blob: 3b5ea68acbb8bead82c3202b8c901141e7ca2d2e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/mm/fault.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 * Modifications for ARM processor (c) 1995-2004 Russell King
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/module.h>
12#include <linux/signal.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/mm.h>
Russell King67306da2008-12-14 18:01:44 +000014#include <linux/hardirq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/init.h>
Nicolas Pitre25ce1dd2007-12-03 15:21:57 -050016#include <linux/kprobes.h>
Russell King33fa9b12008-09-06 11:35:55 +010017#include <linux/uaccess.h>
Nicolas Pitre252d4c22008-09-11 11:52:02 -040018#include <linux/page-flags.h>
Catalin Marinas412bb0a2009-07-24 12:37:09 +010019#include <linux/sched.h>
Russell King65cec8e2009-08-17 20:02:06 +010020#include <linux/highmem.h>
Jamie Iles7ada1892010-02-02 20:24:58 +010021#include <linux/perf_event.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#include <asm/system.h>
24#include <asm/pgtable.h>
25#include <asm/tlbflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#include "fault.h"
28
Russell Kingc88d6aa2009-09-20 12:41:58 +010029/*
Russell Kingdf297bf2009-09-20 13:18:47 +010030 * Fault status register encodings. We steal bit 31 for our own purposes.
Russell Kingc88d6aa2009-09-20 12:41:58 +010031 */
Russell Kingdf297bf2009-09-20 13:18:47 +010032#define FSR_LNX_PF (1 << 31)
Russell Kingc88d6aa2009-09-20 12:41:58 +010033#define FSR_WRITE (1 << 11)
34#define FSR_FS4 (1 << 10)
35#define FSR_FS3_0 (15)
36
37static inline int fsr_fs(unsigned int fsr)
38{
39 return (fsr & FSR_FS3_0) | (fsr & FSR_FS4) >> 6;
40}
41
Catalin Marinas09529f72009-07-24 12:34:55 +010042#ifdef CONFIG_MMU
Nicolas Pitre25ce1dd2007-12-03 15:21:57 -050043
44#ifdef CONFIG_KPROBES
45static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr)
46{
47 int ret = 0;
48
49 if (!user_mode(regs)) {
50 /* kprobe_running() needs smp_processor_id() */
51 preempt_disable();
52 if (kprobe_running() && kprobe_fault_handler(regs, fsr))
53 ret = 1;
54 preempt_enable();
55 }
56
57 return ret;
58}
59#else
60static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr)
61{
62 return 0;
63}
64#endif
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066/*
67 * This is useful to dump out the page tables associated with
68 * 'addr' in mm 'mm'.
69 */
70void show_pte(struct mm_struct *mm, unsigned long addr)
71{
72 pgd_t *pgd;
73
74 if (!mm)
75 mm = &init_mm;
76
77 printk(KERN_ALERT "pgd = %p\n", mm->pgd);
78 pgd = pgd_offset(mm, addr);
Will Deacon29a38192011-02-15 14:31:37 +010079 printk(KERN_ALERT "[%08lx] *pgd=%08llx",
80 addr, (long long)pgd_val(*pgd));
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82 do {
Russell King516295e2010-11-21 16:27:49 +000083 pud_t *pud;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 pmd_t *pmd;
85 pte_t *pte;
86
87 if (pgd_none(*pgd))
88 break;
89
90 if (pgd_bad(*pgd)) {
91 printk("(bad)");
92 break;
93 }
94
Russell King516295e2010-11-21 16:27:49 +000095 pud = pud_offset(pgd, addr);
96 if (PTRS_PER_PUD != 1)
Catalin Marinas140d5dc2011-07-13 16:32:58 +010097 printk(", *pud=%08llx", (long long)pud_val(*pud));
Russell King516295e2010-11-21 16:27:49 +000098
99 if (pud_none(*pud))
100 break;
101
102 if (pud_bad(*pud)) {
103 printk("(bad)");
104 break;
105 }
106
107 pmd = pmd_offset(pud, addr);
Nicolas Pitreda46c792008-09-30 16:10:11 +0100108 if (PTRS_PER_PMD != 1)
Will Deacon29a38192011-02-15 14:31:37 +0100109 printk(", *pmd=%08llx", (long long)pmd_val(*pmd));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111 if (pmd_none(*pmd))
112 break;
113
114 if (pmd_bad(*pmd)) {
115 printk("(bad)");
116 break;
117 }
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 /* We must not map this if we have highmem enabled */
Nicolas Pitre252d4c22008-09-11 11:52:02 -0400120 if (PageHighMem(pfn_to_page(pmd_val(*pmd) >> PAGE_SHIFT)))
121 break;
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 pte = pte_offset_map(pmd, addr);
Will Deacon29a38192011-02-15 14:31:37 +0100124 printk(", *pte=%08llx", (long long)pte_val(*pte));
125 printk(", *ppte=%08llx",
126 (long long)pte_val(pte[PTE_HWTABLE_PTRS]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 pte_unmap(pte);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 } while(0);
129
130 printk("\n");
131}
Catalin Marinas09529f72009-07-24 12:34:55 +0100132#else /* CONFIG_MMU */
133void show_pte(struct mm_struct *mm, unsigned long addr)
134{ }
135#endif /* CONFIG_MMU */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137/*
138 * Oops. The kernel tried to access some page that wasn't present.
139 */
140static void
141__do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
142 struct pt_regs *regs)
143{
144 /*
145 * Are we prepared to handle this kernel fault?
146 */
147 if (fixup_exception(regs))
148 return;
149
150 /*
151 * No handler, we'll have to terminate things with extreme prejudice.
152 */
153 bust_spinlocks(1);
154 printk(KERN_ALERT
155 "Unable to handle kernel %s at virtual address %08lx\n",
156 (addr < PAGE_SIZE) ? "NULL pointer dereference" :
157 "paging request", addr);
158
159 show_pte(mm, addr);
160 die("Oops", regs, fsr);
161 bust_spinlocks(0);
162 do_exit(SIGKILL);
163}
164
165/*
166 * Something tried to access memory that isn't in our memory map..
167 * User mode accesses just cause a SIGSEGV
168 */
169static void
170__do_user_fault(struct task_struct *tsk, unsigned long addr,
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700171 unsigned int fsr, unsigned int sig, int code,
172 struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
174 struct siginfo si;
175
176#ifdef CONFIG_DEBUG_USER
177 if (user_debug & UDBG_SEGV) {
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700178 printk(KERN_DEBUG "%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",
179 tsk->comm, sig, addr, fsr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 show_pte(tsk->mm, addr);
181 show_regs(regs);
182 }
183#endif
184
185 tsk->thread.address = addr;
186 tsk->thread.error_code = fsr;
187 tsk->thread.trap_no = 14;
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700188 si.si_signo = sig;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 si.si_errno = 0;
190 si.si_code = code;
191 si.si_addr = (void __user *)addr;
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700192 force_sig_info(sig, &si, tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193}
194
Russell Kinge5beac32006-09-27 16:13:48 +0100195void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196{
Russell Kinge5beac32006-09-27 16:13:48 +0100197 struct task_struct *tsk = current;
198 struct mm_struct *mm = tsk->active_mm;
199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 /*
201 * If we are in kernel mode at this point, we
202 * have no context to handle this fault with.
203 */
204 if (user_mode(regs))
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700205 __do_user_fault(tsk, addr, fsr, SIGSEGV, SEGV_MAPERR, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 else
207 __do_kernel_fault(mm, addr, fsr, regs);
208}
209
Catalin Marinas09529f72009-07-24 12:34:55 +0100210#ifdef CONFIG_MMU
Nick Piggin5c72fc52007-07-20 09:21:06 +0200211#define VM_FAULT_BADMAP 0x010000
212#define VM_FAULT_BADACCESS 0x020000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
Russell Kingd374bf12009-09-20 12:53:01 +0100214/*
215 * Check that the permissions on the VMA allow for the fault which occurred.
216 * If we encountered a write fault, we must have write permission, otherwise
217 * we allow any permission.
218 */
219static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
220{
221 unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
222
223 if (fsr & FSR_WRITE)
224 mask = VM_WRITE;
Russell Kingdf297bf2009-09-20 13:18:47 +0100225 if (fsr & FSR_LNX_PF)
226 mask = VM_EXEC;
Russell Kingd374bf12009-09-20 12:53:01 +0100227
228 return vma->vm_flags & mask ? false : true;
229}
230
231static int __kprobes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
233 struct task_struct *tsk)
234{
235 struct vm_area_struct *vma;
Russell Kingd374bf12009-09-20 12:53:01 +0100236 int fault;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 vma = find_vma(mm, addr);
239 fault = VM_FAULT_BADMAP;
Russell Kingd374bf12009-09-20 12:53:01 +0100240 if (unlikely(!vma))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 goto out;
Russell Kingd374bf12009-09-20 12:53:01 +0100242 if (unlikely(vma->vm_start > addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 goto check_stack;
244
245 /*
246 * Ok, we have a good vm_area for this
247 * memory access, so we can handle it.
248 */
249good_area:
Russell Kingd374bf12009-09-20 12:53:01 +0100250 if (access_error(fsr, vma)) {
251 fault = VM_FAULT_BADACCESS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 goto out;
Russell Kingd374bf12009-09-20 12:53:01 +0100253 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255 /*
Russell Kingb42c6342009-09-20 12:47:40 +0100256 * If for any reason at all we couldn't handle the fault, make
257 * sure we exit gracefully rather than endlessly redo the fault.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 */
Russell Kingc88d6aa2009-09-20 12:41:58 +0100259 fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, (fsr & FSR_WRITE) ? FAULT_FLAG_WRITE : 0);
Russell Kingb42c6342009-09-20 12:47:40 +0100260 if (unlikely(fault & VM_FAULT_ERROR))
261 return fault;
Nick Piggin83c54072007-07-19 01:47:05 -0700262 if (fault & VM_FAULT_MAJOR)
263 tsk->maj_flt++;
264 else
265 tsk->min_flt++;
266 return fault;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268check_stack:
269 if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
270 goto good_area;
271out:
272 return fault;
273}
274
Nicolas Pitre785d3cd2007-12-03 15:27:56 -0500275static int __kprobes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
277{
278 struct task_struct *tsk;
279 struct mm_struct *mm;
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700280 int fault, sig, code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Nicolas Pitre25ce1dd2007-12-03 15:21:57 -0500282 if (notify_page_fault(regs, fsr))
283 return 0;
284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 tsk = current;
286 mm = tsk->mm;
287
Russell King02fe2842011-06-25 11:44:06 +0100288 /* Enable interrupts if they were enabled in the parent context. */
289 if (interrupts_enabled(regs))
290 local_irq_enable();
291
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 /*
293 * If we're in an interrupt or have no user
294 * context, we must not take the fault..
295 */
Peter Zijlstra6edaf682006-12-06 20:32:18 -0800296 if (in_atomic() || !mm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 goto no_context;
298
Russell King840ff6a2005-09-20 17:52:13 +0100299 /*
300 * As per x86, we may deadlock here. However, since the kernel only
301 * validly references user space from well defined areas of the code,
302 * we can bug out early if this is from code which shouldn't.
303 */
304 if (!down_read_trylock(&mm->mmap_sem)) {
305 if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc))
306 goto no_context;
307 down_read(&mm->mmap_sem);
Russell Kingbf456992009-09-20 12:52:19 +0100308 } else {
309 /*
310 * The above down_read_trylock() might have succeeded in
311 * which case, we'll have missed the might_sleep() from
312 * down_read()
313 */
314 might_sleep();
Imre Deak1d212712009-10-05 13:40:44 +0100315#ifdef CONFIG_DEBUG_VM
316 if (!user_mode(regs) &&
317 !search_exception_tables(regs->ARM_pc))
318 goto no_context;
319#endif
Russell King840ff6a2005-09-20 17:52:13 +0100320 }
321
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 fault = __do_page_fault(mm, addr, fsr, tsk);
323 up_read(&mm->mmap_sem);
324
Peter Zijlstraa8b0ca12011-06-27 14:41:57 +0200325 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
Jamie Iles7ada1892010-02-02 20:24:58 +0100326 if (fault & VM_FAULT_MAJOR)
Peter Zijlstraa8b0ca12011-06-27 14:41:57 +0200327 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, addr);
Jamie Iles7ada1892010-02-02 20:24:58 +0100328 else if (fault & VM_FAULT_MINOR)
Peter Zijlstraa8b0ca12011-06-27 14:41:57 +0200329 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, addr);
Jamie Iles7ada1892010-02-02 20:24:58 +0100330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 /*
Russell Kingff2afb92005-08-04 14:17:33 +0100332 * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 */
Nick Piggin5c72fc52007-07-20 09:21:06 +0200334 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS))))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return 0;
336
Russell Kingb42c6342009-09-20 12:47:40 +0100337 if (fault & VM_FAULT_OOM) {
338 /*
339 * We ran out of memory, call the OOM killer, and return to
340 * userspace (which will retry the fault, or kill us if we
341 * got oom-killed)
342 */
343 pagefault_out_of_memory();
344 return 0;
345 }
346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 * If we are in kernel mode at this point, we
349 * have no context to handle this fault with.
350 */
351 if (!user_mode(regs))
352 goto no_context;
353
Nick Piggin83c54072007-07-19 01:47:05 -0700354 if (fault & VM_FAULT_SIGBUS) {
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700355 /*
356 * We had some memory, but were unable to
357 * successfully fix up this page fault.
358 */
359 sig = SIGBUS;
360 code = BUS_ADRERR;
Nick Piggin83c54072007-07-19 01:47:05 -0700361 } else {
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700362 /*
363 * Something tried to access memory that
364 * isn't in our memory map..
365 */
366 sig = SIGSEGV;
367 code = fault == VM_FAULT_BADACCESS ?
368 SEGV_ACCERR : SEGV_MAPERR;
akpm@osdl.org2d137c22005-04-16 15:23:55 -0700369 }
370
371 __do_user_fault(tsk, addr, fsr, sig, code, regs);
372 return 0;
373
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374no_context:
375 __do_kernel_fault(mm, addr, fsr, regs);
376 return 0;
377}
Catalin Marinas09529f72009-07-24 12:34:55 +0100378#else /* CONFIG_MMU */
379static int
380do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
381{
382 return 0;
383}
384#endif /* CONFIG_MMU */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
386/*
387 * First Level Translation Fault Handler
388 *
389 * We enter here because the first level page table doesn't contain
390 * a valid entry for the address.
391 *
392 * If the address is in kernel space (>= TASK_SIZE), then we are
393 * probably faulting in the vmalloc() area.
394 *
395 * If the init_task's first level page tables contains the relevant
396 * entry, we copy the it to this task. If not, we send the process
397 * a signal, fixup the exception, or oops the kernel.
398 *
399 * NOTE! We MUST NOT take any locks for this case. We may be in an
400 * interrupt or a critical region, and should only copy the information
401 * from the master page table, nothing more.
402 */
Catalin Marinas09529f72009-07-24 12:34:55 +0100403#ifdef CONFIG_MMU
Nicolas Pitre785d3cd2007-12-03 15:27:56 -0500404static int __kprobes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405do_translation_fault(unsigned long addr, unsigned int fsr,
406 struct pt_regs *regs)
407{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 unsigned int index;
409 pgd_t *pgd, *pgd_k;
Russell King516295e2010-11-21 16:27:49 +0000410 pud_t *pud, *pud_k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 pmd_t *pmd, *pmd_k;
412
413 if (addr < TASK_SIZE)
414 return do_page_fault(addr, fsr, regs);
415
Anfei5e27fb72010-06-08 15:16:49 +0100416 if (user_mode(regs))
417 goto bad_area;
418
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 index = pgd_index(addr);
420
421 /*
422 * FIXME: CP15 C1 is write only on ARMv3 architectures.
423 */
424 pgd = cpu_get_pgd() + index;
425 pgd_k = init_mm.pgd + index;
426
427 if (pgd_none(*pgd_k))
428 goto bad_area;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 if (!pgd_present(*pgd))
430 set_pgd(pgd, *pgd_k);
431
Russell King516295e2010-11-21 16:27:49 +0000432 pud = pud_offset(pgd, addr);
433 pud_k = pud_offset(pgd_k, addr);
434
435 if (pud_none(*pud_k))
436 goto bad_area;
437 if (!pud_present(*pud))
438 set_pud(pud, *pud_k);
439
440 pmd = pmd_offset(pud, addr);
441 pmd_k = pmd_offset(pud_k, addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
Kirill A. Shutemov33a9c412010-07-22 13:20:22 +0100443 /*
444 * On ARM one Linux PGD entry contains two hardware entries (see page
445 * tables layout in pgtable.h). We normally guarantee that we always
446 * fill both L1 entries. But create_mapping() doesn't follow the rule.
447 * It can create inidividual L1 entries, so here we have to call
448 * pmd_none() check for the entry really corresponded to address, not
449 * for the first of pair.
450 */
451 index = (addr >> SECTION_SHIFT) & 1;
452 if (pmd_none(pmd_k[index]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 goto bad_area;
454
455 copy_pmd(pmd, pmd_k);
456 return 0;
457
458bad_area:
Russell Kinge5beac32006-09-27 16:13:48 +0100459 do_bad_area(addr, fsr, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 return 0;
461}
Catalin Marinas09529f72009-07-24 12:34:55 +0100462#else /* CONFIG_MMU */
463static int
464do_translation_fault(unsigned long addr, unsigned int fsr,
465 struct pt_regs *regs)
466{
467 return 0;
468}
469#endif /* CONFIG_MMU */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
471/*
472 * Some section permission faults need to be handled gracefully.
473 * They can happen due to a __{get,put}_user during an oops.
474 */
475static int
476do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
477{
Russell Kinge5beac32006-09-27 16:13:48 +0100478 do_bad_area(addr, fsr, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 return 0;
480}
481
482/*
483 * This abort handler always returns "fault".
484 */
485static int
486do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
487{
488 return 1;
489}
490
491static struct fsr_info {
492 int (*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs);
493 int sig;
Russell Kingcfb08102005-06-30 11:06:49 +0100494 int code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 const char *name;
496} fsr_info[] = {
497 /*
498 * The following are the standard ARMv3 and ARMv4 aborts. ARMv5
499 * defines these to be "precise" aborts.
500 */
Russell Kingcfb08102005-06-30 11:06:49 +0100501 { do_bad, SIGSEGV, 0, "vector exception" },
Kirill A. Shutemov3dc91af2010-07-22 13:16:49 +0100502 { do_bad, SIGBUS, BUS_ADRALN, "alignment exception" },
Russell Kingcfb08102005-06-30 11:06:49 +0100503 { do_bad, SIGKILL, 0, "terminal exception" },
Kirill A. Shutemov3dc91af2010-07-22 13:16:49 +0100504 { do_bad, SIGBUS, BUS_ADRALN, "alignment exception" },
Russell Kingcfb08102005-06-30 11:06:49 +0100505 { do_bad, SIGBUS, 0, "external abort on linefetch" },
506 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "section translation fault" },
507 { do_bad, SIGBUS, 0, "external abort on linefetch" },
508 { do_page_fault, SIGSEGV, SEGV_MAPERR, "page translation fault" },
509 { do_bad, SIGBUS, 0, "external abort on non-linefetch" },
510 { do_bad, SIGSEGV, SEGV_ACCERR, "section domain fault" },
511 { do_bad, SIGBUS, 0, "external abort on non-linefetch" },
512 { do_bad, SIGSEGV, SEGV_ACCERR, "page domain fault" },
513 { do_bad, SIGBUS, 0, "external abort on translation" },
514 { do_sect_fault, SIGSEGV, SEGV_ACCERR, "section permission fault" },
515 { do_bad, SIGBUS, 0, "external abort on translation" },
516 { do_page_fault, SIGSEGV, SEGV_ACCERR, "page permission fault" },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 /*
518 * The following are "imprecise" aborts, which are signalled by bit
519 * 10 of the FSR, and may not be recoverable. These are only
520 * supported if the CPU abort handler supports bit 10.
521 */
Russell Kingcfb08102005-06-30 11:06:49 +0100522 { do_bad, SIGBUS, 0, "unknown 16" },
523 { do_bad, SIGBUS, 0, "unknown 17" },
524 { do_bad, SIGBUS, 0, "unknown 18" },
525 { do_bad, SIGBUS, 0, "unknown 19" },
526 { do_bad, SIGBUS, 0, "lock abort" }, /* xscale */
527 { do_bad, SIGBUS, 0, "unknown 21" },
528 { do_bad, SIGBUS, BUS_OBJERR, "imprecise external abort" }, /* xscale */
529 { do_bad, SIGBUS, 0, "unknown 23" },
530 { do_bad, SIGBUS, 0, "dcache parity error" }, /* xscale */
531 { do_bad, SIGBUS, 0, "unknown 25" },
532 { do_bad, SIGBUS, 0, "unknown 26" },
533 { do_bad, SIGBUS, 0, "unknown 27" },
534 { do_bad, SIGBUS, 0, "unknown 28" },
535 { do_bad, SIGBUS, 0, "unknown 29" },
536 { do_bad, SIGBUS, 0, "unknown 30" },
537 { do_bad, SIGBUS, 0, "unknown 31" }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538};
539
540void __init
541hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),
Kirill A. Shutemov6338a6a2010-07-22 13:18:19 +0100542 int sig, int code, const char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543{
Kirill A. Shutemov6338a6a2010-07-22 13:18:19 +0100544 if (nr < 0 || nr >= ARRAY_SIZE(fsr_info))
545 BUG();
546
547 fsr_info[nr].fn = fn;
548 fsr_info[nr].sig = sig;
549 fsr_info[nr].code = code;
550 fsr_info[nr].name = name;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551}
552
553/*
554 * Dispatch a data abort to the relevant handler.
555 */
Russell King7ab3f8d2007-03-02 15:01:36 +0000556asmlinkage void __exception
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
558{
Russell Kingc88d6aa2009-09-20 12:41:58 +0100559 const struct fsr_info *inf = fsr_info + fsr_fs(fsr);
Russell Kingcfb08102005-06-30 11:06:49 +0100560 struct siginfo info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
Russell Kingdf297bf2009-09-20 13:18:47 +0100562 if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 return;
564
565 printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n",
566 inf->name, fsr, addr);
Russell Kingcfb08102005-06-30 11:06:49 +0100567
568 info.si_signo = inf->sig;
569 info.si_errno = 0;
570 info.si_code = inf->code;
571 info.si_addr = (void __user *)addr;
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -0700572 arm_notify_die("", regs, &info, fsr, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573}
574
Kirill A. Shutemovd25ef8b2009-09-25 13:40:49 +0100575
576static struct fsr_info ifsr_info[] = {
577 { do_bad, SIGBUS, 0, "unknown 0" },
578 { do_bad, SIGBUS, 0, "unknown 1" },
579 { do_bad, SIGBUS, 0, "debug event" },
580 { do_bad, SIGSEGV, SEGV_ACCERR, "section access flag fault" },
581 { do_bad, SIGBUS, 0, "unknown 4" },
582 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "section translation fault" },
583 { do_bad, SIGSEGV, SEGV_ACCERR, "page access flag fault" },
584 { do_page_fault, SIGSEGV, SEGV_MAPERR, "page translation fault" },
585 { do_bad, SIGBUS, 0, "external abort on non-linefetch" },
586 { do_bad, SIGSEGV, SEGV_ACCERR, "section domain fault" },
587 { do_bad, SIGBUS, 0, "unknown 10" },
588 { do_bad, SIGSEGV, SEGV_ACCERR, "page domain fault" },
589 { do_bad, SIGBUS, 0, "external abort on translation" },
590 { do_sect_fault, SIGSEGV, SEGV_ACCERR, "section permission fault" },
591 { do_bad, SIGBUS, 0, "external abort on translation" },
592 { do_page_fault, SIGSEGV, SEGV_ACCERR, "page permission fault" },
593 { do_bad, SIGBUS, 0, "unknown 16" },
594 { do_bad, SIGBUS, 0, "unknown 17" },
595 { do_bad, SIGBUS, 0, "unknown 18" },
596 { do_bad, SIGBUS, 0, "unknown 19" },
597 { do_bad, SIGBUS, 0, "unknown 20" },
598 { do_bad, SIGBUS, 0, "unknown 21" },
599 { do_bad, SIGBUS, 0, "unknown 22" },
600 { do_bad, SIGBUS, 0, "unknown 23" },
601 { do_bad, SIGBUS, 0, "unknown 24" },
602 { do_bad, SIGBUS, 0, "unknown 25" },
603 { do_bad, SIGBUS, 0, "unknown 26" },
604 { do_bad, SIGBUS, 0, "unknown 27" },
605 { do_bad, SIGBUS, 0, "unknown 28" },
606 { do_bad, SIGBUS, 0, "unknown 29" },
607 { do_bad, SIGBUS, 0, "unknown 30" },
608 { do_bad, SIGBUS, 0, "unknown 31" },
609};
610
Will Deacon3a4b5dc2010-09-03 10:39:59 +0100611void __init
612hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),
613 int sig, int code, const char *name)
614{
615 if (nr < 0 || nr >= ARRAY_SIZE(ifsr_info))
616 BUG();
617
618 ifsr_info[nr].fn = fn;
619 ifsr_info[nr].sig = sig;
620 ifsr_info[nr].code = code;
621 ifsr_info[nr].name = name;
622}
623
Russell King7ab3f8d2007-03-02 15:01:36 +0000624asmlinkage void __exception
Kirill A. Shutemov4fb28472009-09-25 13:39:47 +0100625do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626{
Kirill A. Shutemovd25ef8b2009-09-25 13:40:49 +0100627 const struct fsr_info *inf = ifsr_info + fsr_fs(ifsr);
628 struct siginfo info;
629
630 if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs))
631 return;
632
633 printk(KERN_ALERT "Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n",
634 inf->name, ifsr, addr);
635
636 info.si_signo = inf->sig;
637 info.si_errno = 0;
638 info.si_code = inf->code;
639 info.si_addr = (void __user *)addr;
640 arm_notify_die("", regs, &info, ifsr, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641}
642
Kirill A. Shutemov993bf4e2010-07-22 13:23:25 +0100643static int __init exceptions_init(void)
644{
645 if (cpu_architecture() >= CPU_ARCH_ARMv6) {
646 hook_fault_code(4, do_translation_fault, SIGSEGV, SEGV_MAPERR,
647 "I-cache maintenance fault");
648 }
649
Kirill A. Shutemovb8ab5392010-07-26 11:20:41 +0100650 if (cpu_architecture() >= CPU_ARCH_ARMv7) {
651 /*
652 * TODO: Access flag faults introduced in ARMv6K.
653 * Runtime check for 'K' extension is needed
654 */
655 hook_fault_code(3, do_bad, SIGSEGV, SEGV_MAPERR,
656 "section access flag fault");
657 hook_fault_code(6, do_bad, SIGSEGV, SEGV_MAPERR,
658 "section access flag fault");
659 }
660
Kirill A. Shutemov993bf4e2010-07-22 13:23:25 +0100661 return 0;
662}
663
664arch_initcall(exceptions_init);