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
  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                    unsigned int pos, unsigned int count,
  80                    void *kbuf, void __user *ubuf)
  81 {
  82         struct pt_regs *regs;
  83
  84         regs = task_pt_regs(target);
  85
  86         /* Abiv1 regs->tls is fake and we need sync here. */
  87         regs->tls = task_thread_info(target)->tp_value;
  88
  89         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
  90 }
  91
  92 static int gpr_set(struct task_struct *target,
  93                     const struct user_regset *regset,
  94                     unsigned int pos, unsigned int count,
  95                     const void *kbuf, const void __user *ubuf)
  96 {
  97         int ret;
  98         struct pt_regs regs;
  99
 100         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
 101         if (ret)
 102                 return ret;
 103
 104         regs.sr = task_pt_regs(target)->sr;
 105 #ifdef CONFIG_CPU_HAS_HILO
 106         regs.dcsr = task_pt_regs(target)->dcsr;
 107 #endif
 108         task_thread_info(target)->tp_value = regs.tls;
 109
 110         *task_pt_regs(target) = regs;
 111
 112         return 0;
 113 }
 114
 115 static int fpr_get(struct task_struct *target,
 116                    const struct user_regset *regset,
 117                    unsigned int pos, unsigned int count,
 118                    void *kbuf, void __user *ubuf)
 119 {
 120         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 121
 122 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 123         int i;
 124         struct user_fp tmp = *regs;
 125
 126         for (i = 0; i < 16; i++) {
 127                 tmp.vr[i*4] = regs->vr[i*2];
 128                 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
 129         }
 130
 131         for (i = 0; i < 32; i++)
 132                 tmp.vr[64 + i] = regs->vr[32 + i];
 133
 134         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 135 #else
 136         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 137 #endif
 138 }
 139
 140 static int fpr_set(struct task_struct *target,
 141                    const struct user_regset *regset,
 142                    unsigned int pos, unsigned int count,
 143                    const void *kbuf, const void __user *ubuf)
 144 {
 145         int ret;
 146         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 147
 148 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 149         int i;
 150         struct user_fp tmp;
 151
 152         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 153
 154         *regs = tmp;
 155
 156         for (i = 0; i < 16; i++) {
 157                 regs->vr[i*2] = tmp.vr[i*4];
 158                 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
 159         }
 160
 161         for (i = 0; i < 32; i++)
 162                 regs->vr[32 + i] = tmp.vr[64 + i];
 163 #else
 164         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 165 #endif
 166
 167         return ret;
 168 }
 169
 170 static const struct user_regset csky_regsets[] = {
 171         [REGSET_GPR] = {
 172                 .core_note_type = NT_PRSTATUS,
 173                 .n = sizeof(struct pt_regs) / sizeof(u32),
 174                 .size = sizeof(u32),
 175                 .align = sizeof(u32),
 176                 .get = &gpr_get,
 177                 .set = &gpr_set,
 178         },
 179         [REGSET_FPR] = {
 180                 .core_note_type = NT_PRFPREG,
 181                 .n = sizeof(struct user_fp) / sizeof(u32),
 182                 .size = sizeof(u32),
 183                 .align = sizeof(u32),
 184                 .get = &fpr_get,
 185                 .set = &fpr_set,
 186         },
 187 };
 188
 189 static const struct user_regset_view user_csky_view = {
 190         .name = "csky",
 191         .e_machine = ELF_ARCH,
 192         .regsets = csky_regsets,
 193         .n = ARRAY_SIZE(csky_regsets),
 194 };
 195
 196 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 197 {
 198         return &user_csky_view;
 199 }
 200
 201 struct pt_regs_offset {
 202         const char *name;
 203         int offset;
 204 };
 205
 206 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 207 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 208
 209 static const struct pt_regs_offset regoffset_table[] = {
 210         REG_OFFSET_NAME(tls),
 211         REG_OFFSET_NAME(lr),
 212         REG_OFFSET_NAME(pc),
 213         REG_OFFSET_NAME(sr),
 214         REG_OFFSET_NAME(usp),
 215         REG_OFFSET_NAME(orig_a0),
 216         REG_OFFSET_NAME(a0),
 217         REG_OFFSET_NAME(a1),
 218         REG_OFFSET_NAME(a2),
 219         REG_OFFSET_NAME(a3),
 220         REG_OFFSET_NAME(regs[0]),
 221         REG_OFFSET_NAME(regs[1]),
 222         REG_OFFSET_NAME(regs[2]),
 223         REG_OFFSET_NAME(regs[3]),
 224         REG_OFFSET_NAME(regs[4]),
 225         REG_OFFSET_NAME(regs[5]),
 226         REG_OFFSET_NAME(regs[6]),
 227         REG_OFFSET_NAME(regs[7]),
 228         REG_OFFSET_NAME(regs[8]),
 229         REG_OFFSET_NAME(regs[9]),
 230 #if defined(__CSKYABIV2__)
 231         REG_OFFSET_NAME(exregs[0]),
 232         REG_OFFSET_NAME(exregs[1]),
 233         REG_OFFSET_NAME(exregs[2]),
 234         REG_OFFSET_NAME(exregs[3]),
 235         REG_OFFSET_NAME(exregs[4]),
 236         REG_OFFSET_NAME(exregs[5]),
 237         REG_OFFSET_NAME(exregs[6]),
 238         REG_OFFSET_NAME(exregs[7]),
 239         REG_OFFSET_NAME(exregs[8]),
 240         REG_OFFSET_NAME(exregs[9]),
 241         REG_OFFSET_NAME(exregs[10]),
 242         REG_OFFSET_NAME(exregs[11]),
 243         REG_OFFSET_NAME(exregs[12]),
 244         REG_OFFSET_NAME(exregs[13]),
 245         REG_OFFSET_NAME(exregs[14]),
 246         REG_OFFSET_NAME(rhi),
 247         REG_OFFSET_NAME(rlo),
 248         REG_OFFSET_NAME(dcsr),
 249 #endif
 250         REG_OFFSET_END,
 251 };
 252
 253 /**
 254  * regs_query_register_offset() - query register offset from its name
 255  * @name:       the name of a register
 256  *
 257  * regs_query_register_offset() returns the offset of a register in struct
 258  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 259  */
 260 int regs_query_register_offset(const char *name)
 261 {
 262         const struct pt_regs_offset *roff;
 263
 264         for (roff = regoffset_table; roff->name != NULL; roff++)
 265                 if (!strcmp(roff->name, name))
 266                         return roff->offset;
 267         return -EINVAL;
 268 }
 269
 270 /**
 271  * regs_within_kernel_stack() - check the address in the stack
 272  * @regs:      pt_regs which contains kernel stack pointer.
 273  * @addr:      address which is checked.
 274  *
 275  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 276  * If @addr is within the kernel stack, it returns true. If not, returns false.
 277  */
 278 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 279 {
 280         return (addr & ~(THREAD_SIZE - 1))  ==
 281                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 282 }
 283
 284 /**
 285  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 286  * @regs:       pt_regs which contains kernel stack pointer.
 287  * @n:          stack entry number.
 288  *
 289  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 290  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 291  * this returns 0.
 292  */
 293 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 294 {
 295         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 296
 297         addr += n;
 298         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 299                 return *addr;
 300         else
 301                 return 0;
 302 }
 303
 304 void ptrace_disable(struct task_struct *child)
 305 {
 306         singlestep_disable(child);
 307 }
 308
 309 long arch_ptrace(struct task_struct *child, long request,
 310                  unsigned long addr, unsigned long data)
 311 {
 312         long ret = -EIO;
 313
 314         switch (request) {
 315         default:
 316                 ret = ptrace_request(child, request, addr, data);
 317                 break;
 318         }
 319
 320         return ret;
 321 }
 322
 323 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 324 {
 325         if (test_thread_flag(TIF_SYSCALL_TRACE))
 326                 if (tracehook_report_syscall_entry(regs))
 327                         syscall_set_nr(current, regs, -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 }
 334
 335 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 336 {
 337         audit_syscall_exit(regs);
 338
 339         if (test_thread_flag(TIF_SYSCALL_TRACE))
 340                 tracehook_report_syscall_exit(regs, 0);
 341
 342         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 343                 trace_sys_exit(regs, syscall_get_return_value(current, regs));
 344 }
 345
 346 extern void show_stack(struct task_struct *task, unsigned long *stack, const char *loglvl);
 347 void show_regs(struct pt_regs *fp)
 348 {
 349         unsigned long   *sp;
 350         unsigned char   *tp;
 351         int     i;
 352
 353         pr_info("\nCURRENT PROCESS:\n\n");
 354         pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
 355
 356         if (current->mm) {
 357                 pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 358                        (int) current->mm->start_code,
 359                        (int) current->mm->end_code,
 360                        (int) current->mm->start_data,
 361                        (int) current->mm->end_data,
 362                        (int) current->mm->end_data,
 363                        (int) current->mm->brk);
 364                 pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 365                        (int) current->mm->start_stack,
 366                        (int) (((unsigned long) current) + 2 * PAGE_SIZE));
 367         }
 368
 369         pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
 370         pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
 371         pr_info("SP: 0x%08lx\n", (long)fp);
 372         pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
 373         pr_info("PSR: 0x%08lx\n", (long)fp->sr);
 374
 375         pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
 376                 fp->a0, fp->a1, fp->a2, fp->a3);
 377 #if defined(__CSKYABIV2__)
 378         pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
 379                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 380         pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
 381                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 382         pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
 383                 fp->regs[8], fp->regs[9], fp->lr);
 384         pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
 385                 fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
 386         pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
 387                 fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
 388         pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
 389                 fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
 390         pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
 391                 fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
 392         pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
 393                 fp->rhi, fp->rlo);
 394 #else
 395         pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
 396                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 397         pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
 398                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 399         pr_info("r14: 0x%08lx   r1: 0x%08lx  r15: 0x%08lx\n",
 400                 fp->regs[8], fp->regs[9], fp->lr);
 401 #endif
 402
 403         pr_info("\nCODE:");
 404         tp = ((unsigned char *) fp->pc) - 0x20;
 405         tp += ((int)tp % 4) ? 2 : 0;
 406         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 407                 if ((i % 0x10) == 0)
 408                         pr_cont("\n%08x: ", (int) (tp + i));
 409                 pr_cont("%08x ", (int) *sp++);
 410         }
 411         pr_cont("\n");
 412
 413         pr_info("\nKERNEL STACK:");
 414         tp = ((unsigned char *) fp) - 0x40;
 415         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 416                 if ((i % 0x10) == 0)
 417                         pr_cont("\n%08x: ", (int) (tp + i));
 418                 pr_cont("%08x ", (int) *sp++);
 419         }
 420         pr_cont("\n");
 421
 422         show_stack(NULL, (unsigned long *)fp->regs[4], KERN_INFO);
 423         return;
 424 }