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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * S390 version
4 * Copyright IBM Corp. 1999, 2000
5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
7 *
8 * Derived from "arch/i386/kernel/traps.c"
9 * Copyright (C) 1991, 1992 Linus Torvalds
10 */
11
12/*
13 * 'Traps.c' handles hardware traps and faults after we have saved some
14 * state in 'asm.s'.
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 if (user_mode(regs)) {
48 force_sig_fault(si_signo, si_code, get_trap_ip(regs));
49 report_user_fault(regs, si_signo, 0);
50 } else {
51 const struct exception_table_entry *fixup;
52 fixup = s390_search_extables(regs->psw.addr);
53 if (fixup)
54 regs->psw.addr = extable_fixup(fixup);
55 else {
56 enum bug_trap_type btt;
57
58 btt = report_bug(regs->psw.addr, regs);
59 if (btt == BUG_TRAP_TYPE_WARN)
60 return;
61 die(regs, str);
62 }
63 }
64}
65
66static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
67{
68 if (notify_die(DIE_TRAP, str, regs, 0,
69 regs->int_code, si_signo) == NOTIFY_STOP)
70 return;
71 do_report_trap(regs, si_signo, si_code, str);
72}
73NOKPROBE_SYMBOL(do_trap);
74
75void do_per_trap(struct pt_regs *regs)
76{
77 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
78 return;
79 if (!current->ptrace)
80 return;
81 force_sig_fault(SIGTRAP, TRAP_HWBKPT,
82 (void __force __user *) current->thread.per_event.address);
83}
84NOKPROBE_SYMBOL(do_per_trap);
85
86void default_trap_handler(struct pt_regs *regs)
87{
88 if (user_mode(regs)) {
89 report_user_fault(regs, SIGSEGV, 0);
90 do_exit(SIGSEGV);
91 } else
92 die(regs, "Unknown program exception");
93}
94
95#define DO_ERROR_INFO(name, signr, sicode, str) \
96void name(struct pt_regs *regs) \
97{ \
98 do_trap(regs, signr, sicode, str); \
99}
100
101DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
102 "addressing exception")
103DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
104 "execute exception")
105DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
106 "fixpoint divide exception")
107DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
108 "fixpoint overflow exception")
109DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
110 "HFP overflow exception")
111DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
112 "HFP underflow exception")
113DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
114 "HFP significance exception")
115DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
116 "HFP divide exception")
117DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
118 "HFP square root exception")
119DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
120 "operand exception")
121DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
122 "privileged operation")
123DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
124 "special operation exception")
125DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
126 "transaction constraint exception")
127
128static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
129{
130 int si_code = 0;
131 /* FPC[2] is Data Exception Code */
132 if ((fpc & 0x00000300) == 0) {
133 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
134 if (fpc & 0x8000) /* invalid fp operation */
135 si_code = FPE_FLTINV;
136 else if (fpc & 0x4000) /* div by 0 */
137 si_code = FPE_FLTDIV;
138 else if (fpc & 0x2000) /* overflow */
139 si_code = FPE_FLTOVF;
140 else if (fpc & 0x1000) /* underflow */
141 si_code = FPE_FLTUND;
142 else if (fpc & 0x0800) /* inexact */
143 si_code = FPE_FLTRES;
144 }
145 do_trap(regs, SIGFPE, si_code, "floating point exception");
146}
147
148void translation_exception(struct pt_regs *regs)
149{
150 /* May never happen. */
151 panic("Translation exception");
152}
153
154void illegal_op(struct pt_regs *regs)
155{
156 __u8 opcode[6];
157 __u16 __user *location;
158 int is_uprobe_insn = 0;
159 int signal = 0;
160
161 location = get_trap_ip(regs);
162
163 if (user_mode(regs)) {
164 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
165 return;
166 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
167 if (current->ptrace)
168 force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
169 else
170 signal = SIGILL;
171#ifdef CONFIG_UPROBES
172 } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
173 is_uprobe_insn = 1;
174#endif
175 } else
176 signal = SIGILL;
177 }
178 /*
179 * We got either an illegal op in kernel mode, or user space trapped
180 * on a uprobes illegal instruction. See if kprobes or uprobes picks
181 * it up. If not, SIGILL.
182 */
183 if (is_uprobe_insn || !user_mode(regs)) {
184 if (notify_die(DIE_BPT, "bpt", regs, 0,
185 3, SIGTRAP) != NOTIFY_STOP)
186 signal = SIGILL;
187 }
188 if (signal)
189 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
190}
191NOKPROBE_SYMBOL(illegal_op);
192
193DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
194 "specification exception");
195
196void vector_exception(struct pt_regs *regs)
197{
198 int si_code, vic;
199
200 if (!MACHINE_HAS_VX) {
201 do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
202 return;
203 }
204
205 /* get vector interrupt code from fpc */
206 save_fpu_regs();
207 vic = (current->thread.fpu.fpc & 0xf00) >> 8;
208 switch (vic) {
209 case 1: /* invalid vector operation */
210 si_code = FPE_FLTINV;
211 break;
212 case 2: /* division by zero */
213 si_code = FPE_FLTDIV;
214 break;
215 case 3: /* overflow */
216 si_code = FPE_FLTOVF;
217 break;
218 case 4: /* underflow */
219 si_code = FPE_FLTUND;
220 break;
221 case 5: /* inexact */
222 si_code = FPE_FLTRES;
223 break;
224 default: /* unknown cause */
225 si_code = 0;
226 }
227 do_trap(regs, SIGFPE, si_code, "vector exception");
228}
229
230void data_exception(struct pt_regs *regs)
231{
232 save_fpu_regs();
233 if (current->thread.fpu.fpc & FPC_DXC_MASK)
234 do_fp_trap(regs, current->thread.fpu.fpc);
235 else
236 do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
237}
238
239void space_switch_exception(struct pt_regs *regs)
240{
241 /* Set user psw back to home space mode. */
242 if (user_mode(regs))
243 regs->psw.mask |= PSW_ASC_HOME;
244 /* Send SIGILL. */
245 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
246}
247
248void kernel_stack_overflow(struct pt_regs *regs)
249{
250 bust_spinlocks(1);
251 printk("Kernel stack overflow.\n");
252 show_regs(regs);
253 bust_spinlocks(0);
254 panic("Corrupt kernel stack, can't continue.");
255}
256NOKPROBE_SYMBOL(kernel_stack_overflow);
257
258void __init trap_init(void)
259{
260 sort_extable(__start_dma_ex_table, __stop_dma_ex_table);
261 local_mcck_enable();
262}
1/*
2 * S390 version
3 * Copyright IBM Corp. 1999, 2000
4 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
5 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
6 *
7 * Derived from "arch/i386/kernel/traps.c"
8 * Copyright (C) 1991, 1992 Linus Torvalds
9 */
10
11/*
12 * 'Traps.c' handles hardware traps and faults after we have saved some
13 * state in 'asm.s'.
14 */
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 /* FPC[2] is Data Exception Code */
160 if ((fpc & 0x00000300) == 0) {
161 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
162 if (fpc & 0x8000) /* invalid fp operation */
163 si_code = FPE_FLTINV;
164 else if (fpc & 0x4000) /* div by 0 */
165 si_code = FPE_FLTDIV;
166 else if (fpc & 0x2000) /* overflow */
167 si_code = FPE_FLTOVF;
168 else if (fpc & 0x1000) /* underflow */
169 si_code = FPE_FLTUND;
170 else if (fpc & 0x0800) /* inexact */
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 * If we get an illegal op in kernel mode, send it through the
225 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
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: /* LDR Rx,Ry */
257 signal = math_emu_ldr(opcode);
258 break;
259 case 0x38: /* LER Rx,Ry */
260 signal = math_emu_ler(opcode);
261 break;
262 case 0x60: /* STD R,D(X,B) */
263 get_user(*((__u16 *) (opcode+2)), location+1);
264 signal = math_emu_std(opcode, regs);
265 break;
266 case 0x68: /* LD R,D(X,B) */
267 get_user(*((__u16 *) (opcode+2)), location+1);
268 signal = math_emu_ld(opcode, regs);
269 break;
270 case 0x70: /* STE R,D(X,B) */
271 get_user(*((__u16 *) (opcode+2)), location+1);
272 signal = math_emu_ste(opcode, regs);
273 break;
274 case 0x78: /* LE R,D(X,B) */
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: /* LDR Rx,Ry */
311 signal = math_emu_ldr(opcode);
312 break;
313 case 0x38: /* LER Rx,Ry */
314 signal = math_emu_ler(opcode);
315 break;
316 case 0x60: /* STD R,D(X,B) */
317 get_user(*((__u16 *) (opcode+2)), location+1);
318 signal = math_emu_std(opcode, regs);
319 break;
320 case 0x68: /* LD R,D(X,B) */
321 get_user(*((__u16 *) (opcode+2)), location+1);
322 signal = math_emu_ld(opcode, regs);
323 break;
324 case 0x70: /* STE R,D(X,B) */
325 get_user(*((__u16 *) (opcode+2)), location+1);
326 signal = math_emu_ste(opcode, regs);
327 break;
328 case 0x78: /* LE R,D(X,B) */
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 /* Set user psw back to home space mode. */
373 if (user_mode(regs))
374 regs->psw.mask |= PSW_ASC_HOME;
375 /* Send SIGILL. */
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}