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1 /*
2  *  linux/arch/m32r/kernel/traps.c
3  *
4  *  Copyright (C) 2001, 2002  Hirokazu Takata, Hiroyuki Kondo,
5  *                            Hitoshi Yamamoto
6  */
7 
8 /*
9  * 'traps.c' handles hardware traps and faults after we have saved some
10  * state in 'entry.S'.
11  */
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/kallsyms.h>
15 #include <linux/stddef.h>
16 #include <linux/ptrace.h>
17 #include <linux/mm.h>
18 #include <asm/page.h>
19 #include <asm/processor.h>
20 
21 #include <asm/uaccess.h>
22 #include <asm/io.h>
23 #include <linux/atomic.h>
24 
25 #include <asm/smp.h>
26 
27 #include <linux/module.h>
28 
29 asmlinkage void alignment_check(void);
30 asmlinkage void ei_handler(void);
31 asmlinkage void rie_handler(void);
32 asmlinkage void debug_trap(void);
33 asmlinkage void cache_flushing_handler(void);
34 asmlinkage void ill_trap(void);
35 
36 #ifdef CONFIG_SMP
37 extern void smp_reschedule_interrupt(void);
38 extern void smp_invalidate_interrupt(void);
39 extern void smp_call_function_interrupt(void);
40 extern void smp_ipi_timer_interrupt(void);
41 extern void smp_flush_cache_all_interrupt(void);
42 extern void smp_call_function_single_interrupt(void);
43 
44 /*
45  * for Boot AP function
46  */
47 asm (
48 	"	.section .eit_vector4,\"ax\"	\n"
49 	"	.global _AP_RE			\n"
50 	"	.global startup_AP		\n"
51 	"_AP_RE:				\n"
52 	"	.fill 32, 4, 0			\n"
53 	"_AP_EI: bra	startup_AP		\n"
54 	"	.previous			\n"
55 );
56 #endif  /* CONFIG_SMP */
57 
58 extern unsigned long	eit_vector[];
59 #define BRA_INSN(func, entry)	\
60 	((unsigned long)func - (unsigned long)eit_vector - entry*4)/4 \
61 	+ 0xff000000UL
62 
set_eit_vector_entries(void)63 static void set_eit_vector_entries(void)
64 {
65 	extern void default_eit_handler(void);
66 	extern void system_call(void);
67 	extern void pie_handler(void);
68 	extern void ace_handler(void);
69 	extern void tme_handler(void);
70 	extern void _flush_cache_copyback_all(void);
71 
72 	eit_vector[0] = 0xd0c00001; /* seth r0, 0x01 */
73 	eit_vector[1] = BRA_INSN(default_eit_handler, 1);
74 	eit_vector[4] = 0xd0c00010; /* seth r0, 0x10 */
75 	eit_vector[5] = BRA_INSN(default_eit_handler, 5);
76 	eit_vector[8] = BRA_INSN(rie_handler, 8);
77 	eit_vector[12] = BRA_INSN(alignment_check, 12);
78 	eit_vector[16] = BRA_INSN(ill_trap, 16);
79 	eit_vector[17] = BRA_INSN(debug_trap, 17);
80 	eit_vector[18] = BRA_INSN(system_call, 18);
81 	eit_vector[19] = BRA_INSN(ill_trap, 19);
82 	eit_vector[20] = BRA_INSN(ill_trap, 20);
83 	eit_vector[21] = BRA_INSN(ill_trap, 21);
84 	eit_vector[22] = BRA_INSN(ill_trap, 22);
85 	eit_vector[23] = BRA_INSN(ill_trap, 23);
86 	eit_vector[24] = BRA_INSN(ill_trap, 24);
87 	eit_vector[25] = BRA_INSN(ill_trap, 25);
88 	eit_vector[26] = BRA_INSN(ill_trap, 26);
89 	eit_vector[27] = BRA_INSN(ill_trap, 27);
90 	eit_vector[28] = BRA_INSN(cache_flushing_handler, 28);
91 	eit_vector[29] = BRA_INSN(ill_trap, 29);
92 	eit_vector[30] = BRA_INSN(ill_trap, 30);
93 	eit_vector[31] = BRA_INSN(ill_trap, 31);
94 	eit_vector[32] = BRA_INSN(ei_handler, 32);
95 	eit_vector[64] = BRA_INSN(pie_handler, 64);
96 #ifdef CONFIG_MMU
97 	eit_vector[68] = BRA_INSN(ace_handler, 68);
98 	eit_vector[72] = BRA_INSN(tme_handler, 72);
99 #endif /* CONFIG_MMU */
100 #ifdef CONFIG_SMP
101 	eit_vector[184] = (unsigned long)smp_reschedule_interrupt;
102 	eit_vector[185] = (unsigned long)smp_invalidate_interrupt;
103 	eit_vector[186] = (unsigned long)smp_call_function_interrupt;
104 	eit_vector[187] = (unsigned long)smp_ipi_timer_interrupt;
105 	eit_vector[188] = (unsigned long)smp_flush_cache_all_interrupt;
106 	eit_vector[189] = 0;	/* CPU_BOOT_IPI */
107 	eit_vector[190] = (unsigned long)smp_call_function_single_interrupt;
108 	eit_vector[191] = 0;
109 #endif
110 	_flush_cache_copyback_all();
111 }
112 
trap_init(void)113 void __init trap_init(void)
114 {
115 	set_eit_vector_entries();
116 
117 	/*
118 	 * Should be a barrier for any external CPU state.
119 	 */
120 	cpu_init();
121 }
122 
123 static int kstack_depth_to_print = 24;
124 
show_trace(struct task_struct * task,unsigned long * stack)125 static void show_trace(struct task_struct *task, unsigned long *stack)
126 {
127 	unsigned long addr;
128 
129 	if (!stack)
130 		stack = (unsigned long*)&stack;
131 
132 	printk("Call Trace: ");
133 	while (!kstack_end(stack)) {
134 		addr = *stack++;
135 		if (__kernel_text_address(addr))
136 			printk("[<%08lx>] %pSR\n", addr, (void *)addr);
137 	}
138 	printk("\n");
139 }
140 
show_stack(struct task_struct * task,unsigned long * sp)141 void show_stack(struct task_struct *task, unsigned long *sp)
142 {
143 	unsigned long  *stack;
144 	int  i;
145 
146 	/*
147 	 * debugging aid: "show_stack(NULL);" prints the
148 	 * back trace for this cpu.
149 	 */
150 
151 	if(sp==NULL) {
152 		if (task)
153 			sp = (unsigned long *)task->thread.sp;
154 		else
155 			sp=(unsigned long*)&sp;
156 	}
157 
158 	stack = sp;
159 	for(i=0; i < kstack_depth_to_print; i++) {
160 		if (kstack_end(stack))
161 			break;
162 		if (i && ((i % 4) == 0))
163 			printk("\n       ");
164 		printk("%08lx ", *stack++);
165 	}
166 	printk("\n");
167 	show_trace(task, sp);
168 }
169 
show_registers(struct pt_regs * regs)170 static void show_registers(struct pt_regs *regs)
171 {
172 	int i = 0;
173 	int in_kernel = 1;
174 	unsigned long sp;
175 
176 	printk("CPU:    %d\n", smp_processor_id());
177 	show_regs(regs);
178 
179 	sp = (unsigned long) (1+regs);
180 	if (user_mode(regs)) {
181 		in_kernel = 0;
182 		sp = regs->spu;
183 		printk("SPU: %08lx\n", sp);
184 	} else {
185 		printk("SPI: %08lx\n", sp);
186 	}
187 	printk("Process %s (pid: %d, process nr: %d, stackpage=%08lx)",
188 		current->comm, task_pid_nr(current), 0xffff & i, 4096+(unsigned long)current);
189 
190 	/*
191 	 * When in-kernel, we also print out the stack and code at the
192 	 * time of the fault..
193 	 */
194 	if (in_kernel) {
195 		printk("\nStack: ");
196 		show_stack(current, (unsigned long*) sp);
197 
198 		printk("\nCode: ");
199 		if (regs->bpc < PAGE_OFFSET)
200 			goto bad;
201 
202 		for(i=0;i<20;i++) {
203 			unsigned char c;
204 			if (__get_user(c, &((unsigned char*)regs->bpc)[i])) {
205 bad:
206 				printk(" Bad PC value.");
207 				break;
208 			}
209 			printk("%02x ", c);
210 		}
211 	}
212 	printk("\n");
213 }
214 
215 static DEFINE_SPINLOCK(die_lock);
216 
die(const char * str,struct pt_regs * regs,long err)217 void die(const char * str, struct pt_regs * regs, long err)
218 {
219 	console_verbose();
220 	spin_lock_irq(&die_lock);
221 	bust_spinlocks(1);
222 	printk("%s: %04lx\n", str, err & 0xffff);
223 	show_registers(regs);
224 	bust_spinlocks(0);
225 	spin_unlock_irq(&die_lock);
226 	do_exit(SIGSEGV);
227 }
228 
die_if_kernel(const char * str,struct pt_regs * regs,long err)229 static __inline__ void die_if_kernel(const char * str,
230 	struct pt_regs * regs, long err)
231 {
232 	if (!user_mode(regs))
233 		die(str, regs, err);
234 }
235 
do_trap(int trapnr,int signr,const char * str,struct pt_regs * regs,long error_code,siginfo_t * info)236 static __inline__ void do_trap(int trapnr, int signr, const char * str,
237 	struct pt_regs * regs, long error_code, siginfo_t *info)
238 {
239 	if (user_mode(regs)) {
240 		/* trap_signal */
241 		struct task_struct *tsk = current;
242 		tsk->thread.error_code = error_code;
243 		tsk->thread.trap_no = trapnr;
244 		if (info)
245 			force_sig_info(signr, info, tsk);
246 		else
247 			force_sig(signr, tsk);
248 		return;
249 	} else {
250 		/* kernel_trap */
251 		if (!fixup_exception(regs))
252 			die(str, regs, error_code);
253 		return;
254 	}
255 }
256 
257 #define DO_ERROR(trapnr, signr, str, name) \
258 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
259 { \
260 	do_trap(trapnr, signr, NULL, regs, error_code, NULL); \
261 }
262 
263 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
264 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
265 { \
266 	siginfo_t info; \
267 	info.si_signo = signr; \
268 	info.si_errno = 0; \
269 	info.si_code = sicode; \
270 	info.si_addr = (void __user *)siaddr; \
271 	do_trap(trapnr, signr, str, regs, error_code, &info); \
272 }
273 
274 DO_ERROR( 1, SIGTRAP, "debug trap", debug_trap)
275 DO_ERROR_INFO(0x20, SIGILL,  "reserved instruction ", rie_handler, ILL_ILLOPC, regs->bpc)
276 DO_ERROR_INFO(0x100, SIGILL,  "privileged instruction", pie_handler, ILL_PRVOPC, regs->bpc)
277 DO_ERROR_INFO(-1, SIGILL,  "illegal trap", ill_trap, ILL_ILLTRP, regs->bpc)
278 
279 extern int handle_unaligned_access(unsigned long, struct pt_regs *);
280 
281 /* This code taken from arch/sh/kernel/traps.c */
do_alignment_check(struct pt_regs * regs,long error_code)282 asmlinkage void do_alignment_check(struct pt_regs *regs, long error_code)
283 {
284 	mm_segment_t oldfs;
285 	unsigned long insn;
286 	int tmp;
287 
288 	oldfs = get_fs();
289 
290 	if (user_mode(regs)) {
291 		local_irq_enable();
292 		current->thread.error_code = error_code;
293 		current->thread.trap_no = 0x17;
294 
295 		set_fs(USER_DS);
296 		if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
297 			set_fs(oldfs);
298 			goto uspace_segv;
299 		}
300 		tmp = handle_unaligned_access(insn, regs);
301 		set_fs(oldfs);
302 
303 		if (!tmp)
304 			return;
305 
306 	uspace_segv:
307 		printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
308 			"access\n", current->comm);
309 		force_sig(SIGSEGV, current);
310 	} else {
311 		set_fs(KERNEL_DS);
312 		if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
313 			set_fs(oldfs);
314 			die("insn faulting in do_address_error", regs, 0);
315 		}
316 		handle_unaligned_access(insn, regs);
317 		set_fs(oldfs);
318 	}
319 }
320