linux/arch/s390/kernel/dumpstack.c
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   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
  26const 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
  42static 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
  54static 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
  63static 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
  72static 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
  81static 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
  90int 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
 111recursion_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                goto unknown;
 119        *visit_mask |= 1UL << info->type;
 120        return 0;
 121unknown:
 122        info->type = STACK_TYPE_UNKNOWN;
 123        return -EINVAL;
 124}
 125
 126void show_stack(struct task_struct *task, unsigned long *stack)
 127{
 128        struct unwind_state state;
 129
 130        printk("Call Trace:\n");
 131        if (!task)
 132                task = current;
 133        unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
 134                printk(state.reliable ? " [<%016lx>] %pSR \n" :
 135                                        "([<%016lx>] %pSR)\n",
 136                       state.ip, (void *) state.ip);
 137        debug_show_held_locks(task ? : current);
 138}
 139
 140static void show_last_breaking_event(struct pt_regs *regs)
 141{
 142        printk("Last Breaking-Event-Address:\n");
 143        printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 144}
 145
 146void show_registers(struct pt_regs *regs)
 147{
 148        struct psw_bits *psw = &psw_bits(regs->psw);
 149        char *mode;
 150
 151        mode = user_mode(regs) ? "User" : "Krnl";
 152        printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 153        if (!user_mode(regs))
 154                pr_cont(" (%pSR)", (void *)regs->psw.addr);
 155        pr_cont("\n");
 156        printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 157               "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
 158               psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
 159        pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 160        printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 161               regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 162        printk("           %016lx %016lx %016lx %016lx\n",
 163               regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 164        printk("           %016lx %016lx %016lx %016lx\n",
 165               regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 166        printk("           %016lx %016lx %016lx %016lx\n",
 167               regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 168        show_code(regs);
 169}
 170
 171void show_regs(struct pt_regs *regs)
 172{
 173        show_regs_print_info(KERN_DEFAULT);
 174        show_registers(regs);
 175        /* Show stack backtrace if pt_regs is from kernel mode */
 176        if (!user_mode(regs))
 177                show_stack(NULL, (unsigned long *) regs->gprs[15]);
 178        show_last_breaking_event(regs);
 179}
 180
 181static DEFINE_SPINLOCK(die_lock);
 182
 183void die(struct pt_regs *regs, const char *str)
 184{
 185        static int die_counter;
 186
 187        oops_enter();
 188        lgr_info_log();
 189        debug_stop_all();
 190        console_verbose();
 191        spin_lock_irq(&die_lock);
 192        bust_spinlocks(1);
 193        printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 194               regs->int_code >> 17, ++die_counter);
 195#ifdef CONFIG_PREEMPT
 196        pr_cont("PREEMPT ");
 197#endif
 198        pr_cont("SMP ");
 199        if (debug_pagealloc_enabled())
 200                pr_cont("DEBUG_PAGEALLOC");
 201        pr_cont("\n");
 202        notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 203        print_modules();
 204        show_regs(regs);
 205        bust_spinlocks(0);
 206        add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 207        spin_unlock_irq(&die_lock);
 208        if (in_interrupt())
 209                panic("Fatal exception in interrupt");
 210        if (panic_on_oops)
 211                panic("Fatal exception: panic_on_oops");
 212        oops_exit();
 213        do_exit(SIGSEGV);
 214}
 215