kernel_5.10 no rt

hc

2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f

 kernel/arch/parisc/mm/fault.c
..
..
@@ -18,6 +18,7 @@
18
18
 #include <linux/extable.h>
19
19
 #include <linux/uaccess.h>
20
20
 #include <linux/hugetlb.h>
21
+#include <linux/perf_event.h>
21
22
 
22
23
 #include <asm/traps.h>
23
24
 
..
..
@@ -66,6 +67,7 @@
66
67
 	case 0x30000000: /* coproc2 */
67
68
 		if (bit22set(inst))
68
69
 			return VM_WRITE;
70
+		fallthrough;
69
71
 
70
72
 	case 0x0: /* indexed/memory management */
71
73
 		if (bit22set(inst)) {
..
..
@@ -273,15 +275,16 @@
273
275
 	if (!mm)
274
276
 		goto no_context;
275
277
 
276
-	flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
278
+	flags = FAULT_FLAG_DEFAULT;
277
279
 	if (user_mode(regs))
278
280
 		flags |= FAULT_FLAG_USER;
279
281
 
280
282
 	acc_type = parisc_acctyp(code, regs->iir);
281
283
 	if (acc_type & VM_WRITE)
282
284
 		flags |= FAULT_FLAG_WRITE;
285
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
283
286
 retry:
284
-	down_read(&mm->mmap_sem);
287
+	mmap_read_lock(mm);
285
288
 	vma = find_vma_prev(mm, address, &prev_vma);
286
289
 	if (!vma || address < vma->vm_start)
287
290
 		goto check_expansion;
..
..
@@ -301,9 +304,9 @@
301
304
 	 * fault.
302
305
 	 */
303
306
 
304
-	fault = handle_mm_fault(vma, address, flags);
307
+	fault = handle_mm_fault(vma, address, flags, regs);
305
308
 
306
-	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
309
+	if (fault_signal_pending(fault, regs))
307
310
 		return;
308
311
 
309
312
 	if (unlikely(fault & VM_FAULT_ERROR)) {
..
..
@@ -322,23 +325,17 @@
322
325
 		BUG();
323
326
 	}
324
327
 	if (flags & FAULT_FLAG_ALLOW_RETRY) {
325
-		if (fault & VM_FAULT_MAJOR)
326
-			current->maj_flt++;
327
-		else
328
-			current->min_flt++;
329
328
 		if (fault & VM_FAULT_RETRY) {
330
-			flags &= ~FAULT_FLAG_ALLOW_RETRY;
331
-
332
329
 			/*
333
-			 * No need to up_read(&mm->mmap_sem) as we would
330
+			 * No need to mmap_read_unlock(mm) as we would
334
331
 			 * have already released it in __lock_page_or_retry
335
332
 			 * in mm/filemap.c.
336
333
 			 */
337
-
334
+			flags |= FAULT_FLAG_TRIED;
338
335
 			goto retry;
339
336
 		}
340
337
 	}
341
-	up_read(&mm->mmap_sem);
338
+	mmap_read_unlock(mm);
342
339
 	return;
343
340
 
344
341
 check_expansion:
..
..
@@ -350,7 +347,7 @@
350
347
  * Something tried to access memory that isn't in our memory map..
351
348
  */
352
349
 bad_area:
353
-	up_read(&mm->mmap_sem);
350
+	mmap_read_unlock(mm);
354
351
 
355
352
 	if (user_mode(regs)) {
356
353
 		int signo, si_code;
..
..
@@ -373,7 +370,7 @@
373
370
 			}
374
371
 
375
372
 			/* probably address is outside of mapped file */
376
-			/* fall through */
373
+			fallthrough;
377
374
 		case 17:	/* NA data TLB miss / page fault */
378
375
 		case 18:	/* Unaligned access - PCXS only */
379
376
 			signo = SIGBUS;
..
..
@@ -403,13 +400,13 @@
403
400
 				lsb = PAGE_SHIFT;
404
401
 
405
402
 			force_sig_mceerr(BUS_MCEERR_AR, (void __user *) address,
406
-					 lsb, current);
403
+					 lsb);
407
404
 			return;
408
405
 		}
409
406
 #endif
410
407
 		show_signal_msg(regs, code, address, tsk, vma);
411
408
 
412
-		force_sig_fault(signo, si_code, (void __user *) address, current);
409
+		force_sig_fault(signo, si_code, (void __user *) address);
413
410
 		return;
414
411
 	}
415
412
 
..
..
@@ -422,8 +419,97 @@
422
419
 	parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);
423
420
 
424
421
   out_of_memory:
425
-	up_read(&mm->mmap_sem);
422
+	mmap_read_unlock(mm);
426
423
 	if (!user_mode(regs))
427
424
 		goto no_context;
428
425
 	pagefault_out_of_memory();
429
426
 }
427
+
428
+/* Handle non-access data TLB miss faults.
429
+ *
430
+ * For probe instructions, accesses to userspace are considered allowed
431
+ * if they lie in a valid VMA and the access type matches. We are not
432
+ * allowed to handle MM faults here so there may be situations where an
433
+ * actual access would fail even though a probe was successful.
434
+ */
435
+int
436
+handle_nadtlb_fault(struct pt_regs *regs)
437
+{
438
+	unsigned long insn = regs->iir;
439
+	int breg, treg, xreg, val = 0;
440
+	struct vm_area_struct *vma, *prev_vma;
441
+	struct task_struct *tsk;
442
+	struct mm_struct *mm;
443
+	unsigned long address;
444
+	unsigned long acc_type;
445
+
446
+	switch (insn & 0x380) {
447
+	case 0x280:
448
+		/* FDC instruction */
449
+		fallthrough;
450
+	case 0x380:
451
+		/* PDC and FIC instructions */
452
+		if (printk_ratelimit()) {
453
+			pr_warn("BUG: nullifying cache flush/purge instruction\n");
454
+			show_regs(regs);
455
+		}
456
+		if (insn & 0x20) {
457
+			/* Base modification */
458
+			breg = (insn >> 21) & 0x1f;
459
+			xreg = (insn >> 16) & 0x1f;
460
+			if (breg && xreg)
461
+				regs->gr[breg] += regs->gr[xreg];
462
+		}
463
+		regs->gr[0] |= PSW_N;
464
+		return 1;
465
+
466
+	case 0x180:
467
+		/* PROBE instruction */
468
+		treg = insn & 0x1f;
469
+		if (regs->isr) {
470
+			tsk = current;
471
+			mm = tsk->mm;
472
+			if (mm) {
473
+				/* Search for VMA */
474
+				address = regs->ior;
475
+				mmap_read_lock(mm);
476
+				vma = find_vma_prev(mm, address, &prev_vma);
477
+				mmap_read_unlock(mm);
478
+
479
+				/*
480
+				 * Check if access to the VMA is okay.
481
+				 * We don't allow for stack expansion.
482
+				 */
483
+				acc_type = (insn & 0x40) ? VM_WRITE : VM_READ;
484
+				if (vma
485
+				    && address >= vma->vm_start
486
+				    && (vma->vm_flags & acc_type) == acc_type)
487
+					val = 1;
488
+			}
489
+		}
490
+		if (treg)
491
+			regs->gr[treg] = val;
492
+		regs->gr[0] |= PSW_N;
493
+		return 1;
494
+
495
+	case 0x300:
496
+		/* LPA instruction */
497
+		if (insn & 0x20) {
498
+			/* Base modification */
499
+			breg = (insn >> 21) & 0x1f;
500
+			xreg = (insn >> 16) & 0x1f;
501
+			if (breg && xreg)
502
+				regs->gr[breg] += regs->gr[xreg];
503
+		}
504
+		treg = insn & 0x1f;
505
+		if (treg)
506
+			regs->gr[treg] = 0;
507
+		regs->gr[0] |= PSW_N;
508
+		return 1;
509
+
510
+	default:
511
+		break;
512
+	}
513
+
514
+	return 0;
515
+}