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15#include <linux/kprobes.h>
16#include <linux/kdebug.h>
17#include <linux/module.h>
18#include <linux/ptrace.h>
19#include <linux/sched.h>
20#include <linux/mm.h>
21#include "entry.h"
22
23int show_unhandled_signals = 1;
24
25static inline void __user *get_trap_ip(struct pt_regs *regs)
26{
27#ifdef CONFIG_64BIT
28 unsigned long address;
29
30 if (regs->int_code & 0x200)
31 address = *(unsigned long *)(current->thread.trap_tdb + 24);
32 else
33 address = regs->psw.addr;
34 return (void __user *)
35 ((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
36#else
37 return (void __user *)
38 ((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
39#endif
40}
41
42static inline void report_user_fault(struct pt_regs *regs, int signr)
43{
44 if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
45 return;
46 if (!unhandled_signal(current, signr))
47 return;
48 if (!printk_ratelimit())
49 return;
50 printk("User process fault: interruption code 0x%X ", regs->int_code);
51 print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
52 printk("\n");
53 show_regs(regs);
54}
55
56int is_valid_bugaddr(unsigned long addr)
57{
58 return 1;
59}
60
61static void __kprobes do_trap(struct pt_regs *regs,
62 int si_signo, int si_code, char *str)
63{
64 siginfo_t info;
65
66 if (notify_die(DIE_TRAP, str, regs, 0,
67 regs->int_code, si_signo) == NOTIFY_STOP)
68 return;
69
70 if (user_mode(regs)) {
71 info.si_signo = si_signo;
72 info.si_errno = 0;
73 info.si_code = si_code;
74 info.si_addr = get_trap_ip(regs);
75 force_sig_info(si_signo, &info, current);
76 report_user_fault(regs, si_signo);
77 } else {
78 const struct exception_table_entry *fixup;
79 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
80 if (fixup)
81 regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
82 else {
83 enum bug_trap_type btt;
84
85 btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
86 if (btt == BUG_TRAP_TYPE_WARN)
87 return;
88 die(regs, str);
89 }
90 }
91}
92
93void __kprobes do_per_trap(struct pt_regs *regs)
94{
95 siginfo_t info;
96
97 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
98 return;
99 if (!current->ptrace)
100 return;
101 info.si_signo = SIGTRAP;
102 info.si_errno = 0;
103 info.si_code = TRAP_HWBKPT;
104 info.si_addr =
105 (void __force __user *) current->thread.per_event.address;
106 force_sig_info(SIGTRAP, &info, current);
107}
108
109void default_trap_handler(struct pt_regs *regs)
110{
111 if (user_mode(regs)) {
112 report_user_fault(regs, SIGSEGV);
113 do_exit(SIGSEGV);
114 } else
115 die(regs, "Unknown program exception");
116}
117
118#define DO_ERROR_INFO(name, signr, sicode, str) \
119void name(struct pt_regs *regs) \
120{ \
121 do_trap(regs, signr, sicode, str); \
122}
123
124DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
125 "addressing exception")
126DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
127 "execute exception")
128DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
129 "fixpoint divide exception")
130DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
131 "fixpoint overflow exception")
132DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
133 "HFP overflow exception")
134DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
135 "HFP underflow exception")
136DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
137 "HFP significance exception")
138DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
139 "HFP divide exception")
140DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
141 "HFP square root exception")
142DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
143 "operand exception")
144DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
145 "privileged operation")
146DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
147 "special operation exception")
148DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
149 "translation exception")
150
151#ifdef CONFIG_64BIT
152DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
153 "transaction constraint exception")
154#endif
155
156static inline void do_fp_trap(struct pt_regs *regs, int fpc)
157{
158 int si_code = 0;
159
160 if ((fpc & 0x00000300) == 0) {
161
162 if (fpc & 0x8000)
163 si_code = FPE_FLTINV;
164 else if (fpc & 0x4000)
165 si_code = FPE_FLTDIV;
166 else if (fpc & 0x2000)
167 si_code = FPE_FLTOVF;
168 else if (fpc & 0x1000)
169 si_code = FPE_FLTUND;
170 else if (fpc & 0x0800)
171 si_code = FPE_FLTRES;
172 }
173 do_trap(regs, SIGFPE, si_code, "floating point exception");
174}
175
176void __kprobes illegal_op(struct pt_regs *regs)
177{
178 siginfo_t info;
179 __u8 opcode[6];
180 __u16 __user *location;
181 int signal = 0;
182
183 location = get_trap_ip(regs);
184
185 if (user_mode(regs)) {
186 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
187 return;
188 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
189 if (current->ptrace) {
190 info.si_signo = SIGTRAP;
191 info.si_errno = 0;
192 info.si_code = TRAP_BRKPT;
193 info.si_addr = location;
194 force_sig_info(SIGTRAP, &info, current);
195 } else
196 signal = SIGILL;
197#ifdef CONFIG_MATHEMU
198 } else if (opcode[0] == 0xb3) {
199 if (get_user(*((__u16 *) (opcode+2)), location+1))
200 return;
201 signal = math_emu_b3(opcode, regs);
202 } else if (opcode[0] == 0xed) {
203 if (get_user(*((__u32 *) (opcode+2)),
204 (__u32 __user *)(location+1)))
205 return;
206 signal = math_emu_ed(opcode, regs);
207 } else if (*((__u16 *) opcode) == 0xb299) {
208 if (get_user(*((__u16 *) (opcode+2)), location+1))
209 return;
210 signal = math_emu_srnm(opcode, regs);
211 } else if (*((__u16 *) opcode) == 0xb29c) {
212 if (get_user(*((__u16 *) (opcode+2)), location+1))
213 return;
214 signal = math_emu_stfpc(opcode, regs);
215 } else if (*((__u16 *) opcode) == 0xb29d) {
216 if (get_user(*((__u16 *) (opcode+2)), location+1))
217 return;
218 signal = math_emu_lfpc(opcode, regs);
219#endif
220 } else
221 signal = SIGILL;
222 } else {
223
224
225
226
227 if (notify_die(DIE_BPT, "bpt", regs, 0,
228 3, SIGTRAP) != NOTIFY_STOP)
229 signal = SIGILL;
230 }
231
232#ifdef CONFIG_MATHEMU
233 if (signal == SIGFPE)
234 do_fp_trap(regs, current->thread.fp_regs.fpc);
235 else if (signal == SIGSEGV)
236 do_trap(regs, signal, SEGV_MAPERR, "user address fault");
237 else
238#endif
239 if (signal)
240 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
241}
242
243
244#ifdef CONFIG_MATHEMU
245void specification_exception(struct pt_regs *regs)
246{
247 __u8 opcode[6];
248 __u16 __user *location = NULL;
249 int signal = 0;
250
251 location = (__u16 __user *) get_trap_ip(regs);
252
253 if (user_mode(regs)) {
254 get_user(*((__u16 *) opcode), location);
255 switch (opcode[0]) {
256 case 0x28:
257 signal = math_emu_ldr(opcode);
258 break;
259 case 0x38:
260 signal = math_emu_ler(opcode);
261 break;
262 case 0x60:
263 get_user(*((__u16 *) (opcode+2)), location+1);
264 signal = math_emu_std(opcode, regs);
265 break;
266 case 0x68:
267 get_user(*((__u16 *) (opcode+2)), location+1);
268 signal = math_emu_ld(opcode, regs);
269 break;
270 case 0x70:
271 get_user(*((__u16 *) (opcode+2)), location+1);
272 signal = math_emu_ste(opcode, regs);
273 break;
274 case 0x78:
275 get_user(*((__u16 *) (opcode+2)), location+1);
276 signal = math_emu_le(opcode, regs);
277 break;
278 default:
279 signal = SIGILL;
280 break;
281 }
282 } else
283 signal = SIGILL;
284
285 if (signal == SIGFPE)
286 do_fp_trap(regs, current->thread.fp_regs.fpc);
287 else if (signal)
288 do_trap(regs, signal, ILL_ILLOPN, "specification exception");
289}
290#else
291DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
292 "specification exception");
293#endif
294
295void data_exception(struct pt_regs *regs)
296{
297 __u16 __user *location;
298 int signal = 0;
299
300 location = get_trap_ip(regs);
301
302 if (MACHINE_HAS_IEEE)
303 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
304
305#ifdef CONFIG_MATHEMU
306 else if (user_mode(regs)) {
307 __u8 opcode[6];
308 get_user(*((__u16 *) opcode), location);
309 switch (opcode[0]) {
310 case 0x28:
311 signal = math_emu_ldr(opcode);
312 break;
313 case 0x38:
314 signal = math_emu_ler(opcode);
315 break;
316 case 0x60:
317 get_user(*((__u16 *) (opcode+2)), location+1);
318 signal = math_emu_std(opcode, regs);
319 break;
320 case 0x68:
321 get_user(*((__u16 *) (opcode+2)), location+1);
322 signal = math_emu_ld(opcode, regs);
323 break;
324 case 0x70:
325 get_user(*((__u16 *) (opcode+2)), location+1);
326 signal = math_emu_ste(opcode, regs);
327 break;
328 case 0x78:
329 get_user(*((__u16 *) (opcode+2)), location+1);
330 signal = math_emu_le(opcode, regs);
331 break;
332 case 0xb3:
333 get_user(*((__u16 *) (opcode+2)), location+1);
334 signal = math_emu_b3(opcode, regs);
335 break;
336 case 0xed:
337 get_user(*((__u32 *) (opcode+2)),
338 (__u32 __user *)(location+1));
339 signal = math_emu_ed(opcode, regs);
340 break;
341 case 0xb2:
342 if (opcode[1] == 0x99) {
343 get_user(*((__u16 *) (opcode+2)), location+1);
344 signal = math_emu_srnm(opcode, regs);
345 } else if (opcode[1] == 0x9c) {
346 get_user(*((__u16 *) (opcode+2)), location+1);
347 signal = math_emu_stfpc(opcode, regs);
348 } else if (opcode[1] == 0x9d) {
349 get_user(*((__u16 *) (opcode+2)), location+1);
350 signal = math_emu_lfpc(opcode, regs);
351 } else
352 signal = SIGILL;
353 break;
354 default:
355 signal = SIGILL;
356 break;
357 }
358 }
359#endif
360 if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
361 signal = SIGFPE;
362 else
363 signal = SIGILL;
364 if (signal == SIGFPE)
365 do_fp_trap(regs, current->thread.fp_regs.fpc);
366 else if (signal)
367 do_trap(regs, signal, ILL_ILLOPN, "data exception");
368}
369
370void space_switch_exception(struct pt_regs *regs)
371{
372
373 if (user_mode(regs))
374 regs->psw.mask |= PSW_ASC_HOME;
375
376 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
377}
378
379void __kprobes kernel_stack_overflow(struct pt_regs * regs)
380{
381 bust_spinlocks(1);
382 printk("Kernel stack overflow.\n");
383 show_regs(regs);
384 bust_spinlocks(0);
385 panic("Corrupt kernel stack, can't continue.");
386}
387
388void __init trap_init(void)
389{
390 local_mcck_enable();
391}
392
