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 abort(void)
 119 {
 120         BUG();
 121
 122         /* if that doesn't kill us, halt */
 123         panic("Oops failed to kill thread");
 124 }
 125
 126 void __init trap_init(void)
 127 {
 128         set_eit_vector_entries();
 129
 130         /*
 131          * Should be a barrier for any external CPU state.
 132          */
 133         cpu_init();
 134 }
 135
 136 static int kstack_depth_to_print = 24;
 137
 138 static void show_trace(struct task_struct *task, unsigned long *stack)
 139 {
 140         unsigned long addr;
 141
 142         if (!stack)
 143                 stack = (unsigned long*)&stack;
 144
 145         printk("Call Trace: ");
 146         while (!kstack_end(stack)) {
 147                 addr = *stack++;
 148                 if (__kernel_text_address(addr))
 149                         printk("[<%08lx>] %pSR\n", addr, (void *)addr);
 150         }
 151         printk("\n");
 152 }
 153
 154 void show_stack(struct task_struct *task, unsigned long *sp)
 155 {
 156         unsigned long  *stack;
 157         int  i;
 158
 159         /*
 160          * debugging aid: "show_stack(NULL);" prints the
 161          * back trace for this cpu.
 162          */
 163
 164         if(sp==NULL) {
 165                 if (task)
 166                         sp = (unsigned long *)task->thread.sp;
 167                 else
 168                         sp=(unsigned long*)&sp;
 169         }
 170
 171         stack = sp;
 172         for(i=0; i < kstack_depth_to_print; i++) {
 173                 if (kstack_end(stack))
 174                         break;
 175                 if (i && ((i % 4) == 0))
 176                         printk("\n       ");
 177                 printk("%08lx ", *stack++);
 178         }
 179         printk("\n");
 180         show_trace(task, sp);
 181 }
 182
 183 static void show_registers(struct pt_regs *regs)
 184 {
 185         int i = 0;
 186         int in_kernel = 1;
 187         unsigned long sp;
 188
 189         printk("CPU:    %d\n", smp_processor_id());
 190         show_regs(regs);
 191
 192         sp = (unsigned long) (1+regs);
 193         if (user_mode(regs)) {
 194                 in_kernel = 0;
 195                 sp = regs->spu;
 196                 printk("SPU: %08lx\n", sp);
 197         } else {
 198                 printk("SPI: %08lx\n", sp);
 199         }
 200         printk("Process %s (pid: %d, process nr: %d, stackpage=%08lx)",
 201                 current->comm, task_pid_nr(current), 0xffff & i, 4096+(unsigned long)current);
 202
 203         /*
 204          * When in-kernel, we also print out the stack and code at the
 205          * time of the fault..
 206          */
 207         if (in_kernel) {
 208                 printk("\nStack: ");
 209                 show_stack(current, (unsigned long*) sp);
 210
 211                 printk("\nCode: ");
 212                 if (regs->bpc < PAGE_OFFSET)
 213                         goto bad;
 214
 215                 for(i=0;i<20;i++) {
 216                         unsigned char c;
 217                         if (__get_user(c, &((unsigned char*)regs->bpc)[i])) {
 218 bad:
 219                                 printk(" Bad PC value.");
 220                                 break;
 221                         }
 222                         printk("%02x ", c);
 223                 }
 224         }
 225         printk("\n");
 226 }
 227
 228 static DEFINE_SPINLOCK(die_lock);
 229
 230 void die(const char * str, struct pt_regs * regs, long err)
 231 {
 232         console_verbose();
 233         spin_lock_irq(&die_lock);
 234         bust_spinlocks(1);
 235         printk("%s: %04lx\n", str, err & 0xffff);
 236         show_registers(regs);
 237         bust_spinlocks(0);
 238         spin_unlock_irq(&die_lock);
 239         do_exit(SIGSEGV);
 240 }
 241
 242 static __inline__ void die_if_kernel(const char * str,
 243         struct pt_regs * regs, long err)
 244 {
 245         if (!user_mode(regs))
 246                 die(str, regs, err);
 247 }
 248
 249 static __inline__ void do_trap(int trapnr, int signr, const char * str,
 250         struct pt_regs * regs, long error_code, siginfo_t *info)
 251 {
 252         if (user_mode(regs)) {
 253                 /* trap_signal */
 254                 struct task_struct *tsk = current;
 255                 tsk->thread.error_code = error_code;
 256                 tsk->thread.trap_no = trapnr;
 257                 if (info)
 258                         force_sig_info(signr, info, tsk);
 259                 else
 260                         force_sig(signr, tsk);
 261                 return;
 262         } else {
 263                 /* kernel_trap */
 264                 if (!fixup_exception(regs))
 265                         die(str, regs, error_code);
 266                 return;
 267         }
 268 }
 269
 270 #define DO_ERROR(trapnr, signr, str, name) \
 271 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 272 { \
 273         do_trap(trapnr, signr, NULL, regs, error_code, NULL); \
 274 }
 275
 276 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
 277 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 278 { \
 279         siginfo_t info; \
 280         info.si_signo = signr; \
 281         info.si_errno = 0; \
 282         info.si_code = sicode; \
 283         info.si_addr = (void __user *)siaddr; \
 284         do_trap(trapnr, signr, str, regs, error_code, &info); \
 285 }
 286
 287 DO_ERROR( 1, SIGTRAP, "debug trap", debug_trap)
 288 DO_ERROR_INFO(0x20, SIGILL,  "reserved instruction ", rie_handler, ILL_ILLOPC, regs->bpc)
 289 DO_ERROR_INFO(0x100, SIGILL,  "privileged instruction", pie_handler, ILL_PRVOPC, regs->bpc)
 290 DO_ERROR_INFO(-1, SIGILL,  "illegal trap", ill_trap, ILL_ILLTRP, regs->bpc)
 291
 292 extern int handle_unaligned_access(unsigned long, struct pt_regs *);
 293
 294 /* This code taken from arch/sh/kernel/traps.c */
 295 asmlinkage void do_alignment_check(struct pt_regs *regs, long error_code)
 296 {
 297         mm_segment_t oldfs;
 298         unsigned long insn;
 299         int tmp;
 300
 301         oldfs = get_fs();
 302
 303         if (user_mode(regs)) {
 304                 local_irq_enable();
 305                 current->thread.error_code = error_code;
 306                 current->thread.trap_no = 0x17;
 307
 308                 set_fs(USER_DS);
 309                 if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
 310                         set_fs(oldfs);
 311                         goto uspace_segv;
 312                 }
 313                 tmp = handle_unaligned_access(insn, regs);
 314                 set_fs(oldfs);
 315
 316                 if (!tmp)
 317                         return;
 318
 319         uspace_segv:
 320                 printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
 321                         "access\n", current->comm);
 322                 force_sig(SIGSEGV, current);
 323         } else {
 324                 set_fs(KERNEL_DS);
 325                 if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
 326                         set_fs(oldfs);
 327                         die("insn faulting in do_address_error", regs, 0);
 328                 }
 329                 handle_unaligned_access(insn, regs);
 330                 set_fs(oldfs);
 331         }
 332 }