arch/s390/kernel/dumpstack.c

   1 /*
   2  * Stack dumping functions
   3  *
   4  *  Copyright IBM Corp. 1999, 2013
   5  */
   6
   7 #include <linux/kallsyms.h>
   8 #include <linux/hardirq.h>
   9 #include <linux/kprobes.h>
  10 #include <linux/utsname.h>
  11 #include <linux/export.h>
  12 #include <linux/kdebug.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/mm.h>
  15 #include <linux/module.h>
  16 #include <linux/sched.h>
  17 #include <asm/processor.h>
  18 #include <asm/debug.h>
  19 #include <asm/dis.h>
  20 #include <asm/ipl.h>
  21
  22 /*
  23  * For dump_trace we have tree different stack to consider:
  24  *   - the panic stack which is used if the kernel stack has overflown
  25  *   - the asynchronous interrupt stack (cpu related)
  26  *   - the synchronous kernel stack (process related)
  27  * The stack trace can start at any of the three stacks and can potentially
  28  * touch all of them. The order is: panic stack, async stack, sync stack.
  29  */
  30 static unsigned long
  31 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
  32              unsigned long low, unsigned long high)
  33 {
  34         struct stack_frame *sf;
  35         struct pt_regs *regs;
  36
  37         while (1) {
  38                 if (sp < low || sp > high - sizeof(*sf))
  39                         return sp;
  40                 sf = (struct stack_frame *) sp;
  41                 /* Follow the backchain. */
  42                 while (1) {
  43                         if (func(data, sf->gprs[8]))
  44                                 return sp;
  45                         low = sp;
  46                         sp = sf->back_chain;
  47                         if (!sp)
  48                                 break;
  49                         if (sp <= low || sp > high - sizeof(*sf))
  50                                 return sp;
  51                         sf = (struct stack_frame *) sp;
  52                 }
  53                 /* Zero backchain detected, check for interrupt frame. */
  54                 sp = (unsigned long) (sf + 1);
  55                 if (sp <= low || sp > high - sizeof(*regs))
  56                         return sp;
  57                 regs = (struct pt_regs *) sp;
  58                 if (!user_mode(regs)) {
  59                         if (func(data, regs->psw.addr))
  60                                 return sp;
  61                 }
  62                 low = sp;
  63                 sp = regs->gprs[15];
  64         }
  65 }
  66
  67 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
  68                 unsigned long sp)
  69 {
  70         unsigned long frame_size;
  71
  72         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  73 #ifdef CONFIG_CHECK_STACK
  74         sp = __dump_trace(func, data, sp,
  75                           S390_lowcore.panic_stack + frame_size - 4096,
  76                           S390_lowcore.panic_stack + frame_size);
  77 #endif
  78         sp = __dump_trace(func, data, sp,
  79                           S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
  80                           S390_lowcore.async_stack + frame_size);
  81         if (task)
  82                 __dump_trace(func, data, sp,
  83                              (unsigned long)task_stack_page(task),
  84                              (unsigned long)task_stack_page(task) + THREAD_SIZE);
  85         else
  86                 __dump_trace(func, data, sp,
  87                              S390_lowcore.thread_info,
  88                              S390_lowcore.thread_info + THREAD_SIZE);
  89 }
  90 EXPORT_SYMBOL_GPL(dump_trace);
  91
  92 static int show_address(void *data, unsigned long address)
  93 {
  94         printk("([<%016lx>] %pSR)\n", address, (void *)address);
  95         return 0;
  96 }
  97
  98 static void show_trace(struct task_struct *task, unsigned long sp)
  99 {
 100         if (!sp)
 101                 sp = task ? task->thread.ksp : current_stack_pointer();
 102         printk("Call Trace:\n");
 103         dump_trace(show_address, NULL, task, sp);
 104         if (!task)
 105                 task = current;
 106         debug_show_held_locks(task);
 107 }
 108
 109 void show_stack(struct task_struct *task, unsigned long *sp)
 110 {
 111         unsigned long *stack;
 112         int i;
 113
 114         stack = sp;
 115         if (!stack) {
 116                 if (!task)
 117                         stack = (unsigned long *)current_stack_pointer();
 118                 else
 119                         stack = (unsigned long *)task->thread.ksp;
 120         }
 121         for (i = 0; i < 20; i++) {
 122                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 123                         break;
 124                 if ((i * sizeof(long) % 32) == 0)
 125                         printk("%s       ", i == 0 ? "" : "\n");
 126                 printk("%016lx ", *stack++);
 127         }
 128         printk("\n");
 129         show_trace(task, (unsigned long)sp);
 130 }
 131
 132 static void show_last_breaking_event(struct pt_regs *regs)
 133 {
 134         printk("Last Breaking-Event-Address:\n");
 135         printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 136 }
 137
 138 void show_registers(struct pt_regs *regs)
 139 {
 140         struct psw_bits *psw = &psw_bits(regs->psw);
 141         char *mode;
 142
 143         mode = user_mode(regs) ? "User" : "Krnl";
 144         printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 145         if (!user_mode(regs))
 146                 printk(" (%pSR)", (void *)regs->psw.addr);
 147         printk("\n");
 148         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 149                "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e,
 150                psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm);
 151         printk(" RI:%x EA:%x", psw->ri, psw->eaba);
 152         printk("\n%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 153                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 154         printk("           %016lx %016lx %016lx %016lx\n",
 155                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 156         printk("           %016lx %016lx %016lx %016lx\n",
 157                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 158         printk("           %016lx %016lx %016lx %016lx\n",
 159                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 160         show_code(regs);
 161 }
 162
 163 void show_regs(struct pt_regs *regs)
 164 {
 165         show_regs_print_info(KERN_DEFAULT);
 166         show_registers(regs);
 167         /* Show stack backtrace if pt_regs is from kernel mode */
 168         if (!user_mode(regs))
 169                 show_trace(NULL, regs->gprs[15]);
 170         show_last_breaking_event(regs);
 171 }
 172
 173 static DEFINE_SPINLOCK(die_lock);
 174
 175 void die(struct pt_regs *regs, const char *str)
 176 {
 177         static int die_counter;
 178
 179         oops_enter();
 180         lgr_info_log();
 181         debug_stop_all();
 182         console_verbose();
 183         spin_lock_irq(&die_lock);
 184         bust_spinlocks(1);
 185         printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 186                regs->int_code >> 17, ++die_counter);
 187 #ifdef CONFIG_PREEMPT
 188         printk("PREEMPT ");
 189 #endif
 190 #ifdef CONFIG_SMP
 191         printk("SMP ");
 192 #endif
 193         if (debug_pagealloc_enabled())
 194                 printk("DEBUG_PAGEALLOC");
 195         printk("\n");
 196         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 197         print_modules();
 198         show_regs(regs);
 199         bust_spinlocks(0);
 200         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 201         spin_unlock_irq(&die_lock);
 202         if (in_interrupt())
 203                 panic("Fatal exception in interrupt");
 204         if (panic_on_oops)
 205                 panic("Fatal exception: panic_on_oops");
 206         oops_exit();
 207         do_exit(SIGSEGV);
 208 }