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 <linux/sched/task_stack.h>
  19 #include <asm/processor.h>
  20 #include <asm/debug.h>
  21 #include <asm/dis.h>
  22 #include <asm/ipl.h>
  23
  24 /*
  25  * For dump_trace we have tree different stack to consider:
  26  *   - the panic stack which is used if the kernel stack has overflown
  27  *   - the asynchronous interrupt stack (cpu related)
  28  *   - the synchronous kernel stack (process related)
  29  * The stack trace can start at any of the three stacks and can potentially
  30  * touch all of them. The order is: panic stack, async stack, sync stack.
  31  */
  32 static unsigned long
  33 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
  34              unsigned long low, unsigned long high)
  35 {
  36         struct stack_frame *sf;
  37         struct pt_regs *regs;
  38
  39         while (1) {
  40                 if (sp < low || sp > high - sizeof(*sf))
  41                         return sp;
  42                 sf = (struct stack_frame *) sp;
  43                 if (func(data, sf->gprs[8], 0))
  44                         return sp;
  45                 /* Follow the backchain. */
  46                 while (1) {
  47                         low = sp;
  48                         sp = sf->back_chain;
  49                         if (!sp)
  50                                 break;
  51                         if (sp <= low || sp > high - sizeof(*sf))
  52                                 return sp;
  53                         sf = (struct stack_frame *) sp;
  54                         if (func(data, sf->gprs[8], 1))
  55                                 return sp;
  56                 }
  57                 /* Zero backchain detected, check for interrupt frame. */
  58                 sp = (unsigned long) (sf + 1);
  59                 if (sp <= low || sp > high - sizeof(*regs))
  60                         return sp;
  61                 regs = (struct pt_regs *) sp;
  62                 if (!user_mode(regs)) {
  63                         if (func(data, regs->psw.addr, 1))
  64                                 return sp;
  65                 }
  66                 low = sp;
  67                 sp = regs->gprs[15];
  68         }
  69 }
  70
  71 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
  72                 unsigned long sp)
  73 {
  74         unsigned long frame_size;
  75
  76         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  77 #ifdef CONFIG_CHECK_STACK
  78         sp = __dump_trace(func, data, sp,
  79                           S390_lowcore.panic_stack + frame_size - 4096,
  80                           S390_lowcore.panic_stack + frame_size);
  81 #endif
  82         sp = __dump_trace(func, data, sp,
  83                           S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
  84                           S390_lowcore.async_stack + frame_size);
  85         task = task ?: current;
  86         __dump_trace(func, data, sp,
  87                      (unsigned long)task_stack_page(task),
  88                      (unsigned long)task_stack_page(task) + THREAD_SIZE);
  89 }
  90 EXPORT_SYMBOL_GPL(dump_trace);
  91
  92 static int show_address(void *data, unsigned long address, int reliable)
  93 {
  94         if (reliable)
  95                 printk(" [<%016lx>] %pSR \n", address, (void *)address);
  96         else
  97                 printk("([<%016lx>] %pSR)\n", address, (void *)address);
  98         return 0;
  99 }
 100
 101 static void show_trace(struct task_struct *task, unsigned long sp)
 102 {
 103         if (!sp)
 104                 sp = task ? task->thread.ksp : current_stack_pointer();
 105         printk("Call Trace:\n");
 106         dump_trace(show_address, NULL, task, sp);
 107         if (!task)
 108                 task = current;
 109         debug_show_held_locks(task);
 110 }
 111
 112 void show_stack(struct task_struct *task, unsigned long *sp)
 113 {
 114         unsigned long *stack;
 115         int i;
 116
 117         stack = sp;
 118         if (!stack) {
 119                 if (!task)
 120                         stack = (unsigned long *)current_stack_pointer();
 121                 else
 122                         stack = (unsigned long *)task->thread.ksp;
 123         }
 124         printk(KERN_DEFAULT "Stack:\n");
 125         for (i = 0; i < 20; i++) {
 126                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 127                         break;
 128                 if (i % 4 == 0)
 129                         printk(KERN_DEFAULT "       ");
 130                 pr_cont("%016lx%c", *stack++, i % 4 == 3 ? '\n' : ' ');
 131         }
 132         show_trace(task, (unsigned long)sp);
 133 }
 134
 135 static void show_last_breaking_event(struct pt_regs *regs)
 136 {
 137         printk("Last Breaking-Event-Address:\n");
 138         printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 139 }
 140
 141 void show_registers(struct pt_regs *regs)
 142 {
 143         struct psw_bits *psw = &psw_bits(regs->psw);
 144         char *mode;
 145
 146         mode = user_mode(regs) ? "User" : "Krnl";
 147         printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 148         if (!user_mode(regs))
 149                 pr_cont(" (%pSR)", (void *)regs->psw.addr);
 150         pr_cont("\n");
 151         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 152                "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e,
 153                psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm);
 154         pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 155         printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 156                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 157         printk("           %016lx %016lx %016lx %016lx\n",
 158                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 159         printk("           %016lx %016lx %016lx %016lx\n",
 160                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 161         printk("           %016lx %016lx %016lx %016lx\n",
 162                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 163         show_code(regs);
 164 }
 165
 166 void show_regs(struct pt_regs *regs)
 167 {
 168         show_regs_print_info(KERN_DEFAULT);
 169         show_registers(regs);
 170         /* Show stack backtrace if pt_regs is from kernel mode */
 171         if (!user_mode(regs))
 172                 show_trace(NULL, regs->gprs[15]);
 173         show_last_breaking_event(regs);
 174 }
 175
 176 static DEFINE_SPINLOCK(die_lock);
 177
 178 void die(struct pt_regs *regs, const char *str)
 179 {
 180         static int die_counter;
 181
 182         oops_enter();
 183         lgr_info_log();
 184         debug_stop_all();
 185         console_verbose();
 186         spin_lock_irq(&die_lock);
 187         bust_spinlocks(1);
 188         printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 189                regs->int_code >> 17, ++die_counter);
 190 #ifdef CONFIG_PREEMPT
 191         pr_cont("PREEMPT ");
 192 #endif
 193 #ifdef CONFIG_SMP
 194         pr_cont("SMP ");
 195 #endif
 196         if (debug_pagealloc_enabled())
 197                 pr_cont("DEBUG_PAGEALLOC");
 198         pr_cont("\n");
 199         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 200         print_modules();
 201         show_regs(regs);
 202         bust_spinlocks(0);
 203         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 204         spin_unlock_irq(&die_lock);
 205         if (in_interrupt())
 206                 panic("Fatal exception in interrupt");
 207         if (panic_on_oops)
 208                 panic("Fatal exception: panic_on_oops");
 209         oops_exit();
 210         do_exit(SIGSEGV);
 211 }