arch/sh/kernel/process_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/kernel/process_64.c
   4  *
   5  * This file handles the architecture-dependent parts of process handling..
   6  *
   7  * Copyright (C) 2000, 2001  Paolo Alberelli
   8  * Copyright (C) 2003 - 2007  Paul Mundt
   9  * Copyright (C) 2003, 2004 Richard Curnow
  10  *
  11  * Started from SH3/4 version:
  12  *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  13  *
  14  *   In turn started from i386 version:
  15  *     Copyright (C) 1995  Linus Torvalds
  16  */
  17 #include <linux/mm.h>
  18 #include <linux/fs.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/reboot.h>
  21 #include <linux/slab.h>
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/io.h>
  25 #include <linux/sched/debug.h>
  26 #include <linux/sched/task.h>
  27 #include <linux/sched/task_stack.h>
  28 #include <asm/syscalls.h>
  29 #include <linux/uaccess.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/mmu_context.h>
  32 #include <asm/fpu.h>
  33 #include <asm/switch_to.h>
  34
  35 struct task_struct *last_task_used_math = NULL;
  36 struct pt_regs fake_swapper_regs = { 0, };
  37
  38 void show_regs(struct pt_regs *regs)
  39 {
  40         unsigned long long ah, al, bh, bl, ch, cl;
  41
  42         printk("\n");
  43         show_regs_print_info(KERN_DEFAULT);
  44
  45         ah = (regs->pc) >> 32;
  46         al = (regs->pc) & 0xffffffff;
  47         bh = (regs->regs[18]) >> 32;
  48         bl = (regs->regs[18]) & 0xffffffff;
  49         ch = (regs->regs[15]) >> 32;
  50         cl = (regs->regs[15]) & 0xffffffff;
  51         printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
  52                ah, al, bh, bl, ch, cl);
  53
  54         ah = (regs->sr) >> 32;
  55         al = (regs->sr) & 0xffffffff;
  56         asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
  57         asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
  58         bh = (bh) >> 32;
  59         bl = (bl) & 0xffffffff;
  60         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
  61         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
  62         ch = (ch) >> 32;
  63         cl = (cl) & 0xffffffff;
  64         printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
  65                ah, al, bh, bl, ch, cl);
  66
  67         ah = (regs->regs[0]) >> 32;
  68         al = (regs->regs[0]) & 0xffffffff;
  69         bh = (regs->regs[1]) >> 32;
  70         bl = (regs->regs[1]) & 0xffffffff;
  71         ch = (regs->regs[2]) >> 32;
  72         cl = (regs->regs[2]) & 0xffffffff;
  73         printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
  74                ah, al, bh, bl, ch, cl);
  75
  76         ah = (regs->regs[3]) >> 32;
  77         al = (regs->regs[3]) & 0xffffffff;
  78         bh = (regs->regs[4]) >> 32;
  79         bl = (regs->regs[4]) & 0xffffffff;
  80         ch = (regs->regs[5]) >> 32;
  81         cl = (regs->regs[5]) & 0xffffffff;
  82         printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
  83                ah, al, bh, bl, ch, cl);
  84
  85         ah = (regs->regs[6]) >> 32;
  86         al = (regs->regs[6]) & 0xffffffff;
  87         bh = (regs->regs[7]) >> 32;
  88         bl = (regs->regs[7]) & 0xffffffff;
  89         ch = (regs->regs[8]) >> 32;
  90         cl = (regs->regs[8]) & 0xffffffff;
  91         printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
  92                ah, al, bh, bl, ch, cl);
  93
  94         ah = (regs->regs[9]) >> 32;
  95         al = (regs->regs[9]) & 0xffffffff;
  96         bh = (regs->regs[10]) >> 32;
  97         bl = (regs->regs[10]) & 0xffffffff;
  98         ch = (regs->regs[11]) >> 32;
  99         cl = (regs->regs[11]) & 0xffffffff;
 100         printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
 101                ah, al, bh, bl, ch, cl);
 102
 103         ah = (regs->regs[12]) >> 32;
 104         al = (regs->regs[12]) & 0xffffffff;
 105         bh = (regs->regs[13]) >> 32;
 106         bl = (regs->regs[13]) & 0xffffffff;
 107         ch = (regs->regs[14]) >> 32;
 108         cl = (regs->regs[14]) & 0xffffffff;
 109         printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
 110                ah, al, bh, bl, ch, cl);
 111
 112         ah = (regs->regs[16]) >> 32;
 113         al = (regs->regs[16]) & 0xffffffff;
 114         bh = (regs->regs[17]) >> 32;
 115         bl = (regs->regs[17]) & 0xffffffff;
 116         ch = (regs->regs[19]) >> 32;
 117         cl = (regs->regs[19]) & 0xffffffff;
 118         printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
 119                ah, al, bh, bl, ch, cl);
 120
 121         ah = (regs->regs[20]) >> 32;
 122         al = (regs->regs[20]) & 0xffffffff;
 123         bh = (regs->regs[21]) >> 32;
 124         bl = (regs->regs[21]) & 0xffffffff;
 125         ch = (regs->regs[22]) >> 32;
 126         cl = (regs->regs[22]) & 0xffffffff;
 127         printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
 128                ah, al, bh, bl, ch, cl);
 129
 130         ah = (regs->regs[23]) >> 32;
 131         al = (regs->regs[23]) & 0xffffffff;
 132         bh = (regs->regs[24]) >> 32;
 133         bl = (regs->regs[24]) & 0xffffffff;
 134         ch = (regs->regs[25]) >> 32;
 135         cl = (regs->regs[25]) & 0xffffffff;
 136         printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
 137                ah, al, bh, bl, ch, cl);
 138
 139         ah = (regs->regs[26]) >> 32;
 140         al = (regs->regs[26]) & 0xffffffff;
 141         bh = (regs->regs[27]) >> 32;
 142         bl = (regs->regs[27]) & 0xffffffff;
 143         ch = (regs->regs[28]) >> 32;
 144         cl = (regs->regs[28]) & 0xffffffff;
 145         printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
 146                ah, al, bh, bl, ch, cl);
 147
 148         ah = (regs->regs[29]) >> 32;
 149         al = (regs->regs[29]) & 0xffffffff;
 150         bh = (regs->regs[30]) >> 32;
 151         bl = (regs->regs[30]) & 0xffffffff;
 152         ch = (regs->regs[31]) >> 32;
 153         cl = (regs->regs[31]) & 0xffffffff;
 154         printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
 155                ah, al, bh, bl, ch, cl);
 156
 157         ah = (regs->regs[32]) >> 32;
 158         al = (regs->regs[32]) & 0xffffffff;
 159         bh = (regs->regs[33]) >> 32;
 160         bl = (regs->regs[33]) & 0xffffffff;
 161         ch = (regs->regs[34]) >> 32;
 162         cl = (regs->regs[34]) & 0xffffffff;
 163         printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
 164                ah, al, bh, bl, ch, cl);
 165
 166         ah = (regs->regs[35]) >> 32;
 167         al = (regs->regs[35]) & 0xffffffff;
 168         bh = (regs->regs[36]) >> 32;
 169         bl = (regs->regs[36]) & 0xffffffff;
 170         ch = (regs->regs[37]) >> 32;
 171         cl = (regs->regs[37]) & 0xffffffff;
 172         printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
 173                ah, al, bh, bl, ch, cl);
 174
 175         ah = (regs->regs[38]) >> 32;
 176         al = (regs->regs[38]) & 0xffffffff;
 177         bh = (regs->regs[39]) >> 32;
 178         bl = (regs->regs[39]) & 0xffffffff;
 179         ch = (regs->regs[40]) >> 32;
 180         cl = (regs->regs[40]) & 0xffffffff;
 181         printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
 182                ah, al, bh, bl, ch, cl);
 183
 184         ah = (regs->regs[41]) >> 32;
 185         al = (regs->regs[41]) & 0xffffffff;
 186         bh = (regs->regs[42]) >> 32;
 187         bl = (regs->regs[42]) & 0xffffffff;
 188         ch = (regs->regs[43]) >> 32;
 189         cl = (regs->regs[43]) & 0xffffffff;
 190         printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
 191                ah, al, bh, bl, ch, cl);
 192
 193         ah = (regs->regs[44]) >> 32;
 194         al = (regs->regs[44]) & 0xffffffff;
 195         bh = (regs->regs[45]) >> 32;
 196         bl = (regs->regs[45]) & 0xffffffff;
 197         ch = (regs->regs[46]) >> 32;
 198         cl = (regs->regs[46]) & 0xffffffff;
 199         printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
 200                ah, al, bh, bl, ch, cl);
 201
 202         ah = (regs->regs[47]) >> 32;
 203         al = (regs->regs[47]) & 0xffffffff;
 204         bh = (regs->regs[48]) >> 32;
 205         bl = (regs->regs[48]) & 0xffffffff;
 206         ch = (regs->regs[49]) >> 32;
 207         cl = (regs->regs[49]) & 0xffffffff;
 208         printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
 209                ah, al, bh, bl, ch, cl);
 210
 211         ah = (regs->regs[50]) >> 32;
 212         al = (regs->regs[50]) & 0xffffffff;
 213         bh = (regs->regs[51]) >> 32;
 214         bl = (regs->regs[51]) & 0xffffffff;
 215         ch = (regs->regs[52]) >> 32;
 216         cl = (regs->regs[52]) & 0xffffffff;
 217         printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
 218                ah, al, bh, bl, ch, cl);
 219
 220         ah = (regs->regs[53]) >> 32;
 221         al = (regs->regs[53]) & 0xffffffff;
 222         bh = (regs->regs[54]) >> 32;
 223         bl = (regs->regs[54]) & 0xffffffff;
 224         ch = (regs->regs[55]) >> 32;
 225         cl = (regs->regs[55]) & 0xffffffff;
 226         printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
 227                ah, al, bh, bl, ch, cl);
 228
 229         ah = (regs->regs[56]) >> 32;
 230         al = (regs->regs[56]) & 0xffffffff;
 231         bh = (regs->regs[57]) >> 32;
 232         bl = (regs->regs[57]) & 0xffffffff;
 233         ch = (regs->regs[58]) >> 32;
 234         cl = (regs->regs[58]) & 0xffffffff;
 235         printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
 236                ah, al, bh, bl, ch, cl);
 237
 238         ah = (regs->regs[59]) >> 32;
 239         al = (regs->regs[59]) & 0xffffffff;
 240         bh = (regs->regs[60]) >> 32;
 241         bl = (regs->regs[60]) & 0xffffffff;
 242         ch = (regs->regs[61]) >> 32;
 243         cl = (regs->regs[61]) & 0xffffffff;
 244         printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
 245                ah, al, bh, bl, ch, cl);
 246
 247         ah = (regs->regs[62]) >> 32;
 248         al = (regs->regs[62]) & 0xffffffff;
 249         bh = (regs->tregs[0]) >> 32;
 250         bl = (regs->tregs[0]) & 0xffffffff;
 251         ch = (regs->tregs[1]) >> 32;
 252         cl = (regs->tregs[1]) & 0xffffffff;
 253         printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
 254                ah, al, bh, bl, ch, cl);
 255
 256         ah = (regs->tregs[2]) >> 32;
 257         al = (regs->tregs[2]) & 0xffffffff;
 258         bh = (regs->tregs[3]) >> 32;
 259         bl = (regs->tregs[3]) & 0xffffffff;
 260         ch = (regs->tregs[4]) >> 32;
 261         cl = (regs->tregs[4]) & 0xffffffff;
 262         printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
 263                ah, al, bh, bl, ch, cl);
 264
 265         ah = (regs->tregs[5]) >> 32;
 266         al = (regs->tregs[5]) & 0xffffffff;
 267         bh = (regs->tregs[6]) >> 32;
 268         bl = (regs->tregs[6]) & 0xffffffff;
 269         ch = (regs->tregs[7]) >> 32;
 270         cl = (regs->tregs[7]) & 0xffffffff;
 271         printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
 272                ah, al, bh, bl, ch, cl);
 273
 274         /*
 275          * If we're in kernel mode, dump the stack too..
 276          */
 277         if (!user_mode(regs)) {
 278                 void show_stack(struct task_struct *tsk, unsigned long *sp);
 279                 unsigned long sp = regs->regs[15] & 0xffffffff;
 280                 struct task_struct *tsk = get_current();
 281
 282                 tsk->thread.kregs = regs;
 283
 284                 show_stack(tsk, (unsigned long *)sp);
 285         }
 286 }
 287
 288 /*
 289  * Free current thread data structures etc..
 290  */
 291 void exit_thread(struct task_struct *tsk)
 292 {
 293         /*
 294          * See arch/sparc/kernel/process.c for the precedent for doing
 295          * this -- RPC.
 296          *
 297          * The SH-5 FPU save/restore approach relies on
 298          * last_task_used_math pointing to a live task_struct.  When
 299          * another task tries to use the FPU for the 1st time, the FPUDIS
 300          * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
 301          * existing FPU state to the FP regs field within
 302          * last_task_used_math before re-loading the new task's FPU state
 303          * (or initialising it if the FPU has been used before).  So if
 304          * last_task_used_math is stale, and its page has already been
 305          * re-allocated for another use, the consequences are rather
 306          * grim. Unless we null it here, there is no other path through
 307          * which it would get safely nulled.
 308          */
 309 #ifdef CONFIG_SH_FPU
 310         if (last_task_used_math == tsk)
 311                 last_task_used_math = NULL;
 312 #endif
 313 }
 314
 315 void flush_thread(void)
 316 {
 317
 318         /* Called by fs/exec.c (setup_new_exec) to remove traces of a
 319          * previously running executable. */
 320 #ifdef CONFIG_SH_FPU
 321         if (last_task_used_math == current) {
 322                 last_task_used_math = NULL;
 323         }
 324         /* Force FPU state to be reinitialised after exec */
 325         clear_used_math();
 326 #endif
 327
 328         /* if we are a kernel thread, about to change to user thread,
 329          * update kreg
 330          */
 331         if(current->thread.kregs==&fake_swapper_regs) {
 332           current->thread.kregs =
 333              ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
 334           current->thread.uregs = current->thread.kregs;
 335         }
 336 }
 337
 338 void release_thread(struct task_struct *dead_task)
 339 {
 340         /* do nothing */
 341 }
 342
 343 /* Fill in the fpu structure for a core dump.. */
 344 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 345 {
 346 #ifdef CONFIG_SH_FPU
 347         int fpvalid;
 348         struct task_struct *tsk = current;
 349
 350         fpvalid = !!tsk_used_math(tsk);
 351         if (fpvalid) {
 352                 if (current == last_task_used_math) {
 353                         enable_fpu();
 354                         save_fpu(tsk);
 355                         disable_fpu();
 356                         last_task_used_math = 0;
 357                         regs->sr |= SR_FD;
 358                 }
 359
 360                 memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));
 361         }
 362
 363         return fpvalid;
 364 #else
 365         return 0; /* Task didn't use the fpu at all. */
 366 #endif
 367 }
 368 EXPORT_SYMBOL(dump_fpu);
 369
 370 asmlinkage void ret_from_fork(void);
 371 asmlinkage void ret_from_kernel_thread(void);
 372
 373 int copy_thread(unsigned long clone_flags, unsigned long usp,
 374                 unsigned long arg, struct task_struct *p)
 375 {
 376         struct pt_regs *childregs;
 377
 378 #ifdef CONFIG_SH_FPU
 379         /* can't happen for a kernel thread */
 380         if (last_task_used_math == current) {
 381                 enable_fpu();
 382                 save_fpu(current);
 383                 disable_fpu();
 384                 last_task_used_math = NULL;
 385                 current_pt_regs()->sr |= SR_FD;
 386         }
 387 #endif
 388         /* Copy from sh version */
 389         childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
 390         p->thread.sp = (unsigned long) childregs;
 391
 392         if (unlikely(p->flags & PF_KTHREAD)) {
 393                 memset(childregs, 0, sizeof(struct pt_regs));
 394                 childregs->regs[2] = (unsigned long)arg;
 395                 childregs->regs[3] = (unsigned long)usp;
 396                 childregs->sr = (1 << 30); /* not user_mode */
 397                 childregs->sr |= SR_FD; /* Invalidate FPU flag */
 398                 p->thread.pc = (unsigned long) ret_from_kernel_thread;
 399                 return 0;
 400         }
 401         *childregs = *current_pt_regs();
 402
 403         /*
 404          * Sign extend the edited stack.
 405          * Note that thread.pc and thread.pc will stay
 406          * 32-bit wide and context switch must take care
 407          * of NEFF sign extension.
 408          */
 409         if (usp)
 410                 childregs->regs[15] = neff_sign_extend(usp);
 411         p->thread.uregs = childregs;
 412
 413         childregs->regs[9] = 0; /* Set return value for child */
 414         childregs->sr |= SR_FD; /* Invalidate FPU flag */
 415
 416         p->thread.pc = (unsigned long) ret_from_fork;
 417
 418         return 0;
 419 }
 420
 421 #ifdef CONFIG_FRAME_POINTER
 422 static int in_sh64_switch_to(unsigned long pc)
 423 {
 424         extern char __sh64_switch_to_end;
 425         /* For a sleeping task, the PC is somewhere in the middle of the function,
 426            so we don't have to worry about masking the LSB off */
 427         return (pc >= (unsigned long) sh64_switch_to) &&
 428                (pc < (unsigned long) &__sh64_switch_to_end);
 429 }
 430 #endif
 431
 432 unsigned long get_wchan(struct task_struct *p)
 433 {
 434         unsigned long pc;
 435
 436         if (!p || p == current || p->state == TASK_RUNNING)
 437                 return 0;
 438
 439         /*
 440          * The same comment as on the Alpha applies here, too ...
 441          */
 442         pc = thread_saved_pc(p);
 443
 444 #ifdef CONFIG_FRAME_POINTER
 445         if (in_sh64_switch_to(pc)) {
 446                 unsigned long schedule_fp;
 447                 unsigned long sh64_switch_to_fp;
 448                 unsigned long schedule_caller_pc;
 449
 450                 sh64_switch_to_fp = (long) p->thread.sp;
 451                 /* r14 is saved at offset 4 in the sh64_switch_to frame */
 452                 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
 453
 454                 /* and the caller of 'schedule' is (currently!) saved at offset 24
 455                    in the frame of schedule (from disasm) */
 456                 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
 457                 return schedule_caller_pc;
 458         }
 459 #endif
 460         return pc;
 461 }