Commit | Line | Data |
---|---|---|
88278ca2 | 1 | /* |
1da177e4 LT |
2 | * fault.c: Page fault handlers for the Sparc. |
3 | * | |
4 | * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) | |
5 | * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) | |
6 | * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) | |
7 | */ | |
8 | ||
9 | #include <asm/head.h> | |
10 | ||
11 | #include <linux/string.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/mman.h> | |
16 | #include <linux/threads.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/signal.h> | |
19 | #include <linux/mm.h> | |
20 | #include <linux/smp.h> | |
a084b667 | 21 | #include <linux/perf_event.h> |
1da177e4 | 22 | #include <linux/interrupt.h> |
1eeb66a1 | 23 | #include <linux/kdebug.h> |
1da177e4 | 24 | |
1da177e4 LT |
25 | #include <asm/page.h> |
26 | #include <asm/pgtable.h> | |
1da177e4 LT |
27 | #include <asm/openprom.h> |
28 | #include <asm/oplib.h> | |
9edfae3f | 29 | #include <asm/setup.h> |
1da177e4 LT |
30 | #include <asm/smp.h> |
31 | #include <asm/traps.h> | |
1da177e4 LT |
32 | #include <asm/uaccess.h> |
33 | ||
e1b2f134 | 34 | #include "mm_32.h" |
4b177647 | 35 | |
e1b2f134 | 36 | int show_unhandled_signals = 1; |
1da177e4 | 37 | |
70168dfa SR |
38 | static void __noreturn unhandled_fault(unsigned long address, |
39 | struct task_struct *tsk, | |
40 | struct pt_regs *regs) | |
1da177e4 | 41 | { |
70168dfa | 42 | if ((unsigned long) address < PAGE_SIZE) { |
1da177e4 LT |
43 | printk(KERN_ALERT |
44 | "Unable to handle kernel NULL pointer dereference\n"); | |
45 | } else { | |
70168dfa SR |
46 | printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n", |
47 | address); | |
1da177e4 LT |
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 : | |
70168dfa | 53 | (unsigned long) tsk->active_mm->pgd)); |
1da177e4 LT |
54 | die_if_kernel("Oops", regs); |
55 | } | |
56 | ||
70168dfa | 57 | asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc, |
1da177e4 LT |
58 | unsigned long address) |
59 | { | |
60 | struct pt_regs regs; | |
61 | unsigned long g2; | |
62 | unsigned int insn; | |
63 | int i; | |
70168dfa | 64 | |
1da177e4 LT |
65 | i = search_extables_range(ret_pc, &g2); |
66 | switch (i) { | |
67 | case 3: | |
68 | /* load & store will be handled by fixup */ | |
69 | return 3; | |
70 | ||
71 | case 1: | |
72 | /* store will be handled by fixup, load will bump out */ | |
73 | /* for _to_ macros */ | |
74 | insn = *((unsigned int *) pc); | |
75 | if ((insn >> 21) & 1) | |
76 | return 1; | |
77 | break; | |
78 | ||
79 | case 2: | |
80 | /* load will be handled by fixup, store will bump out */ | |
81 | /* for _from_ macros */ | |
82 | insn = *((unsigned int *) pc); | |
83 | if (!((insn >> 21) & 1) || ((insn>>19)&0x3f) == 15) | |
70168dfa SR |
84 | return 2; |
85 | break; | |
1da177e4 LT |
86 | |
87 | default: | |
88 | break; | |
6cb79b3f | 89 | } |
1da177e4 | 90 | |
70168dfa | 91 | memset(®s, 0, sizeof(regs)); |
1da177e4 LT |
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 | /* Not reached */ | |
102 | return 0; | |
103 | } | |
104 | ||
4b177647 DM |
105 | static inline void |
106 | show_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 %p (rpc %p) sp %p 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 | ||
126 | static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs, | |
127 | unsigned long addr) | |
128 | { | |
129 | siginfo_t info; | |
130 | ||
131 | info.si_signo = sig; | |
132 | info.si_code = code; | |
133 | info.si_errno = 0; | |
134 | info.si_addr = (void __user *) addr; | |
135 | info.si_trapno = 0; | |
136 | ||
137 | if (unlikely(show_unhandled_signals)) | |
138 | show_signal_msg(regs, sig, info.si_code, | |
139 | addr, current); | |
140 | ||
141 | force_sig_info (sig, &info, current); | |
142 | } | |
143 | ||
1da177e4 LT |
144 | static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault) |
145 | { | |
146 | unsigned int insn; | |
147 | ||
148 | if (text_fault) | |
149 | return regs->pc; | |
150 | ||
70168dfa | 151 | if (regs->psr & PSR_PS) |
1da177e4 | 152 | insn = *(unsigned int *) regs->pc; |
70168dfa | 153 | else |
1da177e4 | 154 | __get_user(insn, (unsigned int *) regs->pc); |
1da177e4 LT |
155 | |
156 | return safe_compute_effective_address(regs, insn); | |
157 | } | |
158 | ||
4b177647 DM |
159 | static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs, |
160 | int text_fault) | |
161 | { | |
162 | unsigned long addr = compute_si_addr(regs, text_fault); | |
163 | ||
164 | __do_fault_siginfo(code, sig, regs, addr); | |
165 | } | |
166 | ||
1da177e4 LT |
167 | asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write, |
168 | unsigned long address) | |
169 | { | |
170 | struct vm_area_struct *vma; | |
171 | struct task_struct *tsk = current; | |
172 | struct mm_struct *mm = tsk->mm; | |
173 | unsigned int fixup; | |
174 | unsigned long g2; | |
1da177e4 | 175 | int from_user = !(regs->psr & PSR_PS); |
4b177647 | 176 | int fault, code; |
759496ba | 177 | unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
1da177e4 | 178 | |
70168dfa | 179 | if (text_fault) |
1da177e4 LT |
180 | address = regs->pc; |
181 | ||
182 | /* | |
183 | * We fault-in kernel-space virtual memory on-demand. The | |
184 | * 'reference' page table is init_mm.pgd. | |
185 | * | |
186 | * NOTE! We MUST NOT take any locks for this case. We may | |
187 | * be in an interrupt or a critical region, and should | |
188 | * only copy the information from the master page table, | |
189 | * nothing more. | |
190 | */ | |
c816be7b | 191 | code = SEGV_MAPERR; |
582a0bae | 192 | if (address >= TASK_SIZE) |
1da177e4 LT |
193 | goto vmalloc_fault; |
194 | ||
1da177e4 LT |
195 | /* |
196 | * If we're in an interrupt or have no user | |
197 | * context, we must not take the fault.. | |
198 | */ | |
70168dfa SR |
199 | if (in_atomic() || !mm) |
200 | goto no_context; | |
1da177e4 | 201 | |
a8b0ca17 | 202 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); |
a084b667 | 203 | |
c29554f5 | 204 | retry: |
1da177e4 LT |
205 | down_read(&mm->mmap_sem); |
206 | ||
70168dfa | 207 | if (!from_user && address >= PAGE_OFFSET) |
1da177e4 LT |
208 | goto bad_area; |
209 | ||
210 | vma = find_vma(mm, address); | |
70168dfa | 211 | if (!vma) |
1da177e4 | 212 | goto bad_area; |
70168dfa | 213 | if (vma->vm_start <= address) |
1da177e4 | 214 | goto good_area; |
70168dfa | 215 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
1da177e4 | 216 | goto bad_area; |
70168dfa | 217 | if (expand_stack(vma, address)) |
1da177e4 LT |
218 | goto bad_area; |
219 | /* | |
220 | * Ok, we have a good vm_area for this memory access, so | |
221 | * we can handle it.. | |
222 | */ | |
223 | good_area: | |
4b177647 | 224 | code = SEGV_ACCERR; |
70168dfa SR |
225 | if (write) { |
226 | if (!(vma->vm_flags & VM_WRITE)) | |
1da177e4 LT |
227 | goto bad_area; |
228 | } else { | |
229 | /* Allow reads even for write-only mappings */ | |
70168dfa | 230 | if (!(vma->vm_flags & (VM_READ | VM_EXEC))) |
1da177e4 LT |
231 | goto bad_area; |
232 | } | |
233 | ||
759496ba JW |
234 | if (from_user) |
235 | flags |= FAULT_FLAG_USER; | |
236 | if (write) | |
237 | flags |= FAULT_FLAG_WRITE; | |
238 | ||
1da177e4 LT |
239 | /* |
240 | * If for any reason at all we couldn't handle the fault, | |
241 | * make sure we exit gracefully rather than endlessly redo | |
242 | * the fault. | |
243 | */ | |
c29554f5 KC |
244 | fault = handle_mm_fault(mm, vma, address, flags); |
245 | ||
246 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) | |
247 | return; | |
248 | ||
83c54070 NP |
249 | if (unlikely(fault & VM_FAULT_ERROR)) { |
250 | if (fault & VM_FAULT_OOM) | |
251 | goto out_of_memory; | |
252 | else if (fault & VM_FAULT_SIGBUS) | |
253 | goto do_sigbus; | |
254 | BUG(); | |
255 | } | |
c29554f5 KC |
256 | |
257 | if (flags & FAULT_FLAG_ALLOW_RETRY) { | |
258 | if (fault & VM_FAULT_MAJOR) { | |
259 | current->maj_flt++; | |
260 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, | |
261 | 1, regs, address); | |
262 | } else { | |
263 | current->min_flt++; | |
264 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, | |
265 | 1, regs, address); | |
266 | } | |
267 | if (fault & VM_FAULT_RETRY) { | |
268 | flags &= ~FAULT_FLAG_ALLOW_RETRY; | |
45cac65b | 269 | flags |= FAULT_FLAG_TRIED; |
c29554f5 KC |
270 | |
271 | /* No need to up_read(&mm->mmap_sem) as we would | |
272 | * have already released it in __lock_page_or_retry | |
273 | * in mm/filemap.c. | |
274 | */ | |
275 | ||
276 | goto retry; | |
277 | } | |
a084b667 | 278 | } |
c29554f5 | 279 | |
1da177e4 LT |
280 | up_read(&mm->mmap_sem); |
281 | return; | |
282 | ||
283 | /* | |
284 | * Something tried to access memory that isn't in our memory map.. | |
285 | * Fix it, but check if it's kernel or user first.. | |
286 | */ | |
287 | bad_area: | |
288 | up_read(&mm->mmap_sem); | |
289 | ||
290 | bad_area_nosemaphore: | |
291 | /* User mode accesses just cause a SIGSEGV */ | |
4b177647 DM |
292 | if (from_user) { |
293 | do_fault_siginfo(code, SIGSEGV, regs, text_fault); | |
1da177e4 LT |
294 | return; |
295 | } | |
296 | ||
297 | /* Is this in ex_table? */ | |
298 | no_context: | |
299 | g2 = regs->u_regs[UREG_G2]; | |
0157141a SR |
300 | if (!from_user) { |
301 | fixup = search_extables_range(regs->pc, &g2); | |
70168dfa SR |
302 | /* Values below 10 are reserved for other things */ |
303 | if (fixup > 10) { | |
1da177e4 LT |
304 | extern const unsigned __memset_start[]; |
305 | extern const unsigned __memset_end[]; | |
306 | extern const unsigned __csum_partial_copy_start[]; | |
307 | extern const unsigned __csum_partial_copy_end[]; | |
308 | ||
309 | #ifdef DEBUG_EXCEPTIONS | |
70168dfa SR |
310 | printk("Exception: PC<%08lx> faddr<%08lx>\n", |
311 | regs->pc, address); | |
1da177e4 LT |
312 | printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n", |
313 | regs->pc, fixup, g2); | |
314 | #endif | |
315 | if ((regs->pc >= (unsigned long)__memset_start && | |
316 | regs->pc < (unsigned long)__memset_end) || | |
317 | (regs->pc >= (unsigned long)__csum_partial_copy_start && | |
318 | regs->pc < (unsigned long)__csum_partial_copy_end)) { | |
70168dfa | 319 | regs->u_regs[UREG_I4] = address; |
1da177e4 LT |
320 | regs->u_regs[UREG_I5] = regs->pc; |
321 | } | |
322 | regs->u_regs[UREG_G2] = g2; | |
323 | regs->pc = fixup; | |
324 | regs->npc = regs->pc + 4; | |
325 | return; | |
326 | } | |
327 | } | |
70168dfa SR |
328 | |
329 | unhandled_fault(address, tsk, regs); | |
1da177e4 LT |
330 | do_exit(SIGKILL); |
331 | ||
332 | /* | |
333 | * We ran out of memory, or some other thing happened to us that made | |
334 | * us unable to handle the page fault gracefully. | |
335 | */ | |
336 | out_of_memory: | |
337 | up_read(&mm->mmap_sem); | |
a923c28f DM |
338 | if (from_user) { |
339 | pagefault_out_of_memory(); | |
340 | return; | |
341 | } | |
1da177e4 LT |
342 | goto no_context; |
343 | ||
344 | do_sigbus: | |
345 | up_read(&mm->mmap_sem); | |
4b177647 | 346 | do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault); |
1da177e4 LT |
347 | if (!from_user) |
348 | goto no_context; | |
349 | ||
350 | vmalloc_fault: | |
351 | { | |
352 | /* | |
353 | * Synchronize this task's top level page-table | |
354 | * with the 'reference' page table. | |
355 | */ | |
356 | int offset = pgd_index(address); | |
357 | pgd_t *pgd, *pgd_k; | |
358 | pmd_t *pmd, *pmd_k; | |
359 | ||
360 | pgd = tsk->active_mm->pgd + offset; | |
361 | pgd_k = init_mm.pgd + offset; | |
362 | ||
363 | if (!pgd_present(*pgd)) { | |
364 | if (!pgd_present(*pgd_k)) | |
365 | goto bad_area_nosemaphore; | |
366 | pgd_val(*pgd) = pgd_val(*pgd_k); | |
367 | return; | |
368 | } | |
369 | ||
370 | pmd = pmd_offset(pgd, address); | |
371 | pmd_k = pmd_offset(pgd_k, address); | |
372 | ||
373 | if (pmd_present(*pmd) || !pmd_present(*pmd_k)) | |
374 | goto bad_area_nosemaphore; | |
70168dfa | 375 | |
1da177e4 LT |
376 | *pmd = *pmd_k; |
377 | return; | |
378 | } | |
379 | } | |
380 | ||
1da177e4 | 381 | /* This always deals with user addresses. */ |
50215d65 | 382 | static void force_user_fault(unsigned long address, int write) |
1da177e4 LT |
383 | { |
384 | struct vm_area_struct *vma; | |
385 | struct task_struct *tsk = current; | |
386 | struct mm_struct *mm = tsk->mm; | |
759496ba | 387 | unsigned int flags = FAULT_FLAG_USER; |
4b177647 | 388 | int code; |
1da177e4 | 389 | |
4b177647 | 390 | code = SEGV_MAPERR; |
1da177e4 | 391 | |
1da177e4 LT |
392 | down_read(&mm->mmap_sem); |
393 | vma = find_vma(mm, address); | |
70168dfa | 394 | if (!vma) |
1da177e4 | 395 | goto bad_area; |
70168dfa | 396 | if (vma->vm_start <= address) |
1da177e4 | 397 | goto good_area; |
70168dfa | 398 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
1da177e4 | 399 | goto bad_area; |
70168dfa | 400 | if (expand_stack(vma, address)) |
1da177e4 LT |
401 | goto bad_area; |
402 | good_area: | |
4b177647 | 403 | code = SEGV_ACCERR; |
70168dfa SR |
404 | if (write) { |
405 | if (!(vma->vm_flags & VM_WRITE)) | |
1da177e4 | 406 | goto bad_area; |
759496ba | 407 | flags |= FAULT_FLAG_WRITE; |
1da177e4 | 408 | } else { |
70168dfa | 409 | if (!(vma->vm_flags & (VM_READ | VM_EXEC))) |
1da177e4 LT |
410 | goto bad_area; |
411 | } | |
759496ba | 412 | switch (handle_mm_fault(mm, vma, address, flags)) { |
1da177e4 LT |
413 | case VM_FAULT_SIGBUS: |
414 | case VM_FAULT_OOM: | |
415 | goto do_sigbus; | |
416 | } | |
417 | up_read(&mm->mmap_sem); | |
418 | return; | |
419 | bad_area: | |
420 | up_read(&mm->mmap_sem); | |
4b177647 | 421 | __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address); |
1da177e4 LT |
422 | return; |
423 | ||
424 | do_sigbus: | |
425 | up_read(&mm->mmap_sem); | |
4b177647 | 426 | __do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address); |
1da177e4 LT |
427 | } |
428 | ||
9088333e DM |
429 | static void check_stack_aligned(unsigned long sp) |
430 | { | |
431 | if (sp & 0x7UL) | |
432 | force_sig(SIGILL, current); | |
433 | } | |
434 | ||
1da177e4 LT |
435 | void window_overflow_fault(void) |
436 | { | |
437 | unsigned long sp; | |
438 | ||
439 | sp = current_thread_info()->rwbuf_stkptrs[0]; | |
70168dfa | 440 | if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK)) |
1da177e4 LT |
441 | force_user_fault(sp + 0x38, 1); |
442 | force_user_fault(sp, 1); | |
9088333e DM |
443 | |
444 | check_stack_aligned(sp); | |
1da177e4 LT |
445 | } |
446 | ||
447 | void window_underflow_fault(unsigned long sp) | |
448 | { | |
70168dfa | 449 | if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK)) |
1da177e4 LT |
450 | force_user_fault(sp + 0x38, 0); |
451 | force_user_fault(sp, 0); | |
9088333e DM |
452 | |
453 | check_stack_aligned(sp); | |
1da177e4 LT |
454 | } |
455 | ||
456 | void window_ret_fault(struct pt_regs *regs) | |
457 | { | |
458 | unsigned long sp; | |
459 | ||
460 | sp = regs->u_regs[UREG_FP]; | |
70168dfa | 461 | if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK)) |
1da177e4 LT |
462 | force_user_fault(sp + 0x38, 0); |
463 | force_user_fault(sp, 0); | |
9088333e DM |
464 | |
465 | check_stack_aligned(sp); | |
1da177e4 | 466 | } |