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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
132 if ((fpc & 0x00000300) == 0) {
133
134 if (fpc & 0x8000)
135 si_code = FPE_FLTINV;
136 else if (fpc & 0x4000)
137 si_code = FPE_FLTDIV;
138 else if (fpc & 0x2000)
139 si_code = FPE_FLTOVF;
140 else if (fpc & 0x1000)
141 si_code = FPE_FLTUND;
142 else if (fpc & 0x0800)
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
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
180
181
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
206 save_fpu_regs();
207 vic = (current->thread.fpu.fpc & 0xf00) >> 8;
208 switch (vic) {
209 case 1:
210 si_code = FPE_FLTINV;
211 break;
212 case 2:
213 si_code = FPE_FLTDIV;
214 break;
215 case 3:
216 si_code = FPE_FLTOVF;
217 break;
218 case 4:
219 si_code = FPE_FLTUND;
220 break;
221 case 5:
222 si_code = FPE_FLTRES;
223 break;
224 default:
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
242 if (user_mode(regs))
243 regs->psw.mask |= PSW_ASC_HOME;
244
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}
263
