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12#include <linux/signal.h>
13#include <linux/rwsem.h>
14#include <linux/sched.h>
15#include <linux/kernel.h>
16#include <linux/errno.h>
17#include <linux/string.h>
18#include <linux/types.h>
19#include <linux/ptrace.h>
20#include <linux/mman.h>
21#include <linux/mm.h>
22#include <linux/smp.h>
23#include <linux/perf_event.h>
24#include <linux/interrupt.h>
25#include <asm/system.h>
26#include <asm/io.h>
27#include <asm/tlb.h>
28#include <asm/uaccess.h>
29#include <asm/pgalloc.h>
30#include <asm/mmu_context.h>
31
32extern void die(const char *,struct pt_regs *,long);
33
34#define PFLAG(val,flag) (( (val) & (flag) ) ? #flag : "" )
35#define PPROT(flag) PFLAG(pgprot_val(prot),flag)
36
37static inline void print_prots(pgprot_t prot)
38{
39 printk("prot is 0x%08lx\n",pgprot_val(prot));
40
41 printk("%s %s %s %s %s\n",PPROT(_PAGE_SHARED),PPROT(_PAGE_READ),
42 PPROT(_PAGE_EXECUTE),PPROT(_PAGE_WRITE),PPROT(_PAGE_USER));
43}
44
45static inline void print_vma(struct vm_area_struct *vma)
46{
47 printk("vma start 0x%08lx\n", vma->vm_start);
48 printk("vma end 0x%08lx\n", vma->vm_end);
49
50 print_prots(vma->vm_page_prot);
51 printk("vm_flags 0x%08lx\n", vma->vm_flags);
52}
53
54static inline void print_task(struct task_struct *tsk)
55{
56 printk("Task pid %d\n", task_pid_nr(tsk));
57}
58
59static pte_t *lookup_pte(struct mm_struct *mm, unsigned long address)
60{
61 pgd_t *dir;
62 pud_t *pud;
63 pmd_t *pmd;
64 pte_t *pte;
65 pte_t entry;
66
67 dir = pgd_offset(mm, address);
68 if (pgd_none(*dir))
69 return NULL;
70
71 pud = pud_offset(dir, address);
72 if (pud_none(*pud))
73 return NULL;
74
75 pmd = pmd_offset(pud, address);
76 if (pmd_none(*pmd))
77 return NULL;
78
79 pte = pte_offset_kernel(pmd, address);
80 entry = *pte;
81 if (pte_none(entry) || !pte_present(entry))
82 return NULL;
83
84 return pte;
85}
86
87
88
89
90
91
92asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
93 unsigned long textaccess, unsigned long address)
94{
95 struct task_struct *tsk;
96 struct mm_struct *mm;
97 struct vm_area_struct * vma;
98 const struct exception_table_entry *fixup;
99 pte_t *pte;
100 int fault;
101
102
103
104
105
106
107
108
109
110
111
112
113 tsk = current;
114 mm = tsk->mm;
115
116
117 local_irq_enable();
118
119 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address);
120
121
122
123
124
125 if (in_atomic() || !mm)
126 goto no_context;
127
128
129 down_read(&mm->mmap_sem);
130
131 vma = find_vma(mm, address);
132
133 if (!vma) {
134#ifdef DEBUG_FAULT
135 print_task(tsk);
136 printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
137 __func__, __LINE__,
138 address,regs->pc,textaccess,writeaccess);
139 show_regs(regs);
140#endif
141 goto bad_area;
142 }
143 if (vma->vm_start <= address) {
144 goto good_area;
145 }
146
147 if (!(vma->vm_flags & VM_GROWSDOWN)) {
148#ifdef DEBUG_FAULT
149 print_task(tsk);
150 printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
151 __func__, __LINE__,
152 address,regs->pc,textaccess,writeaccess);
153 show_regs(regs);
154
155 print_vma(vma);
156#endif
157 goto bad_area;
158 }
159 if (expand_stack(vma, address)) {
160#ifdef DEBUG_FAULT
161 print_task(tsk);
162 printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
163 __func__, __LINE__,
164 address,regs->pc,textaccess,writeaccess);
165 show_regs(regs);
166#endif
167 goto bad_area;
168 }
169
170
171
172
173good_area:
174 if (textaccess) {
175 if (!(vma->vm_flags & VM_EXEC))
176 goto bad_area;
177 } else {
178 if (writeaccess) {
179 if (!(vma->vm_flags & VM_WRITE))
180 goto bad_area;
181 } else {
182 if (!(vma->vm_flags & VM_READ))
183 goto bad_area;
184 }
185 }
186
187
188
189
190
191
192survive:
193 fault = handle_mm_fault(mm, vma, address, writeaccess ? FAULT_FLAG_WRITE : 0);
194 if (unlikely(fault & VM_FAULT_ERROR)) {
195 if (fault & VM_FAULT_OOM)
196 goto out_of_memory;
197 else if (fault & VM_FAULT_SIGBUS)
198 goto do_sigbus;
199 BUG();
200 }
201
202 if (fault & VM_FAULT_MAJOR) {
203 tsk->maj_flt++;
204 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0,
205 regs, address);
206 } else {
207 tsk->min_flt++;
208 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0,
209 regs, address);
210 }
211
212
213
214
215 pte = lookup_pte (mm, address);
216 if (!pte) {
217
218
219
220
221 goto no_pte;
222 }
223
224 __do_tlb_refill(address, textaccess, pte);
225
226no_pte:
227
228 up_read(&mm->mmap_sem);
229 return;
230
231
232
233
234
235bad_area:
236#ifdef DEBUG_FAULT
237 printk("fault:bad area\n");
238#endif
239 up_read(&mm->mmap_sem);
240
241 if (user_mode(regs)) {
242 static int count=0;
243 siginfo_t info;
244 if (count < 4) {
245
246
247 count++;
248 printk("user mode bad_area address=%08lx pid=%d (%s) pc=%08lx\n",
249 address, task_pid_nr(current), current->comm,
250 (unsigned long) regs->pc);
251#if 0
252 show_regs(regs);
253#endif
254 }
255 if (is_global_init(tsk)) {
256 panic("INIT had user mode bad_area\n");
257 }
258 tsk->thread.address = address;
259 tsk->thread.error_code = writeaccess;
260 info.si_signo = SIGSEGV;
261 info.si_errno = 0;
262 info.si_addr = (void *) address;
263 force_sig_info(SIGSEGV, &info, tsk);
264 return;
265 }
266
267no_context:
268#ifdef DEBUG_FAULT
269 printk("fault:No context\n");
270#endif
271
272 fixup = search_exception_tables(regs->pc);
273 if (fixup) {
274 regs->pc = fixup->fixup;
275 return;
276 }
277
278
279
280
281
282
283 if (address < PAGE_SIZE)
284 printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
285 else
286 printk(KERN_ALERT "Unable to handle kernel paging request");
287 printk(" at virtual address %08lx\n", address);
288 printk(KERN_ALERT "pc = %08Lx%08Lx\n", regs->pc >> 32, regs->pc & 0xffffffff);
289 die("Oops", regs, writeaccess);
290 do_exit(SIGKILL);
291
292
293
294
295
296out_of_memory:
297 if (is_global_init(current)) {
298 panic("INIT out of memory\n");
299 yield();
300 goto survive;
301 }
302 printk("fault:Out of memory\n");
303 up_read(&mm->mmap_sem);
304 if (is_global_init(current)) {
305 yield();
306 down_read(&mm->mmap_sem);
307 goto survive;
308 }
309 printk("VM: killing process %s\n", tsk->comm);
310 if (user_mode(regs))
311 do_group_exit(SIGKILL);
312 goto no_context;
313
314do_sigbus:
315 printk("fault:Do sigbus\n");
316 up_read(&mm->mmap_sem);
317
318
319
320
321
322 tsk->thread.address = address;
323 tsk->thread.error_code = writeaccess;
324 tsk->thread.trap_no = 14;
325 force_sig(SIGBUS, tsk);
326
327
328 if (!user_mode(regs))
329 goto no_context;
330}
331
332void local_flush_tlb_one(unsigned long asid, unsigned long page)
333{
334 unsigned long long match, pteh=0, lpage;
335 unsigned long tlb;
336
337
338
339
340 lpage = neff_sign_extend(page);
341 match = (asid << PTEH_ASID_SHIFT) | PTEH_VALID;
342 match |= lpage;
343
344 for_each_itlb_entry(tlb) {
345 asm volatile ("getcfg %1, 0, %0"
346 : "=r" (pteh)
347 : "r" (tlb) );
348
349 if (pteh == match) {
350 __flush_tlb_slot(tlb);
351 break;
352 }
353 }
354
355 for_each_dtlb_entry(tlb) {
356 asm volatile ("getcfg %1, 0, %0"
357 : "=r" (pteh)
358 : "r" (tlb) );
359
360 if (pteh == match) {
361 __flush_tlb_slot(tlb);
362 break;
363 }
364
365 }
366}
367
368void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
369{
370 unsigned long flags;
371
372 if (vma->vm_mm) {
373 page &= PAGE_MASK;
374 local_irq_save(flags);
375 local_flush_tlb_one(get_asid(), page);
376 local_irq_restore(flags);
377 }
378}
379
380void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
381 unsigned long end)
382{
383 unsigned long flags;
384 unsigned long long match, pteh=0, pteh_epn, pteh_low;
385 unsigned long tlb;
386 unsigned int cpu = smp_processor_id();
387 struct mm_struct *mm;
388
389 mm = vma->vm_mm;
390 if (cpu_context(cpu, mm) == NO_CONTEXT)
391 return;
392
393 local_irq_save(flags);
394
395 start &= PAGE_MASK;
396 end &= PAGE_MASK;
397
398 match = (cpu_asid(cpu, mm) << PTEH_ASID_SHIFT) | PTEH_VALID;
399
400
401 for_each_itlb_entry(tlb) {
402 asm volatile ("getcfg %1, 0, %0"
403 : "=r" (pteh)
404 : "r" (tlb) );
405
406 pteh_epn = pteh & PAGE_MASK;
407 pteh_low = pteh & ~PAGE_MASK;
408
409 if (pteh_low == match && pteh_epn >= start && pteh_epn <= end)
410 __flush_tlb_slot(tlb);
411 }
412
413
414 for_each_dtlb_entry(tlb) {
415 asm volatile ("getcfg %1, 0, %0"
416 : "=r" (pteh)
417 : "r" (tlb) );
418
419 pteh_epn = pteh & PAGE_MASK;
420 pteh_low = pteh & ~PAGE_MASK;
421
422 if (pteh_low == match && pteh_epn >= start && pteh_epn <= end)
423 __flush_tlb_slot(tlb);
424 }
425
426 local_irq_restore(flags);
427}
428
429void local_flush_tlb_mm(struct mm_struct *mm)
430{
431 unsigned long flags;
432 unsigned int cpu = smp_processor_id();
433
434 if (cpu_context(cpu, mm) == NO_CONTEXT)
435 return;
436
437 local_irq_save(flags);
438
439 cpu_context(cpu, mm) = NO_CONTEXT;
440 if (mm == current->mm)
441 activate_context(mm, cpu);
442
443 local_irq_restore(flags);
444}
445
446void local_flush_tlb_all(void)
447{
448
449 unsigned long flags, tlb;
450
451 local_irq_save(flags);
452
453
454 for_each_itlb_entry(tlb)
455 __flush_tlb_slot(tlb);
456
457
458 for_each_dtlb_entry(tlb)
459 __flush_tlb_slot(tlb);
460
461 local_irq_restore(flags);
462}
463
464void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
465{
466
467 flush_tlb_all();
468}
469
470void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
471{
472}
473