arch/sh/kernel/process_64.c

   1 /*
   2  * arch/sh/kernel/process_64.c
   3  *
   4  * This file handles the architecture-dependent parts of process handling..
   5  *
   6  * Copyright (C) 2000, 2001  Paolo Alberelli
   7  * Copyright (C) 2003 - 2007  Paul Mundt
   8  * Copyright (C) 2003, 2004 Richard Curnow
   9  *
  10  * Started from SH3/4 version:
  11  *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  12  *
  13  *   In turn started from i386 version:
  14  *     Copyright (C) 1995  Linus Torvalds
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file "COPYING" in the main directory of this archive
  18  * for more details.
  19  */
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/reboot.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/io.h>
  28 #include <linux/sched/debug.h>
  29 #include <linux/sched/task.h>
  30 #include <linux/sched/task_stack.h>
  31 #include <asm/syscalls.h>
  32 #include <linux/uaccess.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/mmu_context.h>
  35 #include <asm/fpu.h>
  36 #include <asm/switch_to.h>
  37
  38 struct task_struct *last_task_used_math = NULL;
  39 struct pt_regs fake_swapper_regs = { 0, };
  40
  41 void show_regs(struct pt_regs *regs)
  42 {
  43         unsigned long long ah, al, bh, bl, ch, cl;
  44
  45         printk("\n");
  46         show_regs_print_info(KERN_DEFAULT);
  47
  48         ah = (regs->pc) >> 32;
  49         al = (regs->pc) & 0xffffffff;
  50         bh = (regs->regs[18]) >> 32;
  51         bl = (regs->regs[18]) & 0xffffffff;
  52         ch = (regs->regs[15]) >> 32;
  53         cl = (regs->regs[15]) & 0xffffffff;
  54         printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
  55                ah, al, bh, bl, ch, cl);
  56
  57         ah = (regs->sr) >> 32;
  58         al = (regs->sr) & 0xffffffff;
  59         asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
  60         asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
  61         bh = (bh) >> 32;
  62         bl = (bl) & 0xffffffff;
  63         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
  64         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
  65         ch = (ch) >> 32;
  66         cl = (cl) & 0xffffffff;
  67         printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
  68                ah, al, bh, bl, ch, cl);
  69
  70         ah = (regs->regs[0]) >> 32;
  71         al = (regs->regs[0]) & 0xffffffff;
  72         bh = (regs->regs[1]) >> 32;
  73         bl = (regs->regs[1]) & 0xffffffff;
  74         ch = (regs->regs[2]) >> 32;
  75         cl = (regs->regs[2]) & 0xffffffff;
  76         printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
  77                ah, al, bh, bl, ch, cl);
  78
  79         ah = (regs->regs[3]) >> 32;
  80         al = (regs->regs[3]) & 0xffffffff;
  81         bh = (regs->regs[4]) >> 32;
  82         bl = (regs->regs[4]) & 0xffffffff;
  83         ch = (regs->regs[5]) >> 32;
  84         cl = (regs->regs[5]) & 0xffffffff;
  85         printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
  86                ah, al, bh, bl, ch, cl);
  87
  88         ah = (regs->regs[6]) >> 32;
  89         al = (regs->regs[6]) & 0xffffffff;
  90         bh = (regs->regs[7]) >> 32;
  91         bl = (regs->regs[7]) & 0xffffffff;
  92         ch = (regs->regs[8]) >> 32;
  93         cl = (regs->regs[8]) & 0xffffffff;
  94         printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
  95                ah, al, bh, bl, ch, cl);
  96
  97         ah = (regs->regs[9]) >> 32;
  98         al = (regs->regs[9]) & 0xffffffff;
  99         bh = (regs->regs[10]) >> 32;
 100         bl = (regs->regs[10]) & 0xffffffff;
 101         ch = (regs->regs[11]) >> 32;
 102         cl = (regs->regs[11]) & 0xffffffff;
 103         printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
 104                ah, al, bh, bl, ch, cl);
 105
 106         ah = (regs->regs[12]) >> 32;
 107         al = (regs->regs[12]) & 0xffffffff;
 108         bh = (regs->regs[13]) >> 32;
 109         bl = (regs->regs[13]) & 0xffffffff;
 110         ch = (regs->regs[14]) >> 32;
 111         cl = (regs->regs[14]) & 0xffffffff;
 112         printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
 113                ah, al, bh, bl, ch, cl);
 114
 115         ah = (regs->regs[16]) >> 32;
 116         al = (regs->regs[16]) & 0xffffffff;
 117         bh = (regs->regs[17]) >> 32;
 118         bl = (regs->regs[17]) & 0xffffffff;
 119         ch = (regs->regs[19]) >> 32;
 120         cl = (regs->regs[19]) & 0xffffffff;
 121         printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
 122                ah, al, bh, bl, ch, cl);
 123
 124         ah = (regs->regs[20]) >> 32;
 125         al = (regs->regs[20]) & 0xffffffff;
 126         bh = (regs->regs[21]) >> 32;
 127         bl = (regs->regs[21]) & 0xffffffff;
 128         ch = (regs->regs[22]) >> 32;
 129         cl = (regs->regs[22]) & 0xffffffff;
 130         printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
 131                ah, al, bh, bl, ch, cl);
 132
 133         ah = (regs->regs[23]) >> 32;
 134         al = (regs->regs[23]) & 0xffffffff;
 135         bh = (regs->regs[24]) >> 32;
 136         bl = (regs->regs[24]) & 0xffffffff;
 137         ch = (regs->regs[25]) >> 32;
 138         cl = (regs->regs[25]) & 0xffffffff;
 139         printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
 140                ah, al, bh, bl, ch, cl);
 141
 142         ah = (regs->regs[26]) >> 32;
 143         al = (regs->regs[26]) & 0xffffffff;
 144         bh = (regs->regs[27]) >> 32;
 145         bl = (regs->regs[27]) & 0xffffffff;
 146         ch = (regs->regs[28]) >> 32;
 147         cl = (regs->regs[28]) & 0xffffffff;
 148         printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
 149                ah, al, bh, bl, ch, cl);
 150
 151         ah = (regs->regs[29]) >> 32;
 152         al = (regs->regs[29]) & 0xffffffff;
 153         bh = (regs->regs[30]) >> 32;
 154         bl = (regs->regs[30]) & 0xffffffff;
 155         ch = (regs->regs[31]) >> 32;
 156         cl = (regs->regs[31]) & 0xffffffff;
 157         printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
 158                ah, al, bh, bl, ch, cl);
 159
 160         ah = (regs->regs[32]) >> 32;
 161         al = (regs->regs[32]) & 0xffffffff;
 162         bh = (regs->regs[33]) >> 32;
 163         bl = (regs->regs[33]) & 0xffffffff;
 164         ch = (regs->regs[34]) >> 32;
 165         cl = (regs->regs[34]) & 0xffffffff;
 166         printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
 167                ah, al, bh, bl, ch, cl);
 168
 169         ah = (regs->regs[35]) >> 32;
 170         al = (regs->regs[35]) & 0xffffffff;
 171         bh = (regs->regs[36]) >> 32;
 172         bl = (regs->regs[36]) & 0xffffffff;
 173         ch = (regs->regs[37]) >> 32;
 174         cl = (regs->regs[37]) & 0xffffffff;
 175         printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
 176                ah, al, bh, bl, ch, cl);
 177
 178         ah = (regs->regs[38]) >> 32;
 179         al = (regs->regs[38]) & 0xffffffff;
 180         bh = (regs->regs[39]) >> 32;
 181         bl = (regs->regs[39]) & 0xffffffff;
 182         ch = (regs->regs[40]) >> 32;
 183         cl = (regs->regs[40]) & 0xffffffff;
 184         printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
 185                ah, al, bh, bl, ch, cl);
 186
 187         ah = (regs->regs[41]) >> 32;
 188         al = (regs->regs[41]) & 0xffffffff;
 189         bh = (regs->regs[42]) >> 32;
 190         bl = (regs->regs[42]) & 0xffffffff;
 191         ch = (regs->regs[43]) >> 32;
 192         cl = (regs->regs[43]) & 0xffffffff;
 193         printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
 194                ah, al, bh, bl, ch, cl);
 195
 196         ah = (regs->regs[44]) >> 32;
 197         al = (regs->regs[44]) & 0xffffffff;
 198         bh = (regs->regs[45]) >> 32;
 199         bl = (regs->regs[45]) & 0xffffffff;
 200         ch = (regs->regs[46]) >> 32;
 201         cl = (regs->regs[46]) & 0xffffffff;
 202         printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
 203                ah, al, bh, bl, ch, cl);
 204
 205         ah = (regs->regs[47]) >> 32;
 206         al = (regs->regs[47]) & 0xffffffff;
 207         bh = (regs->regs[48]) >> 32;
 208         bl = (regs->regs[48]) & 0xffffffff;
 209         ch = (regs->regs[49]) >> 32;
 210         cl = (regs->regs[49]) & 0xffffffff;
 211         printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
 212                ah, al, bh, bl, ch, cl);
 213
 214         ah = (regs->regs[50]) >> 32;
 215         al = (regs->regs[50]) & 0xffffffff;
 216         bh = (regs->regs[51]) >> 32;
 217         bl = (regs->regs[51]) & 0xffffffff;
 218         ch = (regs->regs[52]) >> 32;
 219         cl = (regs->regs[52]) & 0xffffffff;
 220         printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
 221                ah, al, bh, bl, ch, cl);
 222
 223         ah = (regs->regs[53]) >> 32;
 224         al = (regs->regs[53]) & 0xffffffff;
 225         bh = (regs->regs[54]) >> 32;
 226         bl = (regs->regs[54]) & 0xffffffff;
 227         ch = (regs->regs[55]) >> 32;
 228         cl = (regs->regs[55]) & 0xffffffff;
 229         printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
 230                ah, al, bh, bl, ch, cl);
 231
 232         ah = (regs->regs[56]) >> 32;
 233         al = (regs->regs[56]) & 0xffffffff;
 234         bh = (regs->regs[57]) >> 32;
 235         bl = (regs->regs[57]) & 0xffffffff;
 236         ch = (regs->regs[58]) >> 32;
 237         cl = (regs->regs[58]) & 0xffffffff;
 238         printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
 239                ah, al, bh, bl, ch, cl);
 240
 241         ah = (regs->regs[59]) >> 32;
 242         al = (regs->regs[59]) & 0xffffffff;
 243         bh = (regs->regs[60]) >> 32;
 244         bl = (regs->regs[60]) & 0xffffffff;
 245         ch = (regs->regs[61]) >> 32;
 246         cl = (regs->regs[61]) & 0xffffffff;
 247         printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
 248                ah, al, bh, bl, ch, cl);
 249
 250         ah = (regs->regs[62]) >> 32;
 251         al = (regs->regs[62]) & 0xffffffff;
 252         bh = (regs->tregs[0]) >> 32;
 253         bl = (regs->tregs[0]) & 0xffffffff;
 254         ch = (regs->tregs[1]) >> 32;
 255         cl = (regs->tregs[1]) & 0xffffffff;
 256         printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
 257                ah, al, bh, bl, ch, cl);
 258
 259         ah = (regs->tregs[2]) >> 32;
 260         al = (regs->tregs[2]) & 0xffffffff;
 261         bh = (regs->tregs[3]) >> 32;
 262         bl = (regs->tregs[3]) & 0xffffffff;
 263         ch = (regs->tregs[4]) >> 32;
 264         cl = (regs->tregs[4]) & 0xffffffff;
 265         printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
 266                ah, al, bh, bl, ch, cl);
 267
 268         ah = (regs->tregs[5]) >> 32;
 269         al = (regs->tregs[5]) & 0xffffffff;
 270         bh = (regs->tregs[6]) >> 32;
 271         bl = (regs->tregs[6]) & 0xffffffff;
 272         ch = (regs->tregs[7]) >> 32;
 273         cl = (regs->tregs[7]) & 0xffffffff;
 274         printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
 275                ah, al, bh, bl, ch, cl);
 276
 277         /*
 278          * If we're in kernel mode, dump the stack too..
 279          */
 280         if (!user_mode(regs)) {
 281                 void show_stack(struct task_struct *tsk, unsigned long *sp);
 282                 unsigned long sp = regs->regs[15] & 0xffffffff;
 283                 struct task_struct *tsk = get_current();
 284
 285                 tsk->thread.kregs = regs;
 286
 287                 show_stack(tsk, (unsigned long *)sp);
 288         }
 289 }
 290
 291 /*
 292  * Free current thread data structures etc..
 293  */
 294 void exit_thread(struct task_struct *tsk)
 295 {
 296         /*
 297          * See arch/sparc/kernel/process.c for the precedent for doing
 298          * this -- RPC.
 299          *
 300          * The SH-5 FPU save/restore approach relies on
 301          * last_task_used_math pointing to a live task_struct.  When
 302          * another task tries to use the FPU for the 1st time, the FPUDIS
 303          * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
 304          * existing FPU state to the FP regs field within
 305          * last_task_used_math before re-loading the new task's FPU state
 306          * (or initialising it if the FPU has been used before).  So if
 307          * last_task_used_math is stale, and its page has already been
 308          * re-allocated for another use, the consequences are rather
 309          * grim. Unless we null it here, there is no other path through
 310          * which it would get safely nulled.
 311          */
 312 #ifdef CONFIG_SH_FPU
 313         if (last_task_used_math == tsk)
 314                 last_task_used_math = NULL;
 315 #endif
 316 }
 317
 318 void flush_thread(void)
 319 {
 320
 321         /* Called by fs/exec.c (setup_new_exec) to remove traces of a
 322          * previously running executable. */
 323 #ifdef CONFIG_SH_FPU
 324         if (last_task_used_math == current) {
 325                 last_task_used_math = NULL;
 326         }
 327         /* Force FPU state to be reinitialised after exec */
 328         clear_used_math();
 329 #endif
 330
 331         /* if we are a kernel thread, about to change to user thread,
 332          * update kreg
 333          */
 334         if(current->thread.kregs==&fake_swapper_regs) {
 335           current->thread.kregs =
 336              ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
 337           current->thread.uregs = current->thread.kregs;
 338         }
 339 }
 340
 341 void release_thread(struct task_struct *dead_task)
 342 {
 343         /* do nothing */
 344 }
 345
 346 /* Fill in the fpu structure for a core dump.. */
 347 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 348 {
 349 #ifdef CONFIG_SH_FPU
 350         int fpvalid;
 351         struct task_struct *tsk = current;
 352
 353         fpvalid = !!tsk_used_math(tsk);
 354         if (fpvalid) {
 355                 if (current == last_task_used_math) {
 356                         enable_fpu();
 357                         save_fpu(tsk);
 358                         disable_fpu();
 359                         last_task_used_math = 0;
 360                         regs->sr |= SR_FD;
 361                 }
 362
 363                 memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
 364         }
 365
 366         return fpvalid;
 367 #else
 368         return 0; /* Task didn't use the fpu at all. */
 369 #endif
 370 }
 371 EXPORT_SYMBOL(dump_fpu);
 372
 373 asmlinkage void ret_from_fork(void);
 374 asmlinkage void ret_from_kernel_thread(void);
 375
 376 int copy_thread(unsigned long clone_flags, unsigned long usp,
 377                 unsigned long arg, struct task_struct *p)
 378 {
 379         struct pt_regs *childregs;
 380
 381 #ifdef CONFIG_SH_FPU
 382         /* can't happen for a kernel thread */
 383         if (last_task_used_math == current) {
 384                 enable_fpu();
 385                 save_fpu(current);
 386                 disable_fpu();
 387                 last_task_used_math = NULL;
 388                 current_pt_regs()->sr |= SR_FD;
 389         }
 390 #endif
 391         /* Copy from sh version */
 392         childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
 393         p->thread.sp = (unsigned long) childregs;
 394
 395         if (unlikely(p->flags & PF_KTHREAD)) {
 396                 memset(childregs, 0, sizeof(struct pt_regs));
 397                 childregs->regs[2] = (unsigned long)arg;
 398                 childregs->regs[3] = (unsigned long)usp;
 399                 childregs->sr = (1 << 30); /* not user_mode */
 400                 childregs->sr |= SR_FD; /* Invalidate FPU flag */
 401                 p->thread.pc = (unsigned long) ret_from_kernel_thread;
 402                 return 0;
 403         }
 404         *childregs = *current_pt_regs();
 405
 406         /*
 407          * Sign extend the edited stack.
 408          * Note that thread.pc and thread.pc will stay
 409          * 32-bit wide and context switch must take care
 410          * of NEFF sign extension.
 411          */
 412         if (usp)
 413                 childregs->regs[15] = neff_sign_extend(usp);
 414         p->thread.uregs = childregs;
 415
 416         childregs->regs[9] = 0; /* Set return value for child */
 417         childregs->sr |= SR_FD; /* Invalidate FPU flag */
 418
 419         p->thread.pc = (unsigned long) ret_from_fork;
 420
 421         return 0;
 422 }
 423
 424 #ifdef CONFIG_FRAME_POINTER
 425 static int in_sh64_switch_to(unsigned long pc)
 426 {
 427         extern char __sh64_switch_to_end;
 428         /* For a sleeping task, the PC is somewhere in the middle of the function,
 429            so we don't have to worry about masking the LSB off */
 430         return (pc >= (unsigned long) sh64_switch_to) &&
 431                (pc < (unsigned long) &__sh64_switch_to_end);
 432 }
 433 #endif
 434
 435 unsigned long get_wchan(struct task_struct *p)
 436 {
 437         unsigned long pc;
 438
 439         if (!p || p == current || p->state == TASK_RUNNING)
 440                 return 0;
 441
 442         /*
 443          * The same comment as on the Alpha applies here, too ...
 444          */
 445         pc = thread_saved_pc(p);
 446
 447 #ifdef CONFIG_FRAME_POINTER
 448         if (in_sh64_switch_to(pc)) {
 449                 unsigned long schedule_fp;
 450                 unsigned long sh64_switch_to_fp;
 451                 unsigned long schedule_caller_pc;
 452
 453                 sh64_switch_to_fp = (long) p->thread.sp;
 454                 /* r14 is saved at offset 4 in the sh64_switch_to frame */
 455                 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
 456
 457                 /* and the caller of 'schedule' is (currently!) saved at offset 24
 458                    in the frame of schedule (from disasm) */
 459                 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
 460                 return schedule_caller_pc;
 461         }
 462 #endif
 463         return pc;
 464 }