arch/csky/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/audit.h>
   5 #include <linux/elf.h>
   6 #include <linux/errno.h>
   7 #include <linux/kernel.h>
   8 #include <linux/mm.h>
   9 #include <linux/ptrace.h>
  10 #include <linux/regset.h>
  11 #include <linux/sched.h>
  12 #include <linux/sched/task_stack.h>
  13 #include <linux/signal.h>
  14 #include <linux/smp.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/user.h>
  17
  18 #include <asm/thread_info.h>
  19 #include <asm/page.h>
  20 #include <asm/processor.h>
  21 #include <asm/asm-offsets.h>
  22
  23 #include <abi/regdef.h>
  24 #include <abi/ckmmu.h>
  25
  26 #define CREATE_TRACE_POINTS
  27 #include <trace/events/syscalls.h>
  28
  29 /* sets the trace bits. */
  30 #define TRACE_MODE_SI      (1 << 14)
  31 #define TRACE_MODE_RUN     0
  32 #define TRACE_MODE_MASK    ~(0x3 << 14)
  33
  34 /*
  35  * Make sure the single step bit is not set.
  36  */
  37 static void singlestep_disable(struct task_struct *tsk)
  38 {
  39         struct pt_regs *regs;
  40
  41         regs = task_pt_regs(tsk);
  42         regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
  43
  44         /* Enable irq */
  45         regs->sr |= BIT(6);
  46 }
  47
  48 static void singlestep_enable(struct task_struct *tsk)
  49 {
  50         struct pt_regs *regs;
  51
  52         regs = task_pt_regs(tsk);
  53         regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
  54
  55         /* Disable irq */
  56         regs->sr &= ~BIT(6);
  57 }
  58
  59 /*
  60  * Make sure the single step bit is set.
  61  */
  62 void user_enable_single_step(struct task_struct *child)
  63 {
  64         singlestep_enable(child);
  65 }
  66
  67 void user_disable_single_step(struct task_struct *child)
  68 {
  69         singlestep_disable(child);
  70 }
  71
  72 enum csky_regset {
  73         REGSET_GPR,
  74         REGSET_FPR,
  75 };
  76
  77 static int gpr_get(struct task_struct *target,
  78                    const struct user_regset *regset,
  79                    struct membuf to)
  80 {
  81         struct pt_regs *regs = task_pt_regs(target);
  82
  83         /* Abiv1 regs->tls is fake and we need sync here. */
  84         regs->tls = task_thread_info(target)->tp_value;
  85
  86         return membuf_write(&to, regs, sizeof(*regs));
  87 }
  88
  89 static int gpr_set(struct task_struct *target,
  90                     const struct user_regset *regset,
  91                     unsigned int pos, unsigned int count,
  92                     const void *kbuf, const void __user *ubuf)
  93 {
  94         int ret;
  95         struct pt_regs regs;
  96
  97         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
  98         if (ret)
  99                 return ret;
 100
 101         /* BIT(0) of regs.sr is Condition Code/Carry bit */
 102         regs.sr = (regs.sr & BIT(0)) | (task_pt_regs(target)->sr & ~BIT(0));
 103 #ifdef CONFIG_CPU_HAS_HILO
 104         regs.dcsr = task_pt_regs(target)->dcsr;
 105 #endif
 106         task_thread_info(target)->tp_value = regs.tls;
 107
 108         *task_pt_regs(target) = regs;
 109
 110         return 0;
 111 }
 112
 113 static int fpr_get(struct task_struct *target,
 114                    const struct user_regset *regset,
 115                    struct membuf to)
 116 {
 117         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 118
 119 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 120         int i;
 121         struct user_fp tmp = *regs;
 122
 123         for (i = 0; i < 16; i++) {
 124                 tmp.vr[i*4] = regs->vr[i*2];
 125                 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
 126         }
 127
 128         for (i = 0; i < 32; i++)
 129                 tmp.vr[64 + i] = regs->vr[32 + i];
 130
 131         return membuf_write(&to, &tmp, sizeof(tmp));
 132 #else
 133         return membuf_write(&to, regs, sizeof(*regs));
 134 #endif
 135 }
 136
 137 static int fpr_set(struct task_struct *target,
 138                    const struct user_regset *regset,
 139                    unsigned int pos, unsigned int count,
 140                    const void *kbuf, const void __user *ubuf)
 141 {
 142         int ret;
 143         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 144
 145 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 146         int i;
 147         struct user_fp tmp;
 148
 149         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 150
 151         *regs = tmp;
 152
 153         for (i = 0; i < 16; i++) {
 154                 regs->vr[i*2] = tmp.vr[i*4];
 155                 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
 156         }
 157
 158         for (i = 0; i < 32; i++)
 159                 regs->vr[32 + i] = tmp.vr[64 + i];
 160 #else
 161         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 162 #endif
 163
 164         return ret;
 165 }
 166
 167 static const struct user_regset csky_regsets[] = {
 168         [REGSET_GPR] = {
 169                 .core_note_type = NT_PRSTATUS,
 170                 .n = sizeof(struct pt_regs) / sizeof(u32),
 171                 .size = sizeof(u32),
 172                 .align = sizeof(u32),
 173                 .regset_get = gpr_get,
 174                 .set = gpr_set,
 175         },
 176         [REGSET_FPR] = {
 177                 .core_note_type = NT_PRFPREG,
 178                 .n = sizeof(struct user_fp) / sizeof(u32),
 179                 .size = sizeof(u32),
 180                 .align = sizeof(u32),
 181                 .regset_get = fpr_get,
 182                 .set = fpr_set,
 183         },
 184 };
 185
 186 static const struct user_regset_view user_csky_view = {
 187         .name = "csky",
 188         .e_machine = ELF_ARCH,
 189         .regsets = csky_regsets,
 190         .n = ARRAY_SIZE(csky_regsets),
 191 };
 192
 193 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 194 {
 195         return &user_csky_view;
 196 }
 197
 198 struct pt_regs_offset {
 199         const char *name;
 200         int offset;
 201 };
 202
 203 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 204 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 205
 206 static const struct pt_regs_offset regoffset_table[] = {
 207         REG_OFFSET_NAME(tls),
 208         REG_OFFSET_NAME(lr),
 209         REG_OFFSET_NAME(pc),
 210         REG_OFFSET_NAME(sr),
 211         REG_OFFSET_NAME(usp),
 212         REG_OFFSET_NAME(orig_a0),
 213         REG_OFFSET_NAME(a0),
 214         REG_OFFSET_NAME(a1),
 215         REG_OFFSET_NAME(a2),
 216         REG_OFFSET_NAME(a3),
 217         REG_OFFSET_NAME(regs[0]),
 218         REG_OFFSET_NAME(regs[1]),
 219         REG_OFFSET_NAME(regs[2]),
 220         REG_OFFSET_NAME(regs[3]),
 221         REG_OFFSET_NAME(regs[4]),
 222         REG_OFFSET_NAME(regs[5]),
 223         REG_OFFSET_NAME(regs[6]),
 224         REG_OFFSET_NAME(regs[7]),
 225         REG_OFFSET_NAME(regs[8]),
 226         REG_OFFSET_NAME(regs[9]),
 227 #if defined(__CSKYABIV2__)
 228         REG_OFFSET_NAME(exregs[0]),
 229         REG_OFFSET_NAME(exregs[1]),
 230         REG_OFFSET_NAME(exregs[2]),
 231         REG_OFFSET_NAME(exregs[3]),
 232         REG_OFFSET_NAME(exregs[4]),
 233         REG_OFFSET_NAME(exregs[5]),
 234         REG_OFFSET_NAME(exregs[6]),
 235         REG_OFFSET_NAME(exregs[7]),
 236         REG_OFFSET_NAME(exregs[8]),
 237         REG_OFFSET_NAME(exregs[9]),
 238         REG_OFFSET_NAME(exregs[10]),
 239         REG_OFFSET_NAME(exregs[11]),
 240         REG_OFFSET_NAME(exregs[12]),
 241         REG_OFFSET_NAME(exregs[13]),
 242         REG_OFFSET_NAME(exregs[14]),
 243         REG_OFFSET_NAME(rhi),
 244         REG_OFFSET_NAME(rlo),
 245         REG_OFFSET_NAME(dcsr),
 246 #endif
 247         REG_OFFSET_END,
 248 };
 249
 250 /**
 251  * regs_query_register_offset() - query register offset from its name
 252  * @name:       the name of a register
 253  *
 254  * regs_query_register_offset() returns the offset of a register in struct
 255  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 256  */
 257 int regs_query_register_offset(const char *name)
 258 {
 259         const struct pt_regs_offset *roff;
 260
 261         for (roff = regoffset_table; roff->name != NULL; roff++)
 262                 if (!strcmp(roff->name, name))
 263                         return roff->offset;
 264         return -EINVAL;
 265 }
 266
 267 /**
 268  * regs_within_kernel_stack() - check the address in the stack
 269  * @regs:      pt_regs which contains kernel stack pointer.
 270  * @addr:      address which is checked.
 271  *
 272  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 273  * If @addr is within the kernel stack, it returns true. If not, returns false.
 274  */
 275 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 276 {
 277         return (addr & ~(THREAD_SIZE - 1))  ==
 278                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 279 }
 280
 281 /**
 282  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 283  * @regs:       pt_regs which contains kernel stack pointer.
 284  * @n:          stack entry number.
 285  *
 286  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 287  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 288  * this returns 0.
 289  */
 290 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 291 {
 292         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 293
 294         addr += n;
 295         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 296                 return *addr;
 297         else
 298                 return 0;
 299 }
 300
 301 void ptrace_disable(struct task_struct *child)
 302 {
 303         singlestep_disable(child);
 304 }
 305
 306 long arch_ptrace(struct task_struct *child, long request,
 307                  unsigned long addr, unsigned long data)
 308 {
 309         long ret = -EIO;
 310
 311         switch (request) {
 312         default:
 313                 ret = ptrace_request(child, request, addr, data);
 314                 break;
 315         }
 316
 317         return ret;
 318 }
 319
 320 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 321 {
 322         if (test_thread_flag(TIF_SYSCALL_TRACE))
 323                 if (ptrace_report_syscall_entry(regs))
 324                         return -1;
 325
 326         if (secure_computing() == -1)
 327                 return -1;
 328
 329         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 330                 trace_sys_enter(regs, syscall_get_nr(current, regs));
 331
 332         audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
 333         return 0;
 334 }
 335
 336 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 337 {
 338         audit_syscall_exit(regs);
 339
 340         if (test_thread_flag(TIF_SYSCALL_TRACE))
 341                 ptrace_report_syscall_exit(regs, 0);
 342
 343         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 344                 trace_sys_exit(regs, syscall_get_return_value(current, regs));
 345 }
 346
 347 #ifdef CONFIG_CPU_CK860
 348 static void show_iutlb(void)
 349 {
 350         int entry, i;
 351         unsigned long flags;
 352         unsigned long oldpid;
 353         unsigned long entryhi[16], entrylo0[16], entrylo1[16];
 354
 355         oldpid = read_mmu_entryhi();
 356
 357         entry = 0x8000;
 358
 359         local_irq_save(flags);
 360
 361         for (i = 0; i < 16; i++) {
 362                 write_mmu_index(entry);
 363                 tlb_read();
 364                 entryhi[i]  = read_mmu_entryhi();
 365                 entrylo0[i] = read_mmu_entrylo0();
 366                 entrylo1[i] = read_mmu_entrylo1();
 367
 368                 entry++;
 369         }
 370
 371         local_irq_restore(flags);
 372
 373         write_mmu_entryhi(oldpid);
 374
 375         printk("\n\n\n");
 376         for (i = 0; i < 16; i++)
 377                 printk("iutlb[%d]:      entryhi - 0x%lx;        entrylo0 - 0x%lx;"
 378                        "        entrylo1 - 0x%lx\n",
 379                          i, entryhi[i], entrylo0[i], entrylo1[i]);
 380         printk("\n\n\n");
 381 }
 382
 383 static void show_dutlb(void)
 384 {
 385         int entry, i;
 386         unsigned long flags;
 387         unsigned long oldpid;
 388         unsigned long entryhi[16], entrylo0[16], entrylo1[16];
 389
 390         oldpid = read_mmu_entryhi();
 391
 392         entry = 0x4000;
 393
 394         local_irq_save(flags);
 395
 396         for (i = 0; i < 16; i++) {
 397                 write_mmu_index(entry);
 398                 tlb_read();
 399                 entryhi[i]  = read_mmu_entryhi();
 400                 entrylo0[i] = read_mmu_entrylo0();
 401                 entrylo1[i] = read_mmu_entrylo1();
 402
 403                 entry++;
 404         }
 405
 406         local_irq_restore(flags);
 407
 408         write_mmu_entryhi(oldpid);
 409
 410         printk("\n\n\n");
 411         for (i = 0; i < 16; i++)
 412                 printk("dutlb[%d]:      entryhi - 0x%lx;        entrylo0 - 0x%lx;"
 413                        "        entrylo1 - 0x%lx\n",
 414                          i, entryhi[i], entrylo0[i], entrylo1[i]);
 415         printk("\n\n\n");
 416 }
 417
 418 static unsigned long entryhi[1024], entrylo0[1024], entrylo1[1024];
 419 static void show_jtlb(void)
 420 {
 421         int entry;
 422         unsigned long flags;
 423         unsigned long oldpid;
 424
 425         oldpid = read_mmu_entryhi();
 426
 427         entry = 0;
 428
 429         local_irq_save(flags);
 430         while (entry < 1024) {
 431                 write_mmu_index(entry);
 432                 tlb_read();
 433                 entryhi[entry]  = read_mmu_entryhi();
 434                 entrylo0[entry] = read_mmu_entrylo0();
 435                 entrylo1[entry] = read_mmu_entrylo1();
 436
 437                 entry++;
 438         }
 439         local_irq_restore(flags);
 440
 441         write_mmu_entryhi(oldpid);
 442
 443         printk("\n\n\n");
 444
 445         for (entry = 0; entry < 1024; entry++)
 446                 printk("jtlb[%x]:       entryhi - 0x%lx;        entrylo0 - 0x%lx;"
 447                        "        entrylo1 - 0x%lx\n",
 448                          entry, entryhi[entry], entrylo0[entry], entrylo1[entry]);
 449         printk("\n\n\n");
 450 }
 451
 452 static void show_tlb(void)
 453 {
 454         show_iutlb();
 455         show_dutlb();
 456         show_jtlb();
 457 }
 458 #else
 459 static void show_tlb(void)
 460 {
 461         return;
 462 }
 463 #endif
 464
 465 void show_regs(struct pt_regs *fp)
 466 {
 467         pr_info("\nCURRENT PROCESS:\n\n");
 468         pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
 469
 470         if (current->mm) {
 471                 pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 472                        (int) current->mm->start_code,
 473                        (int) current->mm->end_code,
 474                        (int) current->mm->start_data,
 475                        (int) current->mm->end_data,
 476                        (int) current->mm->end_data,
 477                        (int) current->mm->brk);
 478                 pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 479                        (int) current->mm->start_stack,
 480                        (int) (((unsigned long) current) + 2 * PAGE_SIZE));
 481         }
 482
 483         pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
 484         pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
 485         pr_info("SP: 0x%08lx\n", (long)fp->usp);
 486         pr_info("PSR: 0x%08lx\n", (long)fp->sr);
 487         pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
 488         pr_info("PT_REGS: 0x%08lx\n", (long)fp);
 489
 490         pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
 491                 fp->a0, fp->a1, fp->a2, fp->a3);
 492 #if defined(__CSKYABIV2__)
 493         pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
 494                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 495         pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
 496                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 497         pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
 498                 fp->regs[8], fp->regs[9], fp->lr);
 499         pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
 500                 fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
 501         pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
 502                 fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
 503         pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
 504                 fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
 505         pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
 506                 fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
 507         pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
 508                 fp->rhi, fp->rlo);
 509 #else
 510         pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
 511                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 512         pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
 513                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 514         pr_info("r14: 0x%08lx   r1: 0x%08lx\n",
 515                 fp->regs[8], fp->regs[9]);
 516 #endif
 517
 518         show_tlb();
 519
 520         return;
 521 }