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 /* Follow the backchain. */ 42 while (1) { 43 if (func(data, sf->gprs[8])) 44 return sp; 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 } 53 /* Zero backchain detected, check for interrupt frame. */ 54 sp = (unsigned long) (sf + 1); 55 if (sp <= low || sp > high - sizeof(*regs)) 56 return sp; 57 regs = (struct pt_regs *) sp; 58 if (!user_mode(regs)) { 59 if (func(data, regs->psw.addr)) 60 return sp; 61 } 62 low = sp; 63 sp = regs->gprs[15]; 64 } 65 } 66 67 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task, 68 unsigned long sp) 69 { 70 unsigned long frame_size; 71 72 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 73 #ifdef CONFIG_CHECK_STACK 74 sp = __dump_trace(func, data, sp, 75 S390_lowcore.panic_stack + frame_size - 4096, 76 S390_lowcore.panic_stack + frame_size); 77 #endif 78 sp = __dump_trace(func, data, sp, 79 S390_lowcore.async_stack + frame_size - ASYNC_SIZE, 80 S390_lowcore.async_stack + frame_size); 81 if (task) 82 __dump_trace(func, data, sp, 83 (unsigned long)task_stack_page(task), 84 (unsigned long)task_stack_page(task) + THREAD_SIZE); 85 else 86 __dump_trace(func, data, sp, 87 S390_lowcore.thread_info, 88 S390_lowcore.thread_info + THREAD_SIZE); 89 } 90 EXPORT_SYMBOL_GPL(dump_trace); 91 92 struct return_address_data { 93 unsigned long address; 94 int depth; 95 }; 96 97 static int __return_address(void *data, unsigned long address) 98 { 99 struct return_address_data *rd = data; 100 101 if (rd->depth--) 102 return 0; 103 rd->address = address; 104 return 1; 105 } 106 107 unsigned long return_address(int depth) 108 { 109 struct return_address_data rd = { .depth = depth + 2 }; 110 111 dump_trace(__return_address, &rd, NULL, current_stack_pointer()); 112 return rd.address; 113 } 114 EXPORT_SYMBOL_GPL(return_address); 115 116 static int show_address(void *data, unsigned long address) 117 { 118 printk("([<%016lx>] %pSR)\n", address, (void *)address); 119 return 0; 120 } 121 122 static void show_trace(struct task_struct *task, unsigned long sp) 123 { 124 if (!sp) 125 sp = task ? task->thread.ksp : current_stack_pointer(); 126 printk("Call Trace:\n"); 127 dump_trace(show_address, NULL, task, sp); 128 if (!task) 129 task = current; 130 debug_show_held_locks(task); 131 } 132 133 void show_stack(struct task_struct *task, unsigned long *sp) 134 { 135 unsigned long *stack; 136 int i; 137 138 stack = sp; 139 if (!stack) { 140 if (!task) 141 stack = (unsigned long *)current_stack_pointer(); 142 else 143 stack = (unsigned long *)task->thread.ksp; 144 } 145 for (i = 0; i < 20; i++) { 146 if (((addr_t) stack & (THREAD_SIZE-1)) == 0) 147 break; 148 if ((i * sizeof(long) % 32) == 0) 149 printk("%s ", i == 0 ? "" : "\n"); 150 printk("%016lx ", *stack++); 151 } 152 printk("\n"); 153 show_trace(task, (unsigned long)sp); 154 } 155 156 static void show_last_breaking_event(struct pt_regs *regs) 157 { 158 printk("Last Breaking-Event-Address:\n"); 159 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 160 } 161 162 void show_registers(struct pt_regs *regs) 163 { 164 struct psw_bits *psw = &psw_bits(regs->psw); 165 char *mode; 166 167 mode = user_mode(regs) ? "User" : "Krnl"; 168 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 169 if (!user_mode(regs)) 170 printk(" (%pSR)", (void *)regs->psw.addr); 171 printk("\n"); 172 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 173 "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e, 174 psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm); 175 printk(" RI:%x EA:%x", psw->ri, psw->eaba); 176 printk("\n%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 177 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 178 printk(" %016lx %016lx %016lx %016lx\n", 179 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 180 printk(" %016lx %016lx %016lx %016lx\n", 181 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 182 printk(" %016lx %016lx %016lx %016lx\n", 183 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 184 show_code(regs); 185 } 186 187 void show_regs(struct pt_regs *regs) 188 { 189 show_regs_print_info(KERN_DEFAULT); 190 show_registers(regs); 191 /* Show stack backtrace if pt_regs is from kernel mode */ 192 if (!user_mode(regs)) 193 show_trace(NULL, regs->gprs[15]); 194 show_last_breaking_event(regs); 195 } 196 197 static DEFINE_SPINLOCK(die_lock); 198 199 void die(struct pt_regs *regs, const char *str) 200 { 201 static int die_counter; 202 203 oops_enter(); 204 lgr_info_log(); 205 debug_stop_all(); 206 console_verbose(); 207 spin_lock_irq(&die_lock); 208 bust_spinlocks(1); 209 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 210 regs->int_code >> 17, ++die_counter); 211 #ifdef CONFIG_PREEMPT 212 printk("PREEMPT "); 213 #endif 214 #ifdef CONFIG_SMP 215 printk("SMP "); 216 #endif 217 if (debug_pagealloc_enabled()) 218 printk("DEBUG_PAGEALLOC"); 219 printk("\n"); 220 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 221 print_modules(); 222 show_regs(regs); 223 bust_spinlocks(0); 224 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 225 spin_unlock_irq(&die_lock); 226 if (in_interrupt()) 227 panic("Fatal exception in interrupt"); 228 if (panic_on_oops) 229 panic("Fatal exception: panic_on_oops"); 230 oops_exit(); 231 do_exit(SIGSEGV); 232 } 233