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
  46 static void singlestep_enable(struct task_struct *tsk)
  47 {
  48         struct pt_regs *regs;
  49
  50         regs = task_pt_regs(tsk);
  51         regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
  52 }
  53
  54 /*
  55  * Make sure the single step bit is set.
  56  */
  57 void user_enable_single_step(struct task_struct *child)
  58 {
  59         singlestep_enable(child);
  60 }
  61
  62 void user_disable_single_step(struct task_struct *child)
  63 {
  64         singlestep_disable(child);
  65 }
  66
  67 enum csky_regset {
  68         REGSET_GPR,
  69         REGSET_FPR,
  70 };
  71
  72 static int gpr_get(struct task_struct *target,
  73                    const struct user_regset *regset,
  74                    unsigned int pos, unsigned int count,
  75                    void *kbuf, void __user *ubuf)
  76 {
  77         struct pt_regs *regs;
  78
  79         regs = task_pt_regs(target);
  80
  81         /* Abiv1 regs->tls is fake and we need sync here. */
  82         regs->tls = task_thread_info(target)->tp_value;
  83
  84         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
  85 }
  86
  87 static int gpr_set(struct task_struct *target,
  88                     const struct user_regset *regset,
  89                     unsigned int pos, unsigned int count,
  90                     const void *kbuf, const void __user *ubuf)
  91 {
  92         int ret;
  93         struct pt_regs regs;
  94
  95         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
  96         if (ret)
  97                 return ret;
  98
  99         regs.sr = task_pt_regs(target)->sr;
 100 #ifdef CONFIG_CPU_HAS_HILO
 101         regs.dcsr = task_pt_regs(target)->dcsr;
 102 #endif
 103         task_thread_info(target)->tp_value = regs.tls;
 104
 105         *task_pt_regs(target) = regs;
 106
 107         return 0;
 108 }
 109
 110 static int fpr_get(struct task_struct *target,
 111                    const struct user_regset *regset,
 112                    unsigned int pos, unsigned int count,
 113                    void *kbuf, void __user *ubuf)
 114 {
 115         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 116
 117 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 118         int i;
 119         struct user_fp tmp = *regs;
 120
 121         for (i = 0; i < 16; i++) {
 122                 tmp.vr[i*4] = regs->vr[i*2];
 123                 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
 124         }
 125
 126         for (i = 0; i < 32; i++)
 127                 tmp.vr[64 + i] = regs->vr[32 + i];
 128
 129         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 130 #else
 131         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 132 #endif
 133 }
 134
 135 static int fpr_set(struct task_struct *target,
 136                    const struct user_regset *regset,
 137                    unsigned int pos, unsigned int count,
 138                    const void *kbuf, const void __user *ubuf)
 139 {
 140         int ret;
 141         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 142
 143 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 144         int i;
 145         struct user_fp tmp;
 146
 147         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 148
 149         *regs = tmp;
 150
 151         for (i = 0; i < 16; i++) {
 152                 regs->vr[i*2] = tmp.vr[i*4];
 153                 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
 154         }
 155
 156         for (i = 0; i < 32; i++)
 157                 regs->vr[32 + i] = tmp.vr[64 + i];
 158 #else
 159         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 160 #endif
 161
 162         return ret;
 163 }
 164
 165 static const struct user_regset csky_regsets[] = {
 166         [REGSET_GPR] = {
 167                 .core_note_type = NT_PRSTATUS,
 168                 .n = sizeof(struct pt_regs) / sizeof(u32),
 169                 .size = sizeof(u32),
 170                 .align = sizeof(u32),
 171                 .get = &gpr_get,
 172                 .set = &gpr_set,
 173         },
 174         [REGSET_FPR] = {
 175                 .core_note_type = NT_PRFPREG,
 176                 .n = sizeof(struct user_fp) / sizeof(u32),
 177                 .size = sizeof(u32),
 178                 .align = sizeof(u32),
 179                 .get = &fpr_get,
 180                 .set = &fpr_set,
 181         },
 182 };
 183
 184 static const struct user_regset_view user_csky_view = {
 185         .name = "csky",
 186         .e_machine = ELF_ARCH,
 187         .regsets = csky_regsets,
 188         .n = ARRAY_SIZE(csky_regsets),
 189 };
 190
 191 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 192 {
 193         return &user_csky_view;
 194 }
 195
 196 struct pt_regs_offset {
 197         const char *name;
 198         int offset;
 199 };
 200
 201 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 202 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 203
 204 static const struct pt_regs_offset regoffset_table[] = {
 205         REG_OFFSET_NAME(tls),
 206         REG_OFFSET_NAME(lr),
 207         REG_OFFSET_NAME(pc),
 208         REG_OFFSET_NAME(sr),
 209         REG_OFFSET_NAME(usp),
 210         REG_OFFSET_NAME(orig_a0),
 211         REG_OFFSET_NAME(a0),
 212         REG_OFFSET_NAME(a1),
 213         REG_OFFSET_NAME(a2),
 214         REG_OFFSET_NAME(a3),
 215         REG_OFFSET_NAME(regs[0]),
 216         REG_OFFSET_NAME(regs[1]),
 217         REG_OFFSET_NAME(regs[2]),
 218         REG_OFFSET_NAME(regs[3]),
 219         REG_OFFSET_NAME(regs[4]),
 220         REG_OFFSET_NAME(regs[5]),
 221         REG_OFFSET_NAME(regs[6]),
 222         REG_OFFSET_NAME(regs[7]),
 223         REG_OFFSET_NAME(regs[8]),
 224         REG_OFFSET_NAME(regs[9]),
 225 #if defined(__CSKYABIV2__)
 226         REG_OFFSET_NAME(exregs[0]),
 227         REG_OFFSET_NAME(exregs[1]),
 228         REG_OFFSET_NAME(exregs[2]),
 229         REG_OFFSET_NAME(exregs[3]),
 230         REG_OFFSET_NAME(exregs[4]),
 231         REG_OFFSET_NAME(exregs[5]),
 232         REG_OFFSET_NAME(exregs[6]),
 233         REG_OFFSET_NAME(exregs[7]),
 234         REG_OFFSET_NAME(exregs[8]),
 235         REG_OFFSET_NAME(exregs[9]),
 236         REG_OFFSET_NAME(exregs[10]),
 237         REG_OFFSET_NAME(exregs[11]),
 238         REG_OFFSET_NAME(exregs[12]),
 239         REG_OFFSET_NAME(exregs[13]),
 240         REG_OFFSET_NAME(exregs[14]),
 241         REG_OFFSET_NAME(rhi),
 242         REG_OFFSET_NAME(rlo),
 243         REG_OFFSET_NAME(dcsr),
 244 #endif
 245         REG_OFFSET_END,
 246 };
 247
 248 /**
 249  * regs_query_register_offset() - query register offset from its name
 250  * @name:       the name of a register
 251  *
 252  * regs_query_register_offset() returns the offset of a register in struct
 253  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 254  */
 255 int regs_query_register_offset(const char *name)
 256 {
 257         const struct pt_regs_offset *roff;
 258
 259         for (roff = regoffset_table; roff->name != NULL; roff++)
 260                 if (!strcmp(roff->name, name))
 261                         return roff->offset;
 262         return -EINVAL;
 263 }
 264
 265 /**
 266  * regs_within_kernel_stack() - check the address in the stack
 267  * @regs:      pt_regs which contains kernel stack pointer.
 268  * @addr:      address which is checked.
 269  *
 270  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 271  * If @addr is within the kernel stack, it returns true. If not, returns false.
 272  */
 273 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 274 {
 275         return (addr & ~(THREAD_SIZE - 1))  ==
 276                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 277 }
 278
 279 /**
 280  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 281  * @regs:       pt_regs which contains kernel stack pointer.
 282  * @n:          stack entry number.
 283  *
 284  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 285  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 286  * this returns 0.
 287  */
 288 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 289 {
 290         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 291
 292         addr += n;
 293         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 294                 return *addr;
 295         else
 296                 return 0;
 297 }
 298
 299 void ptrace_disable(struct task_struct *child)
 300 {
 301         singlestep_disable(child);
 302 }
 303
 304 long arch_ptrace(struct task_struct *child, long request,
 305                  unsigned long addr, unsigned long data)
 306 {
 307         long ret = -EIO;
 308
 309         switch (request) {
 310         default:
 311                 ret = ptrace_request(child, request, addr, data);
 312                 break;
 313         }
 314
 315         return ret;
 316 }
 317
 318 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 319 {
 320         if (test_thread_flag(TIF_SYSCALL_TRACE))
 321                 if (tracehook_report_syscall_entry(regs))
 322                         syscall_set_nr(current, regs, -1);
 323
 324         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 325                 trace_sys_enter(regs, syscall_get_nr(current, regs));
 326
 327         audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
 328 }
 329
 330 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 331 {
 332         audit_syscall_exit(regs);
 333
 334         if (test_thread_flag(TIF_SYSCALL_TRACE))
 335                 tracehook_report_syscall_exit(regs, 0);
 336
 337         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 338                 trace_sys_exit(regs, syscall_get_return_value(current, regs));
 339 }
 340
 341 extern void show_stack(struct task_struct *task, unsigned long *stack);
 342 void show_regs(struct pt_regs *fp)
 343 {
 344         unsigned long   *sp;
 345         unsigned char   *tp;
 346         int     i;
 347
 348         pr_info("\nCURRENT PROCESS:\n\n");
 349         pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
 350
 351         if (current->mm) {
 352                 pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 353                        (int) current->mm->start_code,
 354                        (int) current->mm->end_code,
 355                        (int) current->mm->start_data,
 356                        (int) current->mm->end_data,
 357                        (int) current->mm->end_data,
 358                        (int) current->mm->brk);
 359                 pr_info("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
 360                        (int) current->mm->start_stack,
 361                        (int) (((unsigned long) current) + 2 * PAGE_SIZE));
 362         }
 363
 364         pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
 365         pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
 366         pr_info("SP: 0x%08lx\n", (long)fp);
 367         pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
 368         pr_info("PSR: 0x%08lx\n", (long)fp->sr);
 369
 370         pr_info(" a0: 0x%08lx   a1: 0x%08lx   a2: 0x%08lx   a3: 0x%08lx\n",
 371                 fp->a0, fp->a1, fp->a2, fp->a3);
 372 #if defined(__CSKYABIV2__)
 373         pr_info(" r4: 0x%08lx   r5: 0x%08lx   r6: 0x%08lx   r7: 0x%08lx\n",
 374                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 375         pr_info(" r8: 0x%08lx   r9: 0x%08lx  r10: 0x%08lx  r11: 0x%08lx\n",
 376                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 377         pr_info("r12: 0x%08lx  r13: 0x%08lx  r15: 0x%08lx\n",
 378                 fp->regs[8], fp->regs[9], fp->lr);
 379         pr_info("r16: 0x%08lx  r17: 0x%08lx  r18: 0x%08lx  r19: 0x%08lx\n",
 380                 fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
 381         pr_info("r20: 0x%08lx  r21: 0x%08lx  r22: 0x%08lx  r23: 0x%08lx\n",
 382                 fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
 383         pr_info("r24: 0x%08lx  r25: 0x%08lx  r26: 0x%08lx  r27: 0x%08lx\n",
 384                 fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
 385         pr_info("r28: 0x%08lx  r29: 0x%08lx  r30: 0x%08lx  tls: 0x%08lx\n",
 386                 fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
 387         pr_info(" hi: 0x%08lx   lo: 0x%08lx\n",
 388                 fp->rhi, fp->rlo);
 389 #else
 390         pr_info(" r6: 0x%08lx   r7: 0x%08lx   r8: 0x%08lx   r9: 0x%08lx\n",
 391                 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
 392         pr_info("r10: 0x%08lx  r11: 0x%08lx  r12: 0x%08lx  r13: 0x%08lx\n",
 393                 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
 394         pr_info("r14: 0x%08lx   r1: 0x%08lx  r15: 0x%08lx\n",
 395                 fp->regs[8], fp->regs[9], fp->lr);
 396 #endif
 397
 398         pr_info("\nCODE:");
 399         tp = ((unsigned char *) fp->pc) - 0x20;
 400         tp += ((int)tp % 4) ? 2 : 0;
 401         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 402                 if ((i % 0x10) == 0)
 403                         pr_cont("\n%08x: ", (int) (tp + i));
 404                 pr_cont("%08x ", (int) *sp++);
 405         }
 406         pr_cont("\n");
 407
 408         pr_info("\nKERNEL STACK:");
 409         tp = ((unsigned char *) fp) - 0x40;
 410         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 411                 if ((i % 0x10) == 0)
 412                         pr_cont("\n%08x: ", (int) (tp + i));
 413                 pr_cont("%08x ", (int) *sp++);
 414         }
 415         pr_cont("\n");
 416
 417         show_stack(NULL, (unsigned long *)fp->regs[4]);
 418         return;
 419 }