arch/s390/kernel/dumpstack.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Stack dumping functions
   4  *
   5  *  Copyright IBM Corp. 1999, 2013
   6  */
   7
   8 #include <linux/kallsyms.h>
   9 #include <linux/hardirq.h>
  10 #include <linux/kprobes.h>
  11 #include <linux/utsname.h>
  12 #include <linux/export.h>
  13 #include <linux/kdebug.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/mm.h>
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/sched/debug.h>
  19 #include <linux/sched/task_stack.h>
  20 #include <asm/processor.h>
  21 #include <asm/debug.h>
  22 #include <asm/dis.h>
  23 #include <asm/ipl.h>
  24
  25 /*
  26  * For dump_trace we have tree different stack to consider:
  27  *   - the panic stack which is used if the kernel stack has overflown
  28  *   - the asynchronous interrupt stack (cpu related)
  29  *   - the synchronous kernel stack (process related)
  30  * The stack trace can start at any of the three stacks and can potentially
  31  * touch all of them. The order is: panic stack, async stack, sync stack.
  32  */
  33 static unsigned long
  34 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
  35              unsigned long low, unsigned long high)
  36 {
  37         struct stack_frame *sf;
  38         struct pt_regs *regs;
  39
  40         while (1) {
  41                 if (sp < low || sp > high - sizeof(*sf))
  42                         return sp;
  43                 sf = (struct stack_frame *) sp;
  44                 if (func(data, sf->gprs[8], 0))
  45                         return sp;
  46                 /* Follow the backchain. */
  47                 while (1) {
  48                         low = sp;
  49                         sp = sf->back_chain;
  50                         if (!sp)
  51                                 break;
  52                         if (sp <= low || sp > high - sizeof(*sf))
  53                                 return sp;
  54                         sf = (struct stack_frame *) sp;
  55                         if (func(data, sf->gprs[8], 1))
  56                                 return sp;
  57                 }
  58                 /* Zero backchain detected, check for interrupt frame. */
  59                 sp = (unsigned long) (sf + 1);
  60                 if (sp <= low || sp > high - sizeof(*regs))
  61                         return sp;
  62                 regs = (struct pt_regs *) sp;
  63                 if (!user_mode(regs)) {
  64                         if (func(data, regs->psw.addr, 1))
  65                                 return sp;
  66                 }
  67                 low = sp;
  68                 sp = regs->gprs[15];
  69         }
  70 }
  71
  72 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
  73                 unsigned long sp)
  74 {
  75         unsigned long frame_size;
  76
  77         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  78 #ifdef CONFIG_CHECK_STACK
  79         sp = __dump_trace(func, data, sp,
  80                           S390_lowcore.panic_stack + frame_size - PAGE_SIZE,
  81                           S390_lowcore.panic_stack + frame_size);
  82 #endif
  83         sp = __dump_trace(func, data, sp,
  84                           S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
  85                           S390_lowcore.async_stack + frame_size);
  86         task = task ?: current;
  87         __dump_trace(func, data, sp,
  88                      (unsigned long)task_stack_page(task),
  89                      (unsigned long)task_stack_page(task) + THREAD_SIZE);
  90 }
  91 EXPORT_SYMBOL_GPL(dump_trace);
  92
  93 static int show_address(void *data, unsigned long address, int reliable)
  94 {
  95         if (reliable)
  96                 printk(" [<%016lx>] %pSR \n", address, (void *)address);
  97         else
  98                 printk("([<%016lx>] %pSR)\n", address, (void *)address);
  99         return 0;
 100 }
 101
 102 void show_stack(struct task_struct *task, unsigned long *stack)
 103 {
 104         unsigned long sp = (unsigned long) stack;
 105
 106         if (!sp)
 107                 sp = task ? task->thread.ksp : current_stack_pointer();
 108         printk("Call Trace:\n");
 109         dump_trace(show_address, NULL, task, sp);
 110         if (!task)
 111                 task = current;
 112         debug_show_held_locks(task);
 113 }
 114
 115 static void show_last_breaking_event(struct pt_regs *regs)
 116 {
 117         printk("Last Breaking-Event-Address:\n");
 118         printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 119 }
 120
 121 void show_registers(struct pt_regs *regs)
 122 {
 123         struct psw_bits *psw = &psw_bits(regs->psw);
 124         char *mode;
 125
 126         mode = user_mode(regs) ? "User" : "Krnl";
 127         printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 128         if (!user_mode(regs))
 129                 pr_cont(" (%pSR)", (void *)regs->psw.addr);
 130         pr_cont("\n");
 131         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 132                "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
 133                psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
 134         pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 135         printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 136                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 137         printk("           %016lx %016lx %016lx %016lx\n",
 138                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 139         printk("           %016lx %016lx %016lx %016lx\n",
 140                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 141         printk("           %016lx %016lx %016lx %016lx\n",
 142                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 143         show_code(regs);
 144 }
 145
 146 void show_regs(struct pt_regs *regs)
 147 {
 148         show_regs_print_info(KERN_DEFAULT);
 149         show_registers(regs);
 150         /* Show stack backtrace if pt_regs is from kernel mode */
 151         if (!user_mode(regs))
 152                 show_stack(NULL, (unsigned long *) regs->gprs[15]);
 153         show_last_breaking_event(regs);
 154 }
 155
 156 static DEFINE_SPINLOCK(die_lock);
 157
 158 void die(struct pt_regs *regs, const char *str)
 159 {
 160         static int die_counter;
 161
 162         oops_enter();
 163         lgr_info_log();
 164         debug_stop_all();
 165         console_verbose();
 166         spin_lock_irq(&die_lock);
 167         bust_spinlocks(1);
 168         printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 169                regs->int_code >> 17, ++die_counter);
 170 #ifdef CONFIG_PREEMPT
 171         pr_cont("PREEMPT ");
 172 #endif
 173 #ifdef CONFIG_SMP
 174         pr_cont("SMP ");
 175 #endif
 176         if (debug_pagealloc_enabled())
 177                 pr_cont("DEBUG_PAGEALLOC");
 178         pr_cont("\n");
 179         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 180         print_modules();
 181         show_regs(regs);
 182         bust_spinlocks(0);
 183         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 184         spin_unlock_irq(&die_lock);
 185         if (in_interrupt())
 186                 panic("Fatal exception in interrupt");
 187         if (panic_on_oops)
 188                 panic("Fatal exception: panic_on_oops");
 189         oops_exit();
 190         do_exit(SIGSEGV);
 191 }