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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Stack dumping functions
4 *
5 * Copyright IBM Corp. 1999, 2013
6 */
7
8#include <linux/kallsyms.h>
9#include <linux/hardirq.h>
10#include <linux/kprobes.h>
11#include <linux/utsname.h>
12#include <linux/export.h>
13#include <linux/kdebug.h>
14#include <linux/ptrace.h>
15#include <linux/mm.h>
16#include <linux/module.h>
17#include <linux/sched.h>
18#include <linux/sched/debug.h>
19#include <linux/sched/task_stack.h>
20#include <asm/processor.h>
21#include <asm/debug.h>
22#include <asm/dis.h>
23#include <asm/ipl.h>
24#include <asm/unwind.h>
25
26const char *stack_type_name(enum stack_type type)
27{
28 switch (type) {
29 case STACK_TYPE_TASK:
30 return "task";
31 case STACK_TYPE_IRQ:
32 return "irq";
33 case STACK_TYPE_NODAT:
34 return "nodat";
35 case STACK_TYPE_RESTART:
36 return "restart";
37 default:
38 return "unknown";
39 }
40}
41EXPORT_SYMBOL_GPL(stack_type_name);
42
43static inline bool in_stack(unsigned long sp, struct stack_info *info,
44 enum stack_type type, unsigned long low,
45 unsigned long high)
46{
47 if (sp < low || sp >= high)
48 return false;
49 info->type = type;
50 info->begin = low;
51 info->end = high;
52 return true;
53}
54
55static bool in_task_stack(unsigned long sp, struct task_struct *task,
56 struct stack_info *info)
57{
58 unsigned long stack;
59
60 stack = (unsigned long) task_stack_page(task);
61 return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
62}
63
64static bool in_irq_stack(unsigned long sp, struct stack_info *info)
65{
66 unsigned long frame_size, top;
67
68 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
69 top = S390_lowcore.async_stack + frame_size;
70 return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
71}
72
73static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
74{
75 unsigned long frame_size, top;
76
77 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
78 top = S390_lowcore.nodat_stack + frame_size;
79 return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
80}
81
82static bool in_restart_stack(unsigned long sp, struct stack_info *info)
83{
84 unsigned long frame_size, top;
85
86 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
87 top = S390_lowcore.restart_stack + frame_size;
88 return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
89}
90
91int get_stack_info(unsigned long sp, struct task_struct *task,
92 struct stack_info *info, unsigned long *visit_mask)
93{
94 if (!sp)
95 goto unknown;
96
97 /* Sanity check: ABI requires SP to be aligned 8 bytes. */
98 if (sp & 0x7)
99 goto unknown;
100
101 /* Check per-task stack */
102 if (in_task_stack(sp, task, info))
103 goto recursion_check;
104
105 if (task != current)
106 goto unknown;
107
108 /* Check per-cpu stacks */
109 if (!in_irq_stack(sp, info) &&
110 !in_nodat_stack(sp, info) &&
111 !in_restart_stack(sp, info))
112 goto unknown;
113
114recursion_check:
115 /*
116 * Make sure we don't iterate through any given stack more than once.
117 * If it comes up a second time then there's something wrong going on:
118 * just break out and report an unknown stack type.
119 */
120 if (*visit_mask & (1UL << info->type))
121 goto unknown;
122 *visit_mask |= 1UL << info->type;
123 return 0;
124unknown:
125 info->type = STACK_TYPE_UNKNOWN;
126 return -EINVAL;
127}
128
129void show_stack(struct task_struct *task, unsigned long *stack,
130 const char *loglvl)
131{
132 struct unwind_state state;
133
134 printk("%sCall Trace:\n", loglvl);
135 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
136 printk(state.reliable ? "%s [<%016lx>] %pSR \n" :
137 "%s([<%016lx>] %pSR)\n",
138 loglvl, state.ip, (void *) state.ip);
139 debug_show_held_locks(task ? : current);
140}
141
142static void show_last_breaking_event(struct pt_regs *regs)
143{
144 printk("Last Breaking-Event-Address:\n");
145 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
146}
147
148void show_registers(struct pt_regs *regs)
149{
150 struct psw_bits *psw = &psw_bits(regs->psw);
151 char *mode;
152
153 mode = user_mode(regs) ? "User" : "Krnl";
154 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
155 if (!user_mode(regs))
156 pr_cont(" (%pSR)", (void *)regs->psw.addr);
157 pr_cont("\n");
158 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
159 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
160 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
161 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
162 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
163 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
164 printk(" %016lx %016lx %016lx %016lx\n",
165 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
166 printk(" %016lx %016lx %016lx %016lx\n",
167 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
168 printk(" %016lx %016lx %016lx %016lx\n",
169 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
170 show_code(regs);
171}
172
173void show_regs(struct pt_regs *regs)
174{
175 show_regs_print_info(KERN_DEFAULT);
176 show_registers(regs);
177 /* Show stack backtrace if pt_regs is from kernel mode */
178 if (!user_mode(regs))
179 show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT);
180 show_last_breaking_event(regs);
181}
182
183static DEFINE_SPINLOCK(die_lock);
184
185void die(struct pt_regs *regs, const char *str)
186{
187 static int die_counter;
188
189 oops_enter();
190 lgr_info_log();
191 debug_stop_all();
192 console_verbose();
193 spin_lock_irq(&die_lock);
194 bust_spinlocks(1);
195 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
196 regs->int_code >> 17, ++die_counter);
197#ifdef CONFIG_PREEMPT
198 pr_cont("PREEMPT ");
199#elif defined(CONFIG_PREEMPT_RT)
200 pr_cont("PREEMPT_RT ");
201#endif
202 pr_cont("SMP ");
203 if (debug_pagealloc_enabled())
204 pr_cont("DEBUG_PAGEALLOC");
205 pr_cont("\n");
206 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
207 print_modules();
208 show_regs(regs);
209 bust_spinlocks(0);
210 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
211 spin_unlock_irq(&die_lock);
212 if (in_interrupt())
213 panic("Fatal exception in interrupt");
214 if (panic_on_oops)
215 panic("Fatal exception: panic_on_oops");
216 oops_exit();
217 do_exit(SIGSEGV);
218}
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 */
30static 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 if (func(data, sf->gprs[8], 0))
42 return sp;
43 /* Follow the backchain. */
44 while (1) {
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 if (func(data, sf->gprs[8], 1))
53 return sp;
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 if (!user_mode(regs)) {
61 if (func(data, regs->psw.addr, 1))
62 return sp;
63 }
64 low = sp;
65 sp = regs->gprs[15];
66 }
67}
68
69void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
70 unsigned long sp)
71{
72 unsigned long frame_size;
73
74 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
75#ifdef CONFIG_CHECK_STACK
76 sp = __dump_trace(func, data, sp,
77 S390_lowcore.panic_stack + frame_size - 4096,
78 S390_lowcore.panic_stack + frame_size);
79#endif
80 sp = __dump_trace(func, data, sp,
81 S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
82 S390_lowcore.async_stack + frame_size);
83 task = task ?: current;
84 __dump_trace(func, data, sp,
85 (unsigned long)task_stack_page(task),
86 (unsigned long)task_stack_page(task) + THREAD_SIZE);
87}
88EXPORT_SYMBOL_GPL(dump_trace);
89
90static int show_address(void *data, unsigned long address, int reliable)
91{
92 if (reliable)
93 printk(" [<%016lx>] %pSR \n", address, (void *)address);
94 else
95 printk("([<%016lx>] %pSR)\n", address, (void *)address);
96 return 0;
97}
98
99static void show_trace(struct task_struct *task, unsigned long sp)
100{
101 if (!sp)
102 sp = task ? task->thread.ksp : current_stack_pointer();
103 printk("Call Trace:\n");
104 dump_trace(show_address, NULL, task, sp);
105 if (!task)
106 task = current;
107 debug_show_held_locks(task);
108}
109
110void show_stack(struct task_struct *task, unsigned long *sp)
111{
112 unsigned long *stack;
113 int i;
114
115 stack = sp;
116 if (!stack) {
117 if (!task)
118 stack = (unsigned long *)current_stack_pointer();
119 else
120 stack = (unsigned long *)task->thread.ksp;
121 }
122 printk(KERN_DEFAULT "Stack:\n");
123 for (i = 0; i < 20; i++) {
124 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
125 break;
126 if (i % 4 == 0)
127 printk(KERN_DEFAULT " ");
128 pr_cont("%016lx%c", *stack++, i % 4 == 3 ? '\n' : ' ');
129 }
130 show_trace(task, (unsigned long)sp);
131}
132
133static void show_last_breaking_event(struct pt_regs *regs)
134{
135 printk("Last Breaking-Event-Address:\n");
136 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
137}
138
139void show_registers(struct pt_regs *regs)
140{
141 struct psw_bits *psw = &psw_bits(regs->psw);
142 char *mode;
143
144 mode = user_mode(regs) ? "User" : "Krnl";
145 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
146 if (!user_mode(regs))
147 pr_cont(" (%pSR)", (void *)regs->psw.addr);
148 pr_cont("\n");
149 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
150 "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e,
151 psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm);
152 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
153 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
154 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
155 printk(" %016lx %016lx %016lx %016lx\n",
156 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
157 printk(" %016lx %016lx %016lx %016lx\n",
158 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
159 printk(" %016lx %016lx %016lx %016lx\n",
160 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
161 show_code(regs);
162}
163
164void show_regs(struct pt_regs *regs)
165{
166 show_regs_print_info(KERN_DEFAULT);
167 show_registers(regs);
168 /* Show stack backtrace if pt_regs is from kernel mode */
169 if (!user_mode(regs))
170 show_trace(NULL, regs->gprs[15]);
171 show_last_breaking_event(regs);
172}
173
174static DEFINE_SPINLOCK(die_lock);
175
176void die(struct pt_regs *regs, const char *str)
177{
178 static int die_counter;
179
180 oops_enter();
181 lgr_info_log();
182 debug_stop_all();
183 console_verbose();
184 spin_lock_irq(&die_lock);
185 bust_spinlocks(1);
186 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
187 regs->int_code >> 17, ++die_counter);
188#ifdef CONFIG_PREEMPT
189 pr_cont("PREEMPT ");
190#endif
191#ifdef CONFIG_SMP
192 pr_cont("SMP ");
193#endif
194 if (debug_pagealloc_enabled())
195 pr_cont("DEBUG_PAGEALLOC");
196 pr_cont("\n");
197 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
198 print_modules();
199 show_regs(regs);
200 bust_spinlocks(0);
201 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
202 spin_unlock_irq(&die_lock);
203 if (in_interrupt())
204 panic("Fatal exception in interrupt");
205 if (panic_on_oops)
206 panic("Fatal exception: panic_on_oops");
207 oops_exit();
208 do_exit(SIGSEGV);
209}