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/pgtable.h>
  22 #include <asm/processor.h>
  23 #include <asm/asm-offsets.h>
  24
  25 #include <abi/regdef.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                    unsigned int pos, unsigned int count,
  81                    void *kbuf, void __user *ubuf)
  82 {
  83         struct pt_regs *regs;
  84
  85         regs = task_pt_regs(target);
  86
  87         /* Abiv1 regs->tls is fake and we need sync here. */
  88         regs->tls = task_thread_info(target)->tp_value;
  89
  90         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
  91 }
  92
  93 static int gpr_set(struct task_struct *target,
  94                     const struct user_regset *regset,
  95                     unsigned int pos, unsigned int count,
  96                     const void *kbuf, const void __user *ubuf)
  97 {
  98         int ret;
  99         struct pt_regs regs;
 100
 101         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
 102         if (ret)
 103                 return ret;
 104
 105         regs.sr = task_pt_regs(target)->sr;
 106 #ifdef CONFIG_CPU_HAS_HILO
 107         regs.dcsr = task_pt_regs(target)->dcsr;
 108 #endif
 109         task_thread_info(target)->tp_value = regs.tls;
 110
 111         *task_pt_regs(target) = regs;
 112
 113         return 0;
 114 }
 115
 116 static int fpr_get(struct task_struct *target,
 117                    const struct user_regset *regset,
 118                    unsigned int pos, unsigned int count,
 119                    void *kbuf, void __user *ubuf)
 120 {
 121         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 122
 123 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 124         int i;
 125         struct user_fp tmp = *regs;
 126
 127         for (i = 0; i < 16; i++) {
 128                 tmp.vr[i*4] = regs->vr[i*2];
 129                 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
 130         }
 131
 132         for (i = 0; i < 32; i++)
 133                 tmp.vr[64 + i] = regs->vr[32 + i];
 134
 135         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 136 #else
 137         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 138 #endif
 139 }
 140
 141 static int fpr_set(struct task_struct *target,
 142                    const struct user_regset *regset,
 143                    unsigned int pos, unsigned int count,
 144                    const void *kbuf, const void __user *ubuf)
 145 {
 146         int ret;
 147         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 148
 149 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 150         int i;
 151         struct user_fp tmp;
 152
 153         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 154
 155         *regs = tmp;
 156
 157         for (i = 0; i < 16; i++) {
 158                 regs->vr[i*2] = tmp.vr[i*4];
 159                 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
 160         }
 161
 162         for (i = 0; i < 32; i++)
 163                 regs->vr[32 + i] = tmp.vr[64 + i];
 164 #else
 165         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 166 #endif
 167
 168         return ret;
 169 }
 170
 171 static const struct user_regset csky_regsets[] = {
 172         [REGSET_GPR] = {
 173                 .core_note_type = NT_PRSTATUS,
 174                 .n = sizeof(struct pt_regs) / sizeof(u32),
 175                 .size = sizeof(u32),
 176                 .align = sizeof(u32),
 177                 .get = &gpr_get,
 178                 .set = &gpr_set,
 179         },
 180         [REGSET_FPR] = {
 181                 .core_note_type = NT_PRFPREG,
 182                 .n = sizeof(struct user_fp) / sizeof(u32),
 183                 .size = sizeof(u32),
 184                 .align = sizeof(u32),
 185                 .get = &fpr_get,
 186                 .set = &fpr_set,
 187         },
 188 };
 189
 190 static const struct user_regset_view user_csky_view = {
 191         .name = "csky",
 192         .e_machine = ELF_ARCH,
 193         .regsets = csky_regsets,
 194         .n = ARRAY_SIZE(csky_regsets),
 195 };
 196
 197 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 198 {
 199         return &user_csky_view;
 200 }
 201
 202 struct pt_regs_offset {
 203         const char *name;
 204         int offset;
 205 };
 206
 207 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 208 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 209
 210 static const struct pt_regs_offset regoffset_table[] = {
 211         REG_OFFSET_NAME(tls),
 212         REG_OFFSET_NAME(lr),
 213         REG_OFFSET_NAME(pc),
 214         REG_OFFSET_NAME(sr),
 215         REG_OFFSET_NAME(usp),
 216         REG_OFFSET_NAME(orig_a0),
 217         REG_OFFSET_NAME(a0),
 218         REG_OFFSET_NAME(a1),
 219         REG_OFFSET_NAME(a2),
 220         REG_OFFSET_NAME(a3),
 221         REG_OFFSET_NAME(regs[0]),
 222         REG_OFFSET_NAME(regs[1]),
 223         REG_OFFSET_NAME(regs[2]),
 224         REG_OFFSET_NAME(regs[3]),
 225         REG_OFFSET_NAME(regs[4]),
 226         REG_OFFSET_NAME(regs[5]),
 227         REG_OFFSET_NAME(regs[6]),
 228         REG_OFFSET_NAME(regs[7]),
 229         REG_OFFSET_NAME(regs[8]),
 230         REG_OFFSET_NAME(regs[9]),
 231 #if defined(__CSKYABIV2__)
 232         REG_OFFSET_NAME(exregs[0]),
 233         REG_OFFSET_NAME(exregs[1]),
 234         REG_OFFSET_NAME(exregs[2]),
 235         REG_OFFSET_NAME(exregs[3]),
 236         REG_OFFSET_NAME(exregs[4]),
 237         REG_OFFSET_NAME(exregs[5]),
 238         REG_OFFSET_NAME(exregs[6]),
 239         REG_OFFSET_NAME(exregs[7]),
 240         REG_OFFSET_NAME(exregs[8]),
 241         REG_OFFSET_NAME(exregs[9]),
 242         REG_OFFSET_NAME(exregs[10]),
 243         REG_OFFSET_NAME(exregs[11]),
 244         REG_OFFSET_NAME(exregs[12]),
 245         REG_OFFSET_NAME(exregs[13]),
 246         REG_OFFSET_NAME(exregs[14]),
 247         REG_OFFSET_NAME(rhi),
 248         REG_OFFSET_NAME(rlo),
 249         REG_OFFSET_NAME(dcsr),
 250 #endif
 251         REG_OFFSET_END,
 252 };
 253
 254 /**
 255  * regs_query_register_offset() - query register offset from its name
 256  * @name:       the name of a register
 257  *
 258  * regs_query_register_offset() returns the offset of a register in struct
 259  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 260  */
 261 int regs_query_register_offset(const char *name)
 262 {
 263         const struct pt_regs_offset *roff;
 264
 265         for (roff = regoffset_table; roff->name != NULL; roff++)
 266                 if (!strcmp(roff->name, name))
 267                         return roff->offset;
 268         return -EINVAL;
 269 }
 270
 271 /**
 272  * regs_within_kernel_stack() - check the address in the stack
 273  * @regs:      pt_regs which contains kernel stack pointer.
 274  * @addr:      address which is checked.
 275  *
 276  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 277  * If @addr is within the kernel stack, it returns true. If not, returns false.
 278  */
 279 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 280 {
 281         return (addr & ~(THREAD_SIZE - 1))  ==
 282                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 283 }
 284
 285 /**
 286  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 287  * @regs:       pt_regs which contains kernel stack pointer.
 288  * @n:          stack entry number.
 289  *
 290  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 291  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 292  * this returns 0.
 293  */
 294 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 295 {
 296         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 297
 298         addr += n;
 299         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 300                 return *addr;
 301         else
 302                 return 0;
 303 }
 304
 305 void ptrace_disable(struct task_struct *child)
 306 {
 307         singlestep_disable(child);
 308 }
 309
 310 long arch_ptrace(struct task_struct *child, long request,
 311                  unsigned long addr, unsigned long data)
 312 {
 313         long ret = -EIO;
 314
 315         switch (request) {
 316         default:
 317                 ret = ptrace_request(child, request, addr, data);
 318                 break;
 319         }
 320
 321         return ret;
 322 }
 323
 324 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 325 {
 326         if (test_thread_flag(TIF_SYSCALL_TRACE))
 327                 if (tracehook_report_syscall_entry(regs))
 328                         syscall_set_nr(current, regs, -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 }
 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                 tracehook_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 extern void show_stack(struct task_struct *task, unsigned long *stack);
 348 void show_regs(struct pt_regs *fp)
 349 {
 350         unsigned long   *sp;
 351         unsigned char   *tp;
 352         int     i;
 353
 354         pr_info("\nCURRENT PROCESS:\n\n");
 355         pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
 356
 357         if (current->mm) {
 358                 pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 359                        (int) current->mm->start_code,
 360                        (int) current->mm->end_code,
 361                        (int) current->mm->start_data,
 362                        (int) current->mm->end_data,
 363                        (int) current->mm->end_data,
 364                        (int) current->mm->brk);
 365                 pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 366                        (int) current->mm->start_stack,
 367                        (int) (((unsigned long) current) + 2 * PAGE_SIZE));
 368         }
 369
 370         pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
 371         pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
 372         pr_info("SP: 0x%08lx\n", (long)fp);
 373         pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
 374         pr_info("PSR: 0x%08lx\n", (long)fp->sr);
 375
 376         pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
 377                 fp->a0, fp->a1, fp->a2, fp->a3);
 378 #if defined(__CSKYABIV2__)
 379         pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
 380                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 381         pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
 382                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 383         pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
 384                 fp->regs[8], fp->regs[9], fp->lr);
 385         pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
 386                 fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
 387         pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
 388                 fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
 389         pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
 390                 fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
 391         pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
 392                 fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
 393         pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
 394                 fp->rhi, fp->rlo);
 395 #else
 396         pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
 397                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 398         pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
 399                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 400         pr_info("r14: 0x%08lx   r1: 0x%08lx  r15: 0x%08lx\n",
 401                 fp->regs[8], fp->regs[9], fp->lr);
 402 #endif
 403
 404         pr_info("\nCODE:");
 405         tp = ((unsigned char *) fp->pc) - 0x20;
 406         tp += ((int)tp % 4) ? 2 : 0;
 407         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 408                 if ((i % 0x10) == 0)
 409                         pr_cont("\n%08x: ", (int) (tp + i));
 410                 pr_cont("%08x ", (int) *sp++);
 411         }
 412         pr_cont("\n");
 413
 414         pr_info("\nKERNEL STACK:");
 415         tp = ((unsigned char *) fp) - 0x40;
 416         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 417                 if ((i % 0x10) == 0)
 418                         pr_cont("\n%08x: ", (int) (tp + i));
 419                 pr_cont("%08x ", (int) *sp++);
 420         }
 421         pr_cont("\n");
 422
 423         show_stack(NULL, (unsigned long *)fp->regs[4]);
 424         return;
 425 }