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>
21 #include <linux/slab.h>
22 #include <linux/uaccess.h>
23 #include <asm/fpu/api.h>
26 static inline void __user *get_trap_ip(struct pt_regs *regs)
28 unsigned long address;
30 if (regs->int_code & 0x200)
31 address = *(unsigned long *)(current->thread.trap_tdb + 24);
33 address = regs->psw.addr;
34 return (void __user *) (address - (regs->int_code >> 16));
37 int is_valid_bugaddr(unsigned long addr)
42 void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
46 if (user_mode(regs)) {
47 info.si_signo = si_signo;
49 info.si_code = si_code;
50 info.si_addr = get_trap_ip(regs);
51 force_sig_info(si_signo, &info, current);
52 report_user_fault(regs, si_signo, 0);
54 const struct exception_table_entry *fixup;
55 fixup = search_exception_tables(regs->psw.addr);
57 regs->psw.addr = extable_fixup(fixup);
59 enum bug_trap_type btt;
61 btt = report_bug(regs->psw.addr, regs);
62 if (btt == BUG_TRAP_TYPE_WARN)
69 static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
71 if (notify_die(DIE_TRAP, str, regs, 0,
72 regs->int_code, si_signo) == NOTIFY_STOP)
74 do_report_trap(regs, si_signo, si_code, str);
76 NOKPROBE_SYMBOL(do_trap);
78 void do_per_trap(struct pt_regs *regs)
82 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
86 info.si_signo = SIGTRAP;
88 info.si_code = TRAP_HWBKPT;
90 (void __force __user *) current->thread.per_event.address;
91 force_sig_info(SIGTRAP, &info, current);
93 NOKPROBE_SYMBOL(do_per_trap);
95 void default_trap_handler(struct pt_regs *regs)
97 if (user_mode(regs)) {
98 report_user_fault(regs, SIGSEGV, 0);
101 die(regs, "Unknown program exception");
104 #define DO_ERROR_INFO(name, signr, sicode, str) \
105 void name(struct pt_regs *regs) \
107 do_trap(regs, signr, sicode, str); \
110 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
111 "addressing exception")
112 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
114 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
115 "fixpoint divide exception")
116 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
117 "fixpoint overflow exception")
118 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
119 "HFP overflow exception")
120 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
121 "HFP underflow exception")
122 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
123 "HFP significance exception")
124 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
125 "HFP divide exception")
126 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
127 "HFP square root exception")
128 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
130 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
131 "privileged operation")
132 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
133 "special operation exception")
134 DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
135 "transaction constraint exception")
137 static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
140 /* FPC[2] is Data Exception Code */
141 if ((fpc & 0x00000300) == 0) {
142 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
143 if (fpc & 0x8000) /* invalid fp operation */
144 si_code = FPE_FLTINV;
145 else if (fpc & 0x4000) /* div by 0 */
146 si_code = FPE_FLTDIV;
147 else if (fpc & 0x2000) /* overflow */
148 si_code = FPE_FLTOVF;
149 else if (fpc & 0x1000) /* underflow */
150 si_code = FPE_FLTUND;
151 else if (fpc & 0x0800) /* inexact */
152 si_code = FPE_FLTRES;
154 do_trap(regs, SIGFPE, si_code, "floating point exception");
157 void translation_exception(struct pt_regs *regs)
159 /* May never happen. */
160 panic("Translation exception");
163 void illegal_op(struct pt_regs *regs)
167 __u16 __user *location;
168 int is_uprobe_insn = 0;
171 location = get_trap_ip(regs);
173 if (user_mode(regs)) {
174 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
176 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
177 if (current->ptrace) {
178 info.si_signo = SIGTRAP;
180 info.si_code = TRAP_BRKPT;
181 info.si_addr = location;
182 force_sig_info(SIGTRAP, &info, current);
185 #ifdef CONFIG_UPROBES
186 } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
193 * We got either an illegal op in kernel mode, or user space trapped
194 * on a uprobes illegal instruction. See if kprobes or uprobes picks
195 * it up. If not, SIGILL.
197 if (is_uprobe_insn || !user_mode(regs)) {
198 if (notify_die(DIE_BPT, "bpt", regs, 0,
199 3, SIGTRAP) != NOTIFY_STOP)
203 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
205 NOKPROBE_SYMBOL(illegal_op);
207 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
208 "specification exception");
210 void vector_exception(struct pt_regs *regs)
214 if (!MACHINE_HAS_VX) {
215 do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
219 /* get vector interrupt code from fpc */
221 vic = (current->thread.fpu.fpc & 0xf00) >> 8;
223 case 1: /* invalid vector operation */
224 si_code = FPE_FLTINV;
226 case 2: /* division by zero */
227 si_code = FPE_FLTDIV;
229 case 3: /* overflow */
230 si_code = FPE_FLTOVF;
232 case 4: /* underflow */
233 si_code = FPE_FLTUND;
235 case 5: /* inexact */
236 si_code = FPE_FLTRES;
238 default: /* unknown cause */
241 do_trap(regs, SIGFPE, si_code, "vector exception");
244 void data_exception(struct pt_regs *regs)
249 if (current->thread.fpu.fpc & FPC_DXC_MASK)
253 if (signal == SIGFPE)
254 do_fp_trap(regs, current->thread.fpu.fpc);
256 do_trap(regs, signal, ILL_ILLOPN, "data exception");
259 void space_switch_exception(struct pt_regs *regs)
261 /* Set user psw back to home space mode. */
263 regs->psw.mask |= PSW_ASC_HOME;
265 do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
268 void kernel_stack_overflow(struct pt_regs *regs)
271 printk("Kernel stack overflow.\n");
274 panic("Corrupt kernel stack, can't continue.");
276 NOKPROBE_SYMBOL(kernel_stack_overflow);
278 void __init trap_init(void)