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[mirror_ubuntu-bionic-kernel.git] / arch / s390 / kernel / dumpstack.c
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 }