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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc.
4 *
5 * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
6 * Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.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/sched/debug.h>
15#include <linux/ptrace.h>
16#include <linux/mman.h>
17#include <linux/signal.h>
18#include <linux/mm.h>
19#include <linux/extable.h>
20#include <linux/init.h>
21#include <linux/perf_event.h>
22#include <linux/interrupt.h>
23#include <linux/kprobes.h>
24#include <linux/kdebug.h>
25#include <linux/percpu.h>
26#include <linux/context_tracking.h>
27#include <linux/uaccess.h>
28
29#include <asm/page.h>
30#include <asm/pgtable.h>
31#include <asm/openprom.h>
32#include <asm/oplib.h>
33#include <asm/asi.h>
34#include <asm/lsu.h>
35#include <asm/sections.h>
36#include <asm/mmu_context.h>
37#include <asm/setup.h>
38
39int show_unhandled_signals = 1;
40
41static inline __kprobes int notify_page_fault(struct pt_regs *regs)
42{
43 int ret = 0;
44
45 /* kprobe_running() needs smp_processor_id() */
46 if (kprobes_built_in() && !user_mode(regs)) {
47 preempt_disable();
48 if (kprobe_running() && kprobe_fault_handler(regs, 0))
49 ret = 1;
50 preempt_enable();
51 }
52 return ret;
53}
54
55static void __kprobes unhandled_fault(unsigned long address,
56 struct task_struct *tsk,
57 struct pt_regs *regs)
58{
59 if ((unsigned long) address < PAGE_SIZE) {
60 printk(KERN_ALERT "Unable to handle kernel NULL "
61 "pointer dereference\n");
62 } else {
63 printk(KERN_ALERT "Unable to handle kernel paging request "
64 "at virtual address %016lx\n", (unsigned long)address);
65 }
66 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
67 (tsk->mm ?
68 CTX_HWBITS(tsk->mm->context) :
69 CTX_HWBITS(tsk->active_mm->context)));
70 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
71 (tsk->mm ? (unsigned long) tsk->mm->pgd :
72 (unsigned long) tsk->active_mm->pgd));
73 die_if_kernel("Oops", regs);
74}
75
76static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
77{
78 printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
79 regs->tpc);
80 printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
81 printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
82 printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
83 dump_stack();
84 unhandled_fault(regs->tpc, current, regs);
85}
86
87/*
88 * We now make sure that mmap_sem is held in all paths that call
89 * this. Additionally, to prevent kswapd from ripping ptes from
90 * under us, raise interrupts around the time that we look at the
91 * pte, kswapd will have to wait to get his smp ipi response from
92 * us. vmtruncate likewise. This saves us having to get pte lock.
93 */
94static unsigned int get_user_insn(unsigned long tpc)
95{
96 pgd_t *pgdp = pgd_offset(current->mm, tpc);
97 pud_t *pudp;
98 pmd_t *pmdp;
99 pte_t *ptep, pte;
100 unsigned long pa;
101 u32 insn = 0;
102
103 if (pgd_none(*pgdp) || unlikely(pgd_bad(*pgdp)))
104 goto out;
105 pudp = pud_offset(pgdp, tpc);
106 if (pud_none(*pudp) || unlikely(pud_bad(*pudp)))
107 goto out;
108
109 /* This disables preemption for us as well. */
110 local_irq_disable();
111
112 pmdp = pmd_offset(pudp, tpc);
113 if (pmd_none(*pmdp) || unlikely(pmd_bad(*pmdp)))
114 goto out_irq_enable;
115
116#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
117 if (is_hugetlb_pmd(*pmdp)) {
118 pa = pmd_pfn(*pmdp) << PAGE_SHIFT;
119 pa += tpc & ~HPAGE_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 } else
126#endif
127 {
128 ptep = pte_offset_map(pmdp, tpc);
129 pte = *ptep;
130 if (pte_present(pte)) {
131 pa = (pte_pfn(pte) << PAGE_SHIFT);
132 pa += (tpc & ~PAGE_MASK);
133
134 /* Use phys bypass so we don't pollute dtlb/dcache. */
135 __asm__ __volatile__("lduwa [%1] %2, %0"
136 : "=r" (insn)
137 : "r" (pa), "i" (ASI_PHYS_USE_EC));
138 }
139 pte_unmap(ptep);
140 }
141out_irq_enable:
142 local_irq_enable();
143out:
144 return insn;
145}
146
147static inline void
148show_signal_msg(struct pt_regs *regs, int sig, int code,
149 unsigned long address, struct task_struct *tsk)
150{
151 if (!unhandled_signal(tsk, sig))
152 return;
153
154 if (!printk_ratelimit())
155 return;
156
157 printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
158 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
159 tsk->comm, task_pid_nr(tsk), address,
160 (void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
161 (void *)regs->u_regs[UREG_FP], code);
162
163 print_vma_addr(KERN_CONT " in ", regs->tpc);
164
165 printk(KERN_CONT "\n");
166}
167
168static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
169 unsigned long fault_addr, unsigned int insn,
170 int fault_code)
171{
172 unsigned long addr;
173 siginfo_t info;
174
175 info.si_code = code;
176 info.si_signo = sig;
177 info.si_errno = 0;
178 if (fault_code & FAULT_CODE_ITLB) {
179 addr = regs->tpc;
180 } else {
181 /* If we were able to probe the faulting instruction, use it
182 * to compute a precise fault address. Otherwise use the fault
183 * time provided address which may only have page granularity.
184 */
185 if (insn)
186 addr = compute_effective_address(regs, insn, 0);
187 else
188 addr = fault_addr;
189 }
190 info.si_addr = (void __user *) addr;
191 info.si_trapno = 0;
192
193 if (unlikely(show_unhandled_signals))
194 show_signal_msg(regs, sig, code, addr, current);
195
196 force_sig_info(sig, &info, current);
197}
198
199static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
200{
201 if (!insn) {
202 if (!regs->tpc || (regs->tpc & 0x3))
203 return 0;
204 if (regs->tstate & TSTATE_PRIV) {
205 insn = *(unsigned int *) regs->tpc;
206 } else {
207 insn = get_user_insn(regs->tpc);
208 }
209 }
210 return insn;
211}
212
213static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
214 int fault_code, unsigned int insn,
215 unsigned long address)
216{
217 unsigned char asi = ASI_P;
218
219 if ((!insn) && (regs->tstate & TSTATE_PRIV))
220 goto cannot_handle;
221
222 /* If user insn could be read (thus insn is zero), that
223 * is fine. We will just gun down the process with a signal
224 * in that case.
225 */
226
227 if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
228 (insn & 0xc0800000) == 0xc0800000) {
229 if (insn & 0x2000)
230 asi = (regs->tstate >> 24);
231 else
232 asi = (insn >> 5);
233 if ((asi & 0xf2) == 0x82) {
234 if (insn & 0x1000000) {
235 handle_ldf_stq(insn, regs);
236 } else {
237 /* This was a non-faulting load. Just clear the
238 * destination register(s) and continue with the next
239 * instruction. -jj
240 */
241 handle_ld_nf(insn, regs);
242 }
243 return;
244 }
245 }
246
247 /* Is this in ex_table? */
248 if (regs->tstate & TSTATE_PRIV) {
249 const struct exception_table_entry *entry;
250
251 entry = search_exception_tables(regs->tpc);
252 if (entry) {
253 regs->tpc = entry->fixup;
254 regs->tnpc = regs->tpc + 4;
255 return;
256 }
257 } else {
258 /* The si_code was set to make clear whether
259 * this was a SEGV_MAPERR or SEGV_ACCERR fault.
260 */
261 do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
262 return;
263 }
264
265cannot_handle:
266 unhandled_fault (address, current, regs);
267}
268
269static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
270{
271 static int times;
272
273 if (times++ < 10)
274 printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
275 "64-bit TPC [%lx]\n",
276 current->comm, current->pid,
277 regs->tpc);
278 show_regs(regs);
279}
280
281asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
282{
283 enum ctx_state prev_state = exception_enter();
284 struct mm_struct *mm = current->mm;
285 struct vm_area_struct *vma;
286 unsigned int insn = 0;
287 int si_code, fault_code, fault;
288 unsigned long address, mm_rss;
289 unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
290
291 fault_code = get_thread_fault_code();
292
293 if (notify_page_fault(regs))
294 goto exit_exception;
295
296 si_code = SEGV_MAPERR;
297 address = current_thread_info()->fault_address;
298
299 if ((fault_code & FAULT_CODE_ITLB) &&
300 (fault_code & FAULT_CODE_DTLB))
301 BUG();
302
303 if (test_thread_flag(TIF_32BIT)) {
304 if (!(regs->tstate & TSTATE_PRIV)) {
305 if (unlikely((regs->tpc >> 32) != 0)) {
306 bogus_32bit_fault_tpc(regs);
307 goto intr_or_no_mm;
308 }
309 }
310 if (unlikely((address >> 32) != 0))
311 goto intr_or_no_mm;
312 }
313
314 if (regs->tstate & TSTATE_PRIV) {
315 unsigned long tpc = regs->tpc;
316
317 /* Sanity check the PC. */
318 if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
319 (tpc >= MODULES_VADDR && tpc < MODULES_END)) {
320 /* Valid, no problems... */
321 } else {
322 bad_kernel_pc(regs, address);
323 goto exit_exception;
324 }
325 } else
326 flags |= FAULT_FLAG_USER;
327
328 /*
329 * If we're in an interrupt or have no user
330 * context, we must not take the fault..
331 */
332 if (faulthandler_disabled() || !mm)
333 goto intr_or_no_mm;
334
335 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
336
337 if (!down_read_trylock(&mm->mmap_sem)) {
338 if ((regs->tstate & TSTATE_PRIV) &&
339 !search_exception_tables(regs->tpc)) {
340 insn = get_fault_insn(regs, insn);
341 goto handle_kernel_fault;
342 }
343
344retry:
345 down_read(&mm->mmap_sem);
346 }
347
348 if (fault_code & FAULT_CODE_BAD_RA)
349 goto do_sigbus;
350
351 vma = find_vma(mm, address);
352 if (!vma)
353 goto bad_area;
354
355 /* Pure DTLB misses do not tell us whether the fault causing
356 * load/store/atomic was a write or not, it only says that there
357 * was no match. So in such a case we (carefully) read the
358 * instruction to try and figure this out. It's an optimization
359 * so it's ok if we can't do this.
360 *
361 * Special hack, window spill/fill knows the exact fault type.
362 */
363 if (((fault_code &
364 (FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
365 (vma->vm_flags & VM_WRITE) != 0) {
366 insn = get_fault_insn(regs, 0);
367 if (!insn)
368 goto continue_fault;
369 /* All loads, stores and atomics have bits 30 and 31 both set
370 * in the instruction. Bit 21 is set in all stores, but we
371 * have to avoid prefetches which also have bit 21 set.
372 */
373 if ((insn & 0xc0200000) == 0xc0200000 &&
374 (insn & 0x01780000) != 0x01680000) {
375 /* Don't bother updating thread struct value,
376 * because update_mmu_cache only cares which tlb
377 * the access came from.
378 */
379 fault_code |= FAULT_CODE_WRITE;
380 }
381 }
382continue_fault:
383
384 if (vma->vm_start <= address)
385 goto good_area;
386 if (!(vma->vm_flags & VM_GROWSDOWN))
387 goto bad_area;
388 if (!(fault_code & FAULT_CODE_WRITE)) {
389 /* Non-faulting loads shouldn't expand stack. */
390 insn = get_fault_insn(regs, insn);
391 if ((insn & 0xc0800000) == 0xc0800000) {
392 unsigned char asi;
393
394 if (insn & 0x2000)
395 asi = (regs->tstate >> 24);
396 else
397 asi = (insn >> 5);
398 if ((asi & 0xf2) == 0x82)
399 goto bad_area;
400 }
401 }
402 if (expand_stack(vma, address))
403 goto bad_area;
404 /*
405 * Ok, we have a good vm_area for this memory access, so
406 * we can handle it..
407 */
408good_area:
409 si_code = SEGV_ACCERR;
410
411 /* If we took a ITLB miss on a non-executable page, catch
412 * that here.
413 */
414 if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
415 WARN(address != regs->tpc,
416 "address (%lx) != regs->tpc (%lx)\n", address, regs->tpc);
417 WARN_ON(regs->tstate & TSTATE_PRIV);
418 goto bad_area;
419 }
420
421 if (fault_code & FAULT_CODE_WRITE) {
422 if (!(vma->vm_flags & VM_WRITE))
423 goto bad_area;
424
425 /* Spitfire has an icache which does not snoop
426 * processor stores. Later processors do...
427 */
428 if (tlb_type == spitfire &&
429 (vma->vm_flags & VM_EXEC) != 0 &&
430 vma->vm_file != NULL)
431 set_thread_fault_code(fault_code |
432 FAULT_CODE_BLKCOMMIT);
433
434 flags |= FAULT_FLAG_WRITE;
435 } else {
436 /* Allow reads even for write-only mappings */
437 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
438 goto bad_area;
439 }
440
441 fault = handle_mm_fault(vma, address, flags);
442
443 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
444 goto exit_exception;
445
446 if (unlikely(fault & VM_FAULT_ERROR)) {
447 if (fault & VM_FAULT_OOM)
448 goto out_of_memory;
449 else if (fault & VM_FAULT_SIGSEGV)
450 goto bad_area;
451 else if (fault & VM_FAULT_SIGBUS)
452 goto do_sigbus;
453 BUG();
454 }
455
456 if (flags & FAULT_FLAG_ALLOW_RETRY) {
457 if (fault & VM_FAULT_MAJOR) {
458 current->maj_flt++;
459 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
460 1, regs, address);
461 } else {
462 current->min_flt++;
463 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
464 1, regs, address);
465 }
466 if (fault & VM_FAULT_RETRY) {
467 flags &= ~FAULT_FLAG_ALLOW_RETRY;
468 flags |= FAULT_FLAG_TRIED;
469
470 /* No need to up_read(&mm->mmap_sem) as we would
471 * have already released it in __lock_page_or_retry
472 * in mm/filemap.c.
473 */
474
475 goto retry;
476 }
477 }
478 up_read(&mm->mmap_sem);
479
480 mm_rss = get_mm_rss(mm);
481#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
482 mm_rss -= (mm->context.thp_pte_count * (HPAGE_SIZE / PAGE_SIZE));
483#endif
484 if (unlikely(mm_rss >
485 mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
486 tsb_grow(mm, MM_TSB_BASE, mm_rss);
487#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
488 mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
489 mm_rss *= REAL_HPAGE_PER_HPAGE;
490 if (unlikely(mm_rss >
491 mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
492 if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
493 tsb_grow(mm, MM_TSB_HUGE, mm_rss);
494 else
495 hugetlb_setup(regs);
496
497 }
498#endif
499exit_exception:
500 exception_exit(prev_state);
501 return;
502
503 /*
504 * Something tried to access memory that isn't in our memory map..
505 * Fix it, but check if it's kernel or user first..
506 */
507bad_area:
508 insn = get_fault_insn(regs, insn);
509 up_read(&mm->mmap_sem);
510
511handle_kernel_fault:
512 do_kernel_fault(regs, si_code, fault_code, insn, address);
513 goto exit_exception;
514
515/*
516 * We ran out of memory, or some other thing happened to us that made
517 * us unable to handle the page fault gracefully.
518 */
519out_of_memory:
520 insn = get_fault_insn(regs, insn);
521 up_read(&mm->mmap_sem);
522 if (!(regs->tstate & TSTATE_PRIV)) {
523 pagefault_out_of_memory();
524 goto exit_exception;
525 }
526 goto handle_kernel_fault;
527
528intr_or_no_mm:
529 insn = get_fault_insn(regs, 0);
530 goto handle_kernel_fault;
531
532do_sigbus:
533 insn = get_fault_insn(regs, insn);
534 up_read(&mm->mmap_sem);
535
536 /*
537 * Send a sigbus, regardless of whether we were in kernel
538 * or user mode.
539 */
540 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);
541
542 /* Kernel mode? Handle exceptions or die */
543 if (regs->tstate & TSTATE_PRIV)
544 goto handle_kernel_fault;
545}
1/*
2 * arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc.
3 *
4 * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
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>
18#include <linux/init.h>
19#include <linux/perf_event.h>
20#include <linux/interrupt.h>
21#include <linux/kprobes.h>
22#include <linux/kdebug.h>
23#include <linux/percpu.h>
24#include <linux/context_tracking.h>
25
26#include <asm/page.h>
27#include <asm/pgtable.h>
28#include <asm/openprom.h>
29#include <asm/oplib.h>
30#include <asm/uaccess.h>
31#include <asm/asi.h>
32#include <asm/lsu.h>
33#include <asm/sections.h>
34#include <asm/mmu_context.h>
35
36int show_unhandled_signals = 1;
37
38static inline __kprobes int notify_page_fault(struct pt_regs *regs)
39{
40 int ret = 0;
41
42 /* kprobe_running() needs smp_processor_id() */
43 if (kprobes_built_in() && !user_mode(regs)) {
44 preempt_disable();
45 if (kprobe_running() && kprobe_fault_handler(regs, 0))
46 ret = 1;
47 preempt_enable();
48 }
49 return ret;
50}
51
52static void __kprobes unhandled_fault(unsigned long address,
53 struct task_struct *tsk,
54 struct pt_regs *regs)
55{
56 if ((unsigned long) address < PAGE_SIZE) {
57 printk(KERN_ALERT "Unable to handle kernel NULL "
58 "pointer dereference\n");
59 } else {
60 printk(KERN_ALERT "Unable to handle kernel paging request "
61 "at virtual address %016lx\n", (unsigned long)address);
62 }
63 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
64 (tsk->mm ?
65 CTX_HWBITS(tsk->mm->context) :
66 CTX_HWBITS(tsk->active_mm->context)));
67 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
68 (tsk->mm ? (unsigned long) tsk->mm->pgd :
69 (unsigned long) tsk->active_mm->pgd));
70 die_if_kernel("Oops", regs);
71}
72
73static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
74{
75 printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
76 regs->tpc);
77 printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
78 printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
79 printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
80 dump_stack();
81 unhandled_fault(regs->tpc, current, regs);
82}
83
84/*
85 * We now make sure that mmap_sem is held in all paths that call
86 * this. Additionally, to prevent kswapd from ripping ptes from
87 * under us, raise interrupts around the time that we look at the
88 * pte, kswapd will have to wait to get his smp ipi response from
89 * us. vmtruncate likewise. This saves us having to get pte lock.
90 */
91static unsigned int get_user_insn(unsigned long tpc)
92{
93 pgd_t *pgdp = pgd_offset(current->mm, tpc);
94 pud_t *pudp;
95 pmd_t *pmdp;
96 pte_t *ptep, pte;
97 unsigned long pa;
98 u32 insn = 0;
99
100 if (pgd_none(*pgdp) || unlikely(pgd_bad(*pgdp)))
101 goto out;
102 pudp = pud_offset(pgdp, tpc);
103 if (pud_none(*pudp) || unlikely(pud_bad(*pudp)))
104 goto out;
105
106 /* This disables preemption for us as well. */
107 local_irq_disable();
108
109 pmdp = pmd_offset(pudp, tpc);
110 if (pmd_none(*pmdp) || unlikely(pmd_bad(*pmdp)))
111 goto out_irq_enable;
112
113#ifdef CONFIG_TRANSPARENT_HUGEPAGE
114 if (pmd_trans_huge(*pmdp)) {
115 if (pmd_trans_splitting(*pmdp))
116 goto out_irq_enable;
117
118 pa = pmd_pfn(*pmdp) << PAGE_SHIFT;
119 pa += tpc & ~HPAGE_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 } else
126#endif
127 {
128 ptep = pte_offset_map(pmdp, tpc);
129 pte = *ptep;
130 if (pte_present(pte)) {
131 pa = (pte_pfn(pte) << PAGE_SHIFT);
132 pa += (tpc & ~PAGE_MASK);
133
134 /* Use phys bypass so we don't pollute dtlb/dcache. */
135 __asm__ __volatile__("lduwa [%1] %2, %0"
136 : "=r" (insn)
137 : "r" (pa), "i" (ASI_PHYS_USE_EC));
138 }
139 pte_unmap(ptep);
140 }
141out_irq_enable:
142 local_irq_enable();
143out:
144 return insn;
145}
146
147static inline void
148show_signal_msg(struct pt_regs *regs, int sig, int code,
149 unsigned long address, struct task_struct *tsk)
150{
151 if (!unhandled_signal(tsk, sig))
152 return;
153
154 if (!printk_ratelimit())
155 return;
156
157 printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
158 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
159 tsk->comm, task_pid_nr(tsk), address,
160 (void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
161 (void *)regs->u_regs[UREG_FP], code);
162
163 print_vma_addr(KERN_CONT " in ", regs->tpc);
164
165 printk(KERN_CONT "\n");
166}
167
168static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
169 unsigned long fault_addr, unsigned int insn,
170 int fault_code)
171{
172 unsigned long addr;
173 siginfo_t info;
174
175 info.si_code = code;
176 info.si_signo = sig;
177 info.si_errno = 0;
178 if (fault_code & FAULT_CODE_ITLB) {
179 addr = regs->tpc;
180 } else {
181 /* If we were able to probe the faulting instruction, use it
182 * to compute a precise fault address. Otherwise use the fault
183 * time provided address which may only have page granularity.
184 */
185 if (insn)
186 addr = compute_effective_address(regs, insn, 0);
187 else
188 addr = fault_addr;
189 }
190 info.si_addr = (void __user *) addr;
191 info.si_trapno = 0;
192
193 if (unlikely(show_unhandled_signals))
194 show_signal_msg(regs, sig, code, addr, current);
195
196 force_sig_info(sig, &info, current);
197}
198
199extern int handle_ldf_stq(u32, struct pt_regs *);
200extern int handle_ld_nf(u32, struct pt_regs *);
201
202static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
203{
204 if (!insn) {
205 if (!regs->tpc || (regs->tpc & 0x3))
206 return 0;
207 if (regs->tstate & TSTATE_PRIV) {
208 insn = *(unsigned int *) regs->tpc;
209 } else {
210 insn = get_user_insn(regs->tpc);
211 }
212 }
213 return insn;
214}
215
216static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
217 int fault_code, unsigned int insn,
218 unsigned long address)
219{
220 unsigned char asi = ASI_P;
221
222 if ((!insn) && (regs->tstate & TSTATE_PRIV))
223 goto cannot_handle;
224
225 /* If user insn could be read (thus insn is zero), that
226 * is fine. We will just gun down the process with a signal
227 * in that case.
228 */
229
230 if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
231 (insn & 0xc0800000) == 0xc0800000) {
232 if (insn & 0x2000)
233 asi = (regs->tstate >> 24);
234 else
235 asi = (insn >> 5);
236 if ((asi & 0xf2) == 0x82) {
237 if (insn & 0x1000000) {
238 handle_ldf_stq(insn, regs);
239 } else {
240 /* This was a non-faulting load. Just clear the
241 * destination register(s) and continue with the next
242 * instruction. -jj
243 */
244 handle_ld_nf(insn, regs);
245 }
246 return;
247 }
248 }
249
250 /* Is this in ex_table? */
251 if (regs->tstate & TSTATE_PRIV) {
252 const struct exception_table_entry *entry;
253
254 entry = search_exception_tables(regs->tpc);
255 if (entry) {
256 regs->tpc = entry->fixup;
257 regs->tnpc = regs->tpc + 4;
258 return;
259 }
260 } else {
261 /* The si_code was set to make clear whether
262 * this was a SEGV_MAPERR or SEGV_ACCERR fault.
263 */
264 do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
265 return;
266 }
267
268cannot_handle:
269 unhandled_fault (address, current, regs);
270}
271
272static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
273{
274 static int times;
275
276 if (times++ < 10)
277 printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
278 "64-bit TPC [%lx]\n",
279 current->comm, current->pid,
280 regs->tpc);
281 show_regs(regs);
282}
283
284asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
285{
286 enum ctx_state prev_state = exception_enter();
287 struct mm_struct *mm = current->mm;
288 struct vm_area_struct *vma;
289 unsigned int insn = 0;
290 int si_code, fault_code, fault;
291 unsigned long address, mm_rss;
292 unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
293
294 fault_code = get_thread_fault_code();
295
296 if (notify_page_fault(regs))
297 goto exit_exception;
298
299 si_code = SEGV_MAPERR;
300 address = current_thread_info()->fault_address;
301
302 if ((fault_code & FAULT_CODE_ITLB) &&
303 (fault_code & FAULT_CODE_DTLB))
304 BUG();
305
306 if (test_thread_flag(TIF_32BIT)) {
307 if (!(regs->tstate & TSTATE_PRIV)) {
308 if (unlikely((regs->tpc >> 32) != 0)) {
309 bogus_32bit_fault_tpc(regs);
310 goto intr_or_no_mm;
311 }
312 }
313 if (unlikely((address >> 32) != 0))
314 goto intr_or_no_mm;
315 }
316
317 if (regs->tstate & TSTATE_PRIV) {
318 unsigned long tpc = regs->tpc;
319
320 /* Sanity check the PC. */
321 if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
322 (tpc >= MODULES_VADDR && tpc < MODULES_END)) {
323 /* Valid, no problems... */
324 } else {
325 bad_kernel_pc(regs, address);
326 goto exit_exception;
327 }
328 } else
329 flags |= FAULT_FLAG_USER;
330
331 /*
332 * If we're in an interrupt or have no user
333 * context, we must not take the fault..
334 */
335 if (in_atomic() || !mm)
336 goto intr_or_no_mm;
337
338 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
339
340 if (!down_read_trylock(&mm->mmap_sem)) {
341 if ((regs->tstate & TSTATE_PRIV) &&
342 !search_exception_tables(regs->tpc)) {
343 insn = get_fault_insn(regs, insn);
344 goto handle_kernel_fault;
345 }
346
347retry:
348 down_read(&mm->mmap_sem);
349 }
350
351 vma = find_vma(mm, address);
352 if (!vma)
353 goto bad_area;
354
355 /* Pure DTLB misses do not tell us whether the fault causing
356 * load/store/atomic was a write or not, it only says that there
357 * was no match. So in such a case we (carefully) read the
358 * instruction to try and figure this out. It's an optimization
359 * so it's ok if we can't do this.
360 *
361 * Special hack, window spill/fill knows the exact fault type.
362 */
363 if (((fault_code &
364 (FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
365 (vma->vm_flags & VM_WRITE) != 0) {
366 insn = get_fault_insn(regs, 0);
367 if (!insn)
368 goto continue_fault;
369 /* All loads, stores and atomics have bits 30 and 31 both set
370 * in the instruction. Bit 21 is set in all stores, but we
371 * have to avoid prefetches which also have bit 21 set.
372 */
373 if ((insn & 0xc0200000) == 0xc0200000 &&
374 (insn & 0x01780000) != 0x01680000) {
375 /* Don't bother updating thread struct value,
376 * because update_mmu_cache only cares which tlb
377 * the access came from.
378 */
379 fault_code |= FAULT_CODE_WRITE;
380 }
381 }
382continue_fault:
383
384 if (vma->vm_start <= address)
385 goto good_area;
386 if (!(vma->vm_flags & VM_GROWSDOWN))
387 goto bad_area;
388 if (!(fault_code & FAULT_CODE_WRITE)) {
389 /* Non-faulting loads shouldn't expand stack. */
390 insn = get_fault_insn(regs, insn);
391 if ((insn & 0xc0800000) == 0xc0800000) {
392 unsigned char asi;
393
394 if (insn & 0x2000)
395 asi = (regs->tstate >> 24);
396 else
397 asi = (insn >> 5);
398 if ((asi & 0xf2) == 0x82)
399 goto bad_area;
400 }
401 }
402 if (expand_stack(vma, address))
403 goto bad_area;
404 /*
405 * Ok, we have a good vm_area for this memory access, so
406 * we can handle it..
407 */
408good_area:
409 si_code = SEGV_ACCERR;
410
411 /* If we took a ITLB miss on a non-executable page, catch
412 * that here.
413 */
414 if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
415 BUG_ON(address != regs->tpc);
416 BUG_ON(regs->tstate & TSTATE_PRIV);
417 goto bad_area;
418 }
419
420 if (fault_code & FAULT_CODE_WRITE) {
421 if (!(vma->vm_flags & VM_WRITE))
422 goto bad_area;
423
424 /* Spitfire has an icache which does not snoop
425 * processor stores. Later processors do...
426 */
427 if (tlb_type == spitfire &&
428 (vma->vm_flags & VM_EXEC) != 0 &&
429 vma->vm_file != NULL)
430 set_thread_fault_code(fault_code |
431 FAULT_CODE_BLKCOMMIT);
432
433 flags |= FAULT_FLAG_WRITE;
434 } else {
435 /* Allow reads even for write-only mappings */
436 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
437 goto bad_area;
438 }
439
440 fault = handle_mm_fault(mm, vma, address, flags);
441
442 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
443 goto exit_exception;
444
445 if (unlikely(fault & VM_FAULT_ERROR)) {
446 if (fault & VM_FAULT_OOM)
447 goto out_of_memory;
448 else if (fault & VM_FAULT_SIGBUS)
449 goto do_sigbus;
450 BUG();
451 }
452
453 if (flags & FAULT_FLAG_ALLOW_RETRY) {
454 if (fault & VM_FAULT_MAJOR) {
455 current->maj_flt++;
456 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
457 1, regs, address);
458 } else {
459 current->min_flt++;
460 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
461 1, regs, address);
462 }
463 if (fault & VM_FAULT_RETRY) {
464 flags &= ~FAULT_FLAG_ALLOW_RETRY;
465 flags |= FAULT_FLAG_TRIED;
466
467 /* No need to up_read(&mm->mmap_sem) as we would
468 * have already released it in __lock_page_or_retry
469 * in mm/filemap.c.
470 */
471
472 goto retry;
473 }
474 }
475 up_read(&mm->mmap_sem);
476
477 mm_rss = get_mm_rss(mm);
478#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
479 mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE));
480#endif
481 if (unlikely(mm_rss >
482 mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
483 tsb_grow(mm, MM_TSB_BASE, mm_rss);
484#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
485 mm_rss = mm->context.huge_pte_count;
486 if (unlikely(mm_rss >
487 mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
488 if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
489 tsb_grow(mm, MM_TSB_HUGE, mm_rss);
490 else
491 hugetlb_setup(regs);
492
493 }
494#endif
495exit_exception:
496 exception_exit(prev_state);
497 return;
498
499 /*
500 * Something tried to access memory that isn't in our memory map..
501 * Fix it, but check if it's kernel or user first..
502 */
503bad_area:
504 insn = get_fault_insn(regs, insn);
505 up_read(&mm->mmap_sem);
506
507handle_kernel_fault:
508 do_kernel_fault(regs, si_code, fault_code, insn, address);
509 goto exit_exception;
510
511/*
512 * We ran out of memory, or some other thing happened to us that made
513 * us unable to handle the page fault gracefully.
514 */
515out_of_memory:
516 insn = get_fault_insn(regs, insn);
517 up_read(&mm->mmap_sem);
518 if (!(regs->tstate & TSTATE_PRIV)) {
519 pagefault_out_of_memory();
520 goto exit_exception;
521 }
522 goto handle_kernel_fault;
523
524intr_or_no_mm:
525 insn = get_fault_insn(regs, 0);
526 goto handle_kernel_fault;
527
528do_sigbus:
529 insn = get_fault_insn(regs, insn);
530 up_read(&mm->mmap_sem);
531
532 /*
533 * Send a sigbus, regardless of whether we were in kernel
534 * or user mode.
535 */
536 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);
537
538 /* Kernel mode? Handle exceptions or die */
539 if (regs->tstate & TSTATE_PRIV)
540 goto handle_kernel_fault;
541}