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