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 <linux/sched/debug.h>
  18 #include <asm/processor.h>
  19 #include <asm/debug.h>
  20 #include <asm/dis.h>
  21 #include <asm/ipl.h>
  22
  23 /*
  24  * For dump_trace we have tree different stack to consider:
  25  *   - the panic stack which is used if the kernel stack has overflown
  26  *   - the asynchronous interrupt stack (cpu related)
  27  *   - the synchronous kernel stack (process related)
  28  * The stack trace can start at any of the three stacks and can potentially
  29  * touch all of them. The order is: panic stack, async stack, sync stack.
  30  */
  31 static unsigned long
  32 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
  33              unsigned long low, unsigned long high)
  34 {
  35         struct stack_frame *sf;
  36         struct pt_regs *regs;
  37
  38         while (1) {
  39                 if (sp < low || sp > high - sizeof(*sf))
  40                         return sp;
  41                 sf = (struct stack_frame *) sp;
  42                 if (func(data, sf->gprs[8], 0))
  43                         return sp;
  44                 /* Follow the backchain. */
  45                 while (1) {
  46                         low = sp;
  47                         sp = sf->back_chain;
  48                         if (!sp)
  49                                 break;
  50                         if (sp <= low || sp > high - sizeof(*sf))
  51                                 return sp;
  52                         sf = (struct stack_frame *) sp;
  53                         if (func(data, sf->gprs[8], 1))
  54                                 return sp;
  55                 }
  56                 /* Zero backchain detected, check for interrupt frame. */
  57                 sp = (unsigned long) (sf + 1);
  58                 if (sp <= low || sp > high - sizeof(*regs))
  59                         return sp;
  60                 regs = (struct pt_regs *) sp;
  61                 if (!user_mode(regs)) {
  62                         if (func(data, regs->psw.addr, 1))
  63                                 return sp;
  64                 }
  65                 low = sp;
  66                 sp = regs->gprs[15];
  67         }
  68 }
  69
  70 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
  71                 unsigned long sp)
  72 {
  73         unsigned long frame_size;
  74
  75         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  76 #ifdef CONFIG_CHECK_STACK
  77         sp = __dump_trace(func, data, sp,
  78                           S390_lowcore.panic_stack + frame_size - 4096,
  79                           S390_lowcore.panic_stack + frame_size);
  80 #endif
  81         sp = __dump_trace(func, data, sp,
  82                           S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
  83                           S390_lowcore.async_stack + frame_size);
  84         task = task ?: current;
  85         __dump_trace(func, data, sp,
  86                      (unsigned long)task_stack_page(task),
  87                      (unsigned long)task_stack_page(task) + THREAD_SIZE);
  88 }
  89 EXPORT_SYMBOL_GPL(dump_trace);
  90
  91 static int show_address(void *data, unsigned long address, int reliable)
  92 {
  93         if (reliable)
  94                 printk(" [<%016lx>] %pSR \n", address, (void *)address);
  95         else
  96                 printk("([<%016lx>] %pSR)\n", address, (void *)address);
  97         return 0;
  98 }
  99
 100 static void show_trace(struct task_struct *task, unsigned long sp)
 101 {
 102         if (!sp)
 103                 sp = task ? task->thread.ksp : current_stack_pointer();
 104         printk("Call Trace:\n");
 105         dump_trace(show_address, NULL, task, sp);
 106         if (!task)
 107                 task = current;
 108         debug_show_held_locks(task);
 109 }
 110
 111 void show_stack(struct task_struct *task, unsigned long *sp)
 112 {
 113         unsigned long *stack;
 114         int i;
 115
 116         stack = sp;
 117         if (!stack) {
 118                 if (!task)
 119                         stack = (unsigned long *)current_stack_pointer();
 120                 else
 121                         stack = (unsigned long *)task->thread.ksp;
 122         }
 123         printk(KERN_DEFAULT "Stack:\n");
 124         for (i = 0; i < 20; i++) {
 125                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 126                         break;
 127                 if (i % 4 == 0)
 128                         printk(KERN_DEFAULT "       ");
 129                 pr_cont("%016lx%c", *stack++, i % 4 == 3 ? '\n' : ' ');
 130         }
 131         show_trace(task, (unsigned long)sp);
 132 }
 133
 134 static void show_last_breaking_event(struct pt_regs *regs)
 135 {
 136         printk("Last Breaking-Event-Address:\n");
 137         printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 138 }
 139
 140 void show_registers(struct pt_regs *regs)
 141 {
 142         struct psw_bits *psw = &psw_bits(regs->psw);
 143         char *mode;
 144
 145         mode = user_mode(regs) ? "User" : "Krnl";
 146         printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 147         if (!user_mode(regs))
 148                 pr_cont(" (%pSR)", (void *)regs->psw.addr);
 149         pr_cont("\n");
 150         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 151                "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e,
 152                psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm);
 153         pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 154         printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 155                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 156         printk("           %016lx %016lx %016lx %016lx\n",
 157                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 158         printk("           %016lx %016lx %016lx %016lx\n",
 159                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 160         printk("           %016lx %016lx %016lx %016lx\n",
 161                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 162         show_code(regs);
 163 }
 164
 165 void show_regs(struct pt_regs *regs)
 166 {
 167         show_regs_print_info(KERN_DEFAULT);
 168         show_registers(regs);
 169         /* Show stack backtrace if pt_regs is from kernel mode */
 170         if (!user_mode(regs))
 171                 show_trace(NULL, regs->gprs[15]);
 172         show_last_breaking_event(regs);
 173 }
 174
 175 static DEFINE_SPINLOCK(die_lock);
 176
 177 void die(struct pt_regs *regs, const char *str)
 178 {
 179         static int die_counter;
 180
 181         oops_enter();
 182         lgr_info_log();
 183         debug_stop_all();
 184         console_verbose();
 185         spin_lock_irq(&die_lock);
 186         bust_spinlocks(1);
 187         printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 188                regs->int_code >> 17, ++die_counter);
 189 #ifdef CONFIG_PREEMPT
 190         pr_cont("PREEMPT ");
 191 #endif
 192 #ifdef CONFIG_SMP
 193         pr_cont("SMP ");
 194 #endif
 195         if (debug_pagealloc_enabled())
 196                 pr_cont("DEBUG_PAGEALLOC");
 197         pr_cont("\n");
 198         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 199         print_modules();
 200         show_regs(regs);
 201         bust_spinlocks(0);
 202         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 203         spin_unlock_irq(&die_lock);
 204         if (in_interrupt())
 205                 panic("Fatal exception in interrupt");
 206         if (panic_on_oops)
 207                 panic("Fatal exception: panic_on_oops");
 208         oops_exit();
 209         do_exit(SIGSEGV);
 210 }