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                    const char *loglvl)
 102 {
 103         unsigned long ret_addr;
 104         int cnt = LOOP_TIMES, graph = 0;
 105         printk("%sCall Trace:\n", loglvl);
 106         if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
 107                 while (!kstack_end(base_reg)) {
 108                         ret_addr = *base_reg++;
 109                         if (__kernel_text_address(ret_addr)) {
 110                                 ret_addr = ftrace_graph_ret_addr(
 111                                                 tsk, &graph, ret_addr, NULL);
 112                                 print_ip_sym(loglvl, ret_addr);
 113                         }
 114                         if (--cnt < 0)
 115                                 break;
 116                 }
 117         } else {
 118                 while (!kstack_end((void *)base_reg) &&
 119                        !((unsigned long)base_reg & 0x3) &&
 120                        ((unsigned long)base_reg >= TASK_SIZE)) {
 121                         unsigned long next_fp;
 122                         ret_addr = base_reg[LP_OFFSET];
 123                         next_fp = base_reg[FP_OFFSET];
 124                         if (__kernel_text_address(ret_addr)) {
 125
 126                                 ret_addr = ftrace_graph_ret_addr(
 127                                                 tsk, &graph, ret_addr, NULL);
 128                                 print_ip_sym(loglvl, ret_addr);
 129                         }
 130                         if (--cnt < 0)
 131                                 break;
 132                         base_reg = (unsigned long *)next_fp;
 133                 }
 134         }
 135         printk("%s\n", loglvl);
 136 }
 137
 138 void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
 139 {
 140         unsigned long *base_reg;
 141
 142         if (!tsk)
 143                 tsk = current;
 144         if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
 145                 if (tsk != current)
 146                         base_reg = (unsigned long *)(tsk->thread.cpu_context.sp);
 147                 else
 148                         __asm__ __volatile__("\tori\t%0, $sp, #0\n":"=r"(base_reg));
 149         } else {
 150                 if (tsk != current)
 151                         base_reg = (unsigned long *)(tsk->thread.cpu_context.fp);
 152                 else
 153                         __asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(base_reg));
 154         }
 155         __dump(tsk, base_reg, loglvl);
 156         barrier();
 157 }
 158
 159 DEFINE_SPINLOCK(die_lock);
 160
 161 /*
 162  * This function is protected against re-entrancy.
 163  */
 164 void die(const char *str, struct pt_regs *regs, int err)
 165 {
 166         struct task_struct *tsk = current;
 167         static int die_counter;
 168
 169         console_verbose();
 170         spin_lock_irq(&die_lock);
 171         bust_spinlocks(1);
 172
 173         pr_emerg("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
 174         print_modules();
 175         pr_emerg("CPU: %i\n", smp_processor_id());
 176         show_regs(regs);
 177         pr_emerg("Process %s (pid: %d, stack limit = 0x%p)\n",
 178                  tsk->comm, tsk->pid, end_of_stack(tsk));
 179
 180         if (!user_mode(regs) || in_interrupt()) {
 181                 dump_mem("Stack: ", regs->sp, (regs->sp + PAGE_SIZE) & PAGE_MASK);
 182                 dump_instr(regs);
 183                 dump_stack();
 184         }
 185
 186         bust_spinlocks(0);
 187         spin_unlock_irq(&die_lock);
 188         do_exit(SIGSEGV);
 189 }
 190
 191 EXPORT_SYMBOL(die);
 192
 193 void die_if_kernel(const char *str, struct pt_regs *regs, int err)
 194 {
 195         if (user_mode(regs))
 196                 return;
 197
 198         die(str, regs, err);
 199 }
 200
 201 int bad_syscall(int n, struct pt_regs *regs)
 202 {
 203         if (current->personality != PER_LINUX) {
 204                 send_sig(SIGSEGV, current, 1);
 205                 return regs->uregs[0];
 206         }
 207
 208         force_sig_fault(SIGILL, ILL_ILLTRP,
 209                         (void __user *)instruction_pointer(regs) - 4);
 210         die_if_kernel("Oops - bad syscall", regs, n);
 211         return regs->uregs[0];
 212 }
 213
 214 void __pte_error(const char *file, int line, unsigned long val)
 215 {
 216         pr_emerg("%s:%d: bad pte %08lx.\n", file, line, val);
 217 }
 218
 219 void __pmd_error(const char *file, int line, unsigned long val)
 220 {
 221         pr_emerg("%s:%d: bad pmd %08lx.\n", file, line, val);
 222 }
 223
 224 void __pgd_error(const char *file, int line, unsigned long val)
 225 {
 226         pr_emerg("%s:%d: bad pgd %08lx.\n", file, line, val);
 227 }
 228
 229 extern char *exception_vector, *exception_vector_end;
 230 void __init trap_init(void)
 231 {
 232         return;
 233 }
 234
 235 void __init early_trap_init(void)
 236 {
 237         unsigned long ivb = 0;
 238         unsigned long base = PAGE_OFFSET;
 239
 240         memcpy((unsigned long *)base, (unsigned long *)&exception_vector,
 241                ((unsigned long)&exception_vector_end -
 242                 (unsigned long)&exception_vector));
 243         ivb = __nds32__mfsr(NDS32_SR_IVB);
 244         /* Check platform support. */
 245         if (((ivb & IVB_mskNIVIC) >> IVB_offNIVIC) < 2)
 246                 panic
 247                     ("IVIC mode is not allowed on the platform with interrupt controller\n");
 248         __nds32__mtsr((ivb & ~IVB_mskESZ) | (IVB_valESZ16 << IVB_offESZ) |
 249                       IVB_BASE, NDS32_SR_IVB);
 250         __nds32__mtsr(INT_MASK_INITAIAL_VAL, NDS32_SR_INT_MASK);
 251
 252         /*
 253          * 0x800 = 128 vectors * 16byte.
 254          * It should be enough to flush a page.
 255          */
 256         cpu_cache_wbinval_page(base, true);
 257 }
 258
 259 static void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
 260 {
 261         struct task_struct *tsk = current;
 262
 263         tsk->thread.trap_no = ENTRY_DEBUG_RELATED;
 264         tsk->thread.error_code = error_code;
 265
 266         force_sig_fault(SIGTRAP, si_code,
 267                         (void __user *)instruction_pointer(regs));
 268 }
 269
 270 void do_debug_trap(unsigned long entry, unsigned long addr,
 271                    unsigned long type, struct pt_regs *regs)
 272 {
 273         if (notify_die(DIE_OOPS, "Oops", regs, addr, type, SIGTRAP)
 274             == NOTIFY_STOP)
 275                 return;
 276
 277         if (user_mode(regs)) {
 278                 /* trap_signal */
 279                 send_sigtrap(regs, 0, TRAP_BRKPT);
 280         } else {
 281                 /* kernel_trap */
 282                 if (!fixup_exception(regs))
 283                         die("unexpected kernel_trap", regs, 0);
 284         }
 285 }
 286
 287 void unhandled_interruption(struct pt_regs *regs)
 288 {
 289         pr_emerg("unhandled_interruption\n");
 290         show_regs(regs);
 291         if (!user_mode(regs))
 292                 do_exit(SIGKILL);
 293         force_sig(SIGKILL);
 294 }
 295
 296 void unhandled_exceptions(unsigned long entry, unsigned long addr,
 297                           unsigned long type, struct pt_regs *regs)
 298 {
 299         pr_emerg("Unhandled Exception: entry: %lx addr:%lx itype:%lx\n", entry,
 300                  addr, type);
 301         show_regs(regs);
 302         if (!user_mode(regs))
 303                 do_exit(SIGKILL);
 304         force_sig(SIGKILL);
 305 }
 306
 307 extern int do_page_fault(unsigned long entry, unsigned long addr,
 308                          unsigned int error_code, struct pt_regs *regs);
 309
 310 /*
 311  * 2:DEF dispatch for TLB MISC exception handler
 312 */
 313
 314 void do_dispatch_tlb_misc(unsigned long entry, unsigned long addr,
 315                           unsigned long type, struct pt_regs *regs)
 316 {
 317         type = type & (ITYPE_mskINST | ITYPE_mskETYPE);
 318         if ((type & ITYPE_mskETYPE) < 5) {
 319                 /* Permission exceptions */
 320                 do_page_fault(entry, addr, type, regs);
 321         } else
 322                 unhandled_exceptions(entry, addr, type, regs);
 323 }
 324
 325 void do_revinsn(struct pt_regs *regs)
 326 {
 327         pr_emerg("Reserved Instruction\n");
 328         show_regs(regs);
 329         if (!user_mode(regs))
 330                 do_exit(SIGILL);
 331         force_sig(SIGILL);
 332 }
 333
 334 #ifdef CONFIG_ALIGNMENT_TRAP
 335 extern int unalign_access_mode;
 336 extern int do_unaligned_access(unsigned long addr, struct pt_regs *regs);
 337 #endif
 338 void do_dispatch_general(unsigned long entry, unsigned long addr,
 339                          unsigned long itype, struct pt_regs *regs,
 340                          unsigned long oipc)
 341 {
 342         unsigned int swid = itype >> ITYPE_offSWID;
 343         unsigned long type = itype & (ITYPE_mskINST | ITYPE_mskETYPE);
 344         if (type == ETYPE_ALIGNMENT_CHECK) {
 345 #ifdef CONFIG_ALIGNMENT_TRAP
 346                 /* Alignment check */
 347                 if (user_mode(regs) && unalign_access_mode) {
 348                         int ret;
 349                         ret = do_unaligned_access(addr, regs);
 350
 351                         if (ret == 0)
 352                                 return;
 353
 354                         if (ret == -EFAULT)
 355                                 pr_emerg
 356                                     ("Unhandled unaligned access exception\n");
 357                 }
 358 #endif
 359                 do_page_fault(entry, addr, type, regs);
 360         } else if (type == ETYPE_RESERVED_INSTRUCTION) {
 361                 /* Reserved instruction */
 362                 do_revinsn(regs);
 363         } else if (type == ETYPE_COPROCESSOR) {
 364                 /* Coprocessor */
 365 #if IS_ENABLED(CONFIG_FPU)
 366                 unsigned int fucop_exist = __nds32__mfsr(NDS32_SR_FUCOP_EXIST);
 367                 unsigned int cpid = ((itype & ITYPE_mskCPID) >> ITYPE_offCPID);
 368
 369                 if ((cpid == FPU_CPID) &&
 370                     (fucop_exist & FUCOP_EXIST_mskCP0ISFPU)) {
 371                         unsigned int subtype = (itype & ITYPE_mskSTYPE);
 372
 373                         if (true == do_fpu_exception(subtype, regs))
 374                                 return;
 375                 }
 376 #endif
 377                 unhandled_exceptions(entry, addr, type, regs);
 378         } else if (type == ETYPE_TRAP && swid == SWID_RAISE_INTERRUPT_LEVEL) {
 379                 /* trap, used on v3 EDM target debugging workaround */
 380                 /*
 381                  * DIPC(OIPC) is passed as parameter before
 382                  * interrupt is enabled, so the DIPC will not be corrupted
 383                  * even though interrupts are coming in
 384                  */
 385                 /*
 386                  * 1. update ipc
 387                  * 2. update pt_regs ipc with oipc
 388                  * 3. update pt_regs ipsw (clear DEX)
 389                  */
 390                 __asm__ volatile ("mtsr %0, $IPC\n\t"::"r" (oipc));
 391                 regs->ipc = oipc;
 392                 if (regs->pipsw & PSW_mskDEX) {
 393                         pr_emerg
 394                             ("Nested Debug exception is possibly happened\n");
 395                         pr_emerg("ipc:%08x pipc:%08x\n",
 396                                  (unsigned int)regs->ipc,
 397                                  (unsigned int)regs->pipc);
 398                 }
 399                 do_debug_trap(entry, addr, itype, regs);
 400                 regs->ipsw &= ~PSW_mskDEX;
 401         } else
 402                 unhandled_exceptions(entry, addr, type, regs);
 403 }