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 sp = sp & PSW_ADDR_INSN; 38 if (sp < low || sp > high - sizeof(*sf)) 39 return sp; 40 sf = (struct stack_frame *) sp; 41 addr = sf->gprs[8] & PSW_ADDR_INSN; 42 printk("([<%016lx>] %pSR)\n", addr, (void *)addr); 43 /* Follow the backchain. */ 44 while (1) { 45 low = sp; 46 sp = sf->back_chain & PSW_ADDR_INSN; 47 if (!sp) 48 break; 49 if (sp <= low || sp > high - sizeof(*sf)) 50 return sp; 51 sf = (struct stack_frame *) sp; 52 addr = sf->gprs[8] & PSW_ADDR_INSN; 53 printk(" [<%016lx>] %pSR\n", addr, (void *)addr); 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 addr = regs->psw.addr & PSW_ADDR_INSN; 61 printk(" [<%016lx>] %pSR\n", addr, (void *)addr); 62 low = sp; 63 sp = regs->gprs[15]; 64 } 65 } 66 67 static void show_trace(struct task_struct *task, unsigned long *stack) 68 { 69 const unsigned long frame_size = 70 STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 71 register unsigned long __r15 asm ("15"); 72 unsigned long sp; 73 74 sp = (unsigned long) stack; 75 if (!sp) 76 sp = task ? task->thread.ksp : __r15; 77 printk("Call Trace:\n"); 78 #ifdef CONFIG_CHECK_STACK 79 sp = __show_trace(sp, 80 S390_lowcore.panic_stack + frame_size - 4096, 81 S390_lowcore.panic_stack + frame_size); 82 #endif 83 sp = __show_trace(sp, 84 S390_lowcore.async_stack + frame_size - ASYNC_SIZE, 85 S390_lowcore.async_stack + frame_size); 86 if (task) 87 __show_trace(sp, (unsigned long) task_stack_page(task), 88 (unsigned long) task_stack_page(task) + THREAD_SIZE); 89 else 90 __show_trace(sp, S390_lowcore.thread_info, 91 S390_lowcore.thread_info + THREAD_SIZE); 92 if (!task) 93 task = current; 94 debug_show_held_locks(task); 95 } 96 97 void show_stack(struct task_struct *task, unsigned long *sp) 98 { 99 register unsigned long *__r15 asm ("15"); 100 unsigned long *stack; 101 int i; 102 103 if (!sp) 104 stack = task ? (unsigned long *) task->thread.ksp : __r15; 105 else 106 stack = sp; 107 108 for (i = 0; i < 20; i++) { 109 if (((addr_t) stack & (THREAD_SIZE-1)) == 0) 110 break; 111 if ((i * sizeof(long) % 32) == 0) 112 printk("%s ", i == 0 ? "" : "\n"); 113 printk("%016lx ", *stack++); 114 } 115 printk("\n"); 116 show_trace(task, sp); 117 } 118 119 static void show_last_breaking_event(struct pt_regs *regs) 120 { 121 printk("Last Breaking-Event-Address:\n"); 122 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]); 123 } 124 125 static inline int mask_bits(struct pt_regs *regs, unsigned long bits) 126 { 127 return (regs->psw.mask & bits) / ((~bits + 1) & bits); 128 } 129 130 void show_registers(struct pt_regs *regs) 131 { 132 char *mode; 133 134 mode = user_mode(regs) ? "User" : "Krnl"; 135 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr); 136 if (!user_mode(regs)) 137 printk(" (%pSR)", (void *)regs->psw.addr); 138 printk("\n"); 139 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x " 140 "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER), 141 mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO), 142 mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY), 143 mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT), 144 mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC), 145 mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM)); 146 printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA)); 147 printk("\n%s GPRS: %016lx %016lx %016lx %016lx\n", mode, 148 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]); 149 printk(" %016lx %016lx %016lx %016lx\n", 150 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]); 151 printk(" %016lx %016lx %016lx %016lx\n", 152 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]); 153 printk(" %016lx %016lx %016lx %016lx\n", 154 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]); 155 show_code(regs); 156 } 157 158 void show_regs(struct pt_regs *regs) 159 { 160 show_regs_print_info(KERN_DEFAULT); 161 show_registers(regs); 162 /* Show stack backtrace if pt_regs is from kernel mode */ 163 if (!user_mode(regs)) 164 show_trace(NULL, (unsigned long *) regs->gprs[15]); 165 show_last_breaking_event(regs); 166 } 167 168 static DEFINE_SPINLOCK(die_lock); 169 170 void die(struct pt_regs *regs, const char *str) 171 { 172 static int die_counter; 173 174 oops_enter(); 175 lgr_info_log(); 176 debug_stop_all(); 177 console_verbose(); 178 spin_lock_irq(&die_lock); 179 bust_spinlocks(1); 180 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff, 181 regs->int_code >> 17, ++die_counter); 182 #ifdef CONFIG_PREEMPT 183 printk("PREEMPT "); 184 #endif 185 #ifdef CONFIG_SMP 186 printk("SMP "); 187 #endif 188 #ifdef CONFIG_DEBUG_PAGEALLOC 189 printk("DEBUG_PAGEALLOC"); 190 #endif 191 printk("\n"); 192 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV); 193 print_modules(); 194 show_regs(regs); 195 bust_spinlocks(0); 196 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); 197 spin_unlock_irq(&die_lock); 198 if (in_interrupt()) 199 panic("Fatal exception in interrupt"); 200 if (panic_on_oops) 201 panic("Fatal exception: panic_on_oops"); 202 oops_exit(); 203 do_exit(SIGSEGV); 204 } 205