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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
5a4f7c66 PM |
2 | #include <linux/bug.h> |
3 | #include <linux/io.h> | |
4 | #include <linux/types.h> | |
5 | #include <linux/kdebug.h> | |
47a3eb95 PM |
6 | #include <linux/signal.h> |
7 | #include <linux/sched.h> | |
b17b0153 | 8 | #include <linux/sched/debug.h> |
68db0cf1 | 9 | #include <linux/sched/task_stack.h> |
9a33fc21 | 10 | #include <linux/uaccess.h> |
1e1030dc | 11 | #include <linux/hardirq.h> |
5f857bce PM |
12 | #include <linux/kernel.h> |
13 | #include <linux/kexec.h> | |
3f07c014 IM |
14 | #include <linux/sched/signal.h> |
15 | ||
d92280d1 PG |
16 | #include <linux/extable.h> |
17 | #include <linux/module.h> /* print_modules */ | |
9ffc9da6 GU |
18 | |
19 | #include <asm/ftrace.h> | |
e115f2c1 | 20 | #include <asm/unwinder.h> |
e839ca52 | 21 | #include <asm/traps.h> |
5a4f7c66 | 22 | |
5f857bce PM |
23 | static DEFINE_SPINLOCK(die_lock); |
24 | ||
9fd5a04d | 25 | void __noreturn die(const char *str, struct pt_regs *regs, long err) |
5f857bce PM |
26 | { |
27 | static int die_counter; | |
28 | ||
29 | oops_enter(); | |
30 | ||
31 | spin_lock_irq(&die_lock); | |
32 | console_verbose(); | |
33 | bust_spinlocks(1); | |
34 | ||
35 | printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter); | |
36 | print_modules(); | |
37 | show_regs(regs); | |
38 | ||
39 | printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm, | |
40 | task_pid_nr(current), task_stack_page(current) + 1); | |
41 | ||
42 | if (!user_mode(regs) || in_interrupt()) | |
ebf0a36a DS |
43 | dump_mem("Stack: ", KERN_DEFAULT, regs->regs[15], |
44 | THREAD_SIZE + (unsigned long)task_stack_page(current)); | |
5f857bce PM |
45 | |
46 | notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV); | |
47 | ||
48 | bust_spinlocks(0); | |
373d4d09 | 49 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
5f857bce PM |
50 | spin_unlock_irq(&die_lock); |
51 | oops_exit(); | |
52 | ||
53 | if (kexec_should_crash(current)) | |
54 | crash_kexec(regs); | |
55 | ||
56 | if (in_interrupt()) | |
57 | panic("Fatal exception in interrupt"); | |
58 | ||
59 | if (panic_on_oops) | |
60 | panic("Fatal exception"); | |
61 | ||
0e25498f | 62 | make_task_dead(SIGSEGV); |
5f857bce PM |
63 | } |
64 | ||
65 | void die_if_kernel(const char *str, struct pt_regs *regs, long err) | |
66 | { | |
67 | if (!user_mode(regs)) | |
68 | die(str, regs, err); | |
69 | } | |
70 | ||
71 | /* | |
72 | * try and fix up kernelspace address errors | |
73 | * - userspace errors just cause EFAULT to be returned, resulting in SEGV | |
74 | * - kernel/userspace interfaces cause a jump to an appropriate handler | |
75 | * - other kernel errors are bad | |
76 | */ | |
77 | void die_if_no_fixup(const char *str, struct pt_regs *regs, long err) | |
78 | { | |
79 | if (!user_mode(regs)) { | |
80 | const struct exception_table_entry *fixup; | |
81 | fixup = search_exception_tables(regs->pc); | |
82 | if (fixup) { | |
83 | regs->pc = fixup->fixup; | |
84 | return; | |
85 | } | |
86 | ||
87 | die(str, regs, err); | |
88 | } | |
89 | } | |
90 | ||
626ac8e1 PM |
91 | #ifdef CONFIG_GENERIC_BUG |
92 | static void handle_BUG(struct pt_regs *regs) | |
5a4f7c66 | 93 | { |
e115f2c1 PM |
94 | const struct bug_entry *bug; |
95 | unsigned long bugaddr = regs->pc; | |
5a4f7c66 | 96 | enum bug_trap_type tt; |
e115f2c1 PM |
97 | |
98 | if (!is_valid_bugaddr(bugaddr)) | |
99 | goto invalid; | |
100 | ||
101 | bug = find_bug(bugaddr); | |
102 | ||
103 | /* Switch unwinders when unwind_stack() is called */ | |
104 | if (bug->flags & BUGFLAG_UNWINDER) | |
105 | unwinder_faulted = 1; | |
106 | ||
107 | tt = report_bug(bugaddr, regs); | |
5a4f7c66 | 108 | if (tt == BUG_TRAP_TYPE_WARN) { |
e115f2c1 | 109 | regs->pc += instruction_size(bugaddr); |
5a4f7c66 PM |
110 | return; |
111 | } | |
112 | ||
e115f2c1 | 113 | invalid: |
5a4f7c66 PM |
114 | die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); |
115 | } | |
116 | ||
117 | int is_valid_bugaddr(unsigned long addr) | |
118 | { | |
2bcfffa4 | 119 | insn_size_t opcode; |
9a33fc21 PM |
120 | |
121 | if (addr < PAGE_OFFSET) | |
122 | return 0; | |
25f12ae4 | 123 | if (get_kernel_nofault(opcode, (insn_size_t *)addr)) |
9a33fc21 | 124 | return 0; |
e115f2c1 | 125 | if (opcode == TRAPA_BUG_OPCODE) |
b344e24a MF |
126 | return 1; |
127 | ||
128 | return 0; | |
5a4f7c66 PM |
129 | } |
130 | #endif | |
131 | ||
132 | /* | |
133 | * Generic trap handler. | |
134 | */ | |
135 | BUILD_TRAP_HANDLER(debug) | |
136 | { | |
137 | TRAP_HANDLER_DECL; | |
138 | ||
139 | /* Rewind */ | |
9d56dd3b | 140 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
5a4f7c66 PM |
141 | |
142 | if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, | |
143 | SIGTRAP) == NOTIFY_STOP) | |
144 | return; | |
145 | ||
3cf5d076 | 146 | force_sig(SIGTRAP); |
5a4f7c66 PM |
147 | } |
148 | ||
149 | /* | |
150 | * Special handler for BUG() traps. | |
151 | */ | |
152 | BUILD_TRAP_HANDLER(bug) | |
153 | { | |
154 | TRAP_HANDLER_DECL; | |
155 | ||
156 | /* Rewind */ | |
9d56dd3b | 157 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
5a4f7c66 PM |
158 | |
159 | if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, | |
160 | SIGTRAP) == NOTIFY_STOP) | |
161 | return; | |
162 | ||
626ac8e1 | 163 | #ifdef CONFIG_GENERIC_BUG |
5a4f7c66 | 164 | if (__kernel_text_address(instruction_pointer(regs))) { |
2bcfffa4 | 165 | insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); |
5a4f7c66 PM |
166 | if (insn == TRAPA_BUG_OPCODE) |
167 | handle_BUG(regs); | |
0ec39885 | 168 | return; |
5a4f7c66 PM |
169 | } |
170 | #endif | |
171 | ||
3cf5d076 | 172 | force_sig(SIGTRAP); |
5a4f7c66 | 173 | } |
1e1030dc PM |
174 | |
175 | BUILD_TRAP_HANDLER(nmi) | |
176 | { | |
177 | TRAP_HANDLER_DECL; | |
178 | ||
178ba00c PZ |
179 | arch_ftrace_nmi_enter(); |
180 | ||
1e1030dc | 181 | nmi_enter(); |
fe3f1d5d | 182 | this_cpu_inc(irq_stat.__nmi_count); |
1e1030dc PM |
183 | |
184 | switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) { | |
185 | case NOTIFY_OK: | |
186 | case NOTIFY_STOP: | |
187 | break; | |
188 | case NOTIFY_BAD: | |
189 | die("Fatal Non-Maskable Interrupt", regs, SIGINT); | |
190 | default: | |
191 | printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n"); | |
192 | break; | |
193 | } | |
194 | ||
195 | nmi_exit(); | |
178ba00c PZ |
196 | |
197 | arch_ftrace_nmi_exit(); | |
1e1030dc | 198 | } |