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),
7 * Derived from "arch/i386/kernel/traps.c"
8 * Copyright (C) 1991, 1992 Linus Torvalds
12 * 'Traps.c' handles hardware traps and faults after we have saved some
15 #include <linux/kprobes.h>
16 #include <linux/kdebug.h>
17 #include <linux/extable.h>
18 #include <linux/ptrace.h>
19 #include <linux/sched.h>
20 #include <linux/sched/debug.h>
22 #include <linux/slab.h>
23 #include <linux/uaccess.h>
24 #include <asm/fpu/api.h>
27 static inline void __user
*get_trap_ip(struct pt_regs
*regs
)
29 unsigned long address
;
31 if (regs
->int_code
& 0x200)
32 address
= *(unsigned long *)(current
->thread
.trap_tdb
+ 24);
34 address
= regs
->psw
.addr
;
35 return (void __user
*) (address
- (regs
->int_code
>> 16));
38 int is_valid_bugaddr(unsigned long addr
)
43 void do_report_trap(struct pt_regs
*regs
, int si_signo
, int si_code
, char *str
)
47 if (user_mode(regs
)) {
48 info
.si_signo
= si_signo
;
50 info
.si_code
= si_code
;
51 info
.si_addr
= get_trap_ip(regs
);
52 force_sig_info(si_signo
, &info
, current
);
53 report_user_fault(regs
, si_signo
, 0);
55 const struct exception_table_entry
*fixup
;
56 fixup
= search_exception_tables(regs
->psw
.addr
);
58 regs
->psw
.addr
= extable_fixup(fixup
);
60 enum bug_trap_type btt
;
62 btt
= report_bug(regs
->psw
.addr
, regs
);
63 if (btt
== BUG_TRAP_TYPE_WARN
)
70 static void do_trap(struct pt_regs
*regs
, int si_signo
, int si_code
, char *str
)
72 if (notify_die(DIE_TRAP
, str
, regs
, 0,
73 regs
->int_code
, si_signo
) == NOTIFY_STOP
)
75 do_report_trap(regs
, si_signo
, si_code
, str
);
77 NOKPROBE_SYMBOL(do_trap
);
79 void do_per_trap(struct pt_regs
*regs
)
83 if (notify_die(DIE_SSTEP
, "sstep", regs
, 0, 0, SIGTRAP
) == NOTIFY_STOP
)
87 info
.si_signo
= SIGTRAP
;
89 info
.si_code
= TRAP_HWBKPT
;
91 (void __force __user
*) current
->thread
.per_event
.address
;
92 force_sig_info(SIGTRAP
, &info
, current
);
94 NOKPROBE_SYMBOL(do_per_trap
);
96 void default_trap_handler(struct pt_regs
*regs
)
98 if (user_mode(regs
)) {
99 report_user_fault(regs
, SIGSEGV
, 0);
102 die(regs
, "Unknown program exception");
105 #define DO_ERROR_INFO(name, signr, sicode, str) \
106 void name(struct pt_regs *regs) \
108 do_trap(regs, signr, sicode, str); \
111 DO_ERROR_INFO(addressing_exception
, SIGILL
, ILL_ILLADR
,
112 "addressing exception")
113 DO_ERROR_INFO(execute_exception
, SIGILL
, ILL_ILLOPN
,
115 DO_ERROR_INFO(divide_exception
, SIGFPE
, FPE_INTDIV
,
116 "fixpoint divide exception")
117 DO_ERROR_INFO(overflow_exception
, SIGFPE
, FPE_INTOVF
,
118 "fixpoint overflow exception")
119 DO_ERROR_INFO(hfp_overflow_exception
, SIGFPE
, FPE_FLTOVF
,
120 "HFP overflow exception")
121 DO_ERROR_INFO(hfp_underflow_exception
, SIGFPE
, FPE_FLTUND
,
122 "HFP underflow exception")
123 DO_ERROR_INFO(hfp_significance_exception
, SIGFPE
, FPE_FLTRES
,
124 "HFP significance exception")
125 DO_ERROR_INFO(hfp_divide_exception
, SIGFPE
, FPE_FLTDIV
,
126 "HFP divide exception")
127 DO_ERROR_INFO(hfp_sqrt_exception
, SIGFPE
, FPE_FLTINV
,
128 "HFP square root exception")
129 DO_ERROR_INFO(operand_exception
, SIGILL
, ILL_ILLOPN
,
131 DO_ERROR_INFO(privileged_op
, SIGILL
, ILL_PRVOPC
,
132 "privileged operation")
133 DO_ERROR_INFO(special_op_exception
, SIGILL
, ILL_ILLOPN
,
134 "special operation exception")
135 DO_ERROR_INFO(transaction_exception
, SIGILL
, ILL_ILLOPN
,
136 "transaction constraint exception")
138 static inline void do_fp_trap(struct pt_regs
*regs
, __u32 fpc
)
141 /* FPC[2] is Data Exception Code */
142 if ((fpc
& 0x00000300) == 0) {
143 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
144 if (fpc
& 0x8000) /* invalid fp operation */
145 si_code
= FPE_FLTINV
;
146 else if (fpc
& 0x4000) /* div by 0 */
147 si_code
= FPE_FLTDIV
;
148 else if (fpc
& 0x2000) /* overflow */
149 si_code
= FPE_FLTOVF
;
150 else if (fpc
& 0x1000) /* underflow */
151 si_code
= FPE_FLTUND
;
152 else if (fpc
& 0x0800) /* inexact */
153 si_code
= FPE_FLTRES
;
155 do_trap(regs
, SIGFPE
, si_code
, "floating point exception");
158 void translation_exception(struct pt_regs
*regs
)
160 /* May never happen. */
161 panic("Translation exception");
164 void illegal_op(struct pt_regs
*regs
)
168 __u16 __user
*location
;
169 int is_uprobe_insn
= 0;
172 location
= get_trap_ip(regs
);
174 if (user_mode(regs
)) {
175 if (get_user(*((__u16
*) opcode
), (__u16 __user
*) location
))
177 if (*((__u16
*) opcode
) == S390_BREAKPOINT_U16
) {
178 if (current
->ptrace
) {
179 info
.si_signo
= SIGTRAP
;
181 info
.si_code
= TRAP_BRKPT
;
182 info
.si_addr
= location
;
183 force_sig_info(SIGTRAP
, &info
, current
);
186 #ifdef CONFIG_UPROBES
187 } else if (*((__u16
*) opcode
) == UPROBE_SWBP_INSN
) {
194 * We got either an illegal op in kernel mode, or user space trapped
195 * on a uprobes illegal instruction. See if kprobes or uprobes picks
196 * it up. If not, SIGILL.
198 if (is_uprobe_insn
|| !user_mode(regs
)) {
199 if (notify_die(DIE_BPT
, "bpt", regs
, 0,
200 3, SIGTRAP
) != NOTIFY_STOP
)
204 do_trap(regs
, signal
, ILL_ILLOPC
, "illegal operation");
206 NOKPROBE_SYMBOL(illegal_op
);
208 DO_ERROR_INFO(specification_exception
, SIGILL
, ILL_ILLOPN
,
209 "specification exception");
211 void vector_exception(struct pt_regs
*regs
)
215 if (!MACHINE_HAS_VX
) {
216 do_trap(regs
, SIGILL
, ILL_ILLOPN
, "illegal operation");
220 /* get vector interrupt code from fpc */
222 vic
= (current
->thread
.fpu
.fpc
& 0xf00) >> 8;
224 case 1: /* invalid vector operation */
225 si_code
= FPE_FLTINV
;
227 case 2: /* division by zero */
228 si_code
= FPE_FLTDIV
;
230 case 3: /* overflow */
231 si_code
= FPE_FLTOVF
;
233 case 4: /* underflow */
234 si_code
= FPE_FLTUND
;
236 case 5: /* inexact */
237 si_code
= FPE_FLTRES
;
239 default: /* unknown cause */
242 do_trap(regs
, SIGFPE
, si_code
, "vector exception");
245 void data_exception(struct pt_regs
*regs
)
250 if (current
->thread
.fpu
.fpc
& FPC_DXC_MASK
)
254 if (signal
== SIGFPE
)
255 do_fp_trap(regs
, current
->thread
.fpu
.fpc
);
257 do_trap(regs
, signal
, ILL_ILLOPN
, "data exception");
260 void space_switch_exception(struct pt_regs
*regs
)
262 /* Set user psw back to home space mode. */
264 regs
->psw
.mask
|= PSW_ASC_HOME
;
266 do_trap(regs
, SIGILL
, ILL_PRVOPC
, "space switch event");
269 void kernel_stack_overflow(struct pt_regs
*regs
)
272 printk("Kernel stack overflow.\n");
275 panic("Corrupt kernel stack, can't continue.");
277 NOKPROBE_SYMBOL(kernel_stack_overflow
);
279 void __init
trap_init(void)