Commit | Line | Data |
---|---|---|
b00dc837 | 1 | /* |
1da177e4 LT |
2 | * arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc. |
3 | * | |
4fe3ebec | 4 | * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net) |
1da177e4 LT |
5 | * Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz) |
6 | */ | |
7 | ||
8 | #include <asm/head.h> | |
9 | ||
10 | #include <linux/string.h> | |
11 | #include <linux/types.h> | |
12 | #include <linux/sched.h> | |
13 | #include <linux/ptrace.h> | |
14 | #include <linux/mman.h> | |
15 | #include <linux/signal.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/module.h> | |
1da177e4 | 18 | #include <linux/init.h> |
a084b667 | 19 | #include <linux/perf_event.h> |
1da177e4 | 20 | #include <linux/interrupt.h> |
05e14cb3 | 21 | #include <linux/kprobes.h> |
1eeb66a1 | 22 | #include <linux/kdebug.h> |
eeabac73 | 23 | #include <linux/percpu.h> |
1da177e4 LT |
24 | |
25 | #include <asm/page.h> | |
26 | #include <asm/pgtable.h> | |
27 | #include <asm/openprom.h> | |
28 | #include <asm/oplib.h> | |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/asi.h> | |
31 | #include <asm/lsu.h> | |
32 | #include <asm/sections.h> | |
7a1ac526 | 33 | #include <asm/mmu_context.h> |
1da177e4 | 34 | |
4b177647 DM |
35 | int show_unhandled_signals = 1; |
36 | ||
4ed5d5e4 | 37 | static inline __kprobes int notify_page_fault(struct pt_regs *regs) |
d98f8f05 | 38 | { |
127cda1e DM |
39 | int ret = 0; |
40 | ||
41 | /* kprobe_running() needs smp_processor_id() */ | |
135d0821 | 42 | if (kprobes_built_in() && !user_mode(regs)) { |
127cda1e DM |
43 | preempt_disable(); |
44 | if (kprobe_running() && kprobe_fault_handler(regs, 0)) | |
45 | ret = 1; | |
46 | preempt_enable(); | |
47 | } | |
48 | return ret; | |
d98f8f05 | 49 | } |
d98f8f05 | 50 | |
05e14cb3 PP |
51 | static void __kprobes unhandled_fault(unsigned long address, |
52 | struct task_struct *tsk, | |
53 | struct pt_regs *regs) | |
1da177e4 LT |
54 | { |
55 | if ((unsigned long) address < PAGE_SIZE) { | |
56 | printk(KERN_ALERT "Unable to handle kernel NULL " | |
57 | "pointer dereference\n"); | |
58 | } else { | |
59 | printk(KERN_ALERT "Unable to handle kernel paging request " | |
60 | "at virtual address %016lx\n", (unsigned long)address); | |
61 | } | |
62 | printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n", | |
63 | (tsk->mm ? | |
64 | CTX_HWBITS(tsk->mm->context) : | |
65 | CTX_HWBITS(tsk->active_mm->context))); | |
66 | printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n", | |
67 | (tsk->mm ? (unsigned long) tsk->mm->pgd : | |
68 | (unsigned long) tsk->active_mm->pgd)); | |
1da177e4 LT |
69 | die_if_kernel("Oops", regs); |
70 | } | |
71 | ||
4ed5d5e4 | 72 | static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr) |
1da177e4 | 73 | { |
1da177e4 LT |
74 | printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n", |
75 | regs->tpc); | |
eb398d10 | 76 | printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]); |
4fe3ebec | 77 | printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]); |
bf941d6c | 78 | printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr); |
c1f193a7 | 79 | dump_stack(); |
1da177e4 LT |
80 | unhandled_fault(regs->tpc, current, regs); |
81 | } | |
82 | ||
83 | /* | |
84 | * We now make sure that mmap_sem is held in all paths that call | |
85 | * this. Additionally, to prevent kswapd from ripping ptes from | |
86 | * under us, raise interrupts around the time that we look at the | |
87 | * pte, kswapd will have to wait to get his smp ipi response from | |
da160546 | 88 | * us. vmtruncate likewise. This saves us having to get pte lock. |
1da177e4 LT |
89 | */ |
90 | static unsigned int get_user_insn(unsigned long tpc) | |
91 | { | |
92 | pgd_t *pgdp = pgd_offset(current->mm, tpc); | |
93 | pud_t *pudp; | |
94 | pmd_t *pmdp; | |
95 | pte_t *ptep, pte; | |
96 | unsigned long pa; | |
97 | u32 insn = 0; | |
98 | unsigned long pstate; | |
99 | ||
100 | if (pgd_none(*pgdp)) | |
101 | goto outret; | |
102 | pudp = pud_offset(pgdp, tpc); | |
103 | if (pud_none(*pudp)) | |
104 | goto outret; | |
105 | pmdp = pmd_offset(pudp, tpc); | |
106 | if (pmd_none(*pmdp)) | |
107 | goto outret; | |
108 | ||
109 | /* This disables preemption for us as well. */ | |
110 | __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate)); | |
111 | __asm__ __volatile__("wrpr %0, %1, %%pstate" | |
112 | : : "r" (pstate), "i" (PSTATE_IE)); | |
113 | ptep = pte_offset_map(pmdp, tpc); | |
114 | pte = *ptep; | |
115 | if (!pte_present(pte)) | |
116 | goto out; | |
117 | ||
c4bce90e | 118 | pa = (pte_pfn(pte) << PAGE_SHIFT); |
1da177e4 LT |
119 | pa += (tpc & ~PAGE_MASK); |
120 | ||
121 | /* Use phys bypass so we don't pollute dtlb/dcache. */ | |
122 | __asm__ __volatile__("lduwa [%1] %2, %0" | |
123 | : "=r" (insn) | |
124 | : "r" (pa), "i" (ASI_PHYS_USE_EC)); | |
125 | ||
126 | out: | |
127 | pte_unmap(ptep); | |
128 | __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate)); | |
129 | outret: | |
130 | return insn; | |
131 | } | |
132 | ||
4b177647 DM |
133 | static inline void |
134 | show_signal_msg(struct pt_regs *regs, int sig, int code, | |
135 | unsigned long address, struct task_struct *tsk) | |
136 | { | |
137 | if (!unhandled_signal(tsk, sig)) | |
138 | return; | |
139 | ||
140 | if (!printk_ratelimit()) | |
141 | return; | |
142 | ||
143 | printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x", | |
144 | task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, | |
145 | tsk->comm, task_pid_nr(tsk), address, | |
146 | (void *)regs->tpc, (void *)regs->u_regs[UREG_I7], | |
147 | (void *)regs->u_regs[UREG_FP], code); | |
148 | ||
149 | print_vma_addr(KERN_CONT " in ", regs->tpc); | |
150 | ||
151 | printk(KERN_CONT "\n"); | |
152 | } | |
153 | ||
1da177e4 LT |
154 | extern unsigned long compute_effective_address(struct pt_regs *, unsigned int, unsigned int); |
155 | ||
156 | static void do_fault_siginfo(int code, int sig, struct pt_regs *regs, | |
157 | unsigned int insn, int fault_code) | |
158 | { | |
4b177647 | 159 | unsigned long addr; |
1da177e4 LT |
160 | siginfo_t info; |
161 | ||
162 | info.si_code = code; | |
163 | info.si_signo = sig; | |
164 | info.si_errno = 0; | |
165 | if (fault_code & FAULT_CODE_ITLB) | |
4b177647 | 166 | addr = regs->tpc; |
1da177e4 | 167 | else |
4b177647 DM |
168 | addr = compute_effective_address(regs, insn, 0); |
169 | info.si_addr = (void __user *) addr; | |
1da177e4 | 170 | info.si_trapno = 0; |
4b177647 DM |
171 | |
172 | if (unlikely(show_unhandled_signals)) | |
173 | show_signal_msg(regs, sig, code, addr, current); | |
174 | ||
1da177e4 LT |
175 | force_sig_info(sig, &info, current); |
176 | } | |
177 | ||
178 | extern int handle_ldf_stq(u32, struct pt_regs *); | |
179 | extern int handle_ld_nf(u32, struct pt_regs *); | |
180 | ||
181 | static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn) | |
182 | { | |
183 | if (!insn) { | |
184 | if (!regs->tpc || (regs->tpc & 0x3)) | |
185 | return 0; | |
186 | if (regs->tstate & TSTATE_PRIV) { | |
187 | insn = *(unsigned int *) regs->tpc; | |
188 | } else { | |
189 | insn = get_user_insn(regs->tpc); | |
190 | } | |
191 | } | |
192 | return insn; | |
193 | } | |
194 | ||
4ed5d5e4 DM |
195 | static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code, |
196 | int fault_code, unsigned int insn, | |
197 | unsigned long address) | |
1da177e4 | 198 | { |
1da177e4 LT |
199 | unsigned char asi = ASI_P; |
200 | ||
201 | if ((!insn) && (regs->tstate & TSTATE_PRIV)) | |
202 | goto cannot_handle; | |
203 | ||
204 | /* If user insn could be read (thus insn is zero), that | |
205 | * is fine. We will just gun down the process with a signal | |
206 | * in that case. | |
207 | */ | |
208 | ||
209 | if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) && | |
210 | (insn & 0xc0800000) == 0xc0800000) { | |
211 | if (insn & 0x2000) | |
212 | asi = (regs->tstate >> 24); | |
213 | else | |
214 | asi = (insn >> 5); | |
215 | if ((asi & 0xf2) == 0x82) { | |
216 | if (insn & 0x1000000) { | |
217 | handle_ldf_stq(insn, regs); | |
218 | } else { | |
219 | /* This was a non-faulting load. Just clear the | |
220 | * destination register(s) and continue with the next | |
221 | * instruction. -jj | |
222 | */ | |
223 | handle_ld_nf(insn, regs); | |
224 | } | |
225 | return; | |
226 | } | |
227 | } | |
228 | ||
1da177e4 LT |
229 | /* Is this in ex_table? */ |
230 | if (regs->tstate & TSTATE_PRIV) { | |
8cf14af0 | 231 | const struct exception_table_entry *entry; |
1da177e4 | 232 | |
622eaec6 DM |
233 | entry = search_exception_tables(regs->tpc); |
234 | if (entry) { | |
8cf14af0 | 235 | regs->tpc = entry->fixup; |
1da177e4 | 236 | regs->tnpc = regs->tpc + 4; |
1da177e4 LT |
237 | return; |
238 | } | |
239 | } else { | |
240 | /* The si_code was set to make clear whether | |
241 | * this was a SEGV_MAPERR or SEGV_ACCERR fault. | |
242 | */ | |
243 | do_fault_siginfo(si_code, SIGSEGV, regs, insn, fault_code); | |
244 | return; | |
245 | } | |
246 | ||
247 | cannot_handle: | |
248 | unhandled_fault (address, current, regs); | |
249 | } | |
250 | ||
4ed5d5e4 | 251 | static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs) |
9b026058 DM |
252 | { |
253 | static int times; | |
254 | ||
255 | if (times++ < 10) | |
256 | printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports " | |
257 | "64-bit TPC [%lx]\n", | |
258 | current->comm, current->pid, | |
259 | regs->tpc); | |
260 | show_regs(regs); | |
261 | } | |
262 | ||
4ed5d5e4 DM |
263 | static void noinline __kprobes bogus_32bit_fault_address(struct pt_regs *regs, |
264 | unsigned long addr) | |
9b026058 DM |
265 | { |
266 | static int times; | |
267 | ||
268 | if (times++ < 10) | |
269 | printk(KERN_ERR "FAULT[%s:%d]: 32-bit process " | |
270 | "reports 64-bit fault address [%lx]\n", | |
271 | current->comm, current->pid, addr); | |
272 | show_regs(regs); | |
273 | } | |
274 | ||
05e14cb3 | 275 | asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs) |
1da177e4 LT |
276 | { |
277 | struct mm_struct *mm = current->mm; | |
278 | struct vm_area_struct *vma; | |
279 | unsigned int insn = 0; | |
83c54070 | 280 | int si_code, fault_code, fault; |
7a1ac526 | 281 | unsigned long address, mm_rss; |
1da177e4 LT |
282 | |
283 | fault_code = get_thread_fault_code(); | |
284 | ||
127cda1e | 285 | if (notify_page_fault(regs)) |
1da177e4 LT |
286 | return; |
287 | ||
288 | si_code = SEGV_MAPERR; | |
289 | address = current_thread_info()->fault_address; | |
290 | ||
291 | if ((fault_code & FAULT_CODE_ITLB) && | |
292 | (fault_code & FAULT_CODE_DTLB)) | |
293 | BUG(); | |
294 | ||
eeabac73 | 295 | if (test_thread_flag(TIF_32BIT)) { |
9b026058 DM |
296 | if (!(regs->tstate & TSTATE_PRIV)) { |
297 | if (unlikely((regs->tpc >> 32) != 0)) { | |
298 | bogus_32bit_fault_tpc(regs); | |
299 | goto intr_or_no_mm; | |
300 | } | |
301 | } | |
302 | if (unlikely((address >> 32) != 0)) { | |
303 | bogus_32bit_fault_address(regs, address); | |
304 | goto intr_or_no_mm; | |
305 | } | |
eeabac73 DM |
306 | } |
307 | ||
1da177e4 | 308 | if (regs->tstate & TSTATE_PRIV) { |
9b026058 | 309 | unsigned long tpc = regs->tpc; |
1da177e4 LT |
310 | |
311 | /* Sanity check the PC. */ | |
be71716e | 312 | if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) || |
1da177e4 LT |
313 | (tpc >= MODULES_VADDR && tpc < MODULES_END)) { |
314 | /* Valid, no problems... */ | |
315 | } else { | |
bf941d6c | 316 | bad_kernel_pc(regs, address); |
1da177e4 LT |
317 | return; |
318 | } | |
319 | } | |
320 | ||
321 | /* | |
322 | * If we're in an interrupt or have no user | |
323 | * context, we must not take the fault.. | |
324 | */ | |
325 | if (in_atomic() || !mm) | |
326 | goto intr_or_no_mm; | |
327 | ||
a8b0ca17 | 328 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); |
a084b667 | 329 | |
1da177e4 LT |
330 | if (!down_read_trylock(&mm->mmap_sem)) { |
331 | if ((regs->tstate & TSTATE_PRIV) && | |
332 | !search_exception_tables(regs->tpc)) { | |
333 | insn = get_fault_insn(regs, insn); | |
334 | goto handle_kernel_fault; | |
335 | } | |
336 | down_read(&mm->mmap_sem); | |
337 | } | |
338 | ||
339 | vma = find_vma(mm, address); | |
340 | if (!vma) | |
341 | goto bad_area; | |
342 | ||
343 | /* Pure DTLB misses do not tell us whether the fault causing | |
344 | * load/store/atomic was a write or not, it only says that there | |
345 | * was no match. So in such a case we (carefully) read the | |
346 | * instruction to try and figure this out. It's an optimization | |
347 | * so it's ok if we can't do this. | |
348 | * | |
349 | * Special hack, window spill/fill knows the exact fault type. | |
350 | */ | |
351 | if (((fault_code & | |
352 | (FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) && | |
353 | (vma->vm_flags & VM_WRITE) != 0) { | |
354 | insn = get_fault_insn(regs, 0); | |
355 | if (!insn) | |
356 | goto continue_fault; | |
73c50a27 DM |
357 | /* All loads, stores and atomics have bits 30 and 31 both set |
358 | * in the instruction. Bit 21 is set in all stores, but we | |
359 | * have to avoid prefetches which also have bit 21 set. | |
360 | */ | |
1da177e4 | 361 | if ((insn & 0xc0200000) == 0xc0200000 && |
73c50a27 | 362 | (insn & 0x01780000) != 0x01680000) { |
1da177e4 LT |
363 | /* Don't bother updating thread struct value, |
364 | * because update_mmu_cache only cares which tlb | |
365 | * the access came from. | |
366 | */ | |
367 | fault_code |= FAULT_CODE_WRITE; | |
368 | } | |
369 | } | |
370 | continue_fault: | |
371 | ||
372 | if (vma->vm_start <= address) | |
373 | goto good_area; | |
374 | if (!(vma->vm_flags & VM_GROWSDOWN)) | |
375 | goto bad_area; | |
376 | if (!(fault_code & FAULT_CODE_WRITE)) { | |
377 | /* Non-faulting loads shouldn't expand stack. */ | |
378 | insn = get_fault_insn(regs, insn); | |
379 | if ((insn & 0xc0800000) == 0xc0800000) { | |
380 | unsigned char asi; | |
381 | ||
382 | if (insn & 0x2000) | |
383 | asi = (regs->tstate >> 24); | |
384 | else | |
385 | asi = (insn >> 5); | |
386 | if ((asi & 0xf2) == 0x82) | |
387 | goto bad_area; | |
388 | } | |
389 | } | |
390 | if (expand_stack(vma, address)) | |
391 | goto bad_area; | |
392 | /* | |
393 | * Ok, we have a good vm_area for this memory access, so | |
394 | * we can handle it.. | |
395 | */ | |
396 | good_area: | |
397 | si_code = SEGV_ACCERR; | |
398 | ||
399 | /* If we took a ITLB miss on a non-executable page, catch | |
400 | * that here. | |
401 | */ | |
402 | if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) { | |
403 | BUG_ON(address != regs->tpc); | |
404 | BUG_ON(regs->tstate & TSTATE_PRIV); | |
405 | goto bad_area; | |
406 | } | |
407 | ||
408 | if (fault_code & FAULT_CODE_WRITE) { | |
409 | if (!(vma->vm_flags & VM_WRITE)) | |
410 | goto bad_area; | |
411 | ||
412 | /* Spitfire has an icache which does not snoop | |
413 | * processor stores. Later processors do... | |
414 | */ | |
415 | if (tlb_type == spitfire && | |
416 | (vma->vm_flags & VM_EXEC) != 0 && | |
417 | vma->vm_file != NULL) | |
418 | set_thread_fault_code(fault_code | | |
419 | FAULT_CODE_BLKCOMMIT); | |
420 | } else { | |
421 | /* Allow reads even for write-only mappings */ | |
422 | if (!(vma->vm_flags & (VM_READ | VM_EXEC))) | |
423 | goto bad_area; | |
424 | } | |
425 | ||
d06063cc | 426 | fault = handle_mm_fault(mm, vma, address, (fault_code & FAULT_CODE_WRITE) ? FAULT_FLAG_WRITE : 0); |
83c54070 NP |
427 | if (unlikely(fault & VM_FAULT_ERROR)) { |
428 | if (fault & VM_FAULT_OOM) | |
429 | goto out_of_memory; | |
430 | else if (fault & VM_FAULT_SIGBUS) | |
431 | goto do_sigbus; | |
1da177e4 LT |
432 | BUG(); |
433 | } | |
a084b667 | 434 | if (fault & VM_FAULT_MAJOR) { |
83c54070 | 435 | current->maj_flt++; |
a8b0ca17 | 436 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address); |
a084b667 | 437 | } else { |
83c54070 | 438 | current->min_flt++; |
a8b0ca17 | 439 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address); |
a084b667 | 440 | } |
1da177e4 | 441 | up_read(&mm->mmap_sem); |
7a1ac526 DM |
442 | |
443 | mm_rss = get_mm_rss(mm); | |
dcc1e8dd DM |
444 | #ifdef CONFIG_HUGETLB_PAGE |
445 | mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE)); | |
446 | #endif | |
7bebd83d | 447 | if (unlikely(mm_rss > |
dcc1e8dd DM |
448 | mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit)) |
449 | tsb_grow(mm, MM_TSB_BASE, mm_rss); | |
450 | #ifdef CONFIG_HUGETLB_PAGE | |
451 | mm_rss = mm->context.huge_pte_count; | |
7bebd83d | 452 | if (unlikely(mm_rss > |
dcc1e8dd DM |
453 | mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) |
454 | tsb_grow(mm, MM_TSB_HUGE, mm_rss); | |
455 | #endif | |
efdc1e20 | 456 | return; |
1da177e4 LT |
457 | |
458 | /* | |
459 | * Something tried to access memory that isn't in our memory map.. | |
460 | * Fix it, but check if it's kernel or user first.. | |
461 | */ | |
462 | bad_area: | |
463 | insn = get_fault_insn(regs, insn); | |
464 | up_read(&mm->mmap_sem); | |
465 | ||
466 | handle_kernel_fault: | |
467 | do_kernel_fault(regs, si_code, fault_code, insn, address); | |
efdc1e20 | 468 | return; |
1da177e4 LT |
469 | |
470 | /* | |
471 | * We ran out of memory, or some other thing happened to us that made | |
472 | * us unable to handle the page fault gracefully. | |
473 | */ | |
474 | out_of_memory: | |
475 | insn = get_fault_insn(regs, insn); | |
476 | up_read(&mm->mmap_sem); | |
a923c28f DM |
477 | if (!(regs->tstate & TSTATE_PRIV)) { |
478 | pagefault_out_of_memory(); | |
479 | return; | |
480 | } | |
1da177e4 LT |
481 | goto handle_kernel_fault; |
482 | ||
483 | intr_or_no_mm: | |
484 | insn = get_fault_insn(regs, 0); | |
485 | goto handle_kernel_fault; | |
486 | ||
487 | do_sigbus: | |
488 | insn = get_fault_insn(regs, insn); | |
489 | up_read(&mm->mmap_sem); | |
490 | ||
491 | /* | |
492 | * Send a sigbus, regardless of whether we were in kernel | |
493 | * or user mode. | |
494 | */ | |
495 | do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, insn, fault_code); | |
496 | ||
497 | /* Kernel mode? Handle exceptions or die */ | |
498 | if (regs->tstate & TSTATE_PRIV) | |
499 | goto handle_kernel_fault; | |
1da177e4 | 500 | } |