arch/nds32/kernel/traps.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4 #include <linux/module.h>
   5 #include <linux/personality.h>
   6 #include <linux/kallsyms.h>
   7 #include <linux/hardirq.h>
   8 #include <linux/kdebug.h>
   9 #include <linux/sched/task_stack.h>
  10 #include <linux/uaccess.h>
  11 #include <linux/ftrace.h>
  12
  13 #include <asm/proc-fns.h>
  14 #include <asm/unistd.h>
  15 #include <asm/fpu.h>
  16
  17 #include <linux/ptrace.h>
  18 #include <nds32_intrinsic.h>
  19
  20 extern void show_pte(struct mm_struct *mm, unsigned long addr);
  21
  22 /*
  23  * Dump out the contents of some memory nicely...
  24  */
  25 void dump_mem(const char *lvl, unsigned long bottom, unsigned long top)
  26 {
  27         unsigned long first;
  28         mm_segment_t fs;
  29         int i;
  30
  31         /*
  32          * We need to switch to kernel mode so that we can use __get_user
  33          * to safely read from kernel space.  Note that we now dump the
  34          * code first, just in case the backtrace kills us.
  35          */
  36         fs = get_fs();
  37         set_fs(KERNEL_DS);
  38
  39         pr_emerg("%s(0x%08lx to 0x%08lx)\n", lvl, bottom, top);
  40
  41         for (first = bottom & ~31; first < top; first += 32) {
  42                 unsigned long p;
  43                 char str[sizeof(" 12345678") * 8 + 1];
  44
  45                 memset(str, ' ', sizeof(str));
  46                 str[sizeof(str) - 1] = '\0';
  47
  48                 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
  49                         if (p >= bottom && p < top) {
  50                                 unsigned long val;
  51                                 if (__get_user(val, (unsigned long *)p) == 0)
  52                                         sprintf(str + i * 9, " %08lx", val);
  53                                 else
  54                                         sprintf(str + i * 9, " ????????");
  55                         }
  56                 }
  57                 pr_emerg("%s%04lx:%s\n", lvl, first & 0xffff, str);
  58         }
  59
  60         set_fs(fs);
  61 }
  62
  63 EXPORT_SYMBOL(dump_mem);
  64
  65 static void dump_instr(struct pt_regs *regs)
  66 {
  67         unsigned long addr = instruction_pointer(regs);
  68         mm_segment_t fs;
  69         char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
  70         int i;
  71
  72         return;
  73         /*
  74          * We need to switch to kernel mode so that we can use __get_user
  75          * to safely read from kernel space.  Note that we now dump the
  76          * code first, just in case the backtrace kills us.
  77          */
  78         fs = get_fs();
  79         set_fs(KERNEL_DS);
  80
  81         pr_emerg("Code: ");
  82         for (i = -4; i < 1; i++) {
  83                 unsigned int val, bad;
  84
  85                 bad = __get_user(val, &((u32 *) addr)[i]);
  86
  87                 if (!bad) {
  88                         p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
  89                 } else {
  90                         p += sprintf(p, "bad PC value");
  91                         break;
  92                 }
  93         }
  94         pr_emerg("Code: %s\n", str);
  95
  96         set_fs(fs);
  97 }
  98
  99 #define LOOP_TIMES (100)
 100 static void __dump(struct task_struct *tsk, unsigned long *base_reg)
 101 {
 102         unsigned long ret_addr;
 103         int cnt = LOOP_TIMES, graph = 0;
 104         pr_emerg("Call Trace:\n");
 105         if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
 106                 while (!kstack_end(base_reg)) {
 107                         ret_addr = *base_reg++;
 108                         if (__kernel_text_address(ret_addr)) {
 109                                 ret_addr = ftrace_graph_ret_addr(
 110                                                 tsk, &graph, ret_addr, NULL);
 111                                 print_ip_sym(ret_addr);
 112                         }
 113                         if (--cnt < 0)
 114                                 break;
 115                 }
 116         } else {
 117                 while (!kstack_end((void *)base_reg) &&
 118                        !((unsigned long)base_reg & 0x3) &&
 119                        ((unsigned long)base_reg >= TASK_SIZE)) {
 120                         unsigned long next_fp;
 121                         ret_addr = base_reg[LP_OFFSET];
 122                         next_fp = base_reg[FP_OFFSET];
 123                         if (__kernel_text_address(ret_addr)) {
 124
 125                                 ret_addr = ftrace_graph_ret_addr(
 126                                                 tsk, &graph, ret_addr, NULL);
 127                                 print_ip_sym(ret_addr);
 128                         }
 129                         if (--cnt < 0)
 130                                 break;
 131                         base_reg = (unsigned long *)next_fp;
 132                 }
 133         }
 134         pr_emerg("\n");
 135 }
 136
 137 void show_stack(struct task_struct *tsk, unsigned long *sp)
 138 {
 139         unsigned long *base_reg;
 140
 141         if (!tsk)
 142                 tsk = current;
 143         if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
 144                 if (tsk != current)
 145                         base_reg = (unsigned long *)(tsk->thread.cpu_context.sp);
 146                 else
 147                         __asm__ __volatile__("\tori\t%0, $sp, #0\n":"=r"(base_reg));
 148         } else {
 149                 if (tsk != current)
 150                         base_reg = (unsigned long *)(tsk->thread.cpu_context.fp);
 151                 else
 152                         __asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(base_reg));
 153         }
 154         __dump(tsk, base_reg);
 155         barrier();
 156 }
 157
 158 DEFINE_SPINLOCK(die_lock);
 159
 160 /*
 161  * This function is protected against re-entrancy.
 162  */
 163 void die(const char *str, struct pt_regs *regs, int err)
 164 {
 165         struct task_struct *tsk = current;
 166         static int die_counter;
 167
 168         console_verbose();
 169         spin_lock_irq(&die_lock);
 170         bust_spinlocks(1);
 171
 172         pr_emerg("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
 173         print_modules();
 174         pr_emerg("CPU: %i\n", smp_processor_id());
 175         show_regs(regs);
 176         pr_emerg("Process %s (pid: %d, stack limit = 0x%p)\n",
 177                  tsk->comm, tsk->pid, end_of_stack(tsk));
 178
 179         if (!user_mode(regs) || in_interrupt()) {
 180                 dump_mem("Stack: ", regs->sp, (regs->sp + PAGE_SIZE) & PAGE_MASK);
 181                 dump_instr(regs);
 182                 dump_stack();
 183         }
 184
 185         bust_spinlocks(0);
 186         spin_unlock_irq(&die_lock);
 187         do_exit(SIGSEGV);
 188 }
 189
 190 EXPORT_SYMBOL(die);
 191
 192 void die_if_kernel(const char *str, struct pt_regs *regs, int err)
 193 {
 194         if (user_mode(regs))
 195                 return;
 196
 197         die(str, regs, err);
 198 }
 199
 200 int bad_syscall(int n, struct pt_regs *regs)
 201 {
 202         if (current->personality != PER_LINUX) {
 203                 send_sig(SIGSEGV, current, 1);
 204                 return regs->uregs[0];
 205         }
 206
 207         force_sig_fault(SIGILL, ILL_ILLTRP,
 208                         (void __user *)instruction_pointer(regs) - 4);
 209         die_if_kernel("Oops - bad syscall", regs, n);
 210         return regs->uregs[0];
 211 }
 212
 213 void __pte_error(const char *file, int line, unsigned long val)
 214 {
 215         pr_emerg("%s:%d: bad pte %08lx.\n", file, line, val);
 216 }
 217
 218 void __pmd_error(const char *file, int line, unsigned long val)
 219 {
 220         pr_emerg("%s:%d: bad pmd %08lx.\n", file, line, val);
 221 }
 222
 223 void __pgd_error(const char *file, int line, unsigned long val)
 224 {
 225         pr_emerg("%s:%d: bad pgd %08lx.\n", file, line, val);
 226 }
 227
 228 extern char *exception_vector, *exception_vector_end;
 229 void __init trap_init(void)
 230 {
 231         return;
 232 }
 233
 234 void __init early_trap_init(void)
 235 {
 236         unsigned long ivb = 0;
 237         unsigned long base = PAGE_OFFSET;
 238
 239         memcpy((unsigned long *)base, (unsigned long *)&exception_vector,
 240                ((unsigned long)&exception_vector_end -
 241                 (unsigned long)&exception_vector));
 242         ivb = __nds32__mfsr(NDS32_SR_IVB);
 243         /* Check platform support. */
 244         if (((ivb & IVB_mskNIVIC) >> IVB_offNIVIC) < 2)
 245                 panic
 246                     ("IVIC mode is not allowed on the platform with interrupt controller\n");
 247         __nds32__mtsr((ivb & ~IVB_mskESZ) | (IVB_valESZ16 << IVB_offESZ) |
 248                       IVB_BASE, NDS32_SR_IVB);
 249         __nds32__mtsr(INT_MASK_INITAIAL_VAL, NDS32_SR_INT_MASK);
 250
 251         /*
 252          * 0x800 = 128 vectors * 16byte.
 253          * It should be enough to flush a page.
 254          */
 255         cpu_cache_wbinval_page(base, true);
 256 }
 257
 258 static void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
 259 {
 260         struct task_struct *tsk = current;
 261
 262         tsk->thread.trap_no = ENTRY_DEBUG_RELATED;
 263         tsk->thread.error_code = error_code;
 264
 265         force_sig_fault(SIGTRAP, si_code,
 266                         (void __user *)instruction_pointer(regs));
 267 }
 268
 269 void do_debug_trap(unsigned long entry, unsigned long addr,
 270                    unsigned long type, struct pt_regs *regs)
 271 {
 272         if (notify_die(DIE_OOPS, "Oops", regs, addr, type, SIGTRAP)
 273             == NOTIFY_STOP)
 274                 return;
 275
 276         if (user_mode(regs)) {
 277                 /* trap_signal */
 278                 send_sigtrap(regs, 0, TRAP_BRKPT);
 279         } else {
 280                 /* kernel_trap */
 281                 if (!fixup_exception(regs))
 282                         die("unexpected kernel_trap", regs, 0);
 283         }
 284 }
 285
 286 void unhandled_interruption(struct pt_regs *regs)
 287 {
 288         pr_emerg("unhandled_interruption\n");
 289         show_regs(regs);
 290         if (!user_mode(regs))
 291                 do_exit(SIGKILL);
 292         force_sig(SIGKILL);
 293 }
 294
 295 void unhandled_exceptions(unsigned long entry, unsigned long addr,
 296                           unsigned long type, struct pt_regs *regs)
 297 {
 298         pr_emerg("Unhandled Exception: entry: %lx addr:%lx itype:%lx\n", entry,
 299                  addr, type);
 300         show_regs(regs);
 301         if (!user_mode(regs))
 302                 do_exit(SIGKILL);
 303         force_sig(SIGKILL);
 304 }
 305
 306 extern int do_page_fault(unsigned long entry, unsigned long addr,
 307                          unsigned int error_code, struct pt_regs *regs);
 308
 309 /*
 310  * 2:DEF dispatch for TLB MISC exception handler
 311 */
 312
 313 void do_dispatch_tlb_misc(unsigned long entry, unsigned long addr,
 314                           unsigned long type, struct pt_regs *regs)
 315 {
 316         type = type & (ITYPE_mskINST | ITYPE_mskETYPE);
 317         if ((type & ITYPE_mskETYPE) < 5) {
 318                 /* Permission exceptions */
 319                 do_page_fault(entry, addr, type, regs);
 320         } else
 321                 unhandled_exceptions(entry, addr, type, regs);
 322 }
 323
 324 void do_revinsn(struct pt_regs *regs)
 325 {
 326         pr_emerg("Reserved Instruction\n");
 327         show_regs(regs);
 328         if (!user_mode(regs))
 329                 do_exit(SIGILL);
 330         force_sig(SIGILL);
 331 }
 332
 333 #ifdef CONFIG_ALIGNMENT_TRAP
 334 extern int unalign_access_mode;
 335 extern int do_unaligned_access(unsigned long addr, struct pt_regs *regs);
 336 #endif
 337 void do_dispatch_general(unsigned long entry, unsigned long addr,
 338                          unsigned long itype, struct pt_regs *regs,
 339                          unsigned long oipc)
 340 {
 341         unsigned int swid = itype >> ITYPE_offSWID;
 342         unsigned long type = itype & (ITYPE_mskINST | ITYPE_mskETYPE);
 343         if (type == ETYPE_ALIGNMENT_CHECK) {
 344 #ifdef CONFIG_ALIGNMENT_TRAP
 345                 /* Alignment check */
 346                 if (user_mode(regs) && unalign_access_mode) {
 347                         int ret;
 348                         ret = do_unaligned_access(addr, regs);
 349
 350                         if (ret == 0)
 351                                 return;
 352
 353                         if (ret == -EFAULT)
 354                                 pr_emerg
 355                                     ("Unhandled unaligned access exception\n");
 356                 }
 357 #endif
 358                 do_page_fault(entry, addr, type, regs);
 359         } else if (type == ETYPE_RESERVED_INSTRUCTION) {
 360                 /* Reserved instruction */
 361                 do_revinsn(regs);
 362         } else if (type == ETYPE_COPROCESSOR) {
 363                 /* Coprocessor */
 364 #if IS_ENABLED(CONFIG_FPU)
 365                 unsigned int fucop_exist = __nds32__mfsr(NDS32_SR_FUCOP_EXIST);
 366                 unsigned int cpid = ((itype & ITYPE_mskCPID) >> ITYPE_offCPID);
 367
 368                 if ((cpid == FPU_CPID) &&
 369                     (fucop_exist & FUCOP_EXIST_mskCP0ISFPU)) {
 370                         unsigned int subtype = (itype & ITYPE_mskSTYPE);
 371
 372                         if (true == do_fpu_exception(subtype, regs))
 373                                 return;
 374                 }
 375 #endif
 376                 unhandled_exceptions(entry, addr, type, regs);
 377         } else if (type == ETYPE_TRAP && swid == SWID_RAISE_INTERRUPT_LEVEL) {
 378                 /* trap, used on v3 EDM target debugging workaround */
 379                 /*
 380                  * DIPC(OIPC) is passed as parameter before
 381                  * interrupt is enabled, so the DIPC will not be corrupted
 382                  * even though interrupts are coming in
 383                  */
 384                 /*
 385                  * 1. update ipc
 386                  * 2. update pt_regs ipc with oipc
 387                  * 3. update pt_regs ipsw (clear DEX)
 388                  */
 389                 __asm__ volatile ("mtsr %0, $IPC\n\t"::"r" (oipc));
 390                 regs->ipc = oipc;
 391                 if (regs->pipsw & PSW_mskDEX) {
 392                         pr_emerg
 393                             ("Nested Debug exception is possibly happened\n");
 394                         pr_emerg("ipc:%08x pipc:%08x\n",
 395                                  (unsigned int)regs->ipc,
 396                                  (unsigned int)regs->pipc);
 397                 }
 398                 do_debug_trap(entry, addr, itype, regs);
 399                 regs->ipsw &= ~PSW_mskDEX;
 400         } else
 401                 unhandled_exceptions(entry, addr, type, regs);
 402 }