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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/openprom.h>
31#include <asm/oplib.h>
32#include <asm/asi.h>
33#include <asm/lsu.h>
34#include <asm/sections.h>
35#include <asm/mmu_context.h>
36#include <asm/setup.h>
37
38int show_unhandled_signals = 1;
39
40static void __kprobes unhandled_fault(unsigned long address,
41 struct task_struct *tsk,
42 struct pt_regs *regs)
43{
44 if ((unsigned long) address < PAGE_SIZE) {
45 printk(KERN_ALERT "Unable to handle kernel NULL "
46 "pointer dereference\n");
47 } else {
48 printk(KERN_ALERT "Unable to handle kernel paging request "
49 "at virtual address %016lx\n", (unsigned long)address);
50 }
51 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
52 (tsk->mm ?
53 CTX_HWBITS(tsk->mm->context) :
54 CTX_HWBITS(tsk->active_mm->context)));
55 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
56 (tsk->mm ? (unsigned long) tsk->mm->pgd :
57 (unsigned long) tsk->active_mm->pgd));
58 die_if_kernel("Oops", regs);
59}
60
61static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
62{
63 printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
64 regs->tpc);
65 printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
66 printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
67 printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
68 dump_stack();
69 unhandled_fault(regs->tpc, current, regs);
70}
71
72/*
73 * We now make sure that mmap_lock is held in all paths that call
74 * this. Additionally, to prevent kswapd from ripping ptes from
75 * under us, raise interrupts around the time that we look at the
76 * pte, kswapd will have to wait to get his smp ipi response from
77 * us. vmtruncate likewise. This saves us having to get pte lock.
78 */
79static unsigned int get_user_insn(unsigned long tpc)
80{
81 pgd_t *pgdp = pgd_offset(current->mm, tpc);
82 p4d_t *p4dp;
83 pud_t *pudp;
84 pmd_t *pmdp;
85 pte_t *ptep, pte;
86 unsigned long pa;
87 u32 insn = 0;
88
89 if (pgd_none(*pgdp) || unlikely(pgd_bad(*pgdp)))
90 goto out;
91 p4dp = p4d_offset(pgdp, tpc);
92 if (p4d_none(*p4dp) || unlikely(p4d_bad(*p4dp)))
93 goto out;
94 pudp = pud_offset(p4dp, tpc);
95 if (pud_none(*pudp) || unlikely(pud_bad(*pudp)))
96 goto out;
97
98 /* This disables preemption for us as well. */
99 local_irq_disable();
100
101 pmdp = pmd_offset(pudp, tpc);
102 if (pmd_none(*pmdp) || unlikely(pmd_bad(*pmdp)))
103 goto out_irq_enable;
104
105#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
106 if (is_hugetlb_pmd(*pmdp)) {
107 pa = pmd_pfn(*pmdp) << PAGE_SHIFT;
108 pa += tpc & ~HPAGE_MASK;
109
110 /* Use phys bypass so we don't pollute dtlb/dcache. */
111 __asm__ __volatile__("lduwa [%1] %2, %0"
112 : "=r" (insn)
113 : "r" (pa), "i" (ASI_PHYS_USE_EC));
114 } else
115#endif
116 {
117 ptep = pte_offset_map(pmdp, tpc);
118 pte = *ptep;
119 if (pte_present(pte)) {
120 pa = (pte_pfn(pte) << PAGE_SHIFT);
121 pa += (tpc & ~PAGE_MASK);
122
123 /* Use phys bypass so we don't pollute dtlb/dcache. */
124 __asm__ __volatile__("lduwa [%1] %2, %0"
125 : "=r" (insn)
126 : "r" (pa), "i" (ASI_PHYS_USE_EC));
127 }
128 pte_unmap(ptep);
129 }
130out_irq_enable:
131 local_irq_enable();
132out:
133 return insn;
134}
135
136static inline void
137show_signal_msg(struct pt_regs *regs, int sig, int code,
138 unsigned long address, struct task_struct *tsk)
139{
140 if (!unhandled_signal(tsk, sig))
141 return;
142
143 if (!printk_ratelimit())
144 return;
145
146 printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
147 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
148 tsk->comm, task_pid_nr(tsk), address,
149 (void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
150 (void *)regs->u_regs[UREG_FP], code);
151
152 print_vma_addr(KERN_CONT " in ", regs->tpc);
153
154 printk(KERN_CONT "\n");
155}
156
157static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
158 unsigned long fault_addr, unsigned int insn,
159 int fault_code)
160{
161 unsigned long addr;
162
163 if (fault_code & FAULT_CODE_ITLB) {
164 addr = regs->tpc;
165 } else {
166 /* If we were able to probe the faulting instruction, use it
167 * to compute a precise fault address. Otherwise use the fault
168 * time provided address which may only have page granularity.
169 */
170 if (insn)
171 addr = compute_effective_address(regs, insn, 0);
172 else
173 addr = fault_addr;
174 }
175
176 if (unlikely(show_unhandled_signals))
177 show_signal_msg(regs, sig, code, addr, current);
178
179 force_sig_fault(sig, code, (void __user *) addr);
180}
181
182static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
183{
184 if (!insn) {
185 if (!regs->tpc || (regs->tpc & 0x3))
186 return 0;
187 if (regs->tstate & TSTATE_PRIV) {
188 insn = *(unsigned int *) regs->tpc;
189 } else {
190 insn = get_user_insn(regs->tpc);
191 }
192 }
193 return insn;
194}
195
196static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
197 int fault_code, unsigned int insn,
198 unsigned long address)
199{
200 unsigned char asi = ASI_P;
201
202 if ((!insn) && (regs->tstate & TSTATE_PRIV))
203 goto cannot_handle;
204
205 /* If user insn could be read (thus insn is zero), that
206 * is fine. We will just gun down the process with a signal
207 * in that case.
208 */
209
210 if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
211 (insn & 0xc0800000) == 0xc0800000) {
212 if (insn & 0x2000)
213 asi = (regs->tstate >> 24);
214 else
215 asi = (insn >> 5);
216 if ((asi & 0xf2) == 0x82) {
217 if (insn & 0x1000000) {
218 handle_ldf_stq(insn, regs);
219 } else {
220 /* This was a non-faulting load. Just clear the
221 * destination register(s) and continue with the next
222 * instruction. -jj
223 */
224 handle_ld_nf(insn, regs);
225 }
226 return;
227 }
228 }
229
230 /* Is this in ex_table? */
231 if (regs->tstate & TSTATE_PRIV) {
232 const struct exception_table_entry *entry;
233
234 entry = search_exception_tables(regs->tpc);
235 if (entry) {
236 regs->tpc = entry->fixup;
237 regs->tnpc = regs->tpc + 4;
238 return;
239 }
240 } else {
241 /* The si_code was set to make clear whether
242 * this was a SEGV_MAPERR or SEGV_ACCERR fault.
243 */
244 do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
245 return;
246 }
247
248cannot_handle:
249 unhandled_fault (address, current, regs);
250}
251
252static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
253{
254 static int times;
255
256 if (times++ < 10)
257 printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
258 "64-bit TPC [%lx]\n",
259 current->comm, current->pid,
260 regs->tpc);
261 show_regs(regs);
262}
263
264asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
265{
266 enum ctx_state prev_state = exception_enter();
267 struct mm_struct *mm = current->mm;
268 struct vm_area_struct *vma;
269 unsigned int insn = 0;
270 int si_code, fault_code;
271 vm_fault_t fault;
272 unsigned long address, mm_rss;
273 unsigned int flags = FAULT_FLAG_DEFAULT;
274
275 fault_code = get_thread_fault_code();
276
277 if (kprobe_page_fault(regs, 0))
278 goto exit_exception;
279
280 si_code = SEGV_MAPERR;
281 address = current_thread_info()->fault_address;
282
283 if ((fault_code & FAULT_CODE_ITLB) &&
284 (fault_code & FAULT_CODE_DTLB))
285 BUG();
286
287 if (test_thread_flag(TIF_32BIT)) {
288 if (!(regs->tstate & TSTATE_PRIV)) {
289 if (unlikely((regs->tpc >> 32) != 0)) {
290 bogus_32bit_fault_tpc(regs);
291 goto intr_or_no_mm;
292 }
293 }
294 if (unlikely((address >> 32) != 0))
295 goto intr_or_no_mm;
296 }
297
298 if (regs->tstate & TSTATE_PRIV) {
299 unsigned long tpc = regs->tpc;
300
301 /* Sanity check the PC. */
302 if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
303 (tpc >= MODULES_VADDR && tpc < MODULES_END)) {
304 /* Valid, no problems... */
305 } else {
306 bad_kernel_pc(regs, address);
307 goto exit_exception;
308 }
309 } else
310 flags |= FAULT_FLAG_USER;
311
312 /*
313 * If we're in an interrupt or have no user
314 * context, we must not take the fault..
315 */
316 if (faulthandler_disabled() || !mm)
317 goto intr_or_no_mm;
318
319 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
320
321 if (!mmap_read_trylock(mm)) {
322 if ((regs->tstate & TSTATE_PRIV) &&
323 !search_exception_tables(regs->tpc)) {
324 insn = get_fault_insn(regs, insn);
325 goto handle_kernel_fault;
326 }
327
328retry:
329 mmap_read_lock(mm);
330 }
331
332 if (fault_code & FAULT_CODE_BAD_RA)
333 goto do_sigbus;
334
335 vma = find_vma(mm, address);
336 if (!vma)
337 goto bad_area;
338
339 /* Pure DTLB misses do not tell us whether the fault causing
340 * load/store/atomic was a write or not, it only says that there
341 * was no match. So in such a case we (carefully) read the
342 * instruction to try and figure this out. It's an optimization
343 * so it's ok if we can't do this.
344 *
345 * Special hack, window spill/fill knows the exact fault type.
346 */
347 if (((fault_code &
348 (FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
349 (vma->vm_flags & VM_WRITE) != 0) {
350 insn = get_fault_insn(regs, 0);
351 if (!insn)
352 goto continue_fault;
353 /* All loads, stores and atomics have bits 30 and 31 both set
354 * in the instruction. Bit 21 is set in all stores, but we
355 * have to avoid prefetches which also have bit 21 set.
356 */
357 if ((insn & 0xc0200000) == 0xc0200000 &&
358 (insn & 0x01780000) != 0x01680000) {
359 /* Don't bother updating thread struct value,
360 * because update_mmu_cache only cares which tlb
361 * the access came from.
362 */
363 fault_code |= FAULT_CODE_WRITE;
364 }
365 }
366continue_fault:
367
368 if (vma->vm_start <= address)
369 goto good_area;
370 if (!(vma->vm_flags & VM_GROWSDOWN))
371 goto bad_area;
372 if (!(fault_code & FAULT_CODE_WRITE)) {
373 /* Non-faulting loads shouldn't expand stack. */
374 insn = get_fault_insn(regs, insn);
375 if ((insn & 0xc0800000) == 0xc0800000) {
376 unsigned char asi;
377
378 if (insn & 0x2000)
379 asi = (regs->tstate >> 24);
380 else
381 asi = (insn >> 5);
382 if ((asi & 0xf2) == 0x82)
383 goto bad_area;
384 }
385 }
386 if (expand_stack(vma, address))
387 goto bad_area;
388 /*
389 * Ok, we have a good vm_area for this memory access, so
390 * we can handle it..
391 */
392good_area:
393 si_code = SEGV_ACCERR;
394
395 /* If we took a ITLB miss on a non-executable page, catch
396 * that here.
397 */
398 if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
399 WARN(address != regs->tpc,
400 "address (%lx) != regs->tpc (%lx)\n", address, regs->tpc);
401 WARN_ON(regs->tstate & TSTATE_PRIV);
402 goto bad_area;
403 }
404
405 if (fault_code & FAULT_CODE_WRITE) {
406 if (!(vma->vm_flags & VM_WRITE))
407 goto bad_area;
408
409 /* Spitfire has an icache which does not snoop
410 * processor stores. Later processors do...
411 */
412 if (tlb_type == spitfire &&
413 (vma->vm_flags & VM_EXEC) != 0 &&
414 vma->vm_file != NULL)
415 set_thread_fault_code(fault_code |
416 FAULT_CODE_BLKCOMMIT);
417
418 flags |= FAULT_FLAG_WRITE;
419 } else {
420 /* Allow reads even for write-only mappings */
421 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
422 goto bad_area;
423 }
424
425 fault = handle_mm_fault(vma, address, flags, regs);
426
427 if (fault_signal_pending(fault, regs))
428 goto exit_exception;
429
430 /* The fault is fully completed (including releasing mmap lock) */
431 if (fault & VM_FAULT_COMPLETED)
432 goto lock_released;
433
434 if (unlikely(fault & VM_FAULT_ERROR)) {
435 if (fault & VM_FAULT_OOM)
436 goto out_of_memory;
437 else if (fault & VM_FAULT_SIGSEGV)
438 goto bad_area;
439 else if (fault & VM_FAULT_SIGBUS)
440 goto do_sigbus;
441 BUG();
442 }
443
444 if (fault & VM_FAULT_RETRY) {
445 flags |= FAULT_FLAG_TRIED;
446
447 /* No need to mmap_read_unlock(mm) as we would
448 * have already released it in __lock_page_or_retry
449 * in mm/filemap.c.
450 */
451
452 goto retry;
453 }
454 mmap_read_unlock(mm);
455
456lock_released:
457 mm_rss = get_mm_rss(mm);
458#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
459 mm_rss -= (mm->context.thp_pte_count * (HPAGE_SIZE / PAGE_SIZE));
460#endif
461 if (unlikely(mm_rss >
462 mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
463 tsb_grow(mm, MM_TSB_BASE, mm_rss);
464#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
465 mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
466 mm_rss *= REAL_HPAGE_PER_HPAGE;
467 if (unlikely(mm_rss >
468 mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
469 if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
470 tsb_grow(mm, MM_TSB_HUGE, mm_rss);
471 else
472 hugetlb_setup(regs);
473
474 }
475#endif
476exit_exception:
477 exception_exit(prev_state);
478 return;
479
480 /*
481 * Something tried to access memory that isn't in our memory map..
482 * Fix it, but check if it's kernel or user first..
483 */
484bad_area:
485 insn = get_fault_insn(regs, insn);
486 mmap_read_unlock(mm);
487
488handle_kernel_fault:
489 do_kernel_fault(regs, si_code, fault_code, insn, address);
490 goto exit_exception;
491
492/*
493 * We ran out of memory, or some other thing happened to us that made
494 * us unable to handle the page fault gracefully.
495 */
496out_of_memory:
497 insn = get_fault_insn(regs, insn);
498 mmap_read_unlock(mm);
499 if (!(regs->tstate & TSTATE_PRIV)) {
500 pagefault_out_of_memory();
501 goto exit_exception;
502 }
503 goto handle_kernel_fault;
504
505intr_or_no_mm:
506 insn = get_fault_insn(regs, 0);
507 goto handle_kernel_fault;
508
509do_sigbus:
510 insn = get_fault_insn(regs, insn);
511 mmap_read_unlock(mm);
512
513 /*
514 * Send a sigbus, regardless of whether we were in kernel
515 * or user mode.
516 */
517 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);
518
519 /* Kernel mode? Handle exceptions or die */
520 if (regs->tstate & TSTATE_PRIV)
521 goto handle_kernel_fault;
522}
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#include <linux/uaccess.h>
26
27#include <asm/page.h>
28#include <asm/pgtable.h>
29#include <asm/openprom.h>
30#include <asm/oplib.h>
31#include <asm/asi.h>
32#include <asm/lsu.h>
33#include <asm/sections.h>
34#include <asm/mmu_context.h>
35#include <asm/setup.h>
36
37int show_unhandled_signals = 1;
38
39static inline __kprobes int notify_page_fault(struct pt_regs *regs)
40{
41 int ret = 0;
42
43 /* kprobe_running() needs smp_processor_id() */
44 if (kprobes_built_in() && !user_mode(regs)) {
45 preempt_disable();
46 if (kprobe_running() && kprobe_fault_handler(regs, 0))
47 ret = 1;
48 preempt_enable();
49 }
50 return ret;
51}
52
53static void __kprobes unhandled_fault(unsigned long address,
54 struct task_struct *tsk,
55 struct pt_regs *regs)
56{
57 if ((unsigned long) address < PAGE_SIZE) {
58 printk(KERN_ALERT "Unable to handle kernel NULL "
59 "pointer dereference\n");
60 } else {
61 printk(KERN_ALERT "Unable to handle kernel paging request "
62 "at virtual address %016lx\n", (unsigned long)address);
63 }
64 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
65 (tsk->mm ?
66 CTX_HWBITS(tsk->mm->context) :
67 CTX_HWBITS(tsk->active_mm->context)));
68 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
69 (tsk->mm ? (unsigned long) tsk->mm->pgd :
70 (unsigned long) tsk->active_mm->pgd));
71 die_if_kernel("Oops", regs);
72}
73
74static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
75{
76 printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
77 regs->tpc);
78 printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
79 printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
80 printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
81 dump_stack();
82 unhandled_fault(regs->tpc, current, regs);
83}
84
85/*
86 * We now make sure that mmap_sem is held in all paths that call
87 * this. Additionally, to prevent kswapd from ripping ptes from
88 * under us, raise interrupts around the time that we look at the
89 * pte, kswapd will have to wait to get his smp ipi response from
90 * us. vmtruncate likewise. This saves us having to get pte lock.
91 */
92static unsigned int get_user_insn(unsigned long tpc)
93{
94 pgd_t *pgdp = pgd_offset(current->mm, tpc);
95 pud_t *pudp;
96 pmd_t *pmdp;
97 pte_t *ptep, pte;
98 unsigned long pa;
99 u32 insn = 0;
100
101 if (pgd_none(*pgdp) || unlikely(pgd_bad(*pgdp)))
102 goto out;
103 pudp = pud_offset(pgdp, tpc);
104 if (pud_none(*pudp) || unlikely(pud_bad(*pudp)))
105 goto out;
106
107 /* This disables preemption for us as well. */
108 local_irq_disable();
109
110 pmdp = pmd_offset(pudp, tpc);
111 if (pmd_none(*pmdp) || unlikely(pmd_bad(*pmdp)))
112 goto out_irq_enable;
113
114#ifdef CONFIG_TRANSPARENT_HUGEPAGE
115 if (pmd_trans_huge(*pmdp)) {
116 pa = pmd_pfn(*pmdp) << PAGE_SHIFT;
117 pa += tpc & ~HPAGE_MASK;
118
119 /* Use phys bypass so we don't pollute dtlb/dcache. */
120 __asm__ __volatile__("lduwa [%1] %2, %0"
121 : "=r" (insn)
122 : "r" (pa), "i" (ASI_PHYS_USE_EC));
123 } else
124#endif
125 {
126 ptep = pte_offset_map(pmdp, tpc);
127 pte = *ptep;
128 if (pte_present(pte)) {
129 pa = (pte_pfn(pte) << PAGE_SHIFT);
130 pa += (tpc & ~PAGE_MASK);
131
132 /* Use phys bypass so we don't pollute dtlb/dcache. */
133 __asm__ __volatile__("lduwa [%1] %2, %0"
134 : "=r" (insn)
135 : "r" (pa), "i" (ASI_PHYS_USE_EC));
136 }
137 pte_unmap(ptep);
138 }
139out_irq_enable:
140 local_irq_enable();
141out:
142 return insn;
143}
144
145static inline void
146show_signal_msg(struct pt_regs *regs, int sig, int code,
147 unsigned long address, struct task_struct *tsk)
148{
149 if (!unhandled_signal(tsk, sig))
150 return;
151
152 if (!printk_ratelimit())
153 return;
154
155 printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
156 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
157 tsk->comm, task_pid_nr(tsk), address,
158 (void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
159 (void *)regs->u_regs[UREG_FP], code);
160
161 print_vma_addr(KERN_CONT " in ", regs->tpc);
162
163 printk(KERN_CONT "\n");
164}
165
166static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
167 unsigned long fault_addr, unsigned int insn,
168 int fault_code)
169{
170 unsigned long addr;
171 siginfo_t info;
172
173 info.si_code = code;
174 info.si_signo = sig;
175 info.si_errno = 0;
176 if (fault_code & FAULT_CODE_ITLB) {
177 addr = regs->tpc;
178 } else {
179 /* If we were able to probe the faulting instruction, use it
180 * to compute a precise fault address. Otherwise use the fault
181 * time provided address which may only have page granularity.
182 */
183 if (insn)
184 addr = compute_effective_address(regs, insn, 0);
185 else
186 addr = fault_addr;
187 }
188 info.si_addr = (void __user *) addr;
189 info.si_trapno = 0;
190
191 if (unlikely(show_unhandled_signals))
192 show_signal_msg(regs, sig, code, addr, current);
193
194 force_sig_info(sig, &info, current);
195}
196
197static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
198{
199 if (!insn) {
200 if (!regs->tpc || (regs->tpc & 0x3))
201 return 0;
202 if (regs->tstate & TSTATE_PRIV) {
203 insn = *(unsigned int *) regs->tpc;
204 } else {
205 insn = get_user_insn(regs->tpc);
206 }
207 }
208 return insn;
209}
210
211static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
212 int fault_code, unsigned int insn,
213 unsigned long address)
214{
215 unsigned char asi = ASI_P;
216
217 if ((!insn) && (regs->tstate & TSTATE_PRIV))
218 goto cannot_handle;
219
220 /* If user insn could be read (thus insn is zero), that
221 * is fine. We will just gun down the process with a signal
222 * in that case.
223 */
224
225 if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
226 (insn & 0xc0800000) == 0xc0800000) {
227 if (insn & 0x2000)
228 asi = (regs->tstate >> 24);
229 else
230 asi = (insn >> 5);
231 if ((asi & 0xf2) == 0x82) {
232 if (insn & 0x1000000) {
233 handle_ldf_stq(insn, regs);
234 } else {
235 /* This was a non-faulting load. Just clear the
236 * destination register(s) and continue with the next
237 * instruction. -jj
238 */
239 handle_ld_nf(insn, regs);
240 }
241 return;
242 }
243 }
244
245 /* Is this in ex_table? */
246 if (regs->tstate & TSTATE_PRIV) {
247 const struct exception_table_entry *entry;
248
249 entry = search_exception_tables(regs->tpc);
250 if (entry) {
251 regs->tpc = entry->fixup;
252 regs->tnpc = regs->tpc + 4;
253 return;
254 }
255 } else {
256 /* The si_code was set to make clear whether
257 * this was a SEGV_MAPERR or SEGV_ACCERR fault.
258 */
259 do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
260 return;
261 }
262
263cannot_handle:
264 unhandled_fault (address, current, regs);
265}
266
267static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
268{
269 static int times;
270
271 if (times++ < 10)
272 printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
273 "64-bit TPC [%lx]\n",
274 current->comm, current->pid,
275 regs->tpc);
276 show_regs(regs);
277}
278
279asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
280{
281 enum ctx_state prev_state = exception_enter();
282 struct mm_struct *mm = current->mm;
283 struct vm_area_struct *vma;
284 unsigned int insn = 0;
285 int si_code, fault_code, fault;
286 unsigned long address, mm_rss;
287 unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
288
289 fault_code = get_thread_fault_code();
290
291 if (notify_page_fault(regs))
292 goto exit_exception;
293
294 si_code = SEGV_MAPERR;
295 address = current_thread_info()->fault_address;
296
297 if ((fault_code & FAULT_CODE_ITLB) &&
298 (fault_code & FAULT_CODE_DTLB))
299 BUG();
300
301 if (test_thread_flag(TIF_32BIT)) {
302 if (!(regs->tstate & TSTATE_PRIV)) {
303 if (unlikely((regs->tpc >> 32) != 0)) {
304 bogus_32bit_fault_tpc(regs);
305 goto intr_or_no_mm;
306 }
307 }
308 if (unlikely((address >> 32) != 0))
309 goto intr_or_no_mm;
310 }
311
312 if (regs->tstate & TSTATE_PRIV) {
313 unsigned long tpc = regs->tpc;
314
315 /* Sanity check the PC. */
316 if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
317 (tpc >= MODULES_VADDR && tpc < MODULES_END)) {
318 /* Valid, no problems... */
319 } else {
320 bad_kernel_pc(regs, address);
321 goto exit_exception;
322 }
323 } else
324 flags |= FAULT_FLAG_USER;
325
326 /*
327 * If we're in an interrupt or have no user
328 * context, we must not take the fault..
329 */
330 if (faulthandler_disabled() || !mm)
331 goto intr_or_no_mm;
332
333 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
334
335 if (!down_read_trylock(&mm->mmap_sem)) {
336 if ((regs->tstate & TSTATE_PRIV) &&
337 !search_exception_tables(regs->tpc)) {
338 insn = get_fault_insn(regs, insn);
339 goto handle_kernel_fault;
340 }
341
342retry:
343 down_read(&mm->mmap_sem);
344 }
345
346 if (fault_code & FAULT_CODE_BAD_RA)
347 goto do_sigbus;
348
349 vma = find_vma(mm, address);
350 if (!vma)
351 goto bad_area;
352
353 /* Pure DTLB misses do not tell us whether the fault causing
354 * load/store/atomic was a write or not, it only says that there
355 * was no match. So in such a case we (carefully) read the
356 * instruction to try and figure this out. It's an optimization
357 * so it's ok if we can't do this.
358 *
359 * Special hack, window spill/fill knows the exact fault type.
360 */
361 if (((fault_code &
362 (FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
363 (vma->vm_flags & VM_WRITE) != 0) {
364 insn = get_fault_insn(regs, 0);
365 if (!insn)
366 goto continue_fault;
367 /* All loads, stores and atomics have bits 30 and 31 both set
368 * in the instruction. Bit 21 is set in all stores, but we
369 * have to avoid prefetches which also have bit 21 set.
370 */
371 if ((insn & 0xc0200000) == 0xc0200000 &&
372 (insn & 0x01780000) != 0x01680000) {
373 /* Don't bother updating thread struct value,
374 * because update_mmu_cache only cares which tlb
375 * the access came from.
376 */
377 fault_code |= FAULT_CODE_WRITE;
378 }
379 }
380continue_fault:
381
382 if (vma->vm_start <= address)
383 goto good_area;
384 if (!(vma->vm_flags & VM_GROWSDOWN))
385 goto bad_area;
386 if (!(fault_code & FAULT_CODE_WRITE)) {
387 /* Non-faulting loads shouldn't expand stack. */
388 insn = get_fault_insn(regs, insn);
389 if ((insn & 0xc0800000) == 0xc0800000) {
390 unsigned char asi;
391
392 if (insn & 0x2000)
393 asi = (regs->tstate >> 24);
394 else
395 asi = (insn >> 5);
396 if ((asi & 0xf2) == 0x82)
397 goto bad_area;
398 }
399 }
400 if (expand_stack(vma, address))
401 goto bad_area;
402 /*
403 * Ok, we have a good vm_area for this memory access, so
404 * we can handle it..
405 */
406good_area:
407 si_code = SEGV_ACCERR;
408
409 /* If we took a ITLB miss on a non-executable page, catch
410 * that here.
411 */
412 if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
413 WARN(address != regs->tpc,
414 "address (%lx) != regs->tpc (%lx)\n", address, regs->tpc);
415 WARN_ON(regs->tstate & TSTATE_PRIV);
416 goto bad_area;
417 }
418
419 if (fault_code & FAULT_CODE_WRITE) {
420 if (!(vma->vm_flags & VM_WRITE))
421 goto bad_area;
422
423 /* Spitfire has an icache which does not snoop
424 * processor stores. Later processors do...
425 */
426 if (tlb_type == spitfire &&
427 (vma->vm_flags & VM_EXEC) != 0 &&
428 vma->vm_file != NULL)
429 set_thread_fault_code(fault_code |
430 FAULT_CODE_BLKCOMMIT);
431
432 flags |= FAULT_FLAG_WRITE;
433 } else {
434 /* Allow reads even for write-only mappings */
435 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
436 goto bad_area;
437 }
438
439 fault = handle_mm_fault(mm, vma, address, flags);
440
441 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
442 goto exit_exception;
443
444 if (unlikely(fault & VM_FAULT_ERROR)) {
445 if (fault & VM_FAULT_OOM)
446 goto out_of_memory;
447 else if (fault & VM_FAULT_SIGSEGV)
448 goto bad_area;
449 else if (fault & VM_FAULT_SIGBUS)
450 goto do_sigbus;
451 BUG();
452 }
453
454 if (flags & FAULT_FLAG_ALLOW_RETRY) {
455 if (fault & VM_FAULT_MAJOR) {
456 current->maj_flt++;
457 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
458 1, regs, address);
459 } else {
460 current->min_flt++;
461 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
462 1, regs, address);
463 }
464 if (fault & VM_FAULT_RETRY) {
465 flags &= ~FAULT_FLAG_ALLOW_RETRY;
466 flags |= FAULT_FLAG_TRIED;
467
468 /* No need to up_read(&mm->mmap_sem) as we would
469 * have already released it in __lock_page_or_retry
470 * in mm/filemap.c.
471 */
472
473 goto retry;
474 }
475 }
476 up_read(&mm->mmap_sem);
477
478 mm_rss = get_mm_rss(mm);
479#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
480 mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE));
481#endif
482 if (unlikely(mm_rss >
483 mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
484 tsb_grow(mm, MM_TSB_BASE, mm_rss);
485#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
486 mm_rss = mm->context.huge_pte_count;
487 if (unlikely(mm_rss >
488 mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
489 if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
490 tsb_grow(mm, MM_TSB_HUGE, mm_rss);
491 else
492 hugetlb_setup(regs);
493
494 }
495#endif
496exit_exception:
497 exception_exit(prev_state);
498 return;
499
500 /*
501 * Something tried to access memory that isn't in our memory map..
502 * Fix it, but check if it's kernel or user first..
503 */
504bad_area:
505 insn = get_fault_insn(regs, insn);
506 up_read(&mm->mmap_sem);
507
508handle_kernel_fault:
509 do_kernel_fault(regs, si_code, fault_code, insn, address);
510 goto exit_exception;
511
512/*
513 * We ran out of memory, or some other thing happened to us that made
514 * us unable to handle the page fault gracefully.
515 */
516out_of_memory:
517 insn = get_fault_insn(regs, insn);
518 up_read(&mm->mmap_sem);
519 if (!(regs->tstate & TSTATE_PRIV)) {
520 pagefault_out_of_memory();
521 goto exit_exception;
522 }
523 goto handle_kernel_fault;
524
525intr_or_no_mm:
526 insn = get_fault_insn(regs, 0);
527 goto handle_kernel_fault;
528
529do_sigbus:
530 insn = get_fault_insn(regs, insn);
531 up_read(&mm->mmap_sem);
532
533 /*
534 * Send a sigbus, regardless of whether we were in kernel
535 * or user mode.
536 */
537 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);
538
539 /* Kernel mode? Handle exceptions or die */
540 if (regs->tstate & TSTATE_PRIV)
541 goto handle_kernel_fault;
542}