arch/m32r/kernel/traps.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/arch/m32r/kernel/traps.c
   4  *
   5  *  Copyright (C) 2001, 2002  Hirokazu Takata, Hiroyuki Kondo,
   6  *                            Hitoshi Yamamoto
   7  */
   8
   9 /*
  10  * 'traps.c' handles hardware traps and faults after we have saved some
  11  * state in 'entry.S'.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/kallsyms.h>
  16 #include <linux/stddef.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/sched/debug.h>
  19 #include <linux/sched/task_stack.h>
  20 #include <linux/mm.h>
  21 #include <linux/cpu.h>
  22
  23 #include <asm/page.h>
  24 #include <asm/processor.h>
  25
  26 #include <linux/uaccess.h>
  27 #include <asm/io.h>
  28 #include <linux/atomic.h>
  29
  30 #include <asm/smp.h>
  31
  32 #include <linux/module.h>
  33
  34 asmlinkage void alignment_check(void);
  35 asmlinkage void ei_handler(void);
  36 asmlinkage void rie_handler(void);
  37 asmlinkage void debug_trap(void);
  38 asmlinkage void cache_flushing_handler(void);
  39 asmlinkage void ill_trap(void);
  40
  41 #ifdef CONFIG_SMP
  42 extern void smp_reschedule_interrupt(void);
  43 extern void smp_invalidate_interrupt(void);
  44 extern void smp_call_function_interrupt(void);
  45 extern void smp_ipi_timer_interrupt(void);
  46 extern void smp_flush_cache_all_interrupt(void);
  47 extern void smp_call_function_single_interrupt(void);
  48
  49 /*
  50  * for Boot AP function
  51  */
  52 asm (
  53         "       .section .eit_vector4,\"ax\"    \n"
  54         "       .global _AP_RE                  \n"
  55         "       .global startup_AP              \n"
  56         "_AP_RE:                                \n"
  57         "       .fill 32, 4, 0                  \n"
  58         "_AP_EI: bra    startup_AP              \n"
  59         "       .previous                       \n"
  60 );
  61 #endif  /* CONFIG_SMP */
  62
  63 extern unsigned long    eit_vector[];
  64 #define BRA_INSN(func, entry)   \
  65         ((unsigned long)func - (unsigned long)eit_vector - entry*4)/4 \
  66         + 0xff000000UL
  67
  68 static void set_eit_vector_entries(void)
  69 {
  70         extern void default_eit_handler(void);
  71         extern void system_call(void);
  72         extern void pie_handler(void);
  73         extern void ace_handler(void);
  74         extern void tme_handler(void);
  75         extern void _flush_cache_copyback_all(void);
  76
  77         eit_vector[0] = 0xd0c00001; /* seth r0, 0x01 */
  78         eit_vector[1] = BRA_INSN(default_eit_handler, 1);
  79         eit_vector[4] = 0xd0c00010; /* seth r0, 0x10 */
  80         eit_vector[5] = BRA_INSN(default_eit_handler, 5);
  81         eit_vector[8] = BRA_INSN(rie_handler, 8);
  82         eit_vector[12] = BRA_INSN(alignment_check, 12);
  83         eit_vector[16] = BRA_INSN(ill_trap, 16);
  84         eit_vector[17] = BRA_INSN(debug_trap, 17);
  85         eit_vector[18] = BRA_INSN(system_call, 18);
  86         eit_vector[19] = BRA_INSN(ill_trap, 19);
  87         eit_vector[20] = BRA_INSN(ill_trap, 20);
  88         eit_vector[21] = BRA_INSN(ill_trap, 21);
  89         eit_vector[22] = BRA_INSN(ill_trap, 22);
  90         eit_vector[23] = BRA_INSN(ill_trap, 23);
  91         eit_vector[24] = BRA_INSN(ill_trap, 24);
  92         eit_vector[25] = BRA_INSN(ill_trap, 25);
  93         eit_vector[26] = BRA_INSN(ill_trap, 26);
  94         eit_vector[27] = BRA_INSN(ill_trap, 27);
  95         eit_vector[28] = BRA_INSN(cache_flushing_handler, 28);
  96         eit_vector[29] = BRA_INSN(ill_trap, 29);
  97         eit_vector[30] = BRA_INSN(ill_trap, 30);
  98         eit_vector[31] = BRA_INSN(ill_trap, 31);
  99         eit_vector[32] = BRA_INSN(ei_handler, 32);
 100         eit_vector[64] = BRA_INSN(pie_handler, 64);
 101 #ifdef CONFIG_MMU
 102         eit_vector[68] = BRA_INSN(ace_handler, 68);
 103         eit_vector[72] = BRA_INSN(tme_handler, 72);
 104 #endif /* CONFIG_MMU */
 105 #ifdef CONFIG_SMP
 106         eit_vector[184] = (unsigned long)smp_reschedule_interrupt;
 107         eit_vector[185] = (unsigned long)smp_invalidate_interrupt;
 108         eit_vector[186] = (unsigned long)smp_call_function_interrupt;
 109         eit_vector[187] = (unsigned long)smp_ipi_timer_interrupt;
 110         eit_vector[188] = (unsigned long)smp_flush_cache_all_interrupt;
 111         eit_vector[189] = 0;    /* CPU_BOOT_IPI */
 112         eit_vector[190] = (unsigned long)smp_call_function_single_interrupt;
 113         eit_vector[191] = 0;
 114 #endif
 115         _flush_cache_copyback_all();
 116 }
 117
 118 void __init trap_init(void)
 119 {
 120         set_eit_vector_entries();
 121
 122         /*
 123          * Should be a barrier for any external CPU state.
 124          */
 125         cpu_init();
 126 }
 127
 128 static int kstack_depth_to_print = 24;
 129
 130 static void show_trace(struct task_struct *task, unsigned long *stack)
 131 {
 132         unsigned long addr;
 133
 134         if (!stack)
 135                 stack = (unsigned long*)&stack;
 136
 137         printk("Call Trace: ");
 138         while (!kstack_end(stack)) {
 139                 addr = *stack++;
 140                 if (__kernel_text_address(addr))
 141                         printk("[<%08lx>] %pSR\n", addr, (void *)addr);
 142         }
 143         printk("\n");
 144 }
 145
 146 void show_stack(struct task_struct *task, unsigned long *sp)
 147 {
 148         unsigned long  *stack;
 149         int  i;
 150
 151         /*
 152          * debugging aid: "show_stack(NULL);" prints the
 153          * back trace for this cpu.
 154          */
 155
 156         if(sp==NULL) {
 157                 if (task)
 158                         sp = (unsigned long *)task->thread.sp;
 159                 else
 160                         sp=(unsigned long*)&sp;
 161         }
 162
 163         stack = sp;
 164         for(i=0; i < kstack_depth_to_print; i++) {
 165                 if (kstack_end(stack))
 166                         break;
 167                 if (i && ((i % 4) == 0))
 168                         printk("\n       ");
 169                 printk("%08lx ", *stack++);
 170         }
 171         printk("\n");
 172         show_trace(task, sp);
 173 }
 174
 175 static void show_registers(struct pt_regs *regs)
 176 {
 177         int i = 0;
 178         int in_kernel = 1;
 179         unsigned long sp;
 180
 181         printk("CPU:    %d\n", smp_processor_id());
 182         show_regs(regs);
 183
 184         sp = (unsigned long) (1+regs);
 185         if (user_mode(regs)) {
 186                 in_kernel = 0;
 187                 sp = regs->spu;
 188                 printk("SPU: %08lx\n", sp);
 189         } else {
 190                 printk("SPI: %08lx\n", sp);
 191         }
 192         printk("Process %s (pid: %d, process nr: %d, stackpage=%08lx)",
 193                 current->comm, task_pid_nr(current), 0xffff & i, 4096+(unsigned long)current);
 194
 195         /*
 196          * When in-kernel, we also print out the stack and code at the
 197          * time of the fault..
 198          */
 199         if (in_kernel) {
 200                 printk("\nStack: ");
 201                 show_stack(current, (unsigned long*) sp);
 202
 203                 printk("\nCode: ");
 204                 if (regs->bpc < PAGE_OFFSET)
 205                         goto bad;
 206
 207                 for(i=0;i<20;i++) {
 208                         unsigned char c;
 209                         if (__get_user(c, &((unsigned char*)regs->bpc)[i])) {
 210 bad:
 211                                 printk(" Bad PC value.");
 212                                 break;
 213                         }
 214                         printk("%02x ", c);
 215                 }
 216         }
 217         printk("\n");
 218 }
 219
 220 static DEFINE_SPINLOCK(die_lock);
 221
 222 void die(const char * str, struct pt_regs * regs, long err)
 223 {
 224         console_verbose();
 225         spin_lock_irq(&die_lock);
 226         bust_spinlocks(1);
 227         printk("%s: %04lx\n", str, err & 0xffff);
 228         show_registers(regs);
 229         bust_spinlocks(0);
 230         spin_unlock_irq(&die_lock);
 231         do_exit(SIGSEGV);
 232 }
 233
 234 static __inline__ void die_if_kernel(const char * str,
 235         struct pt_regs * regs, long err)
 236 {
 237         if (!user_mode(regs))
 238                 die(str, regs, err);
 239 }
 240
 241 static __inline__ void do_trap(int trapnr, int signr, const char * str,
 242         struct pt_regs * regs, long error_code, siginfo_t *info)
 243 {
 244         if (user_mode(regs)) {
 245                 /* trap_signal */
 246                 struct task_struct *tsk = current;
 247                 tsk->thread.error_code = error_code;
 248                 tsk->thread.trap_no = trapnr;
 249                 if (info)
 250                         force_sig_info(signr, info, tsk);
 251                 else
 252                         force_sig(signr, tsk);
 253                 return;
 254         } else {
 255                 /* kernel_trap */
 256                 if (!fixup_exception(regs))
 257                         die(str, regs, error_code);
 258                 return;
 259         }
 260 }
 261
 262 #define DO_ERROR(trapnr, signr, str, name) \
 263 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 264 { \
 265         do_trap(trapnr, signr, NULL, regs, error_code, NULL); \
 266 }
 267
 268 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
 269 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 270 { \
 271         siginfo_t info; \
 272         info.si_signo = signr; \
 273         info.si_errno = 0; \
 274         info.si_code = sicode; \
 275         info.si_addr = (void __user *)siaddr; \
 276         do_trap(trapnr, signr, str, regs, error_code, &info); \
 277 }
 278
 279 DO_ERROR( 1, SIGTRAP, "debug trap", debug_trap)
 280 DO_ERROR_INFO(0x20, SIGILL,  "reserved instruction ", rie_handler, ILL_ILLOPC, regs->bpc)
 281 DO_ERROR_INFO(0x100, SIGILL,  "privileged instruction", pie_handler, ILL_PRVOPC, regs->bpc)
 282 DO_ERROR_INFO(-1, SIGILL,  "illegal trap", ill_trap, ILL_ILLTRP, regs->bpc)
 283
 284 extern int handle_unaligned_access(unsigned long, struct pt_regs *);
 285
 286 /* This code taken from arch/sh/kernel/traps.c */
 287 asmlinkage void do_alignment_check(struct pt_regs *regs, long error_code)
 288 {
 289         mm_segment_t oldfs;
 290         unsigned long insn;
 291         int tmp;
 292
 293         oldfs = get_fs();
 294
 295         if (user_mode(regs)) {
 296                 local_irq_enable();
 297                 current->thread.error_code = error_code;
 298                 current->thread.trap_no = 0x17;
 299
 300                 set_fs(USER_DS);
 301                 if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
 302                         set_fs(oldfs);
 303                         goto uspace_segv;
 304                 }
 305                 tmp = handle_unaligned_access(insn, regs);
 306                 set_fs(oldfs);
 307
 308                 if (!tmp)
 309                         return;
 310
 311         uspace_segv:
 312                 printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
 313                         "access\n", current->comm);
 314                 force_sig(SIGSEGV, current);
 315         } else {
 316                 set_fs(KERNEL_DS);
 317                 if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
 318                         set_fs(oldfs);
 319                         die("insn faulting in do_address_error", regs, 0);
 320                 }
 321                 handle_unaligned_access(insn, regs);
 322                 set_fs(oldfs);
 323         }
 324 }