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10#include <asm/head.h>
11
12#include <linux/string.h>
13#include <linux/types.h>
14#include <linux/sched.h>
15#include <linux/ptrace.h>
16#include <linux/mman.h>
17#include <linux/threads.h>
18#include <linux/kernel.h>
19#include <linux/signal.h>
20#include <linux/mm.h>
21#include <linux/smp.h>
22#include <linux/perf_event.h>
23#include <linux/interrupt.h>
24#include <linux/kdebug.h>
25#include <linux/uaccess.h>
26
27#include <asm/page.h>
28#include <asm/openprom.h>
29#include <asm/oplib.h>
30#include <asm/setup.h>
31#include <asm/smp.h>
32#include <asm/traps.h>
33
34#include "mm_32.h"
35
36int show_unhandled_signals = 1;
37
38static void __noreturn unhandled_fault(unsigned long address,
39 struct task_struct *tsk,
40 struct pt_regs *regs)
41{
42 if ((unsigned long) address < PAGE_SIZE) {
43 printk(KERN_ALERT
44 "Unable to handle kernel NULL pointer dereference\n");
45 } else {
46 printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n",
47 address);
48 }
49 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %08lx\n",
50 (tsk->mm ? tsk->mm->context : tsk->active_mm->context));
51 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %08lx\n",
52 (tsk->mm ? (unsigned long) tsk->mm->pgd :
53 (unsigned long) tsk->active_mm->pgd));
54 die_if_kernel("Oops", regs);
55}
56
57asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc,
58 unsigned long address)
59{
60 struct pt_regs regs;
61 unsigned long g2;
62 unsigned int insn;
63 int i;
64
65 i = search_extables_range(ret_pc, &g2);
66 switch (i) {
67 case 3:
68
69 return 3;
70
71 case 1:
72
73
74 insn = *((unsigned int *) pc);
75 if ((insn >> 21) & 1)
76 return 1;
77 break;
78
79 case 2:
80
81
82 insn = *((unsigned int *) pc);
83 if (!((insn >> 21) & 1) || ((insn>>19)&0x3f) == 15)
84 return 2;
85 break;
86
87 default:
88 break;
89 }
90
91 memset(®s, 0, sizeof(regs));
92 regs.pc = pc;
93 regs.npc = pc + 4;
94 __asm__ __volatile__(
95 "rd %%psr, %0\n\t"
96 "nop\n\t"
97 "nop\n\t"
98 "nop\n" : "=r" (regs.psr));
99 unhandled_fault(address, current, ®s);
100
101
102 return 0;
103}
104
105static inline void
106show_signal_msg(struct pt_regs *regs, int sig, int code,
107 unsigned long address, struct task_struct *tsk)
108{
109 if (!unhandled_signal(tsk, sig))
110 return;
111
112 if (!printk_ratelimit())
113 return;
114
115 printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
116 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
117 tsk->comm, task_pid_nr(tsk), address,
118 (void *)regs->pc, (void *)regs->u_regs[UREG_I7],
119 (void *)regs->u_regs[UREG_FP], code);
120
121 print_vma_addr(KERN_CONT " in ", regs->pc);
122
123 printk(KERN_CONT "\n");
124}
125
126static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
127 unsigned long addr)
128{
129 if (unlikely(show_unhandled_signals))
130 show_signal_msg(regs, sig, code,
131 addr, current);
132
133 force_sig_fault(sig, code, (void __user *) addr, 0);
134}
135
136static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
137{
138 unsigned int insn;
139
140 if (text_fault)
141 return regs->pc;
142
143 if (regs->psr & PSR_PS)
144 insn = *(unsigned int *) regs->pc;
145 else
146 __get_user(insn, (unsigned int *) regs->pc);
147
148 return safe_compute_effective_address(regs, insn);
149}
150
151static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
152 int text_fault)
153{
154 unsigned long addr = compute_si_addr(regs, text_fault);
155
156 __do_fault_siginfo(code, sig, regs, addr);
157}
158
159asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
160 unsigned long address)
161{
162 struct vm_area_struct *vma;
163 struct task_struct *tsk = current;
164 struct mm_struct *mm = tsk->mm;
165 unsigned int fixup;
166 unsigned long g2;
167 int from_user = !(regs->psr & PSR_PS);
168 int code;
169 vm_fault_t fault;
170 unsigned int flags = FAULT_FLAG_DEFAULT;
171
172 if (text_fault)
173 address = regs->pc;
174
175
176
177
178
179
180
181
182
183
184 code = SEGV_MAPERR;
185 if (address >= TASK_SIZE)
186 goto vmalloc_fault;
187
188
189
190
191
192 if (pagefault_disabled() || !mm)
193 goto no_context;
194
195 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
196
197retry:
198 mmap_read_lock(mm);
199
200 if (!from_user && address >= PAGE_OFFSET)
201 goto bad_area;
202
203 vma = find_vma(mm, address);
204 if (!vma)
205 goto bad_area;
206 if (vma->vm_start <= address)
207 goto good_area;
208 if (!(vma->vm_flags & VM_GROWSDOWN))
209 goto bad_area;
210 if (expand_stack(vma, address))
211 goto bad_area;
212
213
214
215
216good_area:
217 code = SEGV_ACCERR;
218 if (write) {
219 if (!(vma->vm_flags & VM_WRITE))
220 goto bad_area;
221 } else {
222
223 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
224 goto bad_area;
225 }
226
227 if (from_user)
228 flags |= FAULT_FLAG_USER;
229 if (write)
230 flags |= FAULT_FLAG_WRITE;
231
232
233
234
235
236
237 fault = handle_mm_fault(vma, address, flags, regs);
238
239 if (fault_signal_pending(fault, regs))
240 return;
241
242 if (unlikely(fault & VM_FAULT_ERROR)) {
243 if (fault & VM_FAULT_OOM)
244 goto out_of_memory;
245 else if (fault & VM_FAULT_SIGSEGV)
246 goto bad_area;
247 else if (fault & VM_FAULT_SIGBUS)
248 goto do_sigbus;
249 BUG();
250 }
251
252 if (flags & FAULT_FLAG_ALLOW_RETRY) {
253 if (fault & VM_FAULT_RETRY) {
254 flags |= FAULT_FLAG_TRIED;
255
256
257
258
259
260
261 goto retry;
262 }
263 }
264
265 mmap_read_unlock(mm);
266 return;
267
268
269
270
271
272bad_area:
273 mmap_read_unlock(mm);
274
275bad_area_nosemaphore:
276
277 if (from_user) {
278 do_fault_siginfo(code, SIGSEGV, regs, text_fault);
279 return;
280 }
281
282
283no_context:
284 g2 = regs->u_regs[UREG_G2];
285 if (!from_user) {
286 fixup = search_extables_range(regs->pc, &g2);
287
288 if (fixup > 10) {
289 extern const unsigned int __memset_start[];
290 extern const unsigned int __memset_end[];
291
292#ifdef DEBUG_EXCEPTIONS
293 printk("Exception: PC<%08lx> faddr<%08lx>\n",
294 regs->pc, address);
295 printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n",
296 regs->pc, fixup, g2);
297#endif
298 if ((regs->pc >= (unsigned long)__memset_start &&
299 regs->pc < (unsigned long)__memset_end)) {
300 regs->u_regs[UREG_I4] = address;
301 regs->u_regs[UREG_I5] = regs->pc;
302 }
303 regs->u_regs[UREG_G2] = g2;
304 regs->pc = fixup;
305 regs->npc = regs->pc + 4;
306 return;
307 }
308 }
309
310 unhandled_fault(address, tsk, regs);
311 do_exit(SIGKILL);
312
313
314
315
316
317out_of_memory:
318 mmap_read_unlock(mm);
319 if (from_user) {
320 pagefault_out_of_memory();
321 return;
322 }
323 goto no_context;
324
325do_sigbus:
326 mmap_read_unlock(mm);
327 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
328 if (!from_user)
329 goto no_context;
330
331vmalloc_fault:
332 {
333
334
335
336
337 int offset = pgd_index(address);
338 pgd_t *pgd, *pgd_k;
339 p4d_t *p4d, *p4d_k;
340 pud_t *pud, *pud_k;
341 pmd_t *pmd, *pmd_k;
342
343 pgd = tsk->active_mm->pgd + offset;
344 pgd_k = init_mm.pgd + offset;
345
346 if (!pgd_present(*pgd)) {
347 if (!pgd_present(*pgd_k))
348 goto bad_area_nosemaphore;
349 pgd_val(*pgd) = pgd_val(*pgd_k);
350 return;
351 }
352
353 p4d = p4d_offset(pgd, address);
354 pud = pud_offset(p4d, address);
355 pmd = pmd_offset(pud, address);
356
357 p4d_k = p4d_offset(pgd_k, address);
358 pud_k = pud_offset(p4d_k, address);
359 pmd_k = pmd_offset(pud_k, address);
360
361 if (pmd_present(*pmd) || !pmd_present(*pmd_k))
362 goto bad_area_nosemaphore;
363
364 *pmd = *pmd_k;
365 return;
366 }
367}
368
369
370static void force_user_fault(unsigned long address, int write)
371{
372 struct vm_area_struct *vma;
373 struct task_struct *tsk = current;
374 struct mm_struct *mm = tsk->mm;
375 unsigned int flags = FAULT_FLAG_USER;
376 int code;
377
378 code = SEGV_MAPERR;
379
380 mmap_read_lock(mm);
381 vma = find_vma(mm, address);
382 if (!vma)
383 goto bad_area;
384 if (vma->vm_start <= address)
385 goto good_area;
386 if (!(vma->vm_flags & VM_GROWSDOWN))
387 goto bad_area;
388 if (expand_stack(vma, address))
389 goto bad_area;
390good_area:
391 code = SEGV_ACCERR;
392 if (write) {
393 if (!(vma->vm_flags & VM_WRITE))
394 goto bad_area;
395 flags |= FAULT_FLAG_WRITE;
396 } else {
397 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
398 goto bad_area;
399 }
400 switch (handle_mm_fault(vma, address, flags, NULL)) {
401 case VM_FAULT_SIGBUS:
402 case VM_FAULT_OOM:
403 goto do_sigbus;
404 }
405 mmap_read_unlock(mm);
406 return;
407bad_area:
408 mmap_read_unlock(mm);
409 __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
410 return;
411
412do_sigbus:
413 mmap_read_unlock(mm);
414 __do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
415}
416
417static void check_stack_aligned(unsigned long sp)
418{
419 if (sp & 0x7UL)
420 force_sig(SIGILL);
421}
422
423void window_overflow_fault(void)
424{
425 unsigned long sp;
426
427 sp = current_thread_info()->rwbuf_stkptrs[0];
428 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
429 force_user_fault(sp + 0x38, 1);
430 force_user_fault(sp, 1);
431
432 check_stack_aligned(sp);
433}
434
435void window_underflow_fault(unsigned long sp)
436{
437 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
438 force_user_fault(sp + 0x38, 0);
439 force_user_fault(sp, 0);
440
441 check_stack_aligned(sp);
442}
443
444void window_ret_fault(struct pt_regs *regs)
445{
446 unsigned long sp;
447
448 sp = regs->u_regs[UREG_FP];
449 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
450 force_user_fault(sp + 0x38, 0);
451 force_user_fault(sp, 0);
452
453 check_stack_aligned(sp);
454}
455