1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include <linux/kprobes.h>
17#include <linux/kdebug.h>
18#include <linux/extable.h>
19#include <linux/ptrace.h>
20#include <linux/sched.h>
21#include <linux/sched/debug.h>
22#include <linux/mm.h>
23#include <linux/slab.h>
24#include <linux/uaccess.h>
25#include <linux/cpu.h>
26#include <asm/fpu/api.h>
27#include "entry.h"
28
29static inline void __user *get_trap_ip(struct pt_regs *regs)
30{
31 unsigned long address;
32
33 if (regs->int_code & 0x200)
34 address = *(unsigned long *)(current->thread.trap_tdb + 24);
35 else
36 address = regs->psw.addr;
37 return (void __user *) (address - (regs->int_code >> 16));
38}
39
40int is_valid_bugaddr(unsigned long addr)
41{
42 return 1;
43}
44
45void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
46{
47 siginfo_t info;
48
49 if (user_mode(regs)) {
50 info.si_signo = si_signo;
51 info.si_errno = 0;
52 info.si_code = si_code;
53 info.si_addr = get_trap_ip(regs);
54 force_sig_info(si_signo, &info, current);
55 report_user_fault(regs, si_signo, 0);
56 } else {
57 const struct exception_table_entry *fixup;
58 fixup = search_exception_tables(regs->psw.addr);
59 if (fixup)
60 regs->psw.addr = extable_fixup(fixup);
61 else {
62 enum bug_trap_type btt;
63
64 btt = report_bug(regs->psw.addr, regs);
65 if (btt == BUG_TRAP_TYPE_WARN)
66 return;
67 die(regs, str);
68 }
69 }
70}
71
72static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
73{
74 if (notify_die(DIE_TRAP, str, regs, 0,
75 regs->int_code, si_signo) == NOTIFY_STOP)
76 return;
77 do_report_trap(regs, si_signo, si_code, str);
78}
79NOKPROBE_SYMBOL(do_trap);
80
81void do_per_trap(struct pt_regs *regs)
82{
83 siginfo_t info;
84
85 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
86 return;
87 if (!current->ptrace)
88 return;
89 info.si_signo = SIGTRAP;
90 info.si_errno = 0;
91 info.si_code = TRAP_HWBKPT;
92 info.si_addr =
93 (void __force __user *) current->thread.per_event.address;
94 force_sig_info(SIGTRAP, &info, current);
95}
96NOKPROBE_SYMBOL(do_per_trap);
97
98void default_trap_handler(struct pt_regs *regs)
99{
100 if (user_mode(regs)) {
101 report_user_fault(regs, SIGSEGV, 0);
102 do_exit(SIGSEGV);
103 } else
104 die(regs, "Unknown program exception");
105}
106
107#define DO_ERROR_INFO(name, signr, sicode, str) \
108void name(struct pt_regs *regs) \
109{ \
110 do_trap(regs, signr, sicode, str); \
111}
112
113DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
114 "addressing exception")
115DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
116 "execute exception")
117DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
118 "fixpoint divide exception")
119DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
120 "fixpoint overflow exception")
121DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
122 "HFP overflow exception")
123DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
124 "HFP underflow exception")
125DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
126 "HFP significance exception")
127DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
128 "HFP divide exception")
129DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
130 "HFP square root exception")
131DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
132 "operand exception")
133DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
134 "privileged operation")
135DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
136 "special operation exception")
137DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
138 "transaction constraint exception")
139
140static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
141{
142 int si_code = 0;
143
144 if ((fpc & 0x00000300) == 0) {
145
146 if (fpc & 0x8000)
147 si_code = FPE_FLTINV;
148 else if (fpc & 0x4000)
149 si_code = FPE_FLTDIV;
150 else if (fpc & 0x2000)
151 si_code = FPE_FLTOVF;
152 else if (fpc & 0x1000)
153 si_code = FPE_FLTUND;
154 else if (fpc & 0x0800)
155 si_code = FPE_FLTRES;
156 }
157 do_trap(regs, SIGFPE, si_code, "floating point exception");
158}
159
160void translation_exception(struct pt_regs *regs)
161{
162
163 panic("Translation exception");
164}
165
166void illegal_op(struct pt_regs *regs)
167{
168 siginfo_t info;
169 __u8 opcode[6];
170 __u16 __user *location;
171 int is_uprobe_insn = 0;
172 int signal = 0;
173
174 location = get_trap_ip(regs);
175
176 if (user_mode(regs)) {
177 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
178 return;
179 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
180 if (current->ptrace) {
181 info.si_signo = SIGTRAP;
182 info.si_errno = 0;
183 info.si_code = TRAP_BRKPT;
184 info.si_addr = location;
185 force_sig_info(SIGTRAP, &info, current);
186 } else
187 signal = SIGILL;
188#ifdef CONFIG_UPROBES
189 } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
190 is_uprobe_insn = 1;
191#endif
192 } else
193 signal = SIGILL;
194 }
195
196
197
198
199
200 if (is_uprobe_insn || !user_mode(regs)) {
201 if (notify_die(DIE_BPT, "bpt", regs, 0,
202 3, SIGTRAP) != NOTIFY_STOP)
203 signal = SIGILL;
204 }
205 if (signal)
206 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
207}
208NOKPROBE_SYMBOL(illegal_op);
209
210DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
211 "specification exception");
212
213void vector_exception(struct pt_regs *regs)
214{
215 int si_code, vic;
216
217 if (!MACHINE_HAS_VX) {
218 do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
219 return;
220 }
221
222
223 save_fpu_regs();
224 vic = (current->thread.fpu.fpc & 0xf00) >> 8;
225 switch (vic) {
226 case 1:
227 si_code = FPE_FLTINV;
228 break;
229 case 2:
230 si_code = FPE_FLTDIV;
231 break;
232 case 3:
233 si_code = FPE_FLTOVF;
234 break;
235 case 4:
236 si_code = FPE_FLTUND;
237 break;
238 case 5:
239 si_code = FPE_FLTRES;
240 break;
241 default:
242 si_code = 0;
243 }
244 do_trap(regs, SIGFPE, si_code, "vector exception");
245}
246
247void data_exception(struct pt_regs *regs)
248{
249 int signal = 0;
250
251 save_fpu_regs();
252 if (current->thread.fpu.fpc & FPC_DXC_MASK)
253 signal = SIGFPE;
254 else
255 signal = SIGILL;
256 if (signal == SIGFPE)
257 do_fp_trap(regs, current->thread.fpu.fpc);
258 else if (signal)
259 do_trap(regs, signal, ILL_ILLOPN, "data exception");
260}
261
262void space_switch_exception(struct pt_regs *regs)
263{
264
265 if (user_mode(regs))
266 regs->psw.mask |= PSW_ASC_HOME;
267
268 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
269}
270
271void kernel_stack_overflow(struct pt_regs *regs)
272{
273 bust_spinlocks(1);
274 printk("Kernel stack overflow.\n");
275 show_regs(regs);
276 bust_spinlocks(0);
277 panic("Corrupt kernel stack, can't continue.");
278}
279NOKPROBE_SYMBOL(kernel_stack_overflow);
280
281void __init trap_init(void)
282{
283 local_mcck_enable();
284}
285
