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 EXPORT_SYMBOL_GPL(stack_type_name);
  42
  43 static 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
  55 static 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
  64 static 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
  73 static 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
  82 static 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
  91 int 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
 114 recursion_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;
 124 unknown:
 125         info->type = STACK_TYPE_UNKNOWN;
 126         return -EINVAL;
 127 }
 128
 129 void 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
 142 static 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
 148 void 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
 173 void 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
 183 static DEFINE_SPINLOCK(die_lock);
 184
 185 void 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 }