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 #include <asm/unwind.h>
  25
  26 const char *stack_type_name(enum stack_type type)
  27 {
  28         switch (type) {
  29         case STACK_TYPE_TASK:
  30                 return "task";
  31         case STACK_TYPE_IRQ:
  32                 return "irq";
  33         case STACK_TYPE_NODAT:
  34                 return "nodat";
  35         case STACK_TYPE_RESTART:
  36                 return "restart";
  37         default:
  38                 return "unknown";
  39         }
  40 }
  41
  42 static inline bool in_stack(unsigned long sp, struct stack_info *info,
  43                             enum stack_type type, unsigned long low,
  44                             unsigned long high)
  45 {
  46         if (sp < low || sp >= high)
  47                 return false;
  48         info->type = type;
  49         info->begin = low;
  50         info->end = high;
  51         return true;
  52 }
  53
  54 static bool in_task_stack(unsigned long sp, struct task_struct *task,
  55                           struct stack_info *info)
  56 {
  57         unsigned long stack;
  58
  59         stack = (unsigned long) task_stack_page(task);
  60         return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
  61 }
  62
  63 static bool in_irq_stack(unsigned long sp, struct stack_info *info)
  64 {
  65         unsigned long frame_size, top;
  66
  67         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  68         top = S390_lowcore.async_stack + frame_size;
  69         return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
  70 }
  71
  72 static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
  73 {
  74         unsigned long frame_size, top;
  75
  76         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  77         top = S390_lowcore.nodat_stack + frame_size;
  78         return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
  79 }
  80
  81 static bool in_restart_stack(unsigned long sp, struct stack_info *info)
  82 {
  83         unsigned long frame_size, top;
  84
  85         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  86         top = S390_lowcore.restart_stack + frame_size;
  87         return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
  88 }
  89
  90 int get_stack_info(unsigned long sp, struct task_struct *task,
  91                    struct stack_info *info, unsigned long *visit_mask)
  92 {
  93         if (!sp)
  94                 goto unknown;
  95
  96         task = task ? : current;
  97
  98         /* Check per-task stack */
  99         if (in_task_stack(sp, task, info))
 100                 goto recursion_check;
 101
 102         if (task != current)
 103                 goto unknown;
 104
 105         /* Check per-cpu stacks */
 106         if (!in_irq_stack(sp, info) &&
 107             !in_nodat_stack(sp, info) &&
 108             !in_restart_stack(sp, info))
 109                 goto unknown;
 110
 111 recursion_check:
 112         /*
 113          * Make sure we don't iterate through any given stack more than once.
 114          * If it comes up a second time then there's something wrong going on:
 115          * just break out and report an unknown stack type.
 116          */
 117         if (*visit_mask & (1UL << info->type)) {
 118                 printk_deferred_once(KERN_WARNING
 119                         "WARNING: stack recursion on stack type %d\n",
 120                         info->type);
 121                 goto unknown;
 122         }
 123         *visit_mask |= 1UL << info->type;
 124         return 0;
 125 unknown:
 126         info->type = STACK_TYPE_UNKNOWN;
 127         return -EINVAL;
 128 }
 129
 130 void show_stack(struct task_struct *task, unsigned long *stack)
 131 {
 132         struct unwind_state state;
 133
 134         printk("Call Trace:\n");
 135         if (!task)
 136                 task = current;
 137         unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
 138                 printk(state.reliable ? " [<%016lx>] %pSR \n" :
 139                                         "([<%016lx>] %pSR)\n",
 140                        state.ip, (void *) state.ip);
 141         debug_show_held_locks(task ? : current);
 142 }
 143
 144 static void show_last_breaking_event(struct pt_regs *regs)
 145 {
 146         printk("Last Breaking-Event-Address:\n");
 147         printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 148 }
 149
 150 void show_registers(struct pt_regs *regs)
 151 {
 152         struct psw_bits *psw = &psw_bits(regs->psw);
 153         char *mode;
 154
 155         mode = user_mode(regs) ? "User" : "Krnl";
 156         printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 157         if (!user_mode(regs))
 158                 pr_cont(" (%pSR)", (void *)regs->psw.addr);
 159         pr_cont("\n");
 160         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 161                "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
 162                psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
 163         pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 164         printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 165                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 166         printk("           %016lx %016lx %016lx %016lx\n",
 167                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 168         printk("           %016lx %016lx %016lx %016lx\n",
 169                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 170         printk("           %016lx %016lx %016lx %016lx\n",
 171                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 172         show_code(regs);
 173 }
 174
 175 void show_regs(struct pt_regs *regs)
 176 {
 177         show_regs_print_info(KERN_DEFAULT);
 178         show_registers(regs);
 179         /* Show stack backtrace if pt_regs is from kernel mode */
 180         if (!user_mode(regs))
 181                 show_stack(NULL, (unsigned long *) regs->gprs[15]);
 182         show_last_breaking_event(regs);
 183 }
 184
 185 static DEFINE_SPINLOCK(die_lock);
 186
 187 void die(struct pt_regs *regs, const char *str)
 188 {
 189         static int die_counter;
 190
 191         oops_enter();
 192         lgr_info_log();
 193         debug_stop_all();
 194         console_verbose();
 195         spin_lock_irq(&die_lock);
 196         bust_spinlocks(1);
 197         printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 198                regs->int_code >> 17, ++die_counter);
 199 #ifdef CONFIG_PREEMPT
 200         pr_cont("PREEMPT ");
 201 #endif
 202         pr_cont("SMP ");
 203         if (debug_pagealloc_enabled())
 204                 pr_cont("DEBUG_PAGEALLOC");
 205         pr_cont("\n");
 206         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 207         print_modules();
 208         show_regs(regs);
 209         bust_spinlocks(0);
 210         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 211         spin_unlock_irq(&die_lock);
 212         if (in_interrupt())
 213                 panic("Fatal exception in interrupt");
 214         if (panic_on_oops)
 215                 panic("Fatal exception: panic_on_oops");
 216         oops_exit();
 217         do_exit(SIGSEGV);
 218 }