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
|
/*
* Traps/Non-MMU Exception handling for ARC
*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* vineetg: May 2011
* -user-space unaligned access emulation
*
* Rahul Trivedi: Codito Technologies 2004
*/
#include <linux/sched/signal.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <linux/ptrace.h>
#include <linux/kprobes.h>
#include <linux/kgdb.h>
#include <asm/setup.h>
#include <asm/unaligned.h>
#include <asm/kprobes.h>
void __init trap_init(void)
{
return;
}
void die(const char *str, struct pt_regs *regs, unsigned long address)
{
show_kernel_fault_diag(str, regs, address);
/* DEAD END */
__asm__("flag 1");
}
/*
* Helper called for bulk of exceptions NOT needing specific handling
* -for user faults enqueues requested signal
* -for kernel, chk if due to copy_(to|from)_user, otherwise die()
*/
static noinline int
unhandled_exception(const char *str, struct pt_regs *regs, siginfo_t *info)
{
if (user_mode(regs)) {
struct task_struct *tsk = current;
tsk->thread.fault_address = (__force unsigned int)info->si_addr;
force_sig_info(info->si_signo, info, tsk);
} else {
/* If not due to copy_(to|from)_user, we are doomed */
if (fixup_exception(regs))
return 0;
die(str, regs, (unsigned long)info->si_addr);
}
return 1;
}
#define DO_ERROR_INFO(signr, str, name, sicode) \
int name(unsigned long address, struct pt_regs *regs) \
{ \
siginfo_t info = { \
.si_signo = signr, \
.si_errno = 0, \
.si_code = sicode, \
.si_addr = (void __user *)address, \
}; \
return unhandled_exception(str, regs, &info);\
}
/*
* Entry points for exceptions NOT needing specific handling
*/
DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC)
DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC)
DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC)
DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", __weak do_memory_error, BUS_ADRERR)
DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT)
DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN)
/*
* Entry Point for Misaligned Data access Exception, for emulating in software
*/
int do_misaligned_access(unsigned long address, struct pt_regs *regs,
struct callee_regs *cregs)
{
/* If emulation not enabled, or failed, kill the task */
if (misaligned_fixup(address, regs, cregs) != 0)
return do_misaligned_error(address, regs);
return 0;
}
/*
* Entry point for miscll errors such as Nested Exceptions
* -Duplicate TLB entry is handled seperately though
*/
void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
{
die("Unhandled Machine Check Exception", regs, address);
}
/*
* Entry point for traps induced by ARCompact TRAP_S <n> insn
* This is same family as TRAP0/SWI insn (use the same vector).
* The only difference being SWI insn take no operand, while TRAP_S does
* which reflects in ECR Reg as 8 bit param.
* Thus TRAP_S <n> can be used for specific purpose
* -1 used for software breakpointing (gdb)
* -2 used by kprobes
*/
void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
{
unsigned int param = regs->ecr_param;
switch (param) {
case 1:
trap_is_brkpt(address, regs);
break;
case 2:
trap_is_kprobe(address, regs);
break;
case 3:
case 4:
kgdb_trap(regs);
break;
default:
break;
}
}
/*
* Entry point for Instruction Error Exception
* -For a corner case, ARC kprobes implementation resorts to using
* this exception, hence the check
*/
void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs)
{
int rc;
/* Check if this exception is caused by kprobes */
rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL);
if (rc == NOTIFY_STOP)
return;
insterror_is_error(address, regs);
}
|
