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 EXPORT_SYMBOL_GPL(stack_type_name);
42
in_stack(unsigned long sp,struct stack_info * info,enum stack_type type,unsigned long low,unsigned long high)43 static 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
in_task_stack(unsigned long sp,struct task_struct * task,struct stack_info * info)55 static 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
in_irq_stack(unsigned long sp,struct stack_info * info)64 static 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
in_nodat_stack(unsigned long sp,struct stack_info * info)73 static 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
in_mcck_stack(unsigned long sp,struct stack_info * info)82 static 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
in_restart_stack(unsigned long sp,struct stack_info * info)91 static 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
get_stack_info(unsigned long sp,struct task_struct * task,struct stack_info * info,unsigned long * visit_mask)100 int 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
124 recursion_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;
134 unknown:
135 info->type = STACK_TYPE_UNKNOWN;
136 return -EINVAL;
137 }
138
show_stack(struct task_struct * task,unsigned long * stack,const char * loglvl)139 void 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
show_last_breaking_event(struct pt_regs * regs)152 static 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
show_registers(struct pt_regs * regs)158 void 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
show_regs(struct pt_regs * regs)183 void 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
193 static DEFINE_SPINLOCK(die_lock);
194
die(struct pt_regs * regs,const char * str)195 void __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 }
229