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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 <linux/slab.h>
22#include <asm/switch_to.h>
23#include "entry.h"
24
25int show_unhandled_signals = 1;
26
27static inline void __user *get_trap_ip(struct pt_regs *regs)
28{
29 unsigned long address;
30
31 if (regs->int_code & 0x200)
32 address = *(unsigned long *)(current->thread.trap_tdb + 24);
33 else
34 address = regs->psw.addr;
35 return (void __user *)
36 ((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
37}
38
39static inline void report_user_fault(struct pt_regs *regs, int signr)
40{
41 if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
42 return;
43 if (!unhandled_signal(current, signr))
44 return;
45 if (!printk_ratelimit())
46 return;
47 printk("User process fault: interruption code %04x ilc:%d ",
48 regs->int_code & 0xffff, regs->int_code >> 17);
49 print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
50 printk("\n");
51 show_regs(regs);
52}
53
54int is_valid_bugaddr(unsigned long addr)
55{
56 return 1;
57}
58
59void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
60{
61 siginfo_t info;
62
63 if (user_mode(regs)) {
64 info.si_signo = si_signo;
65 info.si_errno = 0;
66 info.si_code = si_code;
67 info.si_addr = get_trap_ip(regs);
68 force_sig_info(si_signo, &info, current);
69 report_user_fault(regs, si_signo);
70 } else {
71 const struct exception_table_entry *fixup;
72 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
73 if (fixup)
74 regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
75 else {
76 enum bug_trap_type btt;
77
78 btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
79 if (btt == BUG_TRAP_TYPE_WARN)
80 return;
81 die(regs, str);
82 }
83 }
84}
85
86static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
87{
88 if (notify_die(DIE_TRAP, str, regs, 0,
89 regs->int_code, si_signo) == NOTIFY_STOP)
90 return;
91 do_report_trap(regs, si_signo, si_code, str);
92}
93NOKPROBE_SYMBOL(do_trap);
94
95void do_per_trap(struct pt_regs *regs)
96{
97 siginfo_t info;
98
99 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
100 return;
101 if (!current->ptrace)
102 return;
103 info.si_signo = SIGTRAP;
104 info.si_errno = 0;
105 info.si_code = TRAP_HWBKPT;
106 info.si_addr =
107 (void __force __user *) current->thread.per_event.address;
108 force_sig_info(SIGTRAP, &info, current);
109}
110NOKPROBE_SYMBOL(do_per_trap);
111
112void default_trap_handler(struct pt_regs *regs)
113{
114 if (user_mode(regs)) {
115 report_user_fault(regs, SIGSEGV);
116 do_exit(SIGSEGV);
117 } else
118 die(regs, "Unknown program exception");
119}
120
121#define DO_ERROR_INFO(name, signr, sicode, str) \
122void name(struct pt_regs *regs) \
123{ \
124 do_trap(regs, signr, sicode, str); \
125}
126
127DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
128 "addressing exception")
129DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
130 "execute exception")
131DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
132 "fixpoint divide exception")
133DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
134 "fixpoint overflow exception")
135DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
136 "HFP overflow exception")
137DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
138 "HFP underflow exception")
139DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
140 "HFP significance exception")
141DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
142 "HFP divide exception")
143DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
144 "HFP square root exception")
145DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
146 "operand exception")
147DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
148 "privileged operation")
149DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
150 "special operation exception")
151DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
152 "transaction constraint exception")
153
154static inline void do_fp_trap(struct pt_regs *regs, int fpc)
155{
156 int si_code = 0;
157
158 if ((fpc & 0x00000300) == 0) {
159
160 if (fpc & 0x8000)
161 si_code = FPE_FLTINV;
162 else if (fpc & 0x4000)
163 si_code = FPE_FLTDIV;
164 else if (fpc & 0x2000)
165 si_code = FPE_FLTOVF;
166 else if (fpc & 0x1000)
167 si_code = FPE_FLTUND;
168 else if (fpc & 0x0800)
169 si_code = FPE_FLTRES;
170 }
171 do_trap(regs, SIGFPE, si_code, "floating point exception");
172}
173
174void translation_exception(struct pt_regs *regs)
175{
176
177 panic("Translation exception");
178}
179
180void illegal_op(struct pt_regs *regs)
181{
182 siginfo_t info;
183 __u8 opcode[6];
184 __u16 __user *location;
185 int is_uprobe_insn = 0;
186 int signal = 0;
187
188 location = get_trap_ip(regs);
189
190 if (user_mode(regs)) {
191 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
192 return;
193 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
194 if (current->ptrace) {
195 info.si_signo = SIGTRAP;
196 info.si_errno = 0;
197 info.si_code = TRAP_BRKPT;
198 info.si_addr = location;
199 force_sig_info(SIGTRAP, &info, current);
200 } else
201 signal = SIGILL;
202#ifdef CONFIG_UPROBES
203 } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
204 is_uprobe_insn = 1;
205#endif
206 } else
207 signal = SIGILL;
208 }
209
210
211
212
213
214 if (is_uprobe_insn || !user_mode(regs)) {
215 if (notify_die(DIE_BPT, "bpt", regs, 0,
216 3, SIGTRAP) != NOTIFY_STOP)
217 signal = SIGILL;
218 }
219 if (signal)
220 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
221}
222NOKPROBE_SYMBOL(illegal_op);
223
224DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
225 "specification exception");
226
227int alloc_vector_registers(struct task_struct *tsk)
228{
229 __vector128 *vxrs;
230 int i;
231
232
233 vxrs = kzalloc(sizeof(__vector128) * __NUM_VXRS,
234 GFP_KERNEL|__GFP_REPEAT);
235 if (!vxrs)
236 return -ENOMEM;
237 preempt_disable();
238 if (tsk == current)
239 save_fp_regs(tsk->thread.fp_regs.fprs);
240
241 for (i = 0; i < 16; i++)
242 *(freg_t *) &vxrs[i] = tsk->thread.fp_regs.fprs[i];
243 tsk->thread.vxrs = vxrs;
244 if (tsk == current) {
245 __ctl_set_bit(0, 17);
246 restore_vx_regs(vxrs);
247 }
248 preempt_enable();
249 return 0;
250}
251
252void vector_exception(struct pt_regs *regs)
253{
254 int si_code, vic;
255
256 if (!MACHINE_HAS_VX) {
257 do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
258 return;
259 }
260
261
262 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
263 vic = (current->thread.fp_regs.fpc & 0xf00) >> 8;
264 switch (vic) {
265 case 1:
266 si_code = FPE_FLTINV;
267 break;
268 case 2:
269 si_code = FPE_FLTDIV;
270 break;
271 case 3:
272 si_code = FPE_FLTOVF;
273 break;
274 case 4:
275 si_code = FPE_FLTUND;
276 break;
277 case 5:
278 si_code = FPE_FLTRES;
279 break;
280 default:
281 si_code = 0;
282 }
283 do_trap(regs, SIGFPE, si_code, "vector exception");
284}
285
286static int __init disable_vector_extension(char *str)
287{
288 S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
289 return 1;
290}
291__setup("novx", disable_vector_extension);
292
293void data_exception(struct pt_regs *regs)
294{
295 __u16 __user *location;
296 int signal = 0;
297
298 location = get_trap_ip(regs);
299
300 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
301
302 if (MACHINE_HAS_VX && !current->thread.vxrs &&
303 (current->thread.fp_regs.fpc & FPC_DXC_MASK) == 0xfe00) {
304 alloc_vector_registers(current);
305
306 regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
307 clear_pt_regs_flag(regs, PIF_PER_TRAP);
308 return;
309 }
310 if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
311 signal = SIGFPE;
312 else
313 signal = SIGILL;
314 if (signal == SIGFPE)
315 do_fp_trap(regs, current->thread.fp_regs.fpc);
316 else if (signal)
317 do_trap(regs, signal, ILL_ILLOPN, "data exception");
318}
319
320void space_switch_exception(struct pt_regs *regs)
321{
322
323 if (user_mode(regs))
324 regs->psw.mask |= PSW_ASC_HOME;
325
326 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
327}
328
329void kernel_stack_overflow(struct pt_regs *regs)
330{
331 bust_spinlocks(1);
332 printk("Kernel stack overflow.\n");
333 show_regs(regs);
334 bust_spinlocks(0);
335 panic("Corrupt kernel stack, can't continue.");
336}
337NOKPROBE_SYMBOL(kernel_stack_overflow);
338
339void __init trap_init(void)
340{
341 local_mcck_enable();
342}
343
