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
stack_type_name(enum stack_type type)26 const 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 }
41
in_stack(unsigned long sp,struct stack_info * info,enum stack_type type,unsigned long low,unsigned long high)42 static inline bool in_stack(unsigned long sp, struct stack_info *info,
43 enum stack_type type, unsigned long low,
44 unsigned long high)
45 {
46 if (sp < low || sp >= high)
47 return false;
48 info->type = type;
49 info->begin = low;
50 info->end = high;
51 return true;
52 }
53
in_task_stack(unsigned long sp,struct task_struct * task,struct stack_info * info)54 static bool in_task_stack(unsigned long sp, struct task_struct *task,
55 struct stack_info *info)
56 {
57 unsigned long stack;
58
59 stack = (unsigned long) task_stack_page(task);
60 return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
61 }
62
in_irq_stack(unsigned long sp,struct stack_info * info)63 static bool in_irq_stack(unsigned long sp, struct stack_info *info)
64 {
65 unsigned long frame_size, top;
66
67 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
68 top = S390_lowcore.async_stack + frame_size;
69 return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
70 }
71
in_nodat_stack(unsigned long sp,struct stack_info * info)72 static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
73 {
74 unsigned long frame_size, top;
75
76 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
77 top = S390_lowcore.nodat_stack + frame_size;
78 return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
79 }
80
in_restart_stack(unsigned long sp,struct stack_info * info)81 static bool in_restart_stack(unsigned long sp, struct stack_info *info)
82 {
83 unsigned long frame_size, top;
84
85 frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
86 top = S390_lowcore.restart_stack + frame_size;
87 return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
88 }
89
get_stack_info(unsigned long sp,struct task_struct * task,struct stack_info * info,unsigned long * visit_mask)90 int 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 task = task ? : current;
97
98 /* Check per-task stack */
99 if (in_task_stack(sp, task, info))
100 goto recursion_check;
101
102 if (task != current)
103 goto unknown;
104
105 /* Check per-cpu stacks */
106 if (!in_irq_stack(sp, info) &&
107 !in_nodat_stack(sp, info) &&
108 !in_restart_stack(sp, info))
109 goto unknown;
110
111 recursion_check:
112 /*
113 * Make sure we don't iterate through any given stack more than once.
114 * If it comes up a second time then there's something wrong going on:
115 * just break out and report an unknown stack type.
116 */
117 if (*visit_mask & (1UL << info->type))
118 goto unknown;
119 *visit_mask |= 1UL << info->type;
120 return 0;
121 unknown:
122 info->type = STACK_TYPE_UNKNOWN;
123 return -EINVAL;
124 }
125
show_stack(struct task_struct * task,unsigned long * stack)126 void show_stack(struct task_struct *task, unsigned long *stack)
127 {
128 struct unwind_state state;
129
130 printk("Call Trace:\n");
131 if (!task)
132 task = current;
133 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
134 printk(state.reliable ? " [<%016lx>] %pSR \n" :
135 "([<%016lx>] %pSR)\n",
136 state.ip, (void *) state.ip);
137 debug_show_held_locks(task ? : current);
138 }
139
show_last_breaking_event(struct pt_regs * regs)140 static void show_last_breaking_event(struct pt_regs *regs)
141 {
142 printk("Last Breaking-Event-Address:\n");
143 printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
144 }
145
show_registers(struct pt_regs * regs)146 void show_registers(struct pt_regs *regs)
147 {
148 struct psw_bits *psw = &psw_bits(regs->psw);
149 char *mode;
150
151 mode = user_mode(regs) ? "User" : "Krnl";
152 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
153 if (!user_mode(regs))
154 pr_cont(" (%pSR)", (void *)regs->psw.addr);
155 pr_cont("\n");
156 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
157 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
158 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
159 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
160 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
161 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
162 printk(" %016lx %016lx %016lx %016lx\n",
163 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
164 printk(" %016lx %016lx %016lx %016lx\n",
165 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
166 printk(" %016lx %016lx %016lx %016lx\n",
167 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
168 show_code(regs);
169 }
170
show_regs(struct pt_regs * regs)171 void show_regs(struct pt_regs *regs)
172 {
173 show_regs_print_info(KERN_DEFAULT);
174 show_registers(regs);
175 /* Show stack backtrace if pt_regs is from kernel mode */
176 if (!user_mode(regs))
177 show_stack(NULL, (unsigned long *) regs->gprs[15]);
178 show_last_breaking_event(regs);
179 }
180
181 static DEFINE_SPINLOCK(die_lock);
182
die(struct pt_regs * regs,const char * str)183 void die(struct pt_regs *regs, const char *str)
184 {
185 static int die_counter;
186
187 oops_enter();
188 lgr_info_log();
189 debug_stop_all();
190 console_verbose();
191 spin_lock_irq(&die_lock);
192 bust_spinlocks(1);
193 printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
194 regs->int_code >> 17, ++die_counter);
195 #ifdef CONFIG_PREEMPT
196 pr_cont("PREEMPT ");
197 #endif
198 pr_cont("SMP ");
199 if (debug_pagealloc_enabled())
200 pr_cont("DEBUG_PAGEALLOC");
201 pr_cont("\n");
202 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
203 print_modules();
204 show_regs(regs);
205 bust_spinlocks(0);
206 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
207 spin_unlock_irq(&die_lock);
208 if (in_interrupt())
209 panic("Fatal exception in interrupt");
210 if (panic_on_oops)
211 panic("Fatal exception: panic_on_oops");
212 oops_exit();
213 do_exit(SIGSEGV);
214 }
215