
 346         __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
 347
 348 }
 349
 350 static int setup_frame32(struct ksignal *ksig, struct pt_regs *regs,
 351                          sigset_t *oldset)
 352 {
 353         struct signal_frame32 __user *sf;
 354         int i, err, wsaved;
 355         void __user *tail;
 356         int sigframe_size;
 357         u32 psr;
 358         compat_sigset_t seta;
 359
 360         /* 1. Make sure everything is clean */
 361         synchronize_user_stack();
 362         save_and_clear_fpu();
 363
 364         wsaved = get_thread_wsaved();
 365
 366         sigframe_size = sizeof(*sf);
 367         if (current_thread_info()->fpsaved[0] & FPRS_FEF)
 368                 sigframe_size += sizeof(__siginfo_fpu_t);
 369         if (wsaved)
 370                 sigframe_size += sizeof(__siginfo_rwin_t);
 371
 372         sf = (struct signal_frame32 __user *)
 373                 get_sigframe(ksig, regs, sigframe_size);
 374
 375         if (invalid_frame_pointer(sf, sigframe_size)) {
 376                 if (show_unhandled_signals)
 377                         pr_info("%s[%d] bad frame in setup_frame32: %08lx TPC %08lx O7 %08lx\n",
 378                                 current->comm, current->pid, (unsigned long)sf,
 379                                 regs->tpc, regs->u_regs[UREG_I7]);
 380                 force_sigsegv(ksig->sig);
 381                 return -EINVAL;
 382         }
 383
 384         tail = (sf + 1);
 385
 386         /* 2. Save the current process state */
 387         if (test_thread_flag(TIF_32BIT)) {
 388                 regs->tpc &= 0xffffffff;
 389                 regs->tnpc &= 0xffffffff;
 390         }
 391         err  = put_user(regs->tpc, &sf->info.si_regs.pc);
 392         err |= __put_user(regs->tnpc, &sf->info.si_regs.npc);
 393         err |= __put_user(regs->y, &sf->info.si_regs.y);
 394         psr = tstate_to_psr(regs->tstate);
 395         if (current_thread_info()->fpsaved[0] & FPRS_FEF)
 396                 psr |= PSR_EF;
 397         err |= __put_user(psr, &sf->info.si_regs.psr);
 398         for (i = 0; i < 16; i++)
 399                 err |= __put_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
 400         err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
 401         err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
 402         for (i = 1; i < 16; i++)
 403                 err |= __put_user(((u32 *)regs->u_regs)[2*i],
 404                                   &sf->v8plus.g_upper[i]);
 405         err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
 406                           &sf->v8plus.asi);
 407
 408         if (psr & PSR_EF) {
 409                 __siginfo_fpu_t __user *fp = tail;
 410                 tail += sizeof(*fp);
 411                 err |= save_fpu_state(regs, fp);
 412                 err |= __put_user((u64)fp, &sf->fpu_save);
 413         } else {
 414                 err |= __put_user(0, &sf->fpu_save);
 415         }
 416         if (wsaved) {
 417                 __siginfo_rwin_t __user *rwp = tail;
 418                 tail += sizeof(*rwp);
 419                 err |= save_rwin_state(wsaved, rwp);
 420                 err |= __put_user((u64)rwp, &sf->rwin_save);
 421                 set_thread_wsaved(0);
 422         } else {
 423                 err |= __put_user(0, &sf->rwin_save);
 424         }
 425
 426         /* If these change we need to know - assignments to seta relies on these sizes */
 427         BUILD_BUG_ON(_NSIG_WORDS != 1);
 428         BUILD_BUG_ON(_COMPAT_NSIG_WORDS != 2);
 429         seta.sig[1] = (oldset->sig[0] >> 32);
 430         seta.sig[0] = oldset->sig[0];
 431
 432         err |= __put_user(seta.sig[0], &sf->info.si_mask);
 433         err |= __copy_to_user(sf->extramask, &seta.sig[1],
 434                               (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
 435
 436         if (!wsaved) {
 437                 err |= raw_copy_in_user((u32 __user *)sf,
 438                                         (u32 __user *)(regs->u_regs[UREG_FP]),
 439                                         sizeof(struct reg_window32));
 440         } else {
 441                 struct reg_window *rp;
 442
 443                 rp = &current_thread_info()->reg_window[wsaved - 1];
 444                 for (i = 0; i < 8; i++)
 445                         err |= __put_user(rp->locals[i], &sf->ss.locals[i]);
 446                 for (i = 0; i < 6; i++)
 447                         err |= __put_user(rp->ins[i], &sf->ss.ins[i]);
 448                 err |= __put_user(rp->ins[6], &sf->ss.fp);
 449                 err |= __put_user(rp->ins[7], &sf->ss.callers_pc);
 450         }
 451         if (err)
 452                 return err;
 453
 454         /* 3. signal handler back-trampoline and parameters */
 455         regs->u_regs[UREG_FP] = (unsigned long) sf;
 456         regs->u_regs[UREG_I0] = ksig->sig;
 457         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 458         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 459
 460         /* 4. signal handler */
 461         regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
 462         regs->tnpc = (regs->tpc + 4);
 463         if (test_thread_flag(TIF_32BIT)) {
 464                 regs->tpc &= 0xffffffff;
 465                 regs->tnpc &= 0xffffffff;
 466         }
 467
 468         /* 5. return to kernel instructions */
 469         if (ksig->ka.ka_restorer) {
 470                 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 471         } else {
 472                 unsigned long address = ((unsigned long)&(sf->insns[0]));
 473
 474                 regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
 475
 476                 err  = __put_user(0x821020d8, &sf->insns[0]); /*mov __NR_sigreturn, %g1*/
 477                 err |= __put_user(0x91d02010, &sf->insns[1]); /*t 0x10*/
 478                 if (err)
 479                         return err;
 480                 flush_signal_insns(address);
 481         }
 482         return 0;
 483 }
 484
 485 static int setup_rt_frame32(struct ksignal *ksig, struct pt_regs *regs,
 486                             sigset_t *oldset)
 487 {
 488         struct rt_signal_frame32 __user *sf;
 489         int i, err, wsaved;
 490         void __user *tail;
 491         int sigframe_size;
 492         u32 psr;
 493
 494         /* 1. Make sure everything is clean */
 495         synchronize_user_stack();
 496         save_and_clear_fpu();
 497
 498         wsaved = get_thread_wsaved();
 499
 500         sigframe_size = sizeof(*sf);
 501         if (current_thread_info()->fpsaved[0] & FPRS_FEF)
 502                 sigframe_size += sizeof(__siginfo_fpu_t);
 503         if (wsaved)
 504                 sigframe_size += sizeof(__siginfo_rwin_t);
 505
 506         sf = (struct rt_signal_frame32 __user *)
 507                 get_sigframe(ksig, regs, sigframe_size);
 508
 509         if (invalid_frame_pointer(sf, sigframe_size)) {
 510                 if (show_unhandled_signals)
 511                         pr_info("%s[%d] bad frame in setup_rt_frame32: %08lx TPC %08lx O7 %08lx\n",
 512                                 current->comm, current->pid, (unsigned long)sf,
 513                                 regs->tpc, regs->u_regs[UREG_I7]);
 514                 force_sigsegv(ksig->sig);
 515                 return -EINVAL;
 516         }
 517
 518         tail = (sf + 1);
 519
 520         /* 2. Save the current process state */
 521         if (test_thread_flag(TIF_32BIT)) {
 522                 regs->tpc &= 0xffffffff;
 523                 regs->tnpc &= 0xffffffff;
 524         }
 525         err  = put_user(regs->tpc, &sf->regs.pc);
 526         err |= __put_user(regs->tnpc, &sf->regs.npc);
 527         err |= __put_user(regs->y, &sf->regs.y);
 528         psr = tstate_to_psr(regs->tstate);
 529         if (current_thread_info()->fpsaved[0] & FPRS_FEF)
 530                 psr |= PSR_EF;
 531         err |= __put_user(psr, &sf->regs.psr);
 532         for (i = 0; i < 16; i++)
 533                 err |= __put_user(regs->u_regs[i], &sf->regs.u_regs[i]);
 534         err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
 535         err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
 536         for (i = 1; i < 16; i++)
 537                 err |= __put_user(((u32 *)regs->u_regs)[2*i],
 538                                   &sf->v8plus.g_upper[i]);
 539         err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
 540                           &sf->v8plus.asi);
 541
 542         if (psr & PSR_EF) {
 543                 __siginfo_fpu_t __user *fp = tail;
 544                 tail += sizeof(*fp);
 545                 err |= save_fpu_state(regs, fp);
 546                 err |= __put_user((u64)fp, &sf->fpu_save);
 547         } else {
 548                 err |= __put_user(0, &sf->fpu_save);
 549         }
 550         if (wsaved) {
 551                 __siginfo_rwin_t __user *rwp = tail;
 552                 tail += sizeof(*rwp);
 553                 err |= save_rwin_state(wsaved, rwp);
 554                 err |= __put_user((u64)rwp, &sf->rwin_save);
 555                 set_thread_wsaved(0);
 556         } else {
 557                 err |= __put_user(0, &sf->rwin_save);
 558         }
 559
 560         /* Update the siginfo structure.  */
 561         err |= copy_siginfo_to_user32(&sf->info, &ksig->info);
 562
 563         /* Setup sigaltstack */
 564         err |= __compat_save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
 565
 566         err |= put_compat_sigset(&sf->mask, oldset, sizeof(compat_sigset_t));
 567
 568         if (!wsaved) {
 569                 err |= raw_copy_in_user((u32 __user *)sf,
 570                                         (u32 __user *)(regs->u_regs[UREG_FP]),
 571                                         sizeof(struct reg_window32));
 572         } else {
 573                 struct reg_window *rp;
 574
 575                 rp = &current_thread_info()->reg_window[wsaved - 1];
 576                 for (i = 0; i < 8; i++)
 577                         err |= __put_user(rp->locals[i], &sf->ss.locals[i]);
 578                 for (i = 0; i < 6; i++)
 579                         err |= __put_user(rp->ins[i], &sf->ss.ins[i]);
 580                 err |= __put_user(rp->ins[6], &sf->ss.fp);
 581                 err |= __put_user(rp->ins[7], &sf->ss.callers_pc);
 582         }
 583         if (err)
 584                 return err;
 585
 586         /* 3. signal handler back-trampoline and parameters */
 587         regs->u_regs[UREG_FP] = (unsigned long) sf;
 588         regs->u_regs[UREG_I0] = ksig->sig;
 589         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 590         regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
 591
 592         /* 4. signal handler */
 593         regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
 594         regs->tnpc = (regs->tpc + 4);
 595         if (test_thread_flag(TIF_32BIT)) {
 596                 regs->tpc &= 0xffffffff;
 597                 regs->tnpc &= 0xffffffff;
 598         }
 599
 600         /* 5. return to kernel instructions */
 601         if (ksig->ka.ka_restorer)
 602                 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 603         else {
 604                 unsigned long address = ((unsigned long)&(sf->insns[0]));
 605
 606                 regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
 607
 608                 /* mov __NR_rt_sigreturn, %g1 */
 609                 err |= __put_user(0x82102065, &sf->insns[0]);
 610
 611                 /* t 0x10 */
 612                 err |= __put_user(0x91d02010, &sf->insns[1]);
 613                 if (err)
 614                         return err;
 615
 616                 flush_signal_insns(address);
 617         }
 618         return 0;
 619 }
 620
 621 static inline void handle_signal32(struct ksignal *ksig,
 622                                   struct pt_regs *regs)
 623 {
 624         sigset_t *oldset = sigmask_to_save();
 625         int err;
 626
 627         if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 628                 err = setup_rt_frame32(ksig, regs, oldset);
 629         else
 630                 err = setup_frame32(ksig, regs, oldset);
 631
 632         signal_setup_done(err, ksig, 0);
 633 }
 634
 635 static inline void syscall_restart32(unsigned long orig_i0, struct pt_regs *regs,
 636                                      struct sigaction *sa)
 637 {
 638         switch (regs->u_regs[UREG_I0]) {
 639         case ERESTART_RESTARTBLOCK:
 640         case ERESTARTNOHAND:
 641         no_system_call_restart:
 642                 regs->u_regs[UREG_I0] = EINTR;
 643                 regs->tstate |= TSTATE_ICARRY;
 644                 break;
 645         case ERESTARTSYS:
 646                 if (!(sa->sa_flags & SA_RESTART))
 647                         goto no_system_call_restart;
 648                 fallthrough;
 649         case ERESTARTNOINTR:
 650                 regs->u_regs[UREG_I0] = orig_i0;
 651                 regs->tpc -= 4;
 652                 regs->tnpc -= 4;
 653         }
 654 }
 655
 656 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 657  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 658  * mistake.
 659  */
 660 void do_signal32(struct pt_regs * regs)
 661 {
 662         struct ksignal ksig;
 663         unsigned long orig_i0 = 0;
 664         int restart_syscall = 0;
 665         bool has_handler = get_signal(&ksig);
 666
 667         if (pt_regs_is_syscall(regs) &&
 668             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
 669                 restart_syscall = 1;
 670                 orig_i0 = regs->u_regs[UREG_G6];
 671         }
 672
 673         if (has_handler) {
 674                 if (restart_syscall)
 675                         syscall_restart32(orig_i0, regs, &ksig.ka.sa);
 676                 handle_signal32(&ksig, regs);
 677         } else {
 678                 if (restart_syscall) {
 679                         switch (regs->u_regs[UREG_I0]) {
 680                         case ERESTARTNOHAND:
 681                         case ERESTARTSYS:
 682                         case ERESTARTNOINTR:
 683                                 /* replay the system call when we are done */
 684                                 regs->u_regs[UREG_I0] = orig_i0;
 685                                 regs->tpc -= 4;
 686                                 regs->tnpc -= 4;
 687                                 pt_regs_clear_syscall(regs);
 688                                 fallthrough;
 689                         case ERESTART_RESTARTBLOCK:
 690                                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 691                                 regs->tpc -= 4;
 692                                 regs->tnpc -= 4;
 693                                 pt_regs_clear_syscall(regs);
 694                         }
 695                 }
 696                 restore_saved_sigmask();
 697         }
 698 }
 699
 700 struct sigstack32 {
 701         u32 the_stack;
 702         int cur_status;
 703 };
 704
 705 asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)
 706 {
 707         struct sigstack32 __user *ssptr =
 708                 (struct sigstack32 __user *)((unsigned long)(u_ssptr));
 709         struct sigstack32 __user *ossptr =
 710                 (struct sigstack32 __user *)((unsigned long)(u_ossptr));
 711         int ret = -EFAULT;
 712
 713         /* First see if old state is wanted. */
 714         if (ossptr) {
 715                 if (put_user(current->sas_ss_sp + current->sas_ss_size,
 716                              &ossptr->the_stack) ||
 717                     __put_user(on_sig_stack(sp), &ossptr->cur_status))
 718                         goto out;
 719         }
 720
 721         /* Now see if we want to update the new state. */
 722         if (ssptr) {
 723                 u32 ss_sp;
 724
 725                 if (get_user(ss_sp, &ssptr->the_stack))
 726                         goto out;
 727
 728                 /* If the current stack was set with sigaltstack, don't
 729                  * swap stacks while we are on it.
 730                  */
 731                 ret = -EPERM;
 732                 if (current->sas_ss_sp && on_sig_stack(sp))
 733                         goto out;
 734
 735                 /* Since we don't know the extent of the stack, and we don't
 736                  * track onstack-ness, but rather calculate it, we must
 737                  * presume a size.  Ho hum this interface is lossy.
 738                  */
 739                 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
 740                 current->sas_ss_size = SIGSTKSZ;
 741         }
 742
 743         ret = 0;
 744 out:
 745         return ret;
 746 }
 747
 748 /*
 749  * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
 750  * changes likely come with new fields that should be added below.
 751  */
 752 static_assert(NSIGILL   == 11);
 753 static_assert(NSIGFPE   == 15);
 754 static_assert(NSIGSEGV  == 9);
 755 static_assert(NSIGBUS   == 5);
 756 static_assert(NSIGTRAP  == 6);
 757 static_assert(NSIGCHLD  == 6);
 758 static_assert(NSIGSYS   == 2);
 759 static_assert(sizeof(compat_siginfo_t) == 128);
 760 static_assert(__alignof__(compat_siginfo_t) == 4);
 761 static_assert(offsetof(compat_siginfo_t, si_signo)      == 0x00);
 762 static_assert(offsetof(compat_siginfo_t, si_errno)      == 0x04);
 763 static_assert(offsetof(compat_siginfo_t, si_code)       == 0x08);
 764 static_assert(offsetof(compat_siginfo_t, si_pid)        == 0x0c);
 765 static_assert(offsetof(compat_siginfo_t, si_uid)        == 0x10);
 766 static_assert(offsetof(compat_siginfo_t, si_tid)        == 0x0c);
 767 static_assert(offsetof(compat_siginfo_t, si_overrun)    == 0x10);
 768 static_assert(offsetof(compat_siginfo_t, si_status)     == 0x14);
 769 static_assert(offsetof(compat_siginfo_t, si_utime)      == 0x18);
 770 static_assert(offsetof(compat_siginfo_t, si_stime)      == 0x1c);
 771 static_assert(offsetof(compat_siginfo_t, si_value)      == 0x14);
 772 static_assert(offsetof(compat_siginfo_t, si_int)        == 0x14);
 773 static_assert(offsetof(compat_siginfo_t, si_ptr)        == 0x14);
 774 static_assert(offsetof(compat_siginfo_t, si_addr)       == 0x0c);
 775 static_assert(offsetof(compat_siginfo_t, si_trapno)     == 0x10);
 776 static_assert(offsetof(compat_siginfo_t, si_addr_lsb)   == 0x10);
 777 static_assert(offsetof(compat_siginfo_t, si_lower)      == 0x14);
 778 static_assert(offsetof(compat_siginfo_t, si_upper)      == 0x18);
 779 static_assert(offsetof(compat_siginfo_t, si_pkey)       == 0x14);
 780 static_assert(offsetof(compat_siginfo_t, si_perf_data)  == 0x10);
 781 static_assert(offsetof(compat_siginfo_t, si_perf_type)  == 0x14);
 782 static_assert(offsetof(compat_siginfo_t, si_perf_flags) == 0x18);
 783 static_assert(offsetof(compat_siginfo_t, si_band)       == 0x0c);
 784 static_assert(offsetof(compat_siginfo_t, si_fd)         == 0x10);