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227 lines · 6.1 KiB

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/asm-offsets.h>
21#include <asm/processor.h>
22#include <asm/debug.h>
23#include <asm/dis.h>
24#include <asm/ipl.h>
25#include <asm/unwind.h>
26
27const char *stack_type_name(enum stack_type type)
28{
29 switch (type) {
30 case STACK_TYPE_TASK:
31 return "task";
32 case STACK_TYPE_IRQ:
33 return "irq";
34 case STACK_TYPE_NODAT:
35 return "nodat";
36 case STACK_TYPE_RESTART:
37 return "restart";
38 default:
39 return "unknown";
40 }
41}
42EXPORT_SYMBOL_GPL(stack_type_name);
43
44static inline bool in_stack(unsigned long sp, struct stack_info *info,
45 enum stack_type type, unsigned long stack)
46{
47 if (sp < stack || sp >= stack + THREAD_SIZE)
48 return false;
49 info->type = type;
50 info->begin = stack;
51 info->end = stack + THREAD_SIZE;
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 = (unsigned long)task_stack_page(task);
59
60 return in_stack(sp, info, STACK_TYPE_TASK, stack);
61}
62
63static bool in_irq_stack(unsigned long sp, struct stack_info *info)
64{
65 unsigned long stack = get_lowcore()->async_stack - STACK_INIT_OFFSET;
66
67 return in_stack(sp, info, STACK_TYPE_IRQ, stack);
68}
69
70static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
71{
72 unsigned long stack = get_lowcore()->nodat_stack - STACK_INIT_OFFSET;
73
74 return in_stack(sp, info, STACK_TYPE_NODAT, stack);
75}
76
77static bool in_mcck_stack(unsigned long sp, struct stack_info *info)
78{
79 unsigned long stack = get_lowcore()->mcck_stack - STACK_INIT_OFFSET;
80
81 return in_stack(sp, info, STACK_TYPE_MCCK, stack);
82}
83
84static bool in_restart_stack(unsigned long sp, struct stack_info *info)
85{
86 unsigned long stack = get_lowcore()->restart_stack - STACK_INIT_OFFSET;
87
88 return in_stack(sp, info, STACK_TYPE_RESTART, stack);
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 !in_mcck_stack(sp, info))
113 goto unknown;
114
115recursion_check:
116 /*
117 * Make sure we don't iterate through any given stack more than once.
118 * If it comes up a second time then there's something wrong going on:
119 * just break out and report an unknown stack type.
120 */
121 if (*visit_mask & (1UL << info->type))
122 goto unknown;
123 *visit_mask |= 1UL << info->type;
124 return 0;
125unknown:
126 info->type = STACK_TYPE_UNKNOWN;
127 return -EINVAL;
128}
129
130void show_stack(struct task_struct *task, unsigned long *stack,
131 const char *loglvl)
132{
133 struct unwind_state state;
134
135 printk("%sCall Trace:\n", loglvl);
136 unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
137 printk(state.reliable ? "%s [<%016lx>] %pSR \n" :
138 "%s([<%016lx>] %pSR)\n",
139 loglvl, state.ip, (void *) state.ip);
140 debug_show_held_locks(task ? : current);
141}
142
143static void show_last_breaking_event(struct pt_regs *regs)
144{
145 printk("Last Breaking-Event-Address:\n");
146 printk(" [<%016lx>] ", regs->last_break);
147 if (user_mode(regs)) {
148 print_vma_addr(KERN_CONT, regs->last_break);
149 pr_cont("\n");
150 } else {
151 pr_cont("%pSR\n", (void *)regs->last_break);
152 }
153}
154
155void show_registers(struct pt_regs *regs)
156{
157 struct psw_bits *psw = &psw_bits(regs->psw);
158 unsigned long pswaddr;
159 char *mode;
160
161 pswaddr = regs->psw.addr;
162 if (test_pt_regs_flag(regs, PIF_PSW_ADDR_ADJUSTED))
163 pswaddr = __forward_psw(regs->psw, regs->int_code >> 16);
164 mode = user_mode(regs) ? "User" : "Krnl";
165 printk("%s PSW : %px %px", mode, (void *)regs->psw.mask, (void *)pswaddr);
166 if (!user_mode(regs))
167 pr_cont(" (%pSR)", (void *)pswaddr);
168 pr_cont("\n");
169 printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
170 "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
171 psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
172 pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
173 printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
174 regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
175 printk(" %016lx %016lx %016lx %016lx\n",
176 regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
177 printk(" %016lx %016lx %016lx %016lx\n",
178 regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
179 printk(" %016lx %016lx %016lx %016lx\n",
180 regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
181 show_code(regs);
182}
183
184void show_regs(struct pt_regs *regs)
185{
186 show_regs_print_info(KERN_DEFAULT);
187 show_registers(regs);
188 /* Show stack backtrace if pt_regs is from kernel mode */
189 if (!user_mode(regs))
190 show_stack(NULL, (unsigned long *) regs->gprs[15], KERN_DEFAULT);
191 show_last_breaking_event(regs);
192}
193
194static DEFINE_SPINLOCK(die_lock);
195
196void __noreturn die(struct pt_regs *regs, const char *str)
197{
198 static int die_counter;
199
200 oops_enter();
201 lgr_info_log();
202 debug_stop_all();
203 console_verbose();
204 spin_lock_irq(&die_lock);
205 bust_spinlocks(1);
206 if (test_pt_regs_flag(regs, PIF_WARN_TRAP_SKIPPED))
207 printk("%s: [#%d]", str, ++die_counter);
208 else
209 printk("%s: %04x ilc:%d [#%d]", str, regs->int_code & 0xffff,
210 regs->int_code >> 17, ++die_counter);
211 pr_cont("SMP ");
212 if (debug_pagealloc_enabled())
213 pr_cont("DEBUG_PAGEALLOC");
214 pr_cont("\n");
215 notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
216 print_modules();
217 show_regs(regs);
218 bust_spinlocks(0);
219 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
220 spin_unlock_irq(&die_lock);
221 if (in_interrupt())
222 panic("Fatal exception in interrupt");
223 if (panic_on_oops)
224 panic("Fatal exception: panic_on_oops");
225 oops_exit();
226 make_task_dead(SIGSEGV);
227}