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/tracehook.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/user.h>
  18
  19 #include <asm/thread_info.h>
  20 #include <asm/page.h>
  21 #include <asm/processor.h>
  22 #include <asm/asm-offsets.h>
  23
  24 #include <abi/regdef.h>
  25 #include <abi/ckmmu.h>
  26
  27 #define CREATE_TRACE_POINTS
  28 #include <trace/events/syscalls.h>
  29
  30 /* sets the trace bits. */
  31 #define TRACE_MODE_SI      (1 << 14)
  32 #define TRACE_MODE_RUN     0
  33 #define TRACE_MODE_MASK    ~(0x3 << 14)
  34
  35 /*
  36  * Make sure the single step bit is not set.
  37  */
  38 static void singlestep_disable(struct task_struct *tsk)
  39 {
  40         struct pt_regs *regs;
  41
  42         regs = task_pt_regs(tsk);
  43         regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
  44
  45         /* Enable irq */
  46         regs->sr |= BIT(6);
  47 }
  48
  49 static void singlestep_enable(struct task_struct *tsk)
  50 {
  51         struct pt_regs *regs;
  52
  53         regs = task_pt_regs(tsk);
  54         regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
  55
  56         /* Disable irq */
  57         regs->sr &= ~BIT(6);
  58 }
  59
  60 /*
  61  * Make sure the single step bit is set.
  62  */
  63 void user_enable_single_step(struct task_struct *child)
  64 {
  65         singlestep_enable(child);
  66 }
  67
  68 void user_disable_single_step(struct task_struct *child)
  69 {
  70         singlestep_disable(child);
  71 }
  72
  73 enum csky_regset {
  74         REGSET_GPR,
  75         REGSET_FPR,
  76 };
  77
  78 static int gpr_get(struct task_struct *target,
  79                    const struct user_regset *regset,
  80                    struct membuf to)
  81 {
  82         struct pt_regs *regs = task_pt_regs(target);
  83
  84         /* Abiv1 regs->tls is fake and we need sync here. */
  85         regs->tls = task_thread_info(target)->tp_value;
  86
  87         return membuf_write(&to, regs, sizeof(*regs));
  88 }
  89
  90 static int gpr_set(struct task_struct *target,
  91                     const struct user_regset *regset,
  92                     unsigned int pos, unsigned int count,
  93                     const void *kbuf, const void __user *ubuf)
  94 {
  95         int ret;
  96         struct pt_regs regs;
  97
  98         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
  99         if (ret)
 100                 return ret;
 101
 102         /* BIT(0) of regs.sr is Condition Code/Carry bit */
 103         regs.sr = (regs.sr & BIT(0)) | (task_pt_regs(target)->sr & ~BIT(0));
 104 #ifdef CONFIG_CPU_HAS_HILO
 105         regs.dcsr = task_pt_regs(target)->dcsr;
 106 #endif
 107         task_thread_info(target)->tp_value = regs.tls;
 108
 109         *task_pt_regs(target) = regs;
 110
 111         return 0;
 112 }
 113
 114 static int fpr_get(struct task_struct *target,
 115                    const struct user_regset *regset,
 116                    struct membuf to)
 117 {
 118         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 119
 120 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 121         int i;
 122         struct user_fp tmp = *regs;
 123
 124         for (i = 0; i < 16; i++) {
 125                 tmp.vr[i*4] = regs->vr[i*2];
 126                 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
 127         }
 128
 129         for (i = 0; i < 32; i++)
 130                 tmp.vr[64 + i] = regs->vr[32 + i];
 131
 132         return membuf_write(&to, &tmp, sizeof(tmp));
 133 #else
 134         return membuf_write(&to, regs, sizeof(*regs));
 135 #endif
 136 }
 137
 138 static int fpr_set(struct task_struct *target,
 139                    const struct user_regset *regset,
 140                    unsigned int pos, unsigned int count,
 141                    const void *kbuf, const void __user *ubuf)
 142 {
 143         int ret;
 144         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 145
 146 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 147         int i;
 148         struct user_fp tmp;
 149
 150         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 151
 152         *regs = tmp;
 153
 154         for (i = 0; i < 16; i++) {
 155                 regs->vr[i*2] = tmp.vr[i*4];
 156                 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
 157         }
 158
 159         for (i = 0; i < 32; i++)
 160                 regs->vr[32 + i] = tmp.vr[64 + i];
 161 #else
 162         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 163 #endif
 164
 165         return ret;
 166 }
 167
 168 static const struct user_regset csky_regsets[] = {
 169         [REGSET_GPR] = {
 170                 .core_note_type = NT_PRSTATUS,
 171                 .n = sizeof(struct pt_regs) / sizeof(u32),
 172                 .size = sizeof(u32),
 173                 .align = sizeof(u32),
 174                 .regset_get = gpr_get,
 175                 .set = gpr_set,
 176         },
 177         [REGSET_FPR] = {
 178                 .core_note_type = NT_PRFPREG,
 179                 .n = sizeof(struct user_fp) / sizeof(u32),
 180                 .size = sizeof(u32),
 181                 .align = sizeof(u32),
 182                 .regset_get = fpr_get,
 183                 .set = fpr_set,
 184         },
 185 };
 186
 187 static const struct user_regset_view user_csky_view = {
 188         .name = "csky",
 189         .e_machine = ELF_ARCH,
 190         .regsets = csky_regsets,
 191         .n = ARRAY_SIZE(csky_regsets),
 192 };
 193
 194 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 195 {
 196         return &user_csky_view;
 197 }
 198
 199 struct pt_regs_offset {
 200         const char *name;
 201         int offset;
 202 };
 203
 204 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 205 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 206
 207 static const struct pt_regs_offset regoffset_table[] = {
 208         REG_OFFSET_NAME(tls),
 209         REG_OFFSET_NAME(lr),
 210         REG_OFFSET_NAME(pc),
 211         REG_OFFSET_NAME(sr),
 212         REG_OFFSET_NAME(usp),
 213         REG_OFFSET_NAME(orig_a0),
 214         REG_OFFSET_NAME(a0),
 215         REG_OFFSET_NAME(a1),
 216         REG_OFFSET_NAME(a2),
 217         REG_OFFSET_NAME(a3),
 218         REG_OFFSET_NAME(regs[0]),
 219         REG_OFFSET_NAME(regs[1]),
 220         REG_OFFSET_NAME(regs[2]),
 221         REG_OFFSET_NAME(regs[3]),
 222         REG_OFFSET_NAME(regs[4]),
 223         REG_OFFSET_NAME(regs[5]),
 224         REG_OFFSET_NAME(regs[6]),
 225         REG_OFFSET_NAME(regs[7]),
 226         REG_OFFSET_NAME(regs[8]),
 227         REG_OFFSET_NAME(regs[9]),
 228 #if defined(__CSKYABIV2__)
 229         REG_OFFSET_NAME(exregs[0]),
 230         REG_OFFSET_NAME(exregs[1]),
 231         REG_OFFSET_NAME(exregs[2]),
 232         REG_OFFSET_NAME(exregs[3]),
 233         REG_OFFSET_NAME(exregs[4]),
 234         REG_OFFSET_NAME(exregs[5]),
 235         REG_OFFSET_NAME(exregs[6]),
 236         REG_OFFSET_NAME(exregs[7]),
 237         REG_OFFSET_NAME(exregs[8]),
 238         REG_OFFSET_NAME(exregs[9]),
 239         REG_OFFSET_NAME(exregs[10]),
 240         REG_OFFSET_NAME(exregs[11]),
 241         REG_OFFSET_NAME(exregs[12]),
 242         REG_OFFSET_NAME(exregs[13]),
 243         REG_OFFSET_NAME(exregs[14]),
 244         REG_OFFSET_NAME(rhi),
 245         REG_OFFSET_NAME(rlo),
 246         REG_OFFSET_NAME(dcsr),
 247 #endif
 248         REG_OFFSET_END,
 249 };
 250
 251 /**
 252  * regs_query_register_offset() - query register offset from its name
 253  * @name:       the name of a register
 254  *
 255  * regs_query_register_offset() returns the offset of a register in struct
 256  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 257  */
 258 int regs_query_register_offset(const char *name)
 259 {
 260         const struct pt_regs_offset *roff;
 261
 262         for (roff = regoffset_table; roff->name != NULL; roff++)
 263                 if (!strcmp(roff->name, name))
 264                         return roff->offset;
 265         return -EINVAL;
 266 }
 267
 268 /**
 269  * regs_within_kernel_stack() - check the address in the stack
 270  * @regs:      pt_regs which contains kernel stack pointer.
 271  * @addr:      address which is checked.
 272  *
 273  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 274  * If @addr is within the kernel stack, it returns true. If not, returns false.
 275  */
 276 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 277 {
 278         return (addr & ~(THREAD_SIZE - 1))  ==
 279                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 280 }
 281
 282 /**
 283  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 284  * @regs:       pt_regs which contains kernel stack pointer.
 285  * @n:          stack entry number.
 286  *
 287  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 288  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 289  * this returns 0.
 290  */
 291 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 292 {
 293         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 294
 295         addr += n;
 296         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 297                 return *addr;
 298         else
 299                 return 0;
 300 }
 301
 302 void ptrace_disable(struct task_struct *child)
 303 {
 304         singlestep_disable(child);
 305 }
 306
 307 long arch_ptrace(struct task_struct *child, long request,
 308                  unsigned long addr, unsigned long data)
 309 {
 310         long ret = -EIO;
 311
 312         switch (request) {
 313         default:
 314                 ret = ptrace_request(child, request, addr, data);
 315                 break;
 316         }
 317
 318         return ret;
 319 }
 320
 321 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 322 {
 323         if (test_thread_flag(TIF_SYSCALL_TRACE))
 324                 if (tracehook_report_syscall_entry(regs))
 325                         return -1;
 326
 327         if (secure_computing() == -1)
 328                 return -1;
 329
 330         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 331                 trace_sys_enter(regs, syscall_get_nr(current, regs));
 332
 333         audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
 334         return 0;
 335 }
 336
 337 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 338 {
 339         audit_syscall_exit(regs);
 340
 341         if (test_thread_flag(TIF_SYSCALL_TRACE))
 342                 tracehook_report_syscall_exit(regs, 0);
 343
 344         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 345                 trace_sys_exit(regs, syscall_get_return_value(current, regs));
 346 }
 347
 348 #ifdef CONFIG_CPU_CK860
 349 static void show_iutlb(void)
 350 {
 351         int entry, i;
 352         unsigned long flags;
 353         unsigned long oldpid;
 354         unsigned long entryhi[16], entrylo0[16], entrylo1[16];
 355
 356         oldpid = read_mmu_entryhi();
 357
 358         entry = 0x8000;
 359
 360         local_irq_save(flags);
 361
 362         for (i = 0; i < 16; i++) {
 363                 write_mmu_index(entry);
 364                 tlb_read();
 365                 entryhi[i]  = read_mmu_entryhi();
 366                 entrylo0[i] = read_mmu_entrylo0();
 367                 entrylo1[i] = read_mmu_entrylo1();
 368
 369                 entry++;
 370         }
 371
 372         local_irq_restore(flags);
 373
 374         write_mmu_entryhi(oldpid);
 375
 376         printk("\n\n\n");
 377         for (i = 0; i < 16; i++)
 378                 printk("iutlb[%d]:      entryhi - 0x%lx;        entrylo0 - 0x%lx;"
 379                        "        entrylo1 - 0x%lx\n",
 380                          i, entryhi[i], entrylo0[i], entrylo1[i]);
 381         printk("\n\n\n");
 382 }
 383
 384 static void show_dutlb(void)
 385 {
 386         int entry, i;
 387         unsigned long flags;
 388         unsigned long oldpid;
 389         unsigned long entryhi[16], entrylo0[16], entrylo1[16];
 390
 391         oldpid = read_mmu_entryhi();
 392
 393         entry = 0x4000;
 394
 395         local_irq_save(flags);
 396
 397         for (i = 0; i < 16; i++) {
 398                 write_mmu_index(entry);
 399                 tlb_read();
 400                 entryhi[i]  = read_mmu_entryhi();
 401                 entrylo0[i] = read_mmu_entrylo0();
 402                 entrylo1[i] = read_mmu_entrylo1();
 403
 404                 entry++;
 405         }
 406
 407         local_irq_restore(flags);
 408
 409         write_mmu_entryhi(oldpid);
 410
 411         printk("\n\n\n");
 412         for (i = 0; i < 16; i++)
 413                 printk("dutlb[%d]:      entryhi - 0x%lx;        entrylo0 - 0x%lx;"
 414                        "        entrylo1 - 0x%lx\n",
 415                          i, entryhi[i], entrylo0[i], entrylo1[i]);
 416         printk("\n\n\n");
 417 }
 418
 419 static unsigned long entryhi[1024], entrylo0[1024], entrylo1[1024];
 420 static void show_jtlb(void)
 421 {
 422         int entry;
 423         unsigned long flags;
 424         unsigned long oldpid;
 425
 426         oldpid = read_mmu_entryhi();
 427
 428         entry = 0;
 429
 430         local_irq_save(flags);
 431         while (entry < 1024) {
 432                 write_mmu_index(entry);
 433                 tlb_read();
 434                 entryhi[entry]  = read_mmu_entryhi();
 435                 entrylo0[entry] = read_mmu_entrylo0();
 436                 entrylo1[entry] = read_mmu_entrylo1();
 437
 438                 entry++;
 439         }
 440         local_irq_restore(flags);
 441
 442         write_mmu_entryhi(oldpid);
 443
 444         printk("\n\n\n");
 445
 446         for (entry = 0; entry < 1024; entry++)
 447                 printk("jtlb[%x]:       entryhi - 0x%lx;        entrylo0 - 0x%lx;"
 448                        "        entrylo1 - 0x%lx\n",
 449                          entry, entryhi[entry], entrylo0[entry], entrylo1[entry]);
 450         printk("\n\n\n");
 451 }
 452
 453 static void show_tlb(void)
 454 {
 455         show_iutlb();
 456         show_dutlb();
 457         show_jtlb();
 458 }
 459 #else
 460 static void show_tlb(void)
 461 {
 462         return;
 463 }
 464 #endif
 465
 466 void show_regs(struct pt_regs *fp)
 467 {
 468         pr_info("\nCURRENT PROCESS:\n\n");
 469         pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
 470
 471         if (current->mm) {
 472                 pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 473                        (int) current->mm->start_code,
 474                        (int) current->mm->end_code,
 475                        (int) current->mm->start_data,
 476                        (int) current->mm->end_data,
 477                        (int) current->mm->end_data,
 478                        (int) current->mm->brk);
 479                 pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 480                        (int) current->mm->start_stack,
 481                        (int) (((unsigned long) current) + 2 * PAGE_SIZE));
 482         }
 483
 484         pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
 485         pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
 486         pr_info("SP: 0x%08lx\n", (long)fp->usp);
 487         pr_info("PSR: 0x%08lx\n", (long)fp->sr);
 488         pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
 489         pr_info("PT_REGS: 0x%08lx\n", (long)fp);
 490
 491         pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
 492                 fp->a0, fp->a1, fp->a2, fp->a3);
 493 #if defined(__CSKYABIV2__)
 494         pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
 495                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 496         pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
 497                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 498         pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
 499                 fp->regs[8], fp->regs[9], fp->lr);
 500         pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
 501                 fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
 502         pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
 503                 fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
 504         pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
 505                 fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
 506         pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
 507                 fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
 508         pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
 509                 fp->rhi, fp->rlo);
 510 #else
 511         pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
 512                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 513         pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
 514                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 515         pr_info("r14: 0x%08lx   r1: 0x%08lx\n",
 516                 fp->regs[8], fp->regs[9]);
 517 #endif
 518
 519         show_tlb();
 520
 521         return;
 522 }