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}
  41EXPORT_SYMBOL_GPL(stack_type_name);
  42
  43static inline bool in_stack(unsigned long sp, struct stack_info *info,
  44                            enum stack_type type, unsigned long low,
  45                            unsigned long high)
  46{
  47        if (sp < low || sp >= high)
  48                return false;
  49        info->type = type;
  50        info->begin = low;
  51        info->end = high;
  52        return true;
  53}
  54
  55static bool in_task_stack(unsigned long sp, struct task_struct *task,
  56                          struct stack_info *info)
  57{
  58        unsigned long stack;
  59
  60        stack = (unsigned long) task_stack_page(task);
  61        return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
  62}
  63
  64static bool in_irq_stack(unsigned long sp, struct stack_info *info)
  65{
  66        unsigned long frame_size, top;
  67
  68        frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  69        top = S390_lowcore.async_stack + frame_size;
  70        return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
  71}
  72
  73static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
  74{
  75        unsigned long frame_size, top;
  76
  77        frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  78        top = S390_lowcore.nodat_stack + frame_size;
  79        return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
  80}
  81
  82static bool in_restart_stack(unsigned long sp, struct stack_info *info)
  83{
  84        unsigned long frame_size, top;
  85
  86        frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  87        top = S390_lowcore.restart_stack + frame_size;
  88        return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
  89}
  90
  91int get_stack_info(unsigned long sp, struct task_struct *task,
  92                   struct stack_info *info, unsigned long *visit_mask)
  93{
  94        if (!sp)
  95                goto unknown;
  96
  97        /* Sanity check: ABI requires SP to be aligned 8 bytes. */
  98        if (sp & 0x7)
  99                goto unknown;
 100
 101        /* Check per-task stack */
 102        if (in_task_stack(sp, task, info))
 103                goto recursion_check;
 104
 105        if (task != current)
 106                goto unknown;
 107
 108        /* Check per-cpu stacks */
 109        if (!in_irq_stack(sp, info) &&
 110            !in_nodat_stack(sp, info) &&
 111            !in_restart_stack(sp, info))
 112                goto unknown;
 113
 114recursion_check:
 115        /*
 116         * Make sure we don't iterate through any given stack more than once.
 117         * If it comes up a second time then there's something wrong going on:
 118         * just break out and report an unknown stack type.
 119         */
 120        if (*visit_mask & (1UL << info->type))
 121                goto unknown;
 122        *visit_mask |= 1UL << info->type;
 123        return 0;
 124unknown:
 125        info->type = STACK_TYPE_UNKNOWN;
 126        return -EINVAL;
 127}
 128
 129void show_stack(struct task_struct *task, unsigned long *stack,
 130                       const char *loglvl)
 131{
 132        struct unwind_state state;
 133
 134        printk("%sCall Trace:\n", loglvl);
 135        unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
 136                printk(state.reliable ? "%s [<%016lx>] %pSR \n" :
 137                                        "%s([<%016lx>] %pSR)\n",
 138                       loglvl, state.ip, (void *) state.ip);
 139        debug_show_held_locks(task ? : current);
 140}
 141
 142static void show_last_breaking_event(struct pt_regs *regs)
 143{
 144        printk("Last Breaking-Event-Address:\n");
 145        printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 146}
 147
 148void show_registers(struct pt_regs *regs)
 149{
 150        struct psw_bits *psw = &psw_bits(regs->psw);
 151        char *mode;
 152
 153        mode = user_mode(regs) ? "User" : "Krnl";
 154        printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 155        if (!user_mode(regs))
 156                pr_cont(" (%pSR)", (void *)regs->psw.addr);
 157        pr_cont("\n");
 158        printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 159               "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
 160               psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
 161        pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 162        printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 163               regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 164        printk("           %016lx %016lx %016lx %016lx\n",
 165               regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 166        printk("           %016lx %016lx %016lx %016lx\n",
 167               regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 168        printk("           %016lx %016lx %016lx %016lx\n",
 169               regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 170        show_code(regs);
 171}
 172
 173void show_regs(struct pt_regs *regs)
 174{
 175        show_regs_print_info(KERN_DEFAULT);
 176        show_registers(regs);
 177        /* Show stack backtrace if pt_regs is from kernel mode */
 178        if (!user_mode(regs))
 179                show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT);
 180        show_last_breaking_event(regs);
 181}
 182
 183static DEFINE_SPINLOCK(die_lock);
 184
 185void die(struct pt_regs *regs, const char *str)
 186{
 187        static int die_counter;
 188
 189        oops_enter();
 190        lgr_info_log();
 191        debug_stop_all();
 192        console_verbose();
 193        spin_lock_irq(&die_lock);
 194        bust_spinlocks(1);
 195        printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 196               regs->int_code >> 17, ++die_counter);
 197#ifdef CONFIG_PREEMPT
 198        pr_cont("PREEMPT ");
 199#elif defined(CONFIG_PREEMPT_RT)
 200        pr_cont("PREEMPT_RT ");
 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}
 219