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/module.h>
  15 #include <linux/sched.h>
  16 #include <asm/processor.h>
  17 #include <asm/debug.h>
  18 #include <asm/dis.h>
  19 #include <asm/ipl.h>
  20
  21 /*
  22  * For show_trace we have tree different stack to consider:
  23  *   - the panic stack which is used if the kernel stack has overflown
  24  *   - the asynchronous interrupt stack (cpu related)
  25  *   - the synchronous kernel stack (process related)
  26  * The stack trace can start at any of the three stack and can potentially
  27  * touch all of them. The order is: panic stack, async stack, sync stack.
  28  */
  29 static unsigned long
  30 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  31 {
  32         struct stack_frame *sf;
  33         struct pt_regs *regs;
  34         unsigned long addr;
  35
  36         while (1) {
  37                 if (sp < low || sp > high - sizeof(*sf))
  38                         return sp;
  39                 sf = (struct stack_frame *) sp;
  40                 addr = sf->gprs[8];
  41                 printk("([<%016lx>] %pSR)\n", addr, (void *)addr);
  42                 /* Follow the backchain. */
  43                 while (1) {
  44                         low = sp;
  45                         sp = sf->back_chain;
  46                         if (!sp)
  47                                 break;
  48                         if (sp <= low || sp > high - sizeof(*sf))
  49                                 return sp;
  50                         sf = (struct stack_frame *) sp;
  51                         addr = sf->gprs[8];
  52                         printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
  53                 }
  54                 /* Zero backchain detected, check for interrupt frame. */
  55                 sp = (unsigned long) (sf + 1);
  56                 if (sp <= low || sp > high - sizeof(*regs))
  57                         return sp;
  58                 regs = (struct pt_regs *) sp;
  59                 addr = regs->psw.addr;
  60                 printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
  61                 low = sp;
  62                 sp = regs->gprs[15];
  63         }
  64 }
  65
  66 static void show_trace(struct task_struct *task, unsigned long *stack)
  67 {
  68         const unsigned long frame_size =
  69                 STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  70         register unsigned long __r15 asm ("15");
  71         unsigned long sp;
  72
  73         sp = (unsigned long) stack;
  74         if (!sp)
  75                 sp = task ? task->thread.ksp : __r15;
  76         printk("Call Trace:\n");
  77 #ifdef CONFIG_CHECK_STACK
  78         sp = __show_trace(sp,
  79                           S390_lowcore.panic_stack + frame_size - 4096,
  80                           S390_lowcore.panic_stack + frame_size);
  81 #endif
  82         sp = __show_trace(sp,
  83                           S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
  84                           S390_lowcore.async_stack + frame_size);
  85         if (task)
  86                 __show_trace(sp, (unsigned long) task_stack_page(task),
  87                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
  88         else
  89                 __show_trace(sp, S390_lowcore.thread_info,
  90                              S390_lowcore.thread_info + THREAD_SIZE);
  91         if (!task)
  92                 task = current;
  93         debug_show_held_locks(task);
  94 }
  95
  96 void show_stack(struct task_struct *task, unsigned long *sp)
  97 {
  98         register unsigned long *__r15 asm ("15");
  99         unsigned long *stack;
 100         int i;
 101
 102         if (!sp)
 103                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 104         else
 105                 stack = sp;
 106
 107         for (i = 0; i < 20; i++) {
 108                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 109                         break;
 110                 if ((i * sizeof(long) % 32) == 0)
 111                         printk("%s       ", i == 0 ? "" : "\n");
 112                 printk("%016lx ", *stack++);
 113         }
 114         printk("\n");
 115         show_trace(task, sp);
 116 }
 117
 118 static void show_last_breaking_event(struct pt_regs *regs)
 119 {
 120         printk("Last Breaking-Event-Address:\n");
 121         printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 122 }
 123
 124 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 125 {
 126         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 127 }
 128
 129 void show_registers(struct pt_regs *regs)
 130 {
 131         char *mode;
 132
 133         mode = user_mode(regs) ? "User" : "Krnl";
 134         printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 135         if (!user_mode(regs))
 136                 printk(" (%pSR)", (void *)regs->psw.addr);
 137         printk("\n");
 138         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 139                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 140                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 141                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 142                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 143                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 144                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 145         printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
 146         printk("\n%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 147                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 148         printk("           %016lx %016lx %016lx %016lx\n",
 149                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 150         printk("           %016lx %016lx %016lx %016lx\n",
 151                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 152         printk("           %016lx %016lx %016lx %016lx\n",
 153                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 154         show_code(regs);
 155 }
 156
 157 void show_regs(struct pt_regs *regs)
 158 {
 159         show_regs_print_info(KERN_DEFAULT);
 160         show_registers(regs);
 161         /* Show stack backtrace if pt_regs is from kernel mode */
 162         if (!user_mode(regs))
 163                 show_trace(NULL, (unsigned long *) regs->gprs[15]);
 164         show_last_breaking_event(regs);
 165 }
 166
 167 static DEFINE_SPINLOCK(die_lock);
 168
 169 void die(struct pt_regs *regs, const char *str)
 170 {
 171         static int die_counter;
 172
 173         oops_enter();
 174         lgr_info_log();
 175         debug_stop_all();
 176         console_verbose();
 177         spin_lock_irq(&die_lock);
 178         bust_spinlocks(1);
 179         printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 180                regs->int_code >> 17, ++die_counter);
 181 #ifdef CONFIG_PREEMPT
 182         printk("PREEMPT ");
 183 #endif
 184 #ifdef CONFIG_SMP
 185         printk("SMP ");
 186 #endif
 187 #ifdef CONFIG_DEBUG_PAGEALLOC
 188         printk("DEBUG_PAGEALLOC");
 189 #endif
 190         printk("\n");
 191         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 192         print_modules();
 193         show_regs(regs);
 194         bust_spinlocks(0);
 195         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 196         spin_unlock_irq(&die_lock);
 197         if (in_interrupt())
 198                 panic("Fatal exception in interrupt");
 199         if (panic_on_oops)
 200                 panic("Fatal exception: panic_on_oops");
 201         oops_exit();
 202         do_exit(SIGSEGV);
 203 }