2 * Stack dumping functions
4 * Copyright IBM Corp. 1999, 2013
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>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <asm/processor.h>
18 #include <asm/debug.h>
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.
31 __dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
32 unsigned long low, unsigned long high)
34 struct stack_frame *sf;
38 if (sp < low || sp > high - sizeof(*sf))
40 sf = (struct stack_frame *) sp;
41 /* Follow the backchain. */
43 if (func(data, sf->gprs[8]))
49 if (sp <= low || sp > high - sizeof(*sf))
51 sf = (struct stack_frame *) sp;
53 /* Zero backchain detected, check for interrupt frame. */
54 sp = (unsigned long) (sf + 1);
55 if (sp <= low || sp > high - sizeof(*regs))
57 regs = (struct pt_regs *) sp;
58 if (!user_mode(regs)) {
59 if (func(data, regs->psw.addr))
67 void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
70 unsigned long frame_size;
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);
78 sp = __dump_trace(func, data, sp,
79 S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
80 S390_lowcore.async_stack + frame_size);
82 __dump_trace(func, data, sp,
83 (unsigned long)task_stack_page(task),
84 (unsigned long)task_stack_page(task) + THREAD_SIZE);
86 __dump_trace(func, data, sp,
87 S390_lowcore.thread_info,
88 S390_lowcore.thread_info + THREAD_SIZE);
90 EXPORT_SYMBOL_GPL(dump_trace);
92 struct return_address_data {
93 unsigned long address;
97 static int __return_address(void *data, unsigned long address)
99 struct return_address_data *rd = data;
103 rd->address = address;
107 unsigned long return_address(int depth)
109 struct return_address_data rd = { .depth = depth + 2 };
111 dump_trace(__return_address, &rd, NULL, current_stack_pointer());
114 EXPORT_SYMBOL_GPL(return_address);
116 static int show_address(void *data, unsigned long address)
118 printk("([<%016lx>] %pSR)\n", address, (void *)address);
122 static void show_trace(struct task_struct *task, unsigned long sp)
125 sp = task ? task->thread.ksp : current_stack_pointer();
126 printk("Call Trace:\n");
127 dump_trace(show_address, NULL, task, sp);
130 debug_show_held_locks(task);
133 void show_stack(struct task_struct *task, unsigned long *sp)
135 unsigned long *stack;
141 stack = (unsigned long *)current_stack_pointer();
143 stack = (unsigned long *)task->thread.ksp;
145 for (i = 0; i < 20; i++) {
146 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
148 if ((i * sizeof(long) % 32) == 0)
149 printk("%s ", i == 0 ? "" : "\n");
150 printk("%016lx ", *stack++);
153 show_trace(task, (unsigned long)sp);
156 static void show_last_breaking_event(struct pt_regs *regs)
158 printk("Last Breaking-Event-Address:\n");
159 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
162 void show_registers(struct pt_regs *regs)
164 struct psw_bits *psw = &psw_bits(regs->psw);
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);
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]);
187 void show_regs(struct pt_regs *regs)
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);
197 static DEFINE_SPINLOCK(die_lock);
199 void die(struct pt_regs *regs, const char *str)
201 static int die_counter;
207 spin_lock_irq(&die_lock);
209 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
210 regs->int_code >> 17, ++die_counter);
211 #ifdef CONFIG_PREEMPT
217 if (debug_pagealloc_enabled())
218 printk("DEBUG_PAGEALLOC");
220 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
224 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
225 spin_unlock_irq(&die_lock);
227 panic("Fatal exception in interrupt");
229 panic("Fatal exception: panic_on_oops");