2 * arch/xtensa/kernel/traps.c
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.
12 * Essentially rewritten for the Xtensa architecture port.
14 * Copyright (C) 2001 - 2005 Tensilica Inc.
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>
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
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>
33 #include <linux/hardirq.h>
35 #include <asm/ptrace.h>
36 #include <asm/timex.h>
37 #include <asm/uaccess.h>
38 #include <asm/pgtable.h>
39 #include <asm/processor.h>
43 extern int return_from_debug_flag
;
47 * Machine specific interrupt handlers
50 extern void kernel_exception(void);
51 extern void user_exception(void);
53 extern void fast_syscall_kernel(void);
54 extern void fast_syscall_user(void);
55 extern void fast_alloca(void);
56 extern void fast_unaligned(void);
57 extern void fast_second_level_miss(void);
58 extern void fast_store_prohibited(void);
59 extern void fast_coprocessor(void);
61 extern void do_illegal_instruction (struct pt_regs
*);
62 extern void do_interrupt (struct pt_regs
*);
63 extern void do_unaligned_user (struct pt_regs
*);
64 extern void do_multihit (struct pt_regs
*, unsigned long);
65 extern void do_page_fault (struct pt_regs
*, unsigned long);
66 extern void do_debug (struct pt_regs
*);
67 extern void system_call (struct pt_regs
*);
70 * The vector table must be preceded by a save area (which
71 * implies it must be in RAM, unless one places RAM immediately
72 * before a ROM and puts the vector at the start of the ROM (!))
78 #define COPROCESSOR(x) \
79 { EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
85 } dispatch_init_table_t
;
87 static dispatch_init_table_t __initdata dispatch_init_table
[] = {
89 { EXCCAUSE_ILLEGAL_INSTRUCTION
, 0, do_illegal_instruction
},
90 { EXCCAUSE_SYSTEM_CALL
, KRNL
, fast_syscall_kernel
},
91 { EXCCAUSE_SYSTEM_CALL
, USER
, fast_syscall_user
},
92 { EXCCAUSE_SYSTEM_CALL
, 0, system_call
},
93 /* EXCCAUSE_INSTRUCTION_FETCH unhandled */
94 /* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
95 { EXCCAUSE_LEVEL1_INTERRUPT
, 0, do_interrupt
},
96 { EXCCAUSE_ALLOCA
, USER
|KRNL
, fast_alloca
},
97 /* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
98 /* EXCCAUSE_PRIVILEGED unhandled */
99 #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
100 #ifdef CONFIG_UNALIGNED_USER
101 { EXCCAUSE_UNALIGNED
, USER
, fast_unaligned
},
103 { EXCCAUSE_UNALIGNED
, 0, do_unaligned_user
},
105 { EXCCAUSE_UNALIGNED
, KRNL
, fast_unaligned
},
107 { EXCCAUSE_ITLB_MISS
, 0, do_page_fault
},
108 { EXCCAUSE_ITLB_MISS
, USER
|KRNL
, fast_second_level_miss
},
109 { EXCCAUSE_ITLB_MULTIHIT
, 0, do_multihit
},
110 { EXCCAUSE_ITLB_PRIVILEGE
, 0, do_page_fault
},
111 /* EXCCAUSE_SIZE_RESTRICTION unhandled */
112 { EXCCAUSE_FETCH_CACHE_ATTRIBUTE
, 0, do_page_fault
},
113 { EXCCAUSE_DTLB_MISS
, USER
|KRNL
, fast_second_level_miss
},
114 { EXCCAUSE_DTLB_MISS
, 0, do_page_fault
},
115 { EXCCAUSE_DTLB_MULTIHIT
, 0, do_multihit
},
116 { EXCCAUSE_DTLB_PRIVILEGE
, 0, do_page_fault
},
117 /* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
118 { EXCCAUSE_STORE_CACHE_ATTRIBUTE
, USER
|KRNL
, fast_store_prohibited
},
119 { EXCCAUSE_STORE_CACHE_ATTRIBUTE
, 0, do_page_fault
},
120 { EXCCAUSE_LOAD_CACHE_ATTRIBUTE
, 0, do_page_fault
},
121 /* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
122 #if XTENSA_HAVE_COPROCESSOR(0)
125 #if XTENSA_HAVE_COPROCESSOR(1)
128 #if XTENSA_HAVE_COPROCESSOR(2)
131 #if XTENSA_HAVE_COPROCESSOR(3)
134 #if XTENSA_HAVE_COPROCESSOR(4)
137 #if XTENSA_HAVE_COPROCESSOR(5)
140 #if XTENSA_HAVE_COPROCESSOR(6)
143 #if XTENSA_HAVE_COPROCESSOR(7)
146 { EXCCAUSE_MAPPED_DEBUG
, 0, do_debug
},
151 /* The exception table <exc_table> serves two functions:
152 * 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
153 * 2. it is a temporary memory buffer for the exception handlers.
156 unsigned long exc_table
[EXC_TABLE_SIZE
/4];
158 void die(const char*, struct pt_regs
*, long);
161 __die_if_kernel(const char *str
, struct pt_regs
*regs
, long err
)
163 if (!user_mode(regs
))
168 * Unhandled Exceptions. Kill user task or panic if in kernel space.
171 void do_unhandled(struct pt_regs
*regs
, unsigned long exccause
)
173 __die_if_kernel("Caught unhandled exception - should not happen",
176 /* If in user mode, send SIGILL signal to current process */
177 printk("Caught unhandled exception in '%s' "
178 "(pid = %d, pc = %#010lx) - should not happen\n"
179 "\tEXCCAUSE is %ld\n",
180 current
->comm
, task_pid_nr(current
), regs
->pc
, exccause
);
181 force_sig(SIGILL
, current
);
185 * Multi-hit exception. This if fatal!
188 void do_multihit(struct pt_regs
*regs
, unsigned long exccause
)
190 die("Caught multihit exception", regs
, SIGKILL
);
195 * We currently have no priority encoding.
198 unsigned long ignored_level1_interrupts
;
199 extern void do_IRQ(int, struct pt_regs
*);
201 void do_interrupt (struct pt_regs
*regs
)
203 unsigned long intread
= get_sr (INTREAD
);
204 unsigned long intenable
= get_sr (INTENABLE
);
207 /* Handle all interrupts (no priorities).
208 * (Clear the interrupt before processing, in case it's
209 * edge-triggered or software-generated)
212 for (i
=0, mask
= 1; i
< XCHAL_NUM_INTERRUPTS
; i
++, mask
<<= 1) {
213 if (mask
& (intread
& intenable
)) {
214 set_sr (mask
, INTCLEAR
);
221 * Illegal instruction. Fatal if in kernel space.
225 do_illegal_instruction(struct pt_regs
*regs
)
227 __die_if_kernel("Illegal instruction in kernel", regs
, SIGKILL
);
229 /* If in user mode, send SIGILL signal to current process. */
231 printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
232 current
->comm
, task_pid_nr(current
), regs
->pc
);
233 force_sig(SIGILL
, current
);
238 * Handle unaligned memory accesses from user space. Kill task.
240 * If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
241 * accesses causes from user space.
244 #if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
245 #ifndef CONFIG_UNALIGNED_USER
247 do_unaligned_user (struct pt_regs
*regs
)
251 __die_if_kernel("Unhandled unaligned exception in kernel",
254 current
->thread
.bad_vaddr
= regs
->excvaddr
;
255 current
->thread
.error_code
= -3;
256 printk("Unaligned memory access to %08lx in '%s' "
257 "(pid = %d, pc = %#010lx)\n",
258 regs
->excvaddr
, current
->comm
, task_pid_nr(current
), regs
->pc
);
259 info
.si_signo
= SIGBUS
;
261 info
.si_code
= BUS_ADRALN
;
262 info
.si_addr
= (void *) regs
->excvaddr
;
263 force_sig_info(SIGSEGV
, &info
, current
);
270 do_debug(struct pt_regs
*regs
)
273 /* If remote debugging is configured AND enabled, we give control to
274 * kgdb. Otherwise, we fall through, perhaps giving control to the
279 extern void gdb_handle_exception(struct pt_regs
*);
280 gdb_handle_exception(regs
);
281 return_from_debug_flag
= 1;
286 __die_if_kernel("Breakpoint in kernel", regs
, SIGKILL
);
288 /* If in user mode, send SIGTRAP signal to current process */
290 force_sig(SIGTRAP
, current
);
295 * Initialize dispatch tables.
297 * The exception vectors are stored compressed the __init section in the
298 * dispatch_init_table. This function initializes the following three tables
299 * from that compressed table:
300 * - fast user first dispatch table for user exceptions
301 * - fast kernel first dispatch table for kernel exceptions
302 * - default C-handler C-handler called by the default fast handler.
304 * See vectors.S for more details.
307 #define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler))
309 void __init
trap_init(void)
313 /* Setup default vectors. */
315 for(i
= 0; i
< 64; i
++) {
316 set_handler(EXC_TABLE_FAST_USER
/4 + i
, user_exception
);
317 set_handler(EXC_TABLE_FAST_KERNEL
/4 + i
, kernel_exception
);
318 set_handler(EXC_TABLE_DEFAULT
/4 + i
, do_unhandled
);
321 /* Setup specific handlers. */
323 for(i
= 0; dispatch_init_table
[i
].cause
>= 0; i
++) {
325 int fast
= dispatch_init_table
[i
].fast
;
326 int cause
= dispatch_init_table
[i
].cause
;
327 void *handler
= dispatch_init_table
[i
].handler
;
330 set_handler (EXC_TABLE_DEFAULT
/4 + cause
, handler
);
331 if (fast
&& fast
& USER
)
332 set_handler (EXC_TABLE_FAST_USER
/4 + cause
, handler
);
333 if (fast
&& fast
& KRNL
)
334 set_handler (EXC_TABLE_FAST_KERNEL
/4 + cause
, handler
);
337 /* Initialize EXCSAVE_1 to hold the address of the exception table. */
339 i
= (unsigned long)exc_table
;
340 __asm__
__volatile__("wsr %0, "__stringify(EXCSAVE_1
)"\n" : : "a" (i
));
344 * This function dumps the current valid window frame and other base registers.
347 void show_regs(struct pt_regs
* regs
)
351 wmask
= regs
->wmask
& ~1;
353 for (i
= 0; i
< 16; i
++) {
355 printk ("\n" KERN_INFO
"a%02d: ", i
);
356 printk("%08lx ", regs
->areg
[i
]);
360 printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
361 regs
->pc
, regs
->ps
, regs
->depc
, regs
->excvaddr
);
362 printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
363 regs
->lbeg
, regs
->lend
, regs
->lcount
, regs
->sar
);
365 printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
366 regs
->windowbase
, regs
->windowstart
, regs
->wmask
,
370 void show_trace(struct task_struct
*task
, unsigned long *sp
)
372 unsigned long a0
, a1
, pc
;
373 unsigned long sp_start
, sp_end
;
375 a1
= (unsigned long)sp
;
378 __asm__
__volatile__ ("mov %0, a1\n" : "=a"(a1
));
381 sp_start
= a1
& ~(THREAD_SIZE
-1);
382 sp_end
= sp_start
+ THREAD_SIZE
;
384 printk("Call Trace:");
385 #ifdef CONFIG_KALLSYMS
390 while (a1
> sp_start
&& a1
< sp_end
) {
391 sp
= (unsigned long*)a1
;
396 if (a1
<= (unsigned long) sp
)
399 pc
= MAKE_PC_FROM_RA(a0
, a1
);
401 if (kernel_text_address(pc
)) {
402 printk(" [<%08lx>] ", pc
);
403 print_symbol("%s\n", pc
);
410 * This routine abuses get_user()/put_user() to reference pointers
411 * with at least a bit of error checking ...
414 static int kstack_depth_to_print
= 24;
416 void show_stack(struct task_struct
*task
, unsigned long *sp
)
419 unsigned long *stack
;
422 __asm__
__volatile__ ("mov %0, a1\n" : "=a"(sp
));
428 for (i
= 0; i
< kstack_depth_to_print
; i
++) {
431 if (i
&& ((i
% 8) == 0))
433 printk("%08lx ", *sp
++);
436 show_trace(task
, stack
);
439 void dump_stack(void)
441 show_stack(current
, NULL
);
444 EXPORT_SYMBOL(dump_stack
);
447 void show_code(unsigned int *pc
)
453 for(i
= -3 ; i
< 6 ; i
++) {
455 if (__get_user(insn
, pc
+ i
)) {
456 printk(" (Bad address in pc)\n");
459 printk("%c%08lx%c",(i
?' ':'<'),insn
,(i
?' ':'>'));
463 DEFINE_SPINLOCK(die_lock
);
465 void die(const char * str
, struct pt_regs
* regs
, long err
)
467 static int die_counter
;
471 spin_lock_irq(&die_lock
);
473 printk("%s: sig: %ld [#%d]\n", str
, err
, ++die_counter
);
474 #ifdef CONFIG_PREEMPT
481 if (!user_mode(regs
))
482 show_stack(NULL
, (unsigned long*)regs
->areg
[1]);
484 add_taint(TAINT_DIE
);
485 spin_unlock_irq(&die_lock
);
488 panic("Fatal exception in interrupt");
491 panic("Fatal exception");