1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Regents of the University of California
*/
#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/signal.h>
#include <linux/signal.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <linux/kprobes.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/irq.h>
#include <asm/asm-prototypes.h>
#include <asm/bug.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/csr.h>
int show_unhandled_signals = 1;
static DEFINE_SPINLOCK(die_lock);
void die(struct pt_regs *regs, const char *str)
{
static int die_counter;
int ret;
oops_enter();
spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
pr_emerg("%s [#%d]\n", str, ++die_counter);
print_modules();
show_regs(regs);
ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV);
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
if (ret != NOTIFY_STOP)
do_exit(SIGSEGV);
}
void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
{
struct task_struct *tsk = current;
if (show_unhandled_signals && unhandled_signal(tsk, signo)
&& printk_ratelimit()) {
pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
tsk->comm, task_pid_nr(tsk), signo, code, addr);
print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
pr_cont("\n");
__show_regs(regs);
}
force_sig_fault(signo, code, (void __user *)addr);
}
static void do_trap_error(struct pt_regs *regs, int signo, int code,
unsigned long addr, const char *str)
{
current->thread.bad_cause = regs->cause;
if (user_mode(regs)) {
do_trap(regs, signo, code, addr);
} else {
if (!fixup_exception(regs))
die(regs, str);
}
}
#if defined (CONFIG_XIP_KERNEL) && defined (CONFIG_RISCV_ERRATA_ALTERNATIVE)
#define __trap_section __section(".xip.traps")
#else
#define __trap_section
#endif
#define DO_ERROR_INFO(name, signo, code, str) \
asmlinkage __visible __trap_section void name(struct pt_regs *regs) \
{ \
do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
}
DO_ERROR_INFO(do_trap_unknown,
SIGILL, ILL_ILLTRP, "unknown exception");
DO_ERROR_INFO(do_trap_insn_misaligned,
SIGBUS, BUS_ADRALN, "instruction address misaligned");
DO_ERROR_INFO(do_trap_insn_fault,
SIGSEGV, SEGV_ACCERR, "instruction access fault");
DO_ERROR_INFO(do_trap_insn_illegal,
SIGILL, ILL_ILLOPC, "illegal instruction");
DO_ERROR_INFO(do_trap_load_fault,
SIGSEGV, SEGV_ACCERR, "load access fault");
#ifndef CONFIG_RISCV_M_MODE
DO_ERROR_INFO(do_trap_load_misaligned,
SIGBUS, BUS_ADRALN, "Oops - load address misaligned");
DO_ERROR_INFO(do_trap_store_misaligned,
SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned");
#else
int handle_misaligned_load(struct pt_regs *regs);
int handle_misaligned_store(struct pt_regs *regs);
asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs)
{
if (!handle_misaligned_load(regs))
return;
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - load address misaligned");
}
asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs)
{
if (!handle_misaligned_store(regs))
return;
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
"Oops - store (or AMO) address misaligned");
}
#endif
DO_ERROR_INFO(do_trap_store_fault,
SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
DO_ERROR_INFO(do_trap_ecall_u,
SIGILL, ILL_ILLTRP, "environment call from U-mode");
DO_ERROR_INFO(do_trap_ecall_s,
SIGILL, ILL_ILLTRP, "environment call from S-mode");
DO_ERROR_INFO(do_trap_ecall_m,
SIGILL, ILL_ILLTRP, "environment call from M-mode");
static inline unsigned long get_break_insn_length(unsigned long pc)
{
bug_insn_t insn;
if (get_kernel_nofault(insn, (bug_insn_t *)pc))
return 0;
return GET_INSN_LENGTH(insn);
}
asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
{
#ifdef CONFIG_KPROBES
if (kprobe_single_step_handler(regs))
return;
if (kprobe_breakpoint_handler(regs))
return;
#endif
#ifdef CONFIG_UPROBES
if (uprobe_single_step_handler(regs))
return;
if (uprobe_breakpoint_handler(regs))
return;
#endif
current->thread.bad_cause = regs->cause;
if (user_mode(regs))
force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc);
#ifdef CONFIG_KGDB
else if (notify_die(DIE_TRAP, "EBREAK", regs, 0, regs->cause, SIGTRAP)
== NOTIFY_STOP)
return;
#endif
else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN)
regs->epc += get_break_insn_length(regs->epc);
else
die(regs, "Kernel BUG");
}
NOKPROBE_SYMBOL(do_trap_break);
#ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long pc)
{
bug_insn_t insn;
if (pc < VMALLOC_START)
return 0;
if (get_kernel_nofault(insn, (bug_insn_t *)pc))
return 0;
if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
return (insn == __BUG_INSN_32);
else
return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
}
#endif /* CONFIG_GENERIC_BUG */
/* stvec & scratch is already set from head.S */
void __init trap_init(void)
{
}
#ifdef CONFIG_VMAP_STACK
static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)],
overflow_stack)__aligned(16);
/*
* shadow stack, handled_ kernel_ stack_ overflow(in kernel/entry.S) is used
* to get per-cpu overflow stack(get_overflow_stack).
*/
long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)];
asmlinkage unsigned long get_overflow_stack(void)
{
return (unsigned long)this_cpu_ptr(overflow_stack) +
OVERFLOW_STACK_SIZE;
}
asmlinkage void handle_bad_stack(struct pt_regs *regs)
{
unsigned long tsk_stk = (unsigned long)current->stack;
unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
console_verbose();
pr_emerg("Insufficient stack space to handle exception!\n");
pr_emerg("Task stack: [0x%016lx..0x%016lx]\n",
tsk_stk, tsk_stk + THREAD_SIZE);
pr_emerg("Overflow stack: [0x%016lx..0x%016lx]\n",
ovf_stk, ovf_stk + OVERFLOW_STACK_SIZE);
__show_regs(regs);
panic("Kernel stack overflow");
for (;;)
wait_for_interrupt();
}
#endif
|
