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16#include "asm/irqflags.h"
17#include "asm/ptrace.h"
18#include <linux/kprobes.h>
19#include <linux/kdebug.h>
20#include <linux/randomize_kstack.h>
21#include <linux/extable.h>
22#include <linux/ptrace.h>
23#include <linux/sched.h>
24#include <linux/sched/debug.h>
25#include <linux/mm.h>
26#include <linux/slab.h>
27#include <linux/uaccess.h>
28#include <linux/cpu.h>
29#include <linux/entry-common.h>
30#include <asm/fpu/api.h>
31#include <asm/vtime.h>
32#include "entry.h"
33
34static inline void __user *get_trap_ip(struct pt_regs *regs)
35{
36 unsigned long address;
37
38 if (regs->int_code & 0x200)
39 address = current->thread.trap_tdb.data[3];
40 else
41 address = regs->psw.addr;
42 return (void __user *) (address - (regs->int_code >> 16));
43}
44
45int is_valid_bugaddr(unsigned long addr)
46{
47 return 1;
48}
49
50void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
51{
52 if (user_mode(regs)) {
53 force_sig_fault(si_signo, si_code, get_trap_ip(regs));
54 report_user_fault(regs, si_signo, 0);
55 } else {
56 const struct exception_table_entry *fixup;
57 fixup = s390_search_extables(regs->psw.addr);
58 if (!fixup || !ex_handle(fixup, regs))
59 die(regs, str);
60 }
61}
62
63static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
64{
65 if (notify_die(DIE_TRAP, str, regs, 0,
66 regs->int_code, si_signo) == NOTIFY_STOP)
67 return;
68 do_report_trap(regs, si_signo, si_code, str);
69}
70NOKPROBE_SYMBOL(do_trap);
71
72void do_per_trap(struct pt_regs *regs)
73{
74 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
75 return;
76 if (!current->ptrace)
77 return;
78 force_sig_fault(SIGTRAP, TRAP_HWBKPT,
79 (void __force __user *) current->thread.per_event.address);
80}
81NOKPROBE_SYMBOL(do_per_trap);
82
83static void default_trap_handler(struct pt_regs *regs)
84{
85 if (user_mode(regs)) {
86 report_user_fault(regs, SIGSEGV, 0);
87 do_exit(SIGSEGV);
88 } else
89 die(regs, "Unknown program exception");
90}
91
92#define DO_ERROR_INFO(name, signr, sicode, str) \
93static void name(struct pt_regs *regs) \
94{ \
95 do_trap(regs, signr, sicode, str); \
96}
97
98DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
99 "addressing exception")
100DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
101 "execute exception")
102DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
103 "fixpoint divide exception")
104DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
105 "fixpoint overflow exception")
106DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
107 "HFP overflow exception")
108DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
109 "HFP underflow exception")
110DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
111 "HFP significance exception")
112DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
113 "HFP divide exception")
114DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
115 "HFP square root exception")
116DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
117 "operand exception")
118DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
119 "privileged operation")
120DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
121 "special operation exception")
122DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
123 "transaction constraint exception")
124
125static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
126{
127 int si_code = 0;
128
129 if ((fpc & 0x00000300) == 0) {
130
131 if (fpc & 0x8000)
132 si_code = FPE_FLTINV;
133 else if (fpc & 0x4000)
134 si_code = FPE_FLTDIV;
135 else if (fpc & 0x2000)
136 si_code = FPE_FLTOVF;
137 else if (fpc & 0x1000)
138 si_code = FPE_FLTUND;
139 else if (fpc & 0x0800)
140 si_code = FPE_FLTRES;
141 }
142 do_trap(regs, SIGFPE, si_code, "floating point exception");
143}
144
145static void translation_exception(struct pt_regs *regs)
146{
147
148 panic("Translation exception");
149}
150
151static void illegal_op(struct pt_regs *regs)
152{
153 __u8 opcode[6];
154 __u16 __user *location;
155 int is_uprobe_insn = 0;
156 int signal = 0;
157
158 location = get_trap_ip(regs);
159
160 if (user_mode(regs)) {
161 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
162 return;
163 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
164 if (current->ptrace)
165 force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
166 else
167 signal = SIGILL;
168#ifdef CONFIG_UPROBES
169 } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
170 is_uprobe_insn = 1;
171#endif
172 } else
173 signal = SIGILL;
174 }
175
176
177
178
179
180 if (is_uprobe_insn || !user_mode(regs)) {
181 if (notify_die(DIE_BPT, "bpt", regs, 0,
182 3, SIGTRAP) != NOTIFY_STOP)
183 signal = SIGILL;
184 }
185 if (signal)
186 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
187}
188NOKPROBE_SYMBOL(illegal_op);
189
190DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
191 "specification exception");
192
193static void vector_exception(struct pt_regs *regs)
194{
195 int si_code, vic;
196
197 if (!MACHINE_HAS_VX) {
198 do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
199 return;
200 }
201
202
203 save_fpu_regs();
204 vic = (current->thread.fpu.fpc & 0xf00) >> 8;
205 switch (vic) {
206 case 1:
207 si_code = FPE_FLTINV;
208 break;
209 case 2:
210 si_code = FPE_FLTDIV;
211 break;
212 case 3:
213 si_code = FPE_FLTOVF;
214 break;
215 case 4:
216 si_code = FPE_FLTUND;
217 break;
218 case 5:
219 si_code = FPE_FLTRES;
220 break;
221 default:
222 si_code = 0;
223 }
224 do_trap(regs, SIGFPE, si_code, "vector exception");
225}
226
227static void data_exception(struct pt_regs *regs)
228{
229 save_fpu_regs();
230 if (current->thread.fpu.fpc & FPC_DXC_MASK)
231 do_fp_trap(regs, current->thread.fpu.fpc);
232 else
233 do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
234}
235
236static void space_switch_exception(struct pt_regs *regs)
237{
238
239 if (user_mode(regs))
240 regs->psw.mask |= PSW_ASC_HOME;
241
242 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
243}
244
245static void monitor_event_exception(struct pt_regs *regs)
246{
247 const struct exception_table_entry *fixup;
248
249 if (user_mode(regs))
250 return;
251
252 switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) {
253 case BUG_TRAP_TYPE_NONE:
254 fixup = s390_search_extables(regs->psw.addr);
255 if (fixup)
256 ex_handle(fixup, regs);
257 break;
258 case BUG_TRAP_TYPE_WARN:
259 break;
260 case BUG_TRAP_TYPE_BUG:
261 die(regs, "monitor event");
262 break;
263 }
264}
265
266void kernel_stack_overflow(struct pt_regs *regs)
267{
268 bust_spinlocks(1);
269 printk("Kernel stack overflow.\n");
270 show_regs(regs);
271 bust_spinlocks(0);
272 panic("Corrupt kernel stack, can't continue.");
273}
274NOKPROBE_SYMBOL(kernel_stack_overflow);
275
276static void __init test_monitor_call(void)
277{
278 int val = 1;
279
280 if (!IS_ENABLED(CONFIG_BUG))
281 return;
282 asm volatile(
283 " mc 0,0\n"
284 "0: xgr %0,%0\n"
285 "1:\n"
286 EX_TABLE(0b,1b)
287 : "+d" (val));
288 if (!val)
289 panic("Monitor call doesn't work!\n");
290}
291
292void __init trap_init(void)
293{
294 sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
295 local_mcck_enable();
296 test_monitor_call();
297}
298
299static void (*pgm_check_table[128])(struct pt_regs *regs);
300
301void noinstr __do_pgm_check(struct pt_regs *regs)
302{
303 unsigned long last_break = S390_lowcore.breaking_event_addr;
304 unsigned int trapnr;
305 irqentry_state_t state;
306
307 regs->int_code = *(u32 *)&S390_lowcore.pgm_ilc;
308 regs->int_parm_long = S390_lowcore.trans_exc_code;
309
310 state = irqentry_enter(regs);
311
312 if (user_mode(regs)) {
313 update_timer_sys();
314 if (last_break < 4096)
315 last_break = 1;
316 current->thread.last_break = last_break;
317 regs->args[0] = last_break;
318 }
319
320 if (S390_lowcore.pgm_code & 0x0200) {
321
322 current->thread.trap_tdb = S390_lowcore.pgm_tdb;
323 }
324
325 if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) {
326 if (user_mode(regs)) {
327 struct per_event *ev = ¤t->thread.per_event;
328
329 set_thread_flag(TIF_PER_TRAP);
330 ev->address = S390_lowcore.per_address;
331 ev->cause = *(u16 *)&S390_lowcore.per_code;
332 ev->paid = S390_lowcore.per_access_id;
333 } else {
334
335 __arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
336 do_per_trap(regs);
337 goto out;
338 }
339 }
340
341 if (!irqs_disabled_flags(regs->psw.mask))
342 trace_hardirqs_on();
343 __arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
344
345 trapnr = regs->int_code & PGM_INT_CODE_MASK;
346 if (trapnr)
347 pgm_check_table[trapnr](regs);
348out:
349 local_irq_disable();
350 irqentry_exit(regs, state);
351}
352
353
354
355
356
357
358static void (*pgm_check_table[128])(struct pt_regs *regs) = {
359 [0x00] = default_trap_handler,
360 [0x01] = illegal_op,
361 [0x02] = privileged_op,
362 [0x03] = execute_exception,
363 [0x04] = do_protection_exception,
364 [0x05] = addressing_exception,
365 [0x06] = specification_exception,
366 [0x07] = data_exception,
367 [0x08] = overflow_exception,
368 [0x09] = divide_exception,
369 [0x0a] = overflow_exception,
370 [0x0b] = divide_exception,
371 [0x0c] = hfp_overflow_exception,
372 [0x0d] = hfp_underflow_exception,
373 [0x0e] = hfp_significance_exception,
374 [0x0f] = hfp_divide_exception,
375 [0x10] = do_dat_exception,
376 [0x11] = do_dat_exception,
377 [0x12] = translation_exception,
378 [0x13] = special_op_exception,
379 [0x14] = default_trap_handler,
380 [0x15] = operand_exception,
381 [0x16] = default_trap_handler,
382 [0x17] = default_trap_handler,
383 [0x18] = transaction_exception,
384 [0x19] = default_trap_handler,
385 [0x1a] = default_trap_handler,
386 [0x1b] = vector_exception,
387 [0x1c] = space_switch_exception,
388 [0x1d] = hfp_sqrt_exception,
389 [0x1e ... 0x37] = default_trap_handler,
390 [0x38] = do_dat_exception,
391 [0x39] = do_dat_exception,
392 [0x3a] = do_dat_exception,
393 [0x3b] = do_dat_exception,
394 [0x3c] = default_trap_handler,
395 [0x3d] = do_secure_storage_access,
396 [0x3e] = do_non_secure_storage_access,
397 [0x3f] = do_secure_storage_violation,
398 [0x40] = monitor_event_exception,
399 [0x41 ... 0x7f] = default_trap_handler,
400};
401
402#define COND_TRAP(x) asm( \
403 ".weak " __stringify(x) "\n\t" \
404 ".set " __stringify(x) "," \
405 __stringify(default_trap_handler))
406
407COND_TRAP(do_secure_storage_access);
408COND_TRAP(do_non_secure_storage_access);
409COND_TRAP(do_secure_storage_violation);
410
