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                    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         regs.sr = task_pt_regs(target)->sr;
 102 #ifdef CONFIG_CPU_HAS_HILO
 103         regs.dcsr = task_pt_regs(target)->dcsr;
 104 #endif
 105         task_thread_info(target)->tp_value = regs.tls;
 106
 107         *task_pt_regs(target) = regs;
 108
 109         return 0;
 110 }
 111
 112 static int fpr_get(struct task_struct *target,
 113                    const struct user_regset *regset,
 114                    struct membuf to)
 115 {
 116         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 117
 118 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 119         int i;
 120         struct user_fp tmp = *regs;
 121
 122         for (i = 0; i < 16; i++) {
 123                 tmp.vr[i*4] = regs->vr[i*2];
 124                 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
 125         }
 126
 127         for (i = 0; i < 32; i++)
 128                 tmp.vr[64 + i] = regs->vr[32 + i];
 129
 130         return membuf_write(&to, &tmp, sizeof(tmp));
 131 #else
 132         return membuf_write(&to, regs, sizeof(*regs));
 133 #endif
 134 }
 135
 136 static int fpr_set(struct task_struct *target,
 137                    const struct user_regset *regset,
 138                    unsigned int pos, unsigned int count,
 139                    const void *kbuf, const void __user *ubuf)
 140 {
 141         int ret;
 142         struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
 143
 144 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
 145         int i;
 146         struct user_fp tmp;
 147
 148         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
 149
 150         *regs = tmp;
 151
 152         for (i = 0; i < 16; i++) {
 153                 regs->vr[i*2] = tmp.vr[i*4];
 154                 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
 155         }
 156
 157         for (i = 0; i < 32; i++)
 158                 regs->vr[32 + i] = tmp.vr[64 + i];
 159 #else
 160         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 161 #endif
 162
 163         return ret;
 164 }
 165
 166 static const struct user_regset csky_regsets[] = {
 167         [REGSET_GPR] = {
 168                 .core_note_type = NT_PRSTATUS,
 169                 .n = sizeof(struct pt_regs) / sizeof(u32),
 170                 .size = sizeof(u32),
 171                 .align = sizeof(u32),
 172                 .regset_get = gpr_get,
 173                 .set = gpr_set,
 174         },
 175         [REGSET_FPR] = {
 176                 .core_note_type = NT_PRFPREG,
 177                 .n = sizeof(struct user_fp) / sizeof(u32),
 178                 .size = sizeof(u32),
 179                 .align = sizeof(u32),
 180                 .regset_get = fpr_get,
 181                 .set = fpr_set,
 182         },
 183 };
 184
 185 static const struct user_regset_view user_csky_view = {
 186         .name = "csky",
 187         .e_machine = ELF_ARCH,
 188         .regsets = csky_regsets,
 189         .n = ARRAY_SIZE(csky_regsets),
 190 };
 191
 192 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 193 {
 194         return &user_csky_view;
 195 }
 196
 197 struct pt_regs_offset {
 198         const char *name;
 199         int offset;
 200 };
 201
 202 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 203 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 204
 205 static const struct pt_regs_offset regoffset_table[] = {
 206         REG_OFFSET_NAME(tls),
 207         REG_OFFSET_NAME(lr),
 208         REG_OFFSET_NAME(pc),
 209         REG_OFFSET_NAME(sr),
 210         REG_OFFSET_NAME(usp),
 211         REG_OFFSET_NAME(orig_a0),
 212         REG_OFFSET_NAME(a0),
 213         REG_OFFSET_NAME(a1),
 214         REG_OFFSET_NAME(a2),
 215         REG_OFFSET_NAME(a3),
 216         REG_OFFSET_NAME(regs[0]),
 217         REG_OFFSET_NAME(regs[1]),
 218         REG_OFFSET_NAME(regs[2]),
 219         REG_OFFSET_NAME(regs[3]),
 220         REG_OFFSET_NAME(regs[4]),
 221         REG_OFFSET_NAME(regs[5]),
 222         REG_OFFSET_NAME(regs[6]),
 223         REG_OFFSET_NAME(regs[7]),
 224         REG_OFFSET_NAME(regs[8]),
 225         REG_OFFSET_NAME(regs[9]),
 226 #if defined(__CSKYABIV2__)
 227         REG_OFFSET_NAME(exregs[0]),
 228         REG_OFFSET_NAME(exregs[1]),
 229         REG_OFFSET_NAME(exregs[2]),
 230         REG_OFFSET_NAME(exregs[3]),
 231         REG_OFFSET_NAME(exregs[4]),
 232         REG_OFFSET_NAME(exregs[5]),
 233         REG_OFFSET_NAME(exregs[6]),
 234         REG_OFFSET_NAME(exregs[7]),
 235         REG_OFFSET_NAME(exregs[8]),
 236         REG_OFFSET_NAME(exregs[9]),
 237         REG_OFFSET_NAME(exregs[10]),
 238         REG_OFFSET_NAME(exregs[11]),
 239         REG_OFFSET_NAME(exregs[12]),
 240         REG_OFFSET_NAME(exregs[13]),
 241         REG_OFFSET_NAME(exregs[14]),
 242         REG_OFFSET_NAME(rhi),
 243         REG_OFFSET_NAME(rlo),
 244         REG_OFFSET_NAME(dcsr),
 245 #endif
 246         REG_OFFSET_END,
 247 };
 248
 249 /**
 250  * regs_query_register_offset() - query register offset from its name
 251  * @name:       the name of a register
 252  *
 253  * regs_query_register_offset() returns the offset of a register in struct
 254  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 255  */
 256 int regs_query_register_offset(const char *name)
 257 {
 258         const struct pt_regs_offset *roff;
 259
 260         for (roff = regoffset_table; roff->name != NULL; roff++)
 261                 if (!strcmp(roff->name, name))
 262                         return roff->offset;
 263         return -EINVAL;
 264 }
 265
 266 /**
 267  * regs_within_kernel_stack() - check the address in the stack
 268  * @regs:      pt_regs which contains kernel stack pointer.
 269  * @addr:      address which is checked.
 270  *
 271  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 272  * If @addr is within the kernel stack, it returns true. If not, returns false.
 273  */
 274 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 275 {
 276         return (addr & ~(THREAD_SIZE - 1))  ==
 277                 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 278 }
 279
 280 /**
 281  * regs_get_kernel_stack_nth() - get Nth entry of the stack
 282  * @regs:       pt_regs which contains kernel stack pointer.
 283  * @n:          stack entry number.
 284  *
 285  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 286  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
 287  * this returns 0.
 288  */
 289 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 290 {
 291         unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
 292
 293         addr += n;
 294         if (regs_within_kernel_stack(regs, (unsigned long)addr))
 295                 return *addr;
 296         else
 297                 return 0;
 298 }
 299
 300 void ptrace_disable(struct task_struct *child)
 301 {
 302         singlestep_disable(child);
 303 }
 304
 305 long arch_ptrace(struct task_struct *child, long request,
 306                  unsigned long addr, unsigned long data)
 307 {
 308         long ret = -EIO;
 309
 310         switch (request) {
 311         default:
 312                 ret = ptrace_request(child, request, addr, data);
 313                 break;
 314         }
 315
 316         return ret;
 317 }
 318
 319 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 320 {
 321         if (test_thread_flag(TIF_SYSCALL_TRACE))
 322                 if (tracehook_report_syscall_entry(regs))
 323                         return -1;
 324
 325         if (secure_computing() == -1)
 326                 return -1;
 327
 328         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 329                 trace_sys_enter(regs, syscall_get_nr(current, regs));
 330
 331         audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
 332         return 0;
 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 void show_regs(struct pt_regs *fp)
 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\n",
 395                 fp->regs[8], fp->regs[9]);
 396 #endif
 397
 398         return;
 399 }