arch/cris/arch-v32/kernel/traps.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2003-2006, Axis Communications AB.
   4  */
   5
   6 #include <linux/ptrace.h>
   7 #include <linux/extable.h>
   8 #include <linux/uaccess.h>
   9 #include <linux/sched/debug.h>
  10
  11 #include <hwregs/supp_reg.h>
  12 #include <hwregs/intr_vect_defs.h>
  13 #include <asm/irq.h>
  14
  15 void show_registers(struct pt_regs *regs)
  16 {
  17         /*
  18          * It's possible to use either the USP register or current->thread.usp.
  19          * USP might not correspond to the current process for all cases this
  20          * function is called, and current->thread.usp isn't up to date for the
  21          * current process. Experience shows that using USP is the way to go.
  22          */
  23         unsigned long usp = rdusp();
  24         unsigned long d_mmu_cause;
  25         unsigned long i_mmu_cause;
  26
  27         printk("CPU: %d\n", smp_processor_id());
  28
  29         printk("ERP: %08lx SRP: %08lx  CCS: %08lx USP: %08lx MOF: %08lx\n",
  30                regs->erp, regs->srp, regs->ccs, usp, regs->mof);
  31
  32         printk(" r0: %08lx  r1: %08lx   r2: %08lx  r3: %08lx\n",
  33                regs->r0, regs->r1, regs->r2, regs->r3);
  34
  35         printk(" r4: %08lx  r5: %08lx   r6: %08lx  r7: %08lx\n",
  36                regs->r4, regs->r5, regs->r6, regs->r7);
  37
  38         printk(" r8: %08lx  r9: %08lx  r10: %08lx r11: %08lx\n",
  39                regs->r8, regs->r9, regs->r10, regs->r11);
  40
  41         printk("r12: %08lx r13: %08lx oR10: %08lx acr: %08lx\n",
  42                regs->r12, regs->r13, regs->orig_r10, regs->acr);
  43
  44         printk(" sp: %08lx\n", (unsigned long)regs);
  45
  46         SUPP_BANK_SEL(BANK_IM);
  47         SUPP_REG_RD(RW_MM_CAUSE, i_mmu_cause);
  48
  49         SUPP_BANK_SEL(BANK_DM);
  50         SUPP_REG_RD(RW_MM_CAUSE, d_mmu_cause);
  51
  52         printk("       Data MMU Cause: %08lx\n", d_mmu_cause);
  53         printk("Instruction MMU Cause: %08lx\n", i_mmu_cause);
  54
  55         printk("Process %s (pid: %d, stackpage=%08lx)\n",
  56                current->comm, current->pid, (unsigned long)current);
  57
  58         /*
  59          * When in-kernel, we also print out the stack and code at the
  60          * time of the fault..
  61          */
  62         if (!user_mode(regs)) {
  63                 int i;
  64
  65                 show_stack(NULL, (unsigned long *)usp);
  66
  67                 /*
  68                  * If the previous stack-dump wasn't a kernel one, dump the
  69                  * kernel stack now.
  70                  */
  71                 if (usp != 0)
  72                         show_stack(NULL, NULL);
  73
  74                 printk("\nCode: ");
  75
  76                 if (regs->erp < PAGE_OFFSET)
  77                         goto bad_value;
  78
  79                 /*
  80                  * Quite often the value at regs->erp doesn't point to the
  81                  * interesting instruction, which often is the previous
  82                  * instruction. So dump at an offset large enough that the
  83                  * instruction decoding should be in sync at the interesting
  84                  * point, but small enough to fit on a row. The regs->erp
  85                  * location is pointed out in a ksymoops-friendly way by
  86                  * wrapping the byte for that address in parenthesises.
  87                  */
  88                 for (i = -12; i < 12; i++) {
  89                         unsigned char c;
  90
  91                         if (__get_user(c, &((unsigned char *)regs->erp)[i])) {
  92 bad_value:
  93                                 printk(" Bad IP value.");
  94                                 break;
  95                         }
  96
  97                         if (i == 0)
  98                                 printk("(%02x) ", c);
  99                         else
 100                                 printk("%02x ", c);
 101                 }
 102                 printk("\n");
 103         }
 104 }
 105
 106 void arch_enable_nmi(void)
 107 {
 108         unsigned long flags;
 109
 110         local_save_flags(flags);
 111         flags |= (1 << 30); /* NMI M flag is at bit 30 */
 112         local_irq_restore(flags);
 113 }
 114
 115 extern void (*nmi_handler)(struct pt_regs *);
 116 void handle_nmi(struct pt_regs *regs)
 117 {
 118 #ifdef CONFIG_ETRAXFS
 119         reg_intr_vect_r_nmi r;
 120 #endif
 121
 122         if (nmi_handler)
 123                 nmi_handler(regs);
 124
 125 #ifdef CONFIG_ETRAXFS
 126         /* Wait until nmi is no longer active. */
 127         do {
 128                 r = REG_RD(intr_vect, regi_irq, r_nmi);
 129         } while (r.ext == regk_intr_vect_on);
 130 #endif
 131 }
 132
 133
 134 #ifdef CONFIG_BUG
 135 extern void die_if_kernel(const char *str, struct pt_regs *regs, long err);
 136
 137 /* Copy of the regs at BUG() time.  */
 138 struct pt_regs BUG_regs;
 139
 140 void do_BUG(char *file, unsigned int line)
 141 {
 142         printk("kernel BUG at %s:%d!\n", file, line);
 143         die_if_kernel("Oops", &BUG_regs, 0);
 144 }
 145 EXPORT_SYMBOL(do_BUG);
 146
 147 void fixup_BUG(struct pt_regs *regs)
 148 {
 149         BUG_regs = *regs;
 150
 151 #ifdef CONFIG_DEBUG_BUGVERBOSE
 152         /*
 153          * Fixup the BUG arguments through exception handlers.
 154          */
 155         {
 156                 const struct exception_table_entry *fixup;
 157
 158                 /*
 159                  * ERP points at the "break 14" + 2, compensate for the 2
 160                  * bytes.
 161                  */
 162                 fixup = search_exception_tables(instruction_pointer(regs) - 2);
 163                 if (fixup) {
 164                         /* Adjust the instruction pointer in the stackframe. */
 165                         instruction_pointer(regs) = fixup->fixup;
 166                         arch_fixup(regs);
 167                 }
 168         }
 169 #else
 170         /* Dont try to lookup the filename + line, just dump regs.  */
 171         do_BUG("unknown", 0);
 172 #endif
 173 }
 174
 175 /*
 176  * Break 14 handler. Save regs and jump into the fixup_BUG.
 177  */
 178 __asm__  ( ".text\n\t"
 179            ".global breakh_BUG\n\t"
 180            "breakh_BUG:\n\t"
 181            SAVE_ALL
 182            KGDB_FIXUP
 183            "move.d $sp, $r10\n\t"
 184            "jsr fixup_BUG\n\t"
 185            "nop\n\t"
 186            "jump ret_from_intr\n\t"
 187            "nop\n\t");
 188
 189
 190 #ifdef CONFIG_DEBUG_BUGVERBOSE
 191 void
 192 handle_BUG(struct pt_regs *regs)
 193 {
 194 }
 195 #endif
 196 #endif