1 /* 2 * Stack dumping functions 3 * 4 * Copyright IBM Corp. 1999, 2013 5 */ 6 7 #include <linux/kallsyms.h> 8 #include <linux/hardirq.h> 9 #include <linux/kprobes.h> 10 #include <linux/utsname.h> 11 #include <linux/export.h> 12 #include <linux/kdebug.h> 13 #include <linux/ptrace.h> 14 #include <linux/mm.h> 15 #include <linux/module.h> 16 #include <linux/sched.h> 17 #include <linux/sched/debug.h> 18 #include <linux/sched/task_stack.h> 19 #include <asm/processor.h> 20 #include <asm/debug.h> 21 #include <asm/dis.h> 22 #include <asm/ipl.h> 23 24 /* 25 * For dump_trace we have tree different stack to consider: 26 * - the panic stack which is used if the kernel stack has overflown 27 * - the asynchronous interrupt stack (cpu related) 28 * - the synchronous kernel stack (process related) 29 * The stack trace can start at any of the three stacks and can potentially 30 * touch all of them. The order is: panic stack, async stack, sync stack. 31 */ 32 static unsigned long __dump_trace(dump_trace_func_t func,void * data,unsigned long sp,unsigned long low,unsigned long high)33 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp, 34 unsigned long low, unsigned long high) 35 { 36 struct stack_frame *sf; 37 struct pt_regs *regs; 38 39 while (1) { 40 if (sp < low || sp > high - sizeof(*sf)) 41 return sp; 42 sf = (struct stack_frame *) sp; 43 if (func(data, sf->gprs[8], 0)) 44 return sp; 45 /* Follow the backchain. */ 46 while (1) { 47 low = sp; 48 sp = sf->back_chain; 49 if (!sp) 50 break; 51 if (sp <= low || sp > high - sizeof(*sf)) 52 return sp; 53 sf = (struct stack_frame *) sp; 54 if (func(data, sf->gprs[8], 1)) 55 return sp; 56 } 57 /* Zero backchain detected, check for interrupt frame. */ 58 sp = (unsigned long) (sf + 1); 59 if (sp <= low || sp > high - sizeof(*regs)) 60 return sp; 61 regs = (struct pt_regs *) sp; 62 if (!user_mode(regs)) { 63 if (func(data, regs->psw.addr, 1)) 64 return sp; 65 } 66 low = sp; 67 sp = regs->gprs[15]; 68 } 69 } 70 dump_trace(dump_trace_func_t func,void * data,struct task_struct * task,unsigned long sp)71 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task, 72 unsigned long sp) 73 { 74 unsigned long frame_size; 75 76 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 77 #ifdef CONFIG_CHECK_STACK 78 sp = __dump_trace(func, data, sp, 79 S390_lowcore.panic_stack + frame_size - PAGE_SIZE, 80 S390_lowcore.panic_stack + frame_size); 81 #endif 82 sp = __dump_trace(func, data, sp, 83 S390_lowcore.async_stack + frame_size - ASYNC_SIZE, 84 S390_lowcore.async_stack + frame_size); 85 task = task ?: current; 86 __dump_trace(func, data, sp, 87 (unsigned long)task_stack_page(task), 88 (unsigned long)task_stack_page(task) + THREAD_SIZE); 89 } 90 EXPORT_SYMBOL_GPL(dump_trace); 91 show_address(void * data,unsigned long address,int reliable)92 static int show_address(void *data, unsigned long address, int reliable) 93 { 94 if (reliable) 95 printk(" [<%016lx>] %pSR \n", address, (void *)address); 96 else 97 printk("([<%016lx>] %pSR)\n", address, (void *)address); 98 return 0; 99 } 100 show_stack(struct task_struct * task,unsigned long * stack)101 void show_stack(struct task_struct *task, unsigned long *stack) 102 { 103 unsigned long sp = (unsigned long) stack; 104 105 if (!sp) 106 sp = task ? task->thread.ksp : current_stack_pointer(); 107 printk("Call Trace:\n"); 108 dump_trace(show_address, NULL, task, sp); 109 if (!task) 110 task = current; 111 debug_show_held_locks(task); 112 } 113 show_last_breaking_event(struct pt_regs * regs)114 static void show_last_breaking_event(struct pt_regs *regs) 115 { 116 printk("Last Breaking-Event-Address:\n"); 117 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 118 } 119 show_registers(struct pt_regs * regs)120 void show_registers(struct pt_regs *regs) 121 { 122 struct psw_bits *psw = &psw_bits(regs->psw); 123 char *mode; 124 125 mode = user_mode(regs) ? "User" : "Krnl"; 126 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 127 if (!user_mode(regs)) 128 pr_cont(" (%pSR)", (void *)regs->psw.addr); 129 pr_cont("\n"); 130 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 131 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext, 132 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm); 133 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba); 134 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 135 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 136 printk(" %016lx %016lx %016lx %016lx\n", 137 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 138 printk(" %016lx %016lx %016lx %016lx\n", 139 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 140 printk(" %016lx %016lx %016lx %016lx\n", 141 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 142 show_code(regs); 143 } 144 show_regs(struct pt_regs * regs)145 void show_regs(struct pt_regs *regs) 146 { 147 show_regs_print_info(KERN_DEFAULT); 148 show_registers(regs); 149 /* Show stack backtrace if pt_regs is from kernel mode */ 150 if (!user_mode(regs)) 151 show_stack(NULL, (unsigned long *) regs->gprs[15]); 152 show_last_breaking_event(regs); 153 } 154 155 static DEFINE_SPINLOCK(die_lock); 156 die(struct pt_regs * regs,const char * str)157 void die(struct pt_regs *regs, const char *str) 158 { 159 static int die_counter; 160 161 oops_enter(); 162 lgr_info_log(); 163 debug_stop_all(); 164 console_verbose(); 165 spin_lock_irq(&die_lock); 166 bust_spinlocks(1); 167 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 168 regs->int_code >> 17, ++die_counter); 169 #ifdef CONFIG_PREEMPT 170 pr_cont("PREEMPT "); 171 #endif 172 #ifdef CONFIG_SMP 173 pr_cont("SMP "); 174 #endif 175 if (debug_pagealloc_enabled()) 176 pr_cont("DEBUG_PAGEALLOC"); 177 pr_cont("\n"); 178 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 179 print_modules(); 180 show_regs(regs); 181 bust_spinlocks(0); 182 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 183 spin_unlock_irq(&die_lock); 184 if (in_interrupt()) 185 panic("Fatal exception in interrupt"); 186 if (panic_on_oops) 187 panic("Fatal exception: panic_on_oops"); 188 oops_exit(); 189 do_exit(SIGSEGV); 190 } 191