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/module.h> 15 #include <linux/sched.h> 16 #include <asm/processor.h> 17 #include <asm/debug.h> 18 #include <asm/dis.h> 19 #include <asm/ipl.h> 20 21 /* 22 * For show_trace we have tree different stack to consider: 23 * - the panic stack which is used if the kernel stack has overflown 24 * - the asynchronous interrupt stack (cpu related) 25 * - the synchronous kernel stack (process related) 26 * The stack trace can start at any of the three stack and can potentially 27 * touch all of them. The order is: panic stack, async stack, sync stack. 28 */ 29 static unsigned long 30 __show_trace(unsigned long sp, unsigned long low, unsigned long high) 31 { 32 struct stack_frame *sf; 33 struct pt_regs *regs; 34 unsigned long addr; 35 36 while (1) { 37 if (sp < low || sp > high - sizeof(*sf)) 38 return sp; 39 sf = (struct stack_frame *) sp; 40 addr = sf->gprs[8]; 41 printk("([<%016lx>] %pSR)\n", addr, (void *)addr); 42 /* Follow the backchain. */ 43 while (1) { 44 low = sp; 45 sp = sf->back_chain; 46 if (!sp) 47 break; 48 if (sp <= low || sp > high - sizeof(*sf)) 49 return sp; 50 sf = (struct stack_frame *) sp; 51 addr = sf->gprs[8]; 52 printk(" [<%016lx>] %pSR\n", addr, (void *)addr); 53 } 54 /* Zero backchain detected, check for interrupt frame. */ 55 sp = (unsigned long) (sf + 1); 56 if (sp <= low || sp > high - sizeof(*regs)) 57 return sp; 58 regs = (struct pt_regs *) sp; 59 addr = regs->psw.addr; 60 printk(" [<%016lx>] %pSR\n", addr, (void *)addr); 61 low = sp; 62 sp = regs->gprs[15]; 63 } 64 } 65 66 static void show_trace(struct task_struct *task, unsigned long *stack) 67 { 68 const unsigned long frame_size = 69 STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 70 register unsigned long __r15 asm ("15"); 71 unsigned long sp; 72 73 sp = (unsigned long) stack; 74 if (!sp) 75 sp = task ? task->thread.ksp : __r15; 76 printk("Call Trace:\n"); 77 #ifdef CONFIG_CHECK_STACK 78 sp = __show_trace(sp, 79 S390_lowcore.panic_stack + frame_size - 4096, 80 S390_lowcore.panic_stack + frame_size); 81 #endif 82 sp = __show_trace(sp, 83 S390_lowcore.async_stack + frame_size - ASYNC_SIZE, 84 S390_lowcore.async_stack + frame_size); 85 if (task) 86 __show_trace(sp, (unsigned long) task_stack_page(task), 87 (unsigned long) task_stack_page(task) + THREAD_SIZE); 88 else 89 __show_trace(sp, S390_lowcore.thread_info, 90 S390_lowcore.thread_info + THREAD_SIZE); 91 if (!task) 92 task = current; 93 debug_show_held_locks(task); 94 } 95 96 void show_stack(struct task_struct *task, unsigned long *sp) 97 { 98 register unsigned long *__r15 asm ("15"); 99 unsigned long *stack; 100 int i; 101 102 if (!sp) 103 stack = task ? (unsigned long *) task->thread.ksp : __r15; 104 else 105 stack = sp; 106 107 for (i = 0; i < 20; i++) { 108 if (((addr_t) stack & (THREAD_SIZE-1)) == 0) 109 break; 110 if ((i * sizeof(long) % 32) == 0) 111 printk("%s ", i == 0 ? "" : "\n"); 112 printk("%016lx ", *stack++); 113 } 114 printk("\n"); 115 show_trace(task, sp); 116 } 117 118 static void show_last_breaking_event(struct pt_regs *regs) 119 { 120 printk("Last Breaking-Event-Address:\n"); 121 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 122 } 123 124 static inline int mask_bits(struct pt_regs *regs, unsigned long bits) 125 { 126 return (regs->psw.mask & bits) / ((~bits + 1) & bits); 127 } 128 129 void show_registers(struct pt_regs *regs) 130 { 131 char *mode; 132 133 mode = user_mode(regs) ? "User" : "Krnl"; 134 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 135 if (!user_mode(regs)) 136 printk(" (%pSR)", (void *)regs->psw.addr); 137 printk("\n"); 138 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 139 "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER), 140 mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO), 141 mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY), 142 mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT), 143 mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC), 144 mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM)); 145 printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA)); 146 printk("\n%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 147 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 148 printk(" %016lx %016lx %016lx %016lx\n", 149 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 150 printk(" %016lx %016lx %016lx %016lx\n", 151 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 152 printk(" %016lx %016lx %016lx %016lx\n", 153 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 154 show_code(regs); 155 } 156 157 void show_regs(struct pt_regs *regs) 158 { 159 show_regs_print_info(KERN_DEFAULT); 160 show_registers(regs); 161 /* Show stack backtrace if pt_regs is from kernel mode */ 162 if (!user_mode(regs)) 163 show_trace(NULL, (unsigned long *) regs->gprs[15]); 164 show_last_breaking_event(regs); 165 } 166 167 static DEFINE_SPINLOCK(die_lock); 168 169 void die(struct pt_regs *regs, const char *str) 170 { 171 static int die_counter; 172 173 oops_enter(); 174 lgr_info_log(); 175 debug_stop_all(); 176 console_verbose(); 177 spin_lock_irq(&die_lock); 178 bust_spinlocks(1); 179 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 180 regs->int_code >> 17, ++die_counter); 181 #ifdef CONFIG_PREEMPT 182 printk("PREEMPT "); 183 #endif 184 #ifdef CONFIG_SMP 185 printk("SMP "); 186 #endif 187 #ifdef CONFIG_DEBUG_PAGEALLOC 188 printk("DEBUG_PAGEALLOC"); 189 #endif 190 printk("\n"); 191 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 192 print_modules(); 193 show_regs(regs); 194 bust_spinlocks(0); 195 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 196 spin_unlock_irq(&die_lock); 197 if (in_interrupt()) 198 panic("Fatal exception in interrupt"); 199 if (panic_on_oops) 200 panic("Fatal exception: panic_on_oops"); 201 oops_exit(); 202 do_exit(SIGSEGV); 203 } 204