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_mcck_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.mcck_stack + frame_size;
  88        return in_stack(sp, info, STACK_TYPE_MCCK, top - THREAD_SIZE, top);
  89}
  90
  91static bool in_restart_stack(unsigned long sp, struct stack_info *info)
  92{
  93        unsigned long frame_size, top;
  94
  95        frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  96        top = S390_lowcore.restart_stack + frame_size;
  97        return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
  98}
  99
 100int get_stack_info(unsigned long sp, struct task_struct *task,
 101                   struct stack_info *info, unsigned long *visit_mask)
 102{
 103        if (!sp)
 104                goto unknown;
 105
 106        /* Sanity check: ABI requires SP to be aligned 8 bytes. */
 107        if (sp & 0x7)
 108                goto unknown;
 109
 110        /* Check per-task stack */
 111        if (in_task_stack(sp, task, info))
 112                goto recursion_check;
 113
 114        if (task != current)
 115                goto unknown;
 116
 117        /* Check per-cpu stacks */
 118        if (!in_irq_stack(sp, info) &&
 119            !in_nodat_stack(sp, info) &&
 120            !in_restart_stack(sp, info) &&
 121            !in_mcck_stack(sp, info))
 122                goto unknown;
 123
 124recursion_check:
 125        /*
 126         * Make sure we don't iterate through any given stack more than once.
 127         * If it comes up a second time then there's something wrong going on:
 128         * just break out and report an unknown stack type.
 129         */
 130        if (*visit_mask & (1UL << info->type))
 131                goto unknown;
 132        *visit_mask |= 1UL << info->type;
 133        return 0;
 134unknown:
 135        info->type = STACK_TYPE_UNKNOWN;
 136        return -EINVAL;
 137}
 138
 139void show_stack(struct task_struct *task, unsigned long *stack,
 140                       const char *loglvl)
 141{
 142        struct unwind_state state;
 143
 144        printk("%sCall Trace:\n", loglvl);
 145        unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
 146                printk(state.reliable ? "%s [<%016lx>] %pSR \n" :
 147                                        "%s([<%016lx>] %pSR)\n",
 148                       loglvl, state.ip, (void *) state.ip);
 149        debug_show_held_locks(task ? : current);
 150}
 151
 152static void show_last_breaking_event(struct pt_regs *regs)
 153{
 154        printk("Last Breaking-Event-Address:\n");
 155        printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
 156}
 157
 158void show_registers(struct pt_regs *regs)
 159{
 160        struct psw_bits *psw = &psw_bits(regs->psw);
 161        char *mode;
 162
 163        mode = user_mode(regs) ? "User" : "Krnl";
 164        printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
 165        if (!user_mode(regs))
 166                pr_cont(" (%pSR)", (void *)regs->psw.addr);
 167        pr_cont("\n");
 168        printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 169               "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
 170               psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
 171        pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
 172        printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
 173               regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 174        printk("           %016lx %016lx %016lx %016lx\n",
 175               regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 176        printk("           %016lx %016lx %016lx %016lx\n",
 177               regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 178        printk("           %016lx %016lx %016lx %016lx\n",
 179               regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 180        show_code(regs);
 181}
 182
 183void show_regs(struct pt_regs *regs)
 184{
 185        show_regs_print_info(KERN_DEFAULT);
 186        show_registers(regs);
 187        /* Show stack backtrace if pt_regs is from kernel mode */
 188        if (!user_mode(regs))
 189                show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT);
 190        show_last_breaking_event(regs);
 191}
 192
 193static DEFINE_SPINLOCK(die_lock);
 194
 195void die(struct pt_regs *regs, const char *str)
 196{
 197        static int die_counter;
 198
 199        oops_enter();
 200        lgr_info_log();
 201        debug_stop_all();
 202        console_verbose();
 203        spin_lock_irq(&die_lock);
 204        bust_spinlocks(1);
 205        printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
 206               regs->int_code >> 17, ++die_counter);
 207#ifdef CONFIG_PREEMPT
 208        pr_cont("PREEMPT ");
 209#elif defined(CONFIG_PREEMPT_RT)
 210        pr_cont("PREEMPT_RT ");
 211#endif
 212        pr_cont("SMP ");
 213        if (debug_pagealloc_enabled())
 214                pr_cont("DEBUG_PAGEALLOC");
 215        pr_cont("\n");
 216        notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 217        print_modules();
 218        show_regs(regs);
 219        bust_spinlocks(0);
 220        add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 221        spin_unlock_irq(&die_lock);
 222        if (in_interrupt())
 223                panic("Fatal exception in interrupt");
 224        if (panic_on_oops)
 225                panic("Fatal exception: panic_on_oops");
 226        oops_exit();
 227        do_exit(SIGSEGV);
 228}
 229