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 <asm/processor.h> 18 #include <asm/debug.h> 19 #include <asm/dis.h> 20 #include <asm/ipl.h> 21 22 /* 23 * For dump_trace we have tree different stack to consider: 24 * - the panic stack which is used if the kernel stack has overflown 25 * - the asynchronous interrupt stack (cpu related) 26 * - the synchronous kernel stack (process related) 27 * The stack trace can start at any of the three stacks and can potentially 28 * touch all of them. The order is: panic stack, async stack, sync stack. 29 */ 30 static unsigned long 31 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp, 32 unsigned long low, unsigned long high) 33 { 34 struct stack_frame *sf; 35 struct pt_regs *regs; 36 37 while (1) { 38 if (sp < low || sp > high - sizeof(*sf)) 39 return sp; 40 sf = (struct stack_frame *) sp; 41 if (func(data, sf->gprs[8], 0)) 42 return sp; 43 /* Follow the backchain. */ 44 while (1) { 45 low = sp; 46 sp = sf->back_chain; 47 if (!sp) 48 break; 49 if (sp <= low || sp > high - sizeof(*sf)) 50 return sp; 51 sf = (struct stack_frame *) sp; 52 if (func(data, sf->gprs[8], 1)) 53 return sp; 54 } 55 /* Zero backchain detected, check for interrupt frame. */ 56 sp = (unsigned long) (sf + 1); 57 if (sp <= low || sp > high - sizeof(*regs)) 58 return sp; 59 regs = (struct pt_regs *) sp; 60 if (!user_mode(regs)) { 61 if (func(data, regs->psw.addr, 1)) 62 return sp; 63 } 64 low = sp; 65 sp = regs->gprs[15]; 66 } 67 } 68 69 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task, 70 unsigned long sp) 71 { 72 unsigned long frame_size; 73 74 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 75 #ifdef CONFIG_CHECK_STACK 76 sp = __dump_trace(func, data, sp, 77 S390_lowcore.panic_stack + frame_size - 4096, 78 S390_lowcore.panic_stack + frame_size); 79 #endif 80 sp = __dump_trace(func, data, sp, 81 S390_lowcore.async_stack + frame_size - ASYNC_SIZE, 82 S390_lowcore.async_stack + frame_size); 83 task = task ?: current; 84 __dump_trace(func, data, sp, 85 (unsigned long)task_stack_page(task), 86 (unsigned long)task_stack_page(task) + THREAD_SIZE); 87 } 88 EXPORT_SYMBOL_GPL(dump_trace); 89 90 static int show_address(void *data, unsigned long address, int reliable) 91 { 92 if (reliable) 93 printk(" [<%016lx>] %pSR \n", address, (void *)address); 94 else 95 printk("([<%016lx>] %pSR)\n", address, (void *)address); 96 return 0; 97 } 98 99 static void show_trace(struct task_struct *task, unsigned long sp) 100 { 101 if (!sp) 102 sp = task ? task->thread.ksp : current_stack_pointer(); 103 printk("Call Trace:\n"); 104 dump_trace(show_address, NULL, task, sp); 105 if (!task) 106 task = current; 107 debug_show_held_locks(task); 108 } 109 110 void show_stack(struct task_struct *task, unsigned long *sp) 111 { 112 unsigned long *stack; 113 int i; 114 115 stack = sp; 116 if (!stack) { 117 if (!task) 118 stack = (unsigned long *)current_stack_pointer(); 119 else 120 stack = (unsigned long *)task->thread.ksp; 121 } 122 printk(KERN_DEFAULT "Stack:\n"); 123 for (i = 0; i < 20; i++) { 124 if (((addr_t) stack & (THREAD_SIZE-1)) == 0) 125 break; 126 if (i % 4 == 0) 127 printk(KERN_DEFAULT " "); 128 pr_cont("%016lx%c", *stack++, i % 4 == 3 ? '\n' : ' '); 129 } 130 show_trace(task, (unsigned long)sp); 131 } 132 133 static void show_last_breaking_event(struct pt_regs *regs) 134 { 135 printk("Last Breaking-Event-Address:\n"); 136 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 137 } 138 139 void show_registers(struct pt_regs *regs) 140 { 141 struct psw_bits *psw = &psw_bits(regs->psw); 142 char *mode; 143 144 mode = user_mode(regs) ? "User" : "Krnl"; 145 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 146 if (!user_mode(regs)) 147 pr_cont(" (%pSR)", (void *)regs->psw.addr); 148 pr_cont("\n"); 149 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 150 "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e, 151 psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm); 152 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba); 153 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 154 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 155 printk(" %016lx %016lx %016lx %016lx\n", 156 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 157 printk(" %016lx %016lx %016lx %016lx\n", 158 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 159 printk(" %016lx %016lx %016lx %016lx\n", 160 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 161 show_code(regs); 162 } 163 164 void show_regs(struct pt_regs *regs) 165 { 166 show_regs_print_info(KERN_DEFAULT); 167 show_registers(regs); 168 /* Show stack backtrace if pt_regs is from kernel mode */ 169 if (!user_mode(regs)) 170 show_trace(NULL, regs->gprs[15]); 171 show_last_breaking_event(regs); 172 } 173 174 static DEFINE_SPINLOCK(die_lock); 175 176 void die(struct pt_regs *regs, const char *str) 177 { 178 static int die_counter; 179 180 oops_enter(); 181 lgr_info_log(); 182 debug_stop_all(); 183 console_verbose(); 184 spin_lock_irq(&die_lock); 185 bust_spinlocks(1); 186 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 187 regs->int_code >> 17, ++die_counter); 188 #ifdef CONFIG_PREEMPT 189 pr_cont("PREEMPT "); 190 #endif 191 #ifdef CONFIG_SMP 192 pr_cont("SMP "); 193 #endif 194 if (debug_pagealloc_enabled()) 195 pr_cont("DEBUG_PAGEALLOC"); 196 pr_cont("\n"); 197 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 198 print_modules(); 199 show_regs(regs); 200 bust_spinlocks(0); 201 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 202 spin_unlock_irq(&die_lock); 203 if (in_interrupt()) 204 panic("Fatal exception in interrupt"); 205 if (panic_on_oops) 206 panic("Fatal exception: panic_on_oops"); 207 oops_exit(); 208 do_exit(SIGSEGV); 209 } 210