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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_mcck_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.mcck_stack + frame_size;
88 return in_stack(sp, info, STACK_TYPE_MCCK, top - THREAD_SIZE, top);
89}
90
91static bool in_restart_stack(unsigned long sp, struct stack_info *info)
92{
93 unsigned long frame_size, top;
94
95 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
96 top = S390_lowcore.restart_stack + frame_size;
97 return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
98}
99
100int get_stack_info(unsigned long sp, struct task_struct *task,
101 struct stack_info *info, unsigned long *visit_mask)
102{
103 if (!sp)
104 goto unknown;
105
106 /* Sanity check: ABI requires SP to be aligned 8 bytes. */
107 if (sp & 0x7)
108 goto unknown;
109
110 /* Check per-task stack */
111 if (in_task_stack(sp, task, info))
112 goto recursion_check;
113
114 if (task != current)
115 goto unknown;
116
117 /* Check per-cpu stacks */
118 if (!in_irq_stack(sp, info) &&
119 !in_nodat_stack(sp, info) &&
120 !in_restart_stack(sp, info) &&
121 !in_mcck_stack(sp, info))
122 goto unknown;
123
124recursion_check:
125 /*
126 * Make sure we don't iterate through any given stack more than once.
127 * If it comes up a second time then there's something wrong going on:
128 * just break out and report an unknown stack type.
129 */
130 if (*visit_mask & (1UL << info->type))
131 goto unknown;
132 *visit_mask |= 1UL << info->type;
133 return 0;
134unknown:
135 info->type = STACK_TYPE_UNKNOWN;
136 return -EINVAL;
137}
138
139void show_stack(struct task_struct *task, unsigned long *stack,
140 const char *loglvl)
141{
142 struct unwind_state state;
143
144 printk("%sCall Trace:\n", loglvl);
145 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
146 printk(state.reliable ? "%s [<%016lx>] %pSR \n" :
147 "%s([<%016lx>] %pSR)\n",
148 loglvl, state.ip, (void *) state.ip);
149 debug_show_held_locks(task ? : current);
150}
151
152static void show_last_breaking_event(struct pt_regs *regs)
153{
154 printk("Last Breaking-Event-Address:\n");
155 printk(" [<%016lx>] %pSR\n", regs->last_break, (void *)regs->last_break);
156}
157
158void show_registers(struct pt_regs *regs)
159{
160 struct psw_bits *psw = &psw_bits(regs->psw);
161 char *mode;
162
163 mode = user_mode(regs) ? "User" : "Krnl";
164 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
165 if (!user_mode(regs))
166 pr_cont(" (%pSR)", (void *)regs->psw.addr);
167 pr_cont("\n");
168 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
169 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
170 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
171 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
172 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
173 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
174 printk(" %016lx %016lx %016lx %016lx\n",
175 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
176 printk(" %016lx %016lx %016lx %016lx\n",
177 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
178 printk(" %016lx %016lx %016lx %016lx\n",
179 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
180 show_code(regs);
181}
182
183void show_regs(struct pt_regs *regs)
184{
185 show_regs_print_info(KERN_DEFAULT);
186 show_registers(regs);
187 /* Show stack backtrace if pt_regs is from kernel mode */
188 if (!user_mode(regs))
189 show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT);
190 show_last_breaking_event(regs);
191}
192
193static DEFINE_SPINLOCK(die_lock);
194
195void __noreturn die(struct pt_regs *regs, const char *str)
196{
197 static int die_counter;
198
199 oops_enter();
200 lgr_info_log();
201 debug_stop_all();
202 console_verbose();
203 spin_lock_irq(&die_lock);
204 bust_spinlocks(1);
205 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
206 regs->int_code >> 17, ++die_counter);
207#ifdef CONFIG_PREEMPT
208 pr_cont("PREEMPT ");
209#elif defined(CONFIG_PREEMPT_RT)
210 pr_cont("PREEMPT_RT ");
211#endif
212 pr_cont("SMP ");
213 if (debug_pagealloc_enabled())
214 pr_cont("DEBUG_PAGEALLOC");
215 pr_cont("\n");
216 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
217 print_modules();
218 show_regs(regs);
219 bust_spinlocks(0);
220 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
221 spin_unlock_irq(&die_lock);
222 if (in_interrupt())
223 panic("Fatal exception in interrupt");
224 if (panic_on_oops)
225 panic("Fatal exception: panic_on_oops");
226 oops_exit();
227 make_task_dead(SIGSEGV);
228}
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 /* Follow the backchain. */
42 while (1) {
43 if (func(data, sf->gprs[8]))
44 return sp;
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 }
53 /* Zero backchain detected, check for interrupt frame. */
54 sp = (unsigned long) (sf + 1);
55 if (sp <= low || sp > high - sizeof(*regs))
56 return sp;
57 regs = (struct pt_regs *) sp;
58 if (!user_mode(regs)) {
59 if (func(data, regs->psw.addr))
60 return sp;
61 }
62 low = sp;
63 sp = regs->gprs[15];
64 }
65}
66
67void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
68 unsigned long sp)
69{
70 unsigned long frame_size;
71
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);
77#endif
78 sp = __dump_trace(func, data, sp,
79 S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
80 S390_lowcore.async_stack + frame_size);
81 if (task)
82 __dump_trace(func, data, sp,
83 (unsigned long)task_stack_page(task),
84 (unsigned long)task_stack_page(task) + THREAD_SIZE);
85 else
86 __dump_trace(func, data, sp,
87 S390_lowcore.thread_info,
88 S390_lowcore.thread_info + THREAD_SIZE);
89}
90EXPORT_SYMBOL_GPL(dump_trace);
91
92static int show_address(void *data, unsigned long address)
93{
94 printk("([<%016lx>] %pSR)\n", address, (void *)address);
95 return 0;
96}
97
98static void show_trace(struct task_struct *task, unsigned long sp)
99{
100 if (!sp)
101 sp = task ? task->thread.ksp : current_stack_pointer();
102 printk("Call Trace:\n");
103 dump_trace(show_address, NULL, task, sp);
104 if (!task)
105 task = current;
106 debug_show_held_locks(task);
107}
108
109void show_stack(struct task_struct *task, unsigned long *sp)
110{
111 unsigned long *stack;
112 int i;
113
114 stack = sp;
115 if (!stack) {
116 if (!task)
117 stack = (unsigned long *)current_stack_pointer();
118 else
119 stack = (unsigned long *)task->thread.ksp;
120 }
121 for (i = 0; i < 20; i++) {
122 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
123 break;
124 if ((i * sizeof(long) % 32) == 0)
125 printk("%s ", i == 0 ? "" : "\n");
126 printk("%016lx ", *stack++);
127 }
128 printk("\n");
129 show_trace(task, (unsigned long)sp);
130}
131
132static void show_last_breaking_event(struct pt_regs *regs)
133{
134 printk("Last Breaking-Event-Address:\n");
135 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
136}
137
138void show_registers(struct pt_regs *regs)
139{
140 struct psw_bits *psw = &psw_bits(regs->psw);
141 char *mode;
142
143 mode = user_mode(regs) ? "User" : "Krnl";
144 printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
145 if (!user_mode(regs))
146 printk(" (%pSR)", (void *)regs->psw.addr);
147 printk("\n");
148 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
149 "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e,
150 psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm);
151 printk(" RI:%x EA:%x", psw->ri, psw->eaba);
152 printk("\n%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
153 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
154 printk(" %016lx %016lx %016lx %016lx\n",
155 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
156 printk(" %016lx %016lx %016lx %016lx\n",
157 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
158 printk(" %016lx %016lx %016lx %016lx\n",
159 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
160 show_code(regs);
161}
162
163void show_regs(struct pt_regs *regs)
164{
165 show_regs_print_info(KERN_DEFAULT);
166 show_registers(regs);
167 /* Show stack backtrace if pt_regs is from kernel mode */
168 if (!user_mode(regs))
169 show_trace(NULL, regs->gprs[15]);
170 show_last_breaking_event(regs);
171}
172
173static DEFINE_SPINLOCK(die_lock);
174
175void die(struct pt_regs *regs, const char *str)
176{
177 static int die_counter;
178
179 oops_enter();
180 lgr_info_log();
181 debug_stop_all();
182 console_verbose();
183 spin_lock_irq(&die_lock);
184 bust_spinlocks(1);
185 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
186 regs->int_code >> 17, ++die_counter);
187#ifdef CONFIG_PREEMPT
188 printk("PREEMPT ");
189#endif
190#ifdef CONFIG_SMP
191 printk("SMP ");
192#endif
193 if (debug_pagealloc_enabled())
194 printk("DEBUG_PAGEALLOC");
195 printk("\n");
196 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
197 print_modules();
198 show_regs(regs);
199 bust_spinlocks(0);
200 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
201 spin_unlock_irq(&die_lock);
202 if (in_interrupt())
203 panic("Fatal exception in interrupt");
204 if (panic_on_oops)
205 panic("Fatal exception: panic_on_oops");
206 oops_exit();
207 do_exit(SIGSEGV);
208}