Commit | Line | Data |
---|---|---|
cf9750ba RK |
1 | /* |
2 | * Kernel traps/events for Hexagon processor | |
3 | * | |
8914d7e8 | 4 | * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved. |
cf9750ba RK |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 and | |
8 | * only version 2 as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
18 | * 02110-1301, USA. | |
19 | */ | |
20 | ||
21 | #include <linux/init.h> | |
22 | #include <linux/sched.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/kallsyms.h> | |
25 | #include <linux/kdebug.h> | |
26 | #include <linux/syscalls.h> | |
27 | #include <linux/signal.h> | |
28 | #include <linux/tracehook.h> | |
29 | #include <asm/traps.h> | |
30 | #include <asm/vm_fault.h> | |
31 | #include <asm/syscall.h> | |
32 | #include <asm/registers.h> | |
33 | #include <asm/unistd.h> | |
34 | #include <asm/sections.h> | |
35 | #ifdef CONFIG_KGDB | |
36 | # include <linux/kgdb.h> | |
37 | #endif | |
38 | ||
39 | #define TRAP_SYSCALL 1 | |
40 | #define TRAP_DEBUG 0xdb | |
41 | ||
42 | void __init trap_init(void) | |
43 | { | |
44 | } | |
45 | ||
46 | #ifdef CONFIG_GENERIC_BUG | |
47 | /* Maybe should resemble arch/sh/kernel/traps.c ?? */ | |
48 | int is_valid_bugaddr(unsigned long addr) | |
49 | { | |
50 | return 1; | |
51 | } | |
52 | #endif /* CONFIG_GENERIC_BUG */ | |
53 | ||
54 | static const char *ex_name(int ex) | |
55 | { | |
56 | switch (ex) { | |
57 | case HVM_GE_C_XPROT: | |
58 | case HVM_GE_C_XUSER: | |
59 | return "Execute protection fault"; | |
60 | case HVM_GE_C_RPROT: | |
61 | case HVM_GE_C_RUSER: | |
62 | return "Read protection fault"; | |
63 | case HVM_GE_C_WPROT: | |
64 | case HVM_GE_C_WUSER: | |
65 | return "Write protection fault"; | |
66 | case HVM_GE_C_XMAL: | |
67 | return "Misaligned instruction"; | |
db0fe532 RK |
68 | case HVM_GE_C_WREG: |
69 | return "Multiple writes to same register in packet"; | |
70 | case HVM_GE_C_PCAL: | |
71 | return "Program counter values that are not properly aligned"; | |
cf9750ba RK |
72 | case HVM_GE_C_RMAL: |
73 | return "Misaligned data load"; | |
74 | case HVM_GE_C_WMAL: | |
75 | return "Misaligned data store"; | |
76 | case HVM_GE_C_INVI: | |
77 | case HVM_GE_C_PRIVI: | |
78 | return "Illegal instruction"; | |
79 | case HVM_GE_C_BUS: | |
80 | return "Precise bus error"; | |
81 | case HVM_GE_C_CACHE: | |
82 | return "Cache error"; | |
83 | ||
84 | case 0xdb: | |
85 | return "Debugger trap"; | |
86 | ||
87 | default: | |
88 | return "Unrecognized exception"; | |
89 | } | |
90 | } | |
91 | ||
92 | static void do_show_stack(struct task_struct *task, unsigned long *fp, | |
93 | unsigned long ip) | |
94 | { | |
95 | int kstack_depth_to_print = 24; | |
96 | unsigned long offset, size; | |
97 | const char *name = NULL; | |
98 | unsigned long *newfp; | |
99 | unsigned long low, high; | |
100 | char tmpstr[128]; | |
101 | char *modname; | |
102 | int i; | |
103 | ||
104 | if (task == NULL) | |
105 | task = current; | |
106 | ||
107 | printk(KERN_INFO "CPU#%d, %s/%d, Call Trace:\n", | |
108 | raw_smp_processor_id(), task->comm, | |
109 | task_pid_nr(task)); | |
110 | ||
111 | if (fp == NULL) { | |
112 | if (task == current) { | |
113 | asm("%0 = r30" : "=r" (fp)); | |
114 | } else { | |
115 | fp = (unsigned long *) | |
116 | ((struct hexagon_switch_stack *) | |
117 | task->thread.switch_sp)->fp; | |
118 | } | |
119 | } | |
120 | ||
121 | if ((((unsigned long) fp) & 0x3) || ((unsigned long) fp < 0x1000)) { | |
122 | printk(KERN_INFO "-- Corrupt frame pointer %p\n", fp); | |
123 | return; | |
124 | } | |
125 | ||
126 | /* Saved link reg is one word above FP */ | |
127 | if (!ip) | |
128 | ip = *(fp+1); | |
129 | ||
130 | /* Expect kernel stack to be in-bounds */ | |
131 | low = (unsigned long)task_stack_page(task); | |
132 | high = low + THREAD_SIZE - 8; | |
133 | low += sizeof(struct thread_info); | |
134 | ||
135 | for (i = 0; i < kstack_depth_to_print; i++) { | |
136 | ||
137 | name = kallsyms_lookup(ip, &size, &offset, &modname, tmpstr); | |
138 | ||
139 | printk(KERN_INFO "[%p] 0x%lx: %s + 0x%lx", fp, ip, name, | |
140 | offset); | |
141 | if (((unsigned long) fp < low) || (high < (unsigned long) fp)) | |
142 | printk(KERN_CONT " (FP out of bounds!)"); | |
143 | if (modname) | |
144 | printk(KERN_CONT " [%s] ", modname); | |
145 | printk(KERN_CONT "\n"); | |
146 | ||
147 | newfp = (unsigned long *) *fp; | |
148 | ||
149 | if (((unsigned long) newfp) & 0x3) { | |
150 | printk(KERN_INFO "-- Corrupt frame pointer %p\n", | |
151 | newfp); | |
152 | break; | |
153 | } | |
154 | ||
155 | /* Attempt to continue past exception. */ | |
156 | if (0 == newfp) { | |
157 | struct pt_regs *regs = (struct pt_regs *) (((void *)fp) | |
158 | + 8); | |
159 | ||
160 | if (regs->syscall_nr != -1) { | |
161 | printk(KERN_INFO "-- trap0 -- syscall_nr: %ld", | |
162 | regs->syscall_nr); | |
163 | printk(KERN_CONT " psp: %lx elr: %lx\n", | |
164 | pt_psp(regs), pt_elr(regs)); | |
165 | break; | |
166 | } else { | |
167 | /* really want to see more ... */ | |
168 | kstack_depth_to_print += 6; | |
169 | printk(KERN_INFO "-- %s (0x%lx) badva: %lx\n", | |
170 | ex_name(pt_cause(regs)), pt_cause(regs), | |
171 | pt_badva(regs)); | |
172 | } | |
173 | ||
174 | newfp = (unsigned long *) regs->r30; | |
175 | ip = pt_elr(regs); | |
176 | } else { | |
177 | ip = *(newfp + 1); | |
178 | } | |
179 | ||
180 | /* If link reg is null, we are done. */ | |
181 | if (ip == 0x0) | |
182 | break; | |
183 | ||
184 | /* If newfp isn't larger, we're tracing garbage. */ | |
185 | if (newfp > fp) | |
186 | fp = newfp; | |
187 | else | |
188 | break; | |
189 | } | |
190 | } | |
191 | ||
192 | void show_stack(struct task_struct *task, unsigned long *fp) | |
193 | { | |
194 | /* Saved link reg is one word above FP */ | |
195 | do_show_stack(task, fp, 0); | |
196 | } | |
197 | ||
cf9750ba RK |
198 | int die(const char *str, struct pt_regs *regs, long err) |
199 | { | |
200 | static struct { | |
201 | spinlock_t lock; | |
202 | int counter; | |
203 | } die = { | |
204 | .lock = __SPIN_LOCK_UNLOCKED(die.lock), | |
205 | .counter = 0 | |
206 | }; | |
207 | ||
208 | console_verbose(); | |
209 | oops_enter(); | |
210 | ||
211 | spin_lock_irq(&die.lock); | |
212 | bust_spinlocks(1); | |
213 | printk(KERN_EMERG "Oops: %s[#%d]:\n", str, ++die.counter); | |
214 | ||
215 | if (notify_die(DIE_OOPS, str, regs, err, pt_cause(regs), SIGSEGV) == | |
216 | NOTIFY_STOP) | |
217 | return 1; | |
218 | ||
219 | print_modules(); | |
220 | show_regs(regs); | |
221 | do_show_stack(current, ®s->r30, pt_elr(regs)); | |
222 | ||
223 | bust_spinlocks(0); | |
373d4d09 | 224 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
cf9750ba RK |
225 | |
226 | spin_unlock_irq(&die.lock); | |
227 | ||
228 | if (in_interrupt()) | |
229 | panic("Fatal exception in interrupt"); | |
230 | ||
231 | if (panic_on_oops) | |
232 | panic("Fatal exception"); | |
233 | ||
234 | oops_exit(); | |
235 | do_exit(err); | |
236 | return 0; | |
237 | } | |
238 | ||
239 | int die_if_kernel(char *str, struct pt_regs *regs, long err) | |
240 | { | |
241 | if (!user_mode(regs)) | |
242 | return die(str, regs, err); | |
243 | else | |
244 | return 0; | |
245 | } | |
246 | ||
247 | /* | |
248 | * It's not clear that misaligned fetches are ever recoverable. | |
249 | */ | |
250 | static void misaligned_instruction(struct pt_regs *regs) | |
251 | { | |
252 | die_if_kernel("Misaligned Instruction", regs, 0); | |
253 | force_sig(SIGBUS, current); | |
254 | } | |
255 | ||
256 | /* | |
257 | * Misaligned loads and stores, on the other hand, can be | |
258 | * emulated, and probably should be, some day. But for now | |
259 | * they will be considered fatal. | |
260 | */ | |
261 | static void misaligned_data_load(struct pt_regs *regs) | |
262 | { | |
263 | die_if_kernel("Misaligned Data Load", regs, 0); | |
264 | force_sig(SIGBUS, current); | |
265 | } | |
266 | ||
267 | static void misaligned_data_store(struct pt_regs *regs) | |
268 | { | |
269 | die_if_kernel("Misaligned Data Store", regs, 0); | |
270 | force_sig(SIGBUS, current); | |
271 | } | |
272 | ||
273 | static void illegal_instruction(struct pt_regs *regs) | |
274 | { | |
275 | die_if_kernel("Illegal Instruction", regs, 0); | |
276 | force_sig(SIGILL, current); | |
277 | } | |
278 | ||
279 | /* | |
280 | * Precise bus errors may be recoverable with a a retry, | |
281 | * but for now, treat them as irrecoverable. | |
282 | */ | |
283 | static void precise_bus_error(struct pt_regs *regs) | |
284 | { | |
285 | die_if_kernel("Precise Bus Error", regs, 0); | |
286 | force_sig(SIGBUS, current); | |
287 | } | |
288 | ||
289 | /* | |
290 | * If anything is to be done here other than panic, | |
291 | * it will probably be complex and migrate to another | |
292 | * source module. For now, just die. | |
293 | */ | |
294 | static void cache_error(struct pt_regs *regs) | |
295 | { | |
296 | die("Cache Error", regs, 0); | |
297 | } | |
298 | ||
299 | /* | |
300 | * General exception handler | |
301 | */ | |
302 | void do_genex(struct pt_regs *regs) | |
303 | { | |
304 | /* | |
305 | * Decode Cause and Dispatch | |
306 | */ | |
307 | switch (pt_cause(regs)) { | |
308 | case HVM_GE_C_XPROT: | |
309 | case HVM_GE_C_XUSER: | |
310 | execute_protection_fault(regs); | |
311 | break; | |
312 | case HVM_GE_C_RPROT: | |
313 | case HVM_GE_C_RUSER: | |
314 | read_protection_fault(regs); | |
315 | break; | |
316 | case HVM_GE_C_WPROT: | |
317 | case HVM_GE_C_WUSER: | |
318 | write_protection_fault(regs); | |
319 | break; | |
320 | case HVM_GE_C_XMAL: | |
321 | misaligned_instruction(regs); | |
322 | break; | |
db0fe532 RK |
323 | case HVM_GE_C_WREG: |
324 | illegal_instruction(regs); | |
325 | break; | |
326 | case HVM_GE_C_PCAL: | |
327 | misaligned_instruction(regs); | |
328 | break; | |
cf9750ba RK |
329 | case HVM_GE_C_RMAL: |
330 | misaligned_data_load(regs); | |
331 | break; | |
332 | case HVM_GE_C_WMAL: | |
333 | misaligned_data_store(regs); | |
334 | break; | |
335 | case HVM_GE_C_INVI: | |
336 | case HVM_GE_C_PRIVI: | |
337 | illegal_instruction(regs); | |
338 | break; | |
339 | case HVM_GE_C_BUS: | |
340 | precise_bus_error(regs); | |
341 | break; | |
342 | case HVM_GE_C_CACHE: | |
343 | cache_error(regs); | |
344 | break; | |
345 | default: | |
346 | /* Halt and catch fire */ | |
347 | panic("Unrecognized exception 0x%lx\n", pt_cause(regs)); | |
348 | break; | |
349 | } | |
350 | } | |
351 | ||
352 | /* Indirect system call dispatch */ | |
353 | long sys_syscall(void) | |
354 | { | |
355 | printk(KERN_ERR "sys_syscall invoked!\n"); | |
356 | return -ENOSYS; | |
357 | } | |
358 | ||
359 | void do_trap0(struct pt_regs *regs) | |
360 | { | |
cf9750ba RK |
361 | syscall_fn syscall; |
362 | ||
363 | switch (pt_cause(regs)) { | |
364 | case TRAP_SYSCALL: | |
365 | /* System call is trap0 #1 */ | |
366 | ||
367 | /* allow strace to catch syscall args */ | |
368 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) && | |
369 | tracehook_report_syscall_entry(regs))) | |
370 | return; /* return -ENOSYS somewhere? */ | |
371 | ||
372 | /* Interrupts should be re-enabled for syscall processing */ | |
373 | __vmsetie(VM_INT_ENABLE); | |
374 | ||
375 | /* | |
376 | * System call number is in r6, arguments in r0..r5. | |
377 | * Fortunately, no Linux syscall has more than 6 arguments, | |
378 | * and Hexagon ABI passes first 6 arguments in registers. | |
379 | * 64-bit arguments are passed in odd/even register pairs. | |
380 | * Fortunately, we have no system calls that take more | |
381 | * than three arguments with more than one 64-bit value. | |
382 | * Should that change, we'd need to redesign to copy | |
383 | * between user and kernel stacks. | |
384 | */ | |
385 | regs->syscall_nr = regs->r06; | |
386 | ||
387 | /* | |
388 | * GPR R0 carries the first parameter, and is also used | |
389 | * to report the return value. We need a backup of | |
390 | * the user's value in case we need to do a late restart | |
391 | * of the system call. | |
392 | */ | |
393 | regs->restart_r0 = regs->r00; | |
394 | ||
395 | if ((unsigned long) regs->syscall_nr >= __NR_syscalls) { | |
396 | regs->r00 = -1; | |
397 | } else { | |
398 | syscall = (syscall_fn) | |
399 | (sys_call_table[regs->syscall_nr]); | |
a11e67c2 | 400 | regs->r00 = syscall(regs->r00, regs->r01, |
cf9750ba RK |
401 | regs->r02, regs->r03, |
402 | regs->r04, regs->r05); | |
403 | } | |
404 | ||
cf9750ba RK |
405 | /* allow strace to get the syscall return state */ |
406 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE))) | |
407 | tracehook_report_syscall_exit(regs, 0); | |
408 | ||
409 | break; | |
410 | case TRAP_DEBUG: | |
411 | /* Trap0 0xdb is debug breakpoint */ | |
412 | if (user_mode(regs)) { | |
413 | struct siginfo info; | |
414 | ||
415 | info.si_signo = SIGTRAP; | |
416 | info.si_errno = 0; | |
417 | /* | |
418 | * Some architecures add some per-thread state | |
419 | * to distinguish between breakpoint traps and | |
420 | * trace traps. We may want to do that, and | |
421 | * set the si_code value appropriately, or we | |
422 | * may want to use a different trap0 flavor. | |
423 | */ | |
424 | info.si_code = TRAP_BRKPT; | |
425 | info.si_addr = (void __user *) pt_elr(regs); | |
8914d7e8 | 426 | force_sig_info(SIGTRAP, &info, current); |
cf9750ba RK |
427 | } else { |
428 | #ifdef CONFIG_KGDB | |
429 | kgdb_handle_exception(pt_cause(regs), SIGTRAP, | |
430 | TRAP_BRKPT, regs); | |
431 | #endif | |
432 | } | |
433 | break; | |
434 | } | |
435 | /* Ignore other trap0 codes for now, especially 0 (Angel calls) */ | |
436 | } | |
437 | ||
438 | /* | |
439 | * Machine check exception handler | |
440 | */ | |
441 | void do_machcheck(struct pt_regs *regs) | |
442 | { | |
443 | /* Halt and catch fire */ | |
444 | __vmstop(); | |
445 | } | |
7777746c RK |
446 | |
447 | /* | |
448 | * Treat this like the old 0xdb trap. | |
449 | */ | |
450 | ||
451 | void do_debug_exception(struct pt_regs *regs) | |
452 | { | |
453 | regs->hvmer.vmest &= ~HVM_VMEST_CAUSE_MSK; | |
454 | regs->hvmer.vmest |= (TRAP_DEBUG << HVM_VMEST_CAUSE_SFT); | |
455 | do_trap0(regs); | |
456 | } |