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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1da177e4 | 3 | * S390 version |
a53c8fab | 4 | * Copyright IBM Corp. 1999, 2000 |
1da177e4 LT |
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 | */ | |
1bca09f7 HC |
16 | #include <linux/kprobes.h> |
17 | #include <linux/kdebug.h> | |
dcc096c5 | 18 | #include <linux/extable.h> |
73b7d40f | 19 | #include <linux/ptrace.h> |
1bca09f7 | 20 | #include <linux/sched.h> |
b17b0153 | 21 | #include <linux/sched/debug.h> |
1da177e4 | 22 | #include <linux/mm.h> |
80703617 | 23 | #include <linux/slab.h> |
7c0f6ba6 | 24 | #include <linux/uaccess.h> |
92acfb74 | 25 | #include <linux/cpu.h> |
b0753902 | 26 | #include <asm/fpu/api.h> |
a806170e | 27 | #include "entry.h" |
1da177e4 | 28 | |
d35339a4 MS |
29 | static inline void __user *get_trap_ip(struct pt_regs *regs) |
30 | { | |
d35339a4 MS |
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; | |
9cb1ccec | 37 | return (void __user *) (address - (regs->int_code >> 16)); |
d35339a4 MS |
38 | } |
39 | ||
c0007f1a HC |
40 | int is_valid_bugaddr(unsigned long addr) |
41 | { | |
42 | return 1; | |
43 | } | |
44 | ||
2a0a5b22 | 45 | void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str) |
aa33c8cb | 46 | { |
7d256175 | 47 | if (user_mode(regs)) { |
9507a5d0 | 48 | force_sig_fault(si_signo, si_code, get_trap_ip(regs), current); |
5d7eccec | 49 | report_user_fault(regs, si_signo, 0); |
1da177e4 LT |
50 | } else { |
51 | const struct exception_table_entry *fixup; | |
9cb1ccec | 52 | fixup = search_exception_tables(regs->psw.addr); |
1da177e4 | 53 | if (fixup) |
fecc868a | 54 | regs->psw.addr = extable_fixup(fixup); |
c0007f1a HC |
55 | else { |
56 | enum bug_trap_type btt; | |
57 | ||
9cb1ccec | 58 | btt = report_bug(regs->psw.addr, regs); |
c0007f1a HC |
59 | if (btt == BUG_TRAP_TYPE_WARN) |
60 | return; | |
aa33c8cb | 61 | die(regs, str); |
c0007f1a | 62 | } |
1da177e4 LT |
63 | } |
64 | } | |
65 | ||
7a5388de | 66 | static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str) |
2a0a5b22 JW |
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 | } | |
7a5388de | 73 | NOKPROBE_SYMBOL(do_trap); |
2a0a5b22 | 74 | |
7a5388de | 75 | void do_per_trap(struct pt_regs *regs) |
1da177e4 | 76 | { |
5e9a2692 | 77 | if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP) |
4ba069b8 | 78 | return; |
73b7d40f MS |
79 | if (!current->ptrace) |
80 | return; | |
9507a5d0 EB |
81 | force_sig_fault(SIGTRAP, TRAP_HWBKPT, |
82 | (void __force __user *) current->thread.per_event.address, current); | |
1da177e4 | 83 | } |
7a5388de | 84 | NOKPROBE_SYMBOL(do_per_trap); |
1da177e4 | 85 | |
b01a37a7 | 86 | void default_trap_handler(struct pt_regs *regs) |
1da177e4 | 87 | { |
7d256175 | 88 | if (user_mode(regs)) { |
5d7eccec | 89 | report_user_fault(regs, SIGSEGV, 0); |
6ea50968 | 90 | do_exit(SIGSEGV); |
1da177e4 | 91 | } else |
aa33c8cb | 92 | die(regs, "Unknown program exception"); |
1da177e4 LT |
93 | } |
94 | ||
1e54622e | 95 | #define DO_ERROR_INFO(name, signr, sicode, str) \ |
b01a37a7 HC |
96 | void name(struct pt_regs *regs) \ |
97 | { \ | |
98 | do_trap(regs, signr, sicode, str); \ | |
1da177e4 LT |
99 | } |
100 | ||
1e54622e MS |
101 | DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR, |
102 | "addressing exception") | |
103 | DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN, | |
104 | "execute exception") | |
105 | DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV, | |
106 | "fixpoint divide exception") | |
107 | DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF, | |
108 | "fixpoint overflow exception") | |
109 | DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF, | |
110 | "HFP overflow exception") | |
111 | DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND, | |
112 | "HFP underflow exception") | |
113 | DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES, | |
114 | "HFP significance exception") | |
115 | DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV, | |
116 | "HFP divide exception") | |
117 | DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV, | |
118 | "HFP square root exception") | |
119 | DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN, | |
120 | "operand exception") | |
121 | DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC, | |
122 | "privileged operation") | |
123 | DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN, | |
124 | "special operation exception") | |
d35339a4 MS |
125 | DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN, |
126 | "transaction constraint exception") | |
d35339a4 | 127 | |
9977e886 | 128 | static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc) |
1da177e4 | 129 | { |
aa33c8cb | 130 | int si_code = 0; |
1da177e4 LT |
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 */ | |
aa33c8cb | 135 | si_code = FPE_FLTINV; |
1da177e4 | 136 | else if (fpc & 0x4000) /* div by 0 */ |
aa33c8cb | 137 | si_code = FPE_FLTDIV; |
1da177e4 | 138 | else if (fpc & 0x2000) /* overflow */ |
aa33c8cb | 139 | si_code = FPE_FLTOVF; |
1da177e4 | 140 | else if (fpc & 0x1000) /* underflow */ |
aa33c8cb | 141 | si_code = FPE_FLTUND; |
1da177e4 | 142 | else if (fpc & 0x0800) /* inexact */ |
aa33c8cb | 143 | si_code = FPE_FLTRES; |
1da177e4 | 144 | } |
aa33c8cb | 145 | do_trap(regs, SIGFPE, si_code, "floating point exception"); |
1da177e4 LT |
146 | } |
147 | ||
e56da345 HC |
148 | void translation_exception(struct pt_regs *regs) |
149 | { | |
150 | /* May never happen. */ | |
e1d12d70 | 151 | panic("Translation exception"); |
e56da345 HC |
152 | } |
153 | ||
7a5388de | 154 | void illegal_op(struct pt_regs *regs) |
1da177e4 | 155 | { |
1da177e4 | 156 | __u8 opcode[6]; |
d2c993d8 | 157 | __u16 __user *location; |
2a0a5b22 | 158 | int is_uprobe_insn = 0; |
1da177e4 LT |
159 | int signal = 0; |
160 | ||
d35339a4 | 161 | location = get_trap_ip(regs); |
1da177e4 | 162 | |
7d256175 | 163 | if (user_mode(regs)) { |
12bae235 HC |
164 | if (get_user(*((__u16 *) opcode), (__u16 __user *) location)) |
165 | return; | |
1da177e4 | 166 | if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) { |
9507a5d0 EB |
167 | if (current->ptrace) |
168 | force_sig_fault(SIGTRAP, TRAP_BRKPT, location, current); | |
169 | else | |
1da177e4 | 170 | signal = SIGILL; |
2a0a5b22 JW |
171 | #ifdef CONFIG_UPROBES |
172 | } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) { | |
173 | is_uprobe_insn = 1; | |
1da177e4 LT |
174 | #endif |
175 | } else | |
176 | signal = SIGILL; | |
2a0a5b22 JW |
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)) { | |
aa33c8cb | 184 | if (notify_die(DIE_BPT, "bpt", regs, 0, |
35df8d53 HC |
185 | 3, SIGTRAP) != NOTIFY_STOP) |
186 | signal = SIGILL; | |
187 | } | |
aa33c8cb MS |
188 | if (signal) |
189 | do_trap(regs, signal, ILL_ILLOPC, "illegal operation"); | |
1da177e4 | 190 | } |
7a5388de | 191 | NOKPROBE_SYMBOL(illegal_op); |
1da177e4 | 192 | |
1e54622e MS |
193 | DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN, |
194 | "specification exception"); | |
1da177e4 | 195 | |
80703617 MS |
196 | void 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 */ | |
d0164ee2 | 206 | save_fpu_regs(); |
904818e2 | 207 | vic = (current->thread.fpu.fpc & 0xf00) >> 8; |
80703617 MS |
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 | ||
b01a37a7 | 230 | void data_exception(struct pt_regs *regs) |
1da177e4 | 231 | { |
1da177e4 LT |
232 | int signal = 0; |
233 | ||
d0164ee2 | 234 | save_fpu_regs(); |
904818e2 | 235 | if (current->thread.fpu.fpc & FPC_DXC_MASK) |
1da177e4 LT |
236 | signal = SIGFPE; |
237 | else | |
238 | signal = SIGILL; | |
5a79859a | 239 | if (signal == SIGFPE) |
904818e2 | 240 | do_fp_trap(regs, current->thread.fpu.fpc); |
aa33c8cb MS |
241 | else if (signal) |
242 | do_trap(regs, signal, ILL_ILLOPN, "data exception"); | |
1da177e4 LT |
243 | } |
244 | ||
b01a37a7 | 245 | void space_switch_exception(struct pt_regs *regs) |
1da177e4 | 246 | { |
1da177e4 | 247 | /* Set user psw back to home space mode. */ |
7d256175 | 248 | if (user_mode(regs)) |
1da177e4 LT |
249 | regs->psw.mask |= PSW_ASC_HOME; |
250 | /* Send SIGILL. */ | |
aa33c8cb | 251 | do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event"); |
1da177e4 LT |
252 | } |
253 | ||
7a5388de | 254 | void kernel_stack_overflow(struct pt_regs *regs) |
1da177e4 | 255 | { |
77eb65cb HC |
256 | bust_spinlocks(1); |
257 | printk("Kernel stack overflow.\n"); | |
258 | show_regs(regs); | |
259 | bust_spinlocks(0); | |
1da177e4 LT |
260 | panic("Corrupt kernel stack, can't continue."); |
261 | } | |
7a5388de | 262 | NOKPROBE_SYMBOL(kernel_stack_overflow); |
1da177e4 | 263 | |
1da177e4 LT |
264 | void __init trap_init(void) |
265 | { | |
f3e1a273 | 266 | local_mcck_enable(); |
1da177e4 | 267 | } |