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
|
#include <os.h>
#include <hypervisor.h>
#include <lib.h>
/*
* These are assembler stubs in entry.S.
* They are the actual entry points for virtual exceptions.
*/
void divide_error(void);
void debug(void);
void int3(void);
void overflow(void);
void bounds(void);
void invalid_op(void);
void device_not_available(void);
void double_fault(void);
void coprocessor_segment_overrun(void);
void invalid_TSS(void);
void segment_not_present(void);
void stack_segment(void);
void general_protection(void);
void page_fault(void);
void coprocessor_error(void);
void simd_coprocessor_error(void);
void alignment_check(void);
void spurious_interrupt_bug(void);
void machine_check(void);
extern void do_exit(void);
int kstack_depth_to_print = 24;
static inline int kernel_text_address(unsigned long addr)
{
return ( (addr >> 20) > 0x800 && (addr >> 20) < 0x804 );
}
void show_trace(unsigned long * stack)
{
int i;
unsigned long addr;
if (!stack)
stack = (unsigned long*)&stack;
printk("Call Trace: ");
i = 1;
while (((long) stack & (4095)) != 0) {
addr = *stack++;
if (kernel_text_address(addr)) {
printf("0x%lx", addr);
i++;
}
}
printk("\n");
}
void dump_regs(struct pt_regs *regs) {
printk("Register dump:");
printk("ebx: \t 0x%lx", regs->ebx);
printk("ecx: \t 0x%lx", regs->ecx);
printk("edx: \t 0x%lx", regs->edx);
printk("esi: \t 0x%lx", regs->esi);
printk("edi: \t 0x%lx", regs->edi);
printk("ebp: \t 0x%lx", regs->ebp);
printk("eax: \t 0x%lx", regs->eax);
printk("xds: \t 0x%x", regs->xds);
printk("xes: \t 0x%x", regs->xes);
printk("orig_eax: \t 0x%lx", regs->orig_eax);
printk("eip: \t 0x%lx", regs->eip);
printk("xcs: \t 0x%x", regs->xcs);
printk("eflags: \t 0x%lx", regs->eflags);
printk("esp: \t 0x%lx", regs->esp);
printk("xss: \t 0x%x", regs->xss);
};
static inline void dump_code(unsigned eip)
{
unsigned *ptr = (unsigned *)eip;
int x;
printk("Bytes at eip:\n");
for (x = -4; x < 5; x++)
printf("%x", ptr[x]);
}
/*
* C handlers here have their parameter-list constructed by the
* assembler stubs above. Each one gets a pointer to a list
* of register values (to be restored at end of exception).
* Some will also receive an error code -- this is the code that
* was generated by the processor for the underlying real exception.
*
* Note that the page-fault exception is special. It also receives
* the faulting linear address. Normally this would be found in
* register CR2, but that is not accessible in a virtualised OS.
*/
static void inline do_trap(int trapnr, char *str,
struct pt_regs * regs, long error_code)
{
printk("FATAL: Unhandled Trap (see mini-os:traps.c)");
printf("%d %s", trapnr, str);
dump_regs(regs);
show_trace((void *)regs->esp);
dump_code(regs->eip);
do_exit();
}
#define DO_ERROR(trapnr, str, name) \
void do_##name(struct pt_regs * regs, long error_code) \
{ \
do_trap(trapnr, str, regs, error_code); \
}
#define DO_ERROR_INFO(trapnr, str, name, sicode, siaddr) \
void do_##name(struct pt_regs * regs, long error_code) \
{ \
do_trap(trapnr, str, regs, error_code); \
}
DO_ERROR_INFO( 0, "divide error", divide_error, FPE_INTDIV, regs->eip)
DO_ERROR( 3, "int3", int3)
DO_ERROR( 4, "overflow", overflow)
DO_ERROR( 5, "bounds", bounds)
DO_ERROR_INFO( 6, "invalid operand", invalid_op, ILL_ILLOPN, regs->eip)
DO_ERROR( 7, "device not available", device_not_available)
DO_ERROR( 8, "double fault", double_fault)
DO_ERROR( 9, "coprocessor segment overrun", coprocessor_segment_overrun)
DO_ERROR(10, "invalid TSS", invalid_TSS)
DO_ERROR(11, "segment not present", segment_not_present)
DO_ERROR(12, "stack segment", stack_segment)
DO_ERROR_INFO(17, "alignment check", alignment_check, BUS_ADRALN, 0)
DO_ERROR(18, "machine check", machine_check)
void do_page_fault(struct pt_regs * regs, long error_code,
unsigned long address)
{
printk("Page fault\n");
printk("Address: 0x%lx", address);
printk("Error Code: 0x%lx", error_code);
printk("eip: \t 0x%lx", regs->eip);
do_exit();
}
void do_general_protection(struct pt_regs * regs, long error_code)
{
HYPERVISOR_shared_info->events_mask = 0;
printk("GPF\n");
printk("Error Code: 0x%lx", error_code);
dump_regs(regs);
dump_code(regs->eip);
do_exit();
}
void do_debug(struct pt_regs * regs, long error_code)
{
printk("Debug exception\n");
#define TF_MASK 0x100
regs->eflags &= ~TF_MASK;
dump_regs(regs);
do_exit();
}
void do_coprocessor_error(struct pt_regs * regs, long error_code)
{
printk("Copro error\n");
dump_regs(regs);
dump_code(regs->eip);
do_exit();
}
void simd_math_error(void *eip)
{
printk("SIMD error\n");
}
void do_simd_coprocessor_error(struct pt_regs * regs,
long error_code)
{
printk("SIMD copro error\n");
}
void do_spurious_interrupt_bug(struct pt_regs * regs,
long error_code)
{
}
/*
* Submit a virtual IDT to teh hypervisor. This consists of tuples
* (interrupt vector, privilege ring, CS:EIP of handler).
* The 'privilege ring' field specifies the least-privileged ring that
* can trap to that vector using a software-interrupt instruction (INT).
*/
static trap_info_t trap_table[] = {
{ 0, 0, __KERNEL_CS, (unsigned long)divide_error },
{ 1, 0, __KERNEL_CS, (unsigned long)debug },
{ 3, 3, __KERNEL_CS, (unsigned long)int3 },
{ 4, 3, __KERNEL_CS, (unsigned long)overflow },
{ 5, 3, __KERNEL_CS, (unsigned long)bounds },
{ 6, 0, __KERNEL_CS, (unsigned long)invalid_op },
{ 7, 0, __KERNEL_CS, (unsigned long)device_not_available },
{ 8, 0, __KERNEL_CS, (unsigned long)double_fault },
{ 9, 0, __KERNEL_CS, (unsigned long)coprocessor_segment_overrun },
{ 10, 0, __KERNEL_CS, (unsigned long)invalid_TSS },
{ 11, 0, __KERNEL_CS, (unsigned long)segment_not_present },
{ 12, 0, __KERNEL_CS, (unsigned long)stack_segment },
{ 13, 0, __KERNEL_CS, (unsigned long)general_protection },
{ 14, 0, __KERNEL_CS, (unsigned long)page_fault },
{ 15, 0, __KERNEL_CS, (unsigned long)spurious_interrupt_bug },
{ 16, 0, __KERNEL_CS, (unsigned long)coprocessor_error },
{ 17, 0, __KERNEL_CS, (unsigned long)alignment_check },
{ 18, 0, __KERNEL_CS, (unsigned long)machine_check },
{ 19, 0, __KERNEL_CS, (unsigned long)simd_coprocessor_error },
{ 0, 0, 0, 0 }
};
void trap_init(void)
{
HYPERVISOR_set_trap_table(trap_table);
}
|
