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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 stack)
45{
46 if (sp < stack || sp >= stack + THREAD_SIZE)
47 return false;
48 info->type = type;
49 info->begin = stack;
50 info->end = stack + THREAD_SIZE;
51 return true;
52}
53
54static bool in_task_stack(unsigned long sp, struct task_struct *task,
55 struct stack_info *info)
56{
57 unsigned long stack = (unsigned long)task_stack_page(task);
58
59 return in_stack(sp, info, STACK_TYPE_TASK, stack);
60}
61
62static bool in_irq_stack(unsigned long sp, struct stack_info *info)
63{
64 unsigned long stack = get_lowcore()->async_stack - STACK_INIT_OFFSET;
65
66 return in_stack(sp, info, STACK_TYPE_IRQ, stack);
67}
68
69static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
70{
71 unsigned long stack = get_lowcore()->nodat_stack - STACK_INIT_OFFSET;
72
73 return in_stack(sp, info, STACK_TYPE_NODAT, stack);
74}
75
76static bool in_mcck_stack(unsigned long sp, struct stack_info *info)
77{
78 unsigned long stack = get_lowcore()->mcck_stack - STACK_INIT_OFFSET;
79
80 return in_stack(sp, info, STACK_TYPE_MCCK, stack);
81}
82
83static bool in_restart_stack(unsigned long sp, struct stack_info *info)
84{
85 unsigned long stack = get_lowcore()->restart_stack - STACK_INIT_OFFSET;
86
87 return in_stack(sp, info, STACK_TYPE_RESTART, stack);
88}
89
90int get_stack_info(unsigned long sp, struct task_struct *task,
91 struct stack_info *info, unsigned long *visit_mask)
92{
93 if (!sp)
94 goto unknown;
95
96 /* Sanity check: ABI requires SP to be aligned 8 bytes. */
97 if (sp & 0x7)
98 goto unknown;
99
100 /* Check per-task stack */
101 if (in_task_stack(sp, task, info))
102 goto recursion_check;
103
104 if (task != current)
105 goto unknown;
106
107 /* Check per-cpu stacks */
108 if (!in_irq_stack(sp, info) &&
109 !in_nodat_stack(sp, info) &&
110 !in_restart_stack(sp, info) &&
111 !in_mcck_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>] ", regs->last_break);
146 if (user_mode(regs)) {
147 print_vma_addr(KERN_CONT, regs->last_break);
148 pr_cont("\n");
149 } else {
150 pr_cont("%pSR\n", (void *)regs->last_break);
151 }
152}
153
154void show_registers(struct pt_regs *regs)
155{
156 struct psw_bits *psw = &psw_bits(regs->psw);
157 char *mode;
158
159 mode = user_mode(regs) ? "User" : "Krnl";
160 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
161 if (!user_mode(regs))
162 pr_cont(" (%pSR)", (void *)regs->psw.addr);
163 pr_cont("\n");
164 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
165 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
166 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
167 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
168 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
169 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
170 printk(" %016lx %016lx %016lx %016lx\n",
171 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
172 printk(" %016lx %016lx %016lx %016lx\n",
173 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
174 printk(" %016lx %016lx %016lx %016lx\n",
175 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
176 show_code(regs);
177}
178
179void show_regs(struct pt_regs *regs)
180{
181 show_regs_print_info(KERN_DEFAULT);
182 show_registers(regs);
183 /* Show stack backtrace if pt_regs is from kernel mode */
184 if (!user_mode(regs))
185 show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT);
186 show_last_breaking_event(regs);
187}
188
189static DEFINE_SPINLOCK(die_lock);
190
191void __noreturn die(struct pt_regs *regs, const char *str)
192{
193 static int die_counter;
194
195 oops_enter();
196 lgr_info_log();
197 debug_stop_all();
198 console_verbose();
199 spin_lock_irq(&die_lock);
200 bust_spinlocks(1);
201 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
202 regs->int_code >> 17, ++die_counter);
203#ifdef CONFIG_PREEMPT
204 pr_cont("PREEMPT ");
205#elif defined(CONFIG_PREEMPT_RT)
206 pr_cont("PREEMPT_RT ");
207#endif
208 pr_cont("SMP ");
209 if (debug_pagealloc_enabled())
210 pr_cont("DEBUG_PAGEALLOC");
211 pr_cont("\n");
212 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
213 print_modules();
214 show_regs(regs);
215 bust_spinlocks(0);
216 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
217 spin_unlock_irq(&die_lock);
218 if (in_interrupt())
219 panic("Fatal exception in interrupt");
220 if (panic_on_oops)
221 panic("Fatal exception: panic_on_oops");
222 oops_exit();
223 make_task_dead(SIGSEGV);
224}
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#ifndef CONFIG_64BIT
22#define LONG "%08lx "
23#define FOURLONG "%08lx %08lx %08lx %08lx\n"
24static int kstack_depth_to_print = 12;
25#else /* CONFIG_64BIT */
26#define LONG "%016lx "
27#define FOURLONG "%016lx %016lx %016lx %016lx\n"
28static int kstack_depth_to_print = 20;
29#endif /* CONFIG_64BIT */
30
31/*
32 * For show_trace we have tree different stack to consider:
33 * - the panic stack which is used if the kernel stack has overflown
34 * - the asynchronous interrupt stack (cpu related)
35 * - the synchronous kernel stack (process related)
36 * The stack trace can start at any of the three stack and can potentially
37 * touch all of them. The order is: panic stack, async stack, sync stack.
38 */
39static unsigned long
40__show_trace(unsigned long sp, unsigned long low, unsigned long high)
41{
42 struct stack_frame *sf;
43 struct pt_regs *regs;
44 unsigned long addr;
45
46 while (1) {
47 sp = sp & PSW_ADDR_INSN;
48 if (sp < low || sp > high - sizeof(*sf))
49 return sp;
50 sf = (struct stack_frame *) sp;
51 addr = sf->gprs[8] & PSW_ADDR_INSN;
52 printk("([<%016lx>] %pSR)\n", addr, (void *)addr);
53 /* Follow the backchain. */
54 while (1) {
55 low = sp;
56 sp = sf->back_chain & PSW_ADDR_INSN;
57 if (!sp)
58 break;
59 if (sp <= low || sp > high - sizeof(*sf))
60 return sp;
61 sf = (struct stack_frame *) sp;
62 addr = sf->gprs[8] & PSW_ADDR_INSN;
63 printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
64 }
65 /* Zero backchain detected, check for interrupt frame. */
66 sp = (unsigned long) (sf + 1);
67 if (sp <= low || sp > high - sizeof(*regs))
68 return sp;
69 regs = (struct pt_regs *) sp;
70 addr = regs->psw.addr & PSW_ADDR_INSN;
71 printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
72 low = sp;
73 sp = regs->gprs[15];
74 }
75}
76
77static void show_trace(struct task_struct *task, unsigned long *stack)
78{
79 const unsigned long frame_size =
80 STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
81 register unsigned long __r15 asm ("15");
82 unsigned long sp;
83
84 sp = (unsigned long) stack;
85 if (!sp)
86 sp = task ? task->thread.ksp : __r15;
87 printk("Call Trace:\n");
88#ifdef CONFIG_CHECK_STACK
89 sp = __show_trace(sp,
90 S390_lowcore.panic_stack + frame_size - 4096,
91 S390_lowcore.panic_stack + frame_size);
92#endif
93 sp = __show_trace(sp,
94 S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
95 S390_lowcore.async_stack + frame_size);
96 if (task)
97 __show_trace(sp, (unsigned long) task_stack_page(task),
98 (unsigned long) task_stack_page(task) + THREAD_SIZE);
99 else
100 __show_trace(sp, S390_lowcore.thread_info,
101 S390_lowcore.thread_info + THREAD_SIZE);
102 if (!task)
103 task = current;
104 debug_show_held_locks(task);
105}
106
107void show_stack(struct task_struct *task, unsigned long *sp)
108{
109 register unsigned long *__r15 asm ("15");
110 unsigned long *stack;
111 int i;
112
113 if (!sp)
114 stack = task ? (unsigned long *) task->thread.ksp : __r15;
115 else
116 stack = sp;
117
118 for (i = 0; i < kstack_depth_to_print; i++) {
119 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
120 break;
121 if ((i * sizeof(long) % 32) == 0)
122 printk("%s ", i == 0 ? "" : "\n");
123 printk(LONG, *stack++);
124 }
125 printk("\n");
126 show_trace(task, sp);
127}
128
129static void show_last_breaking_event(struct pt_regs *regs)
130{
131#ifdef CONFIG_64BIT
132 printk("Last Breaking-Event-Address:\n");
133 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
134#endif
135}
136
137static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
138{
139 return (regs->psw.mask & bits) / ((~bits + 1) & bits);
140}
141
142void show_registers(struct pt_regs *regs)
143{
144 char *mode;
145
146 mode = user_mode(regs) ? "User" : "Krnl";
147 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
148 if (!user_mode(regs))
149 printk(" (%pSR)", (void *)regs->psw.addr);
150 printk("\n");
151 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
152 "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
153 mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
154 mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
155 mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
156 mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
157 mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
158#ifdef CONFIG_64BIT
159 printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
160#endif
161 printk("\n%s GPRS: " FOURLONG, mode,
162 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
163 printk(" " FOURLONG,
164 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
165 printk(" " FOURLONG,
166 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
167 printk(" " FOURLONG,
168 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
169 show_code(regs);
170}
171
172void show_regs(struct pt_regs *regs)
173{
174 show_regs_print_info(KERN_DEFAULT);
175 show_registers(regs);
176 /* Show stack backtrace if pt_regs is from kernel mode */
177 if (!user_mode(regs))
178 show_trace(NULL, (unsigned long *) regs->gprs[15]);
179 show_last_breaking_event(regs);
180}
181
182static DEFINE_SPINLOCK(die_lock);
183
184void die(struct pt_regs *regs, const char *str)
185{
186 static int die_counter;
187
188 oops_enter();
189 lgr_info_log();
190 debug_stop_all();
191 console_verbose();
192 spin_lock_irq(&die_lock);
193 bust_spinlocks(1);
194 printk("%s: %04x [#%d] ", str, regs->int_code & 0xffff, ++die_counter);
195#ifdef CONFIG_PREEMPT
196 printk("PREEMPT ");
197#endif
198#ifdef CONFIG_SMP
199 printk("SMP ");
200#endif
201#ifdef CONFIG_DEBUG_PAGEALLOC
202 printk("DEBUG_PAGEALLOC");
203#endif
204 printk("\n");
205 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
206 print_modules();
207 show_regs(regs);
208 bust_spinlocks(0);
209 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
210 spin_unlock_irq(&die_lock);
211 if (in_interrupt())
212 panic("Fatal exception in interrupt");
213 if (panic_on_oops)
214 panic("Fatal exception: panic_on_oops");
215 oops_exit();
216 do_exit(SIGSEGV);
217}