ia64/linux-2.6.18-xen.hg

view arch/xtensa/kernel/traps.c @ 647:a5bb490065f6

Fix the build after public header sync.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Wed Aug 13 14:01:49 2008 +0100 (2008-08-13)
parents 831230e53067
children
line source
1 /*
2 * arch/xtensa/kernel/traps.c
3 *
4 * Exception handling.
5 *
6 * Derived from code with the following copyrights:
7 * Copyright (C) 1994 - 1999 by Ralf Baechle
8 * Modified for R3000 by Paul M. Antoine, 1995, 1996
9 * Complete output from die() by Ulf Carlsson, 1998
10 * Copyright (C) 1999 Silicon Graphics, Inc.
11 *
12 * Essentially rewritten for the Xtensa architecture port.
13 *
14 * Copyright (C) 2001 - 2005 Tensilica Inc.
15 *
16 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
17 * Chris Zankel <chris@zankel.net>
18 * Marc Gauthier<marc@tensilica.com, marc@alumni.uwaterloo.ca>
19 * Kevin Chea
20 *
21 * This file is subject to the terms and conditions of the GNU General Public
22 * License. See the file "COPYING" in the main directory of this archive
23 * for more details.
24 */
26 #include <linux/kernel.h>
27 #include <linux/sched.h>
28 #include <linux/init.h>
29 #include <linux/module.h>
30 #include <linux/stringify.h>
31 #include <linux/kallsyms.h>
32 #include <linux/delay.h>
34 #include <asm/ptrace.h>
35 #include <asm/timex.h>
36 #include <asm/uaccess.h>
37 #include <asm/pgtable.h>
38 #include <asm/processor.h>
40 #ifdef CONFIG_KGDB
41 extern int gdb_enter;
42 extern int return_from_debug_flag;
43 #endif
45 /*
46 * Machine specific interrupt handlers
47 */
49 extern void kernel_exception(void);
50 extern void user_exception(void);
52 extern void fast_syscall_kernel(void);
53 extern void fast_syscall_user(void);
54 extern void fast_alloca(void);
55 extern void fast_unaligned(void);
56 extern void fast_second_level_miss(void);
57 extern void fast_store_prohibited(void);
58 extern void fast_coprocessor(void);
60 extern void do_illegal_instruction (struct pt_regs*);
61 extern void do_interrupt (struct pt_regs*);
62 extern void do_unaligned_user (struct pt_regs*);
63 extern void do_multihit (struct pt_regs*, unsigned long);
64 extern void do_page_fault (struct pt_regs*, unsigned long);
65 extern void do_debug (struct pt_regs*);
66 extern void system_call (struct pt_regs*);
68 /*
69 * The vector table must be preceded by a save area (which
70 * implies it must be in RAM, unless one places RAM immediately
71 * before a ROM and puts the vector at the start of the ROM (!))
72 */
74 #define KRNL 0x01
75 #define USER 0x02
77 #define COPROCESSOR(x) \
78 { XCHAL_EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
80 typedef struct {
81 int cause;
82 int fast;
83 void* handler;
84 } dispatch_init_table_t;
86 dispatch_init_table_t __init dispatch_init_table[] = {
88 { XCHAL_EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
89 { XCHAL_EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel },
90 { XCHAL_EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
91 { XCHAL_EXCCAUSE_SYSTEM_CALL, 0, system_call },
92 /* XCHAL_EXCCAUSE_INSTRUCTION_FETCH unhandled */
93 /* XCHAL_EXCCAUSE_LOAD_STORE_ERROR unhandled*/
94 { XCHAL_EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
95 { XCHAL_EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca },
96 /* XCHAL_EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
97 /* XCHAL_EXCCAUSE_PRIVILEGED unhandled */
98 #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
99 #ifdef CONFIG_UNALIGNED_USER
100 { XCHAL_EXCCAUSE_UNALIGNED, USER, fast_unaligned },
101 #else
102 { XCHAL_EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
103 #endif
104 { XCHAL_EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
105 #endif
106 { XCHAL_EXCCAUSE_ITLB_MISS, 0, do_page_fault },
107 { XCHAL_EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss},
108 { XCHAL_EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
109 { XCHAL_EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
110 /* XCHAL_EXCCAUSE_SIZE_RESTRICTION unhandled */
111 { XCHAL_EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
112 { XCHAL_EXCCAUSE_DTLB_MISS, USER|KRNL, fast_second_level_miss},
113 { XCHAL_EXCCAUSE_DTLB_MISS, 0, do_page_fault },
114 { XCHAL_EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
115 { XCHAL_EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
116 /* XCHAL_EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
117 { XCHAL_EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited },
118 { XCHAL_EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
119 { XCHAL_EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
120 /* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
121 #if (XCHAL_CP_MASK & 1)
122 COPROCESSOR(0),
123 #endif
124 #if (XCHAL_CP_MASK & 2)
125 COPROCESSOR(1),
126 #endif
127 #if (XCHAL_CP_MASK & 4)
128 COPROCESSOR(2),
129 #endif
130 #if (XCHAL_CP_MASK & 8)
131 COPROCESSOR(3),
132 #endif
133 #if (XCHAL_CP_MASK & 16)
134 COPROCESSOR(4),
135 #endif
136 #if (XCHAL_CP_MASK & 32)
137 COPROCESSOR(5),
138 #endif
139 #if (XCHAL_CP_MASK & 64)
140 COPROCESSOR(6),
141 #endif
142 #if (XCHAL_CP_MASK & 128)
143 COPROCESSOR(7),
144 #endif
145 { EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
146 { -1, -1, 0 }
148 };
150 /* The exception table <exc_table> serves two functions:
151 * 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
152 * 2. it is a temporary memory buffer for the exception handlers.
153 */
155 unsigned long exc_table[EXC_TABLE_SIZE/4];
157 void die(const char*, struct pt_regs*, long);
159 static inline void
160 __die_if_kernel(const char *str, struct pt_regs *regs, long err)
161 {
162 if (!user_mode(regs))
163 die(str, regs, err);
164 }
166 /*
167 * Unhandled Exceptions. Kill user task or panic if in kernel space.
168 */
170 void do_unhandled(struct pt_regs *regs, unsigned long exccause)
171 {
172 __die_if_kernel("Caught unhandled exception - should not happen",
173 regs, SIGKILL);
175 /* If in user mode, send SIGILL signal to current process */
176 printk("Caught unhandled exception in '%s' "
177 "(pid = %d, pc = %#010lx) - should not happen\n"
178 "\tEXCCAUSE is %ld\n",
179 current->comm, current->pid, regs->pc, exccause);
180 force_sig(SIGILL, current);
181 }
183 /*
184 * Multi-hit exception. This if fatal!
185 */
187 void do_multihit(struct pt_regs *regs, unsigned long exccause)
188 {
189 die("Caught multihit exception", regs, SIGKILL);
190 }
192 /*
193 * Level-1 interrupt.
194 * We currently have no priority encoding.
195 */
197 unsigned long ignored_level1_interrupts;
198 extern void do_IRQ(int, struct pt_regs *);
200 void do_interrupt (struct pt_regs *regs)
201 {
202 unsigned long intread = get_sr (INTREAD);
203 unsigned long intenable = get_sr (INTENABLE);
204 int i, mask;
206 /* Handle all interrupts (no priorities).
207 * (Clear the interrupt before processing, in case it's
208 * edge-triggered or software-generated)
209 */
211 for (i=0, mask = 1; i < XCHAL_NUM_INTERRUPTS; i++, mask <<= 1) {
212 if (mask & (intread & intenable)) {
213 set_sr (mask, INTCLEAR);
214 do_IRQ (i,regs);
215 }
216 }
217 }
219 /*
220 * Illegal instruction. Fatal if in kernel space.
221 */
223 void
224 do_illegal_instruction(struct pt_regs *regs)
225 {
226 __die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
228 /* If in user mode, send SIGILL signal to current process. */
230 printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
231 current->comm, current->pid, regs->pc);
232 force_sig(SIGILL, current);
233 }
236 /*
237 * Handle unaligned memory accesses from user space. Kill task.
238 *
239 * If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
240 * accesses causes from user space.
241 */
243 #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
244 #ifndef CONFIG_UNALIGNED_USER
245 void
246 do_unaligned_user (struct pt_regs *regs)
247 {
248 siginfo_t info;
250 __die_if_kernel("Unhandled unaligned exception in kernel",
251 regs, SIGKILL);
253 current->thread.bad_vaddr = regs->excvaddr;
254 current->thread.error_code = -3;
255 printk("Unaligned memory access to %08lx in '%s' "
256 "(pid = %d, pc = %#010lx)\n",
257 regs->excvaddr, current->comm, current->pid, regs->pc);
258 info.si_signo = SIGBUS;
259 info.si_errno = 0;
260 info.si_code = BUS_ADRALN;
261 info.si_addr = (void *) regs->excvaddr;
262 force_sig_info(SIGSEGV, &info, current);
264 }
265 #endif
266 #endif
268 void
269 do_debug(struct pt_regs *regs)
270 {
271 #ifdef CONFIG_KGDB
272 /* If remote debugging is configured AND enabled, we give control to
273 * kgdb. Otherwise, we fall through, perhaps giving control to the
274 * native debugger.
275 */
277 if (gdb_enter) {
278 extern void gdb_handle_exception(struct pt_regs *);
279 gdb_handle_exception(regs);
280 return_from_debug_flag = 1;
281 return;
282 }
283 #endif
285 __die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
287 /* If in user mode, send SIGTRAP signal to current process */
289 force_sig(SIGTRAP, current);
290 }
293 /*
294 * Initialize dispatch tables.
295 *
296 * The exception vectors are stored compressed the __init section in the
297 * dispatch_init_table. This function initializes the following three tables
298 * from that compressed table:
299 * - fast user first dispatch table for user exceptions
300 * - fast kernel first dispatch table for kernel exceptions
301 * - default C-handler C-handler called by the default fast handler.
302 *
303 * See vectors.S for more details.
304 */
306 #define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler))
308 void trap_init(void)
309 {
310 int i;
312 /* Setup default vectors. */
314 for(i = 0; i < 64; i++) {
315 set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
316 set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
317 set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
318 }
320 /* Setup specific handlers. */
322 for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
324 int fast = dispatch_init_table[i].fast;
325 int cause = dispatch_init_table[i].cause;
326 void *handler = dispatch_init_table[i].handler;
328 if (fast == 0)
329 set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
330 if (fast && fast & USER)
331 set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
332 if (fast && fast & KRNL)
333 set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
334 }
336 /* Initialize EXCSAVE_1 to hold the address of the exception table. */
338 i = (unsigned long)exc_table;
339 __asm__ __volatile__("wsr %0, "__stringify(EXCSAVE_1)"\n" : : "a" (i));
340 }
342 /*
343 * This function dumps the current valid window frame and other base registers.
344 */
346 void show_regs(struct pt_regs * regs)
347 {
348 int i, wmask;
350 wmask = regs->wmask & ~1;
352 for (i = 0; i < 32; i++) {
353 if (wmask & (1 << (i / 4)))
354 break;
355 if ((i % 8) == 0)
356 printk ("\n" KERN_INFO "a%02d: ", i);
357 printk("%08lx ", regs->areg[i]);
358 }
359 printk("\n");
361 printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
362 regs->pc, regs->ps, regs->depc, regs->excvaddr);
363 printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
364 regs->lbeg, regs->lend, regs->lcount, regs->sar);
365 if (user_mode(regs))
366 printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
367 regs->windowbase, regs->windowstart, regs->wmask,
368 regs->syscall);
369 }
371 void show_trace(struct task_struct *task, unsigned long *sp)
372 {
373 unsigned long a0, a1, pc;
374 unsigned long sp_start, sp_end;
376 a1 = (unsigned long)sp;
378 if (a1 == 0)
379 __asm__ __volatile__ ("mov %0, a1\n" : "=a"(a1));
382 sp_start = a1 & ~(THREAD_SIZE-1);
383 sp_end = sp_start + THREAD_SIZE;
385 printk("Call Trace:");
386 #ifdef CONFIG_KALLSYMS
387 printk("\n");
388 #endif
389 spill_registers();
391 while (a1 > sp_start && a1 < sp_end) {
392 sp = (unsigned long*)a1;
394 a0 = *(sp - 4);
395 a1 = *(sp - 3);
397 if (a1 <= (unsigned long) sp)
398 break;
400 pc = MAKE_PC_FROM_RA(a0, a1);
402 if (kernel_text_address(pc)) {
403 printk(" [<%08lx>] ", pc);
404 print_symbol("%s\n", pc);
405 }
406 }
407 printk("\n");
408 }
410 /*
411 * This routine abuses get_user()/put_user() to reference pointers
412 * with at least a bit of error checking ...
413 */
415 static int kstack_depth_to_print = 24;
417 void show_stack(struct task_struct *task, unsigned long *sp)
418 {
419 int i = 0;
420 unsigned long *stack;
422 if (sp == 0)
423 __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
425 stack = sp;
427 printk("\nStack: ");
429 for (i = 0; i < kstack_depth_to_print; i++) {
430 if (kstack_end(sp))
431 break;
432 if (i && ((i % 8) == 0))
433 printk("\n ");
434 printk("%08lx ", *sp++);
435 }
436 printk("\n");
437 show_trace(task, stack);
438 }
440 void dump_stack(void)
441 {
442 show_stack(current, NULL);
443 }
445 EXPORT_SYMBOL(dump_stack);
448 void show_code(unsigned int *pc)
449 {
450 long i;
452 printk("\nCode:");
454 for(i = -3 ; i < 6 ; i++) {
455 unsigned long insn;
456 if (__get_user(insn, pc + i)) {
457 printk(" (Bad address in pc)\n");
458 break;
459 }
460 printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>'));
461 }
462 }
464 DEFINE_SPINLOCK(die_lock);
466 void die(const char * str, struct pt_regs * regs, long err)
467 {
468 static int die_counter;
469 int nl = 0;
471 console_verbose();
472 spin_lock_irq(&die_lock);
474 printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter);
475 #ifdef CONFIG_PREEMPT
476 printk("PREEMPT ");
477 nl = 1;
478 #endif
479 if (nl)
480 printk("\n");
481 show_regs(regs);
482 if (!user_mode(regs))
483 show_stack(NULL, (unsigned long*)regs->areg[1]);
485 spin_unlock_irq(&die_lock);
487 if (in_interrupt())
488 panic("Fatal exception in interrupt");
490 if (panic_on_oops)
491 panic("Fatal exception");
493 do_exit(err);
494 }