summarylogtreecommitdiffstats
path: root/vmmon.patch
blob: bb6235c29accd39173c4c3cc002ebd43b5f8206a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
--- a/vmmon/Makefile
+++ b/vmmon/Makefile
@@ -43,7 +43,11 @@ INCLUDE      += -I$(SRCROOT)/shared
 endif
 
 
+ifdef KVERSION
+VM_UNAME = $(KVERSION)
+else
 VM_UNAME = $(shell uname -r)
+endif
 
 # Header directory for the running kernel
 ifdef LINUXINCLUDE
@@ -100,6 +104,13 @@ auto-build: $(DRIVER_KO)
 $(DRIVER): $(DRIVER_KO)
 	if [ $< -nt $@ ] || [ ! -e $@ ] ; then cp -f $< $@; fi
 
+# Use SUBDIRS on 2.x, 3.x, 4.x.  Use M on newer kernels.
+ifeq ($(filter-out 2 3 4,$(firstword $(subst ., ,$(VM_UNAME)))),)
+DIRVAR := SUBDIRS
+else
+DIRVAR := M
+endif
+
 # Pass gcc version down the chain, so we can detect if kernel attempts to use unapproved compiler
 VM_CCVER := $(VMCCVER)
 export VM_CCVER
@@ -117,7 +128,7 @@ prebuild:: ;
 postbuild:: ;
 
 $(DRIVER_KO): prebuild
-	$(MAKE) -C $(BUILD_DIR) SUBDIRS=$$PWD SRCROOT=$$PWD/$(SRCROOT) \
+	$(MAKE) -C $(BUILD_DIR) $(DIRVAR)=$$PWD SRCROOT=$$PWD/$(SRCROOT) \
 	  MODULEBUILDDIR=$(MODULEBUILDDIR) modules
 	$(MAKE) -C $$PWD SRCROOT=$$PWD/$(SRCROOT) \
 	  MODULEBUILDDIR=$(MODULEBUILDDIR) postbuild
--- a/vmmon/linux/driver.c
+++ b/vmmon/linux/driver.c
@@ -104,7 +104,9 @@ long LinuxDriver_Ioctl(struct file *filp
 
 static int LinuxDriver_Close(struct inode *inode, struct file *filp);
 static unsigned int LinuxDriverPoll(struct file *file, poll_table *wait);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 17, 0)
+static vm_fault_t LinuxDriverFault(struct vm_fault *fault);
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 static int LinuxDriverFault(struct vm_fault *fault);
 #elif defined(VMW_NOPAGE_2624)
 static int LinuxDriverFault(struct vm_area_struct *vma, struct vm_fault *fault);
@@ -115,7 +117,7 @@ static struct page *LinuxDriverNoPage(st
 #endif
 static int LinuxDriverMmap(struct file *filp, struct vm_area_struct *vma);
 
-static void LinuxDriverPollTimeout(unsigned long clientData);
+static void LinuxDriverPollTimeout(struct timer_list *clientData);
 static unsigned int LinuxDriverEstimateTSCkHz(void);
 
 static struct vm_operations_struct vmuser_mops = {
@@ -227,7 +229,7 @@ LinuxDriverEstimateTSCkHz(void)
  *----------------------------------------------------------------------
  */
 static void
-LinuxDriverEstimateTSCkHzDeferred(unsigned long data)
+LinuxDriverEstimateTSCkHzDeferred(struct timer_list *data)
 {
    LinuxDriverEstimateTSCkHz();
 }
@@ -265,9 +267,7 @@ LinuxDriverInitTSCkHz(void)
    }
 
    Vmx86_ReadTSCAndUptime(&tsckHzStartTime);
-   tscTimer.function = LinuxDriverEstimateTSCkHzDeferred;
    tscTimer.expires  = jiffies + 4 * HZ;
-   tscTimer.data     = 0;
    add_timer(&tscTimer);
 }
 
@@ -309,9 +309,13 @@ init_module(void)
     */
 
    init_waitqueue_head(&linuxState.pollQueue);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0) && !defined(timer_setup)
    init_timer(&linuxState.pollTimer);
    linuxState.pollTimer.data = 0;
-   linuxState.pollTimer.function = LinuxDriverPollTimeout;
+   linuxState.pollTimer.function = (void *)LinuxDriverPollTimeout;
+#else
+   timer_setup(&linuxState.pollTimer, LinuxDriverPollTimeout, 0);
+#endif
 
    linuxState.fastClockThread = NULL;
    linuxState.fastClockFile = NULL;
@@ -360,7 +364,13 @@ init_module(void)
        linuxState.deviceName, linuxState.major, linuxState.minor);
 
    HostIF_InitUptime();
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0) && !defined(timer_setup)
    init_timer(&tscTimer);
+   tscTimer.function = (void *)LinuxDriverEstimateTSCkHzDeferred;
+   tscTimer.data = (unsigned long)&tscTimer;
+#else
+   timer_setup(&tscTimer, LinuxDriverEstimateTSCkHzDeferred, 0);
+#endif
    LinuxDriverInitTSCkHz();
    Vmx86_InitIDList();
 
@@ -741,14 +751,12 @@ void
 LinuxDriverWakeUp(Bool selective)  // IN:
 {
    if (selective && linuxState.pollList != NULL) {
-      struct timeval tv;
       VmTimeType now;
       VMLinux *p;
       VMLinux *next;
 
       HostIF_PollListLock(1);
-      do_gettimeofday(&tv);
-      now = tv.tv_sec * 1000000ULL + tv.tv_usec;
+      now = ktime_get_ns() / NSEC_PER_USEC;
 
       for (p = linuxState.pollList; p != NULL; p = next) {
          next = p->pollForw;
@@ -815,12 +823,10 @@ LinuxDriverPoll(struct file *filp,  // I
       }
    } else {
       if (linuxState.fastClockThread && vmLinux->pollTimeoutPtr != NULL) {
-         struct timeval tv;
+         u64 now = ktime_get_ns() / NSEC_PER_USEC;
 
-         do_gettimeofday(&tv);
          poll_wait(filp, &vmLinux->pollQueue, wait);
-         vmLinux->pollTime = *vmLinux->pollTimeoutPtr +
-                                       tv.tv_sec * 1000000ULL + tv.tv_usec;
+         vmLinux->pollTime = *vmLinux->pollTimeoutPtr + now;
          if (vmLinux->pollBack == NULL) {
             HostIF_PollListLock(2);
             if (vmLinux->pollBack == NULL) {
@@ -858,7 +864,7 @@ LinuxDriverPoll(struct file *filp,  // I
  */
 
 static void
-LinuxDriverPollTimeout(unsigned long clientData)  // IN:
+LinuxDriverPollTimeout(struct timer_list *clientData)  // IN:
 {
    LinuxDriverWakeUp(FALSE);
 }
@@ -884,7 +890,12 @@ LinuxDriverPollTimeout(unsigned long cli
  */
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
-static int
+static
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 17, 0)
+vm_fault_t
+#else
+int
+#endif
 LinuxDriverFault(struct vm_fault *fault)     //IN/OUT
 #elif defined(VMW_NOPAGE_2624)
 static int LinuxDriverFault(struct vm_area_struct *vma, //IN
--- a/vmmon/linux/hostif.c
+++ b/vmmon/linux/hostif.c
@@ -68,6 +68,8 @@
 #endif
 
 #include <asm/io.h>
+#include <asm/tlbflush.h>
+#include <asm/irq_vectors.h>
 #include <asm/uaccess.h>
 #include <linux/mc146818rtc.h>
 #include <linux/capability.h>
@@ -77,6 +79,7 @@
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 #include <linux/taskstats_kern.h> // For linux/sched/signal.h without version check
 #endif
+#include <linux/eventfd.h>
 
 #include "vmware.h"
 #include "x86apic.h"
@@ -629,6 +632,15 @@ HostIF_FastClockUnlock(int callerID) //
    MutexUnlock(&fastClockMutex, callerID);
 }
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
+static int crosspage_set_exec(pte_t *pte, unsigned long addr, void *data)
+{
+	struct page *p = data;
+
+	set_pte(pte, mk_pte(p, VM_PAGE_KERNEL_EXEC));
+	return 0;
+}
+#endif
 
 /*
  *-----------------------------------------------------------------------------
@@ -695,7 +707,29 @@ HostIF_PollListUnlock(int callerID) // I
 static void *
 MapCrossPage(struct page *p)  // IN:
 {
+#if COMPAT_LINUX_VERSION_CHECK_LT(5, 8, 0)
    return vmap(&p, 1, VM_MAP, VM_PAGE_KERNEL_EXEC);
+#else
+   void *addr;
+
+   addr = vmap(&p, 1, VM_MAP, VM_PAGE_KERNEL_EXEC);
+   if (!addr)
+	   return NULL;
+
+   /* Starting with 5.8, vmap() always sets the NX bit, but the cross
+    * page needs to be executable. */
+   if (apply_to_page_range(current->mm, (unsigned long)addr, PAGE_SIZE,
+			   crosspage_set_exec, p)) {
+      vunmap(addr);
+      return NULL;
+   }
+
+   preempt_disable();
+   __flush_tlb_all();
+   preempt_enable();
+
+   return addr;
+#endif
 }
 
 
@@ -1164,16 +1198,7 @@ HostIFGetUserPages(void *uvAddr,
 {
    int retval;
 
-   down_read(&current->mm->mmap_sem);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
-   retval = get_user_pages((unsigned long)uvAddr, numPages, 0, ppages, NULL);
-#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
-   retval = get_user_pages((unsigned long)uvAddr, numPages, 0, 0, ppages, NULL);
-#else
-   retval = get_user_pages(current, current->mm, (unsigned long)uvAddr,
-                           numPages, 0, 0, ppages, NULL);
-#endif
-   up_read(&current->mm->mmap_sem);
+   retval = get_user_pages_fast((unsigned long)uvAddr, numPages, 0, ppages);
 
    return retval != numPages;
 }
@@ -1574,9 +1599,13 @@ HostIF_EstimateLockedPageLimit(const VMD
     * since at least 2.6.0.
     */
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
    extern unsigned long totalram_pages;
 
    unsigned int totalPhysicalPages = totalram_pages;
+#else
+   unsigned int totalPhysicalPages = totalram_pages();
+#endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 28)
    return MemDefaults_CalcMaxLockedPages(totalPhysicalPages);
@@ -1594,17 +1623,36 @@ HostIF_EstimateLockedPageLimit(const VMD
    unsigned int reservedPages = MEMDEFAULTS_MIN_HOST_PAGES;
    unsigned int hugePages = (vm == NULL) ? 0 :
       BYTES_2_PAGES(vm->memInfo.hugePageBytes);
-   unsigned int lockedPages = global_page_state(NR_PAGETABLE) +
-                              global_page_state(NR_SLAB_UNRECLAIMABLE) +
-                              global_page_state(NR_UNEVICTABLE) +
-                              hugePages + reservedPages;
-   unsigned int anonPages =
+   unsigned int lockedPages = hugePages + reservedPages;
+   unsigned int anonPages;
+   unsigned int swapPages = BYTES_2_PAGES(linuxState.swapSize);
+
+   /* global_page_state is global_zone_page_state in 4.14. */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 14, 0)
+   lockedPages += global_zone_page_state(NR_PAGETABLE);
+#else
+   lockedPages += global_page_state(NR_PAGETABLE);
+#endif
+   /* NR_SLAB_* moved from zone to node in 4.13. */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0)
+   lockedPages += global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B);
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 13, 0)
+   lockedPages += global_node_page_state(NR_SLAB_UNRECLAIMABLE);
+#else
+   lockedPages += global_page_state(NR_SLAB_UNRECLAIMABLE);
+#endif
+   /* NR_UNEVICTABLE moved from global to node in 4.8. */
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
-      global_page_state(NR_ANON_MAPPED);
+   lockedPages += global_node_page_state(NR_UNEVICTABLE);
 #else
-      global_page_state(NR_ANON_PAGES);
+   lockedPages += global_page_state(NR_UNEVICTABLE);
+#endif
+   /* NR_ANON_MAPPED moved & changed name in 4.8. */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
+   anonPages = global_node_page_state(NR_ANON_MAPPED);
+#else
+   anonPages = global_page_state(NR_ANON_PAGES);
 #endif
-   unsigned int swapPages = BYTES_2_PAGES(linuxState.swapSize);
 
    if (anonPages > swapPages) {
       lockedPages += anonPages - swapPages; 
@@ -1664,6 +1712,49 @@ HostIF_WaitForFreePages(unsigned int tim
 /*
  *----------------------------------------------------------------------
  *
+ * HostIFGetTime --
+ *
+ *      Reads the current time in UPTIME_FREQ units.
+ *
+ * Results:
+ *      The uptime, in units of UPTIME_FREQ.
+ *
+ * Side effects:
+ *      None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static uint64
+HostIFGetTime(void)
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
+   struct timeval tv;
+
+   do_gettimeofday(&tv);
+   return tv.tv_usec * (UPTIME_FREQ / 1000000) + tv.tv_sec * UPTIME_FREQ;
+#else
+   struct timespec64 now;
+
+   /*
+    * Use raw time used by Posix timers.  This time is not affected by
+    * NTP adjustments, so it may drift from real time and monotonic time,
+    * but it will stay in sync with other timers.
+    */
+   ktime_get_raw_ts64(&now);
+   /*
+    * UPTIME_FREQ resolution is lower than tv_nsec,
+    * so we have to do division...
+    */
+   ASSERT_ON_COMPILE(1000000000 % UPTIME_FREQ == 0);
+   return now.tv_nsec / (1000000000 / UPTIME_FREQ) + now.tv_sec * UPTIME_FREQ;
+#endif
+}
+
+
+/*
+ *----------------------------------------------------------------------
+ *
  * HostIFReadUptimeWork --
  *
  *      Reads the current uptime.  The uptime is based on getimeofday,
@@ -1692,16 +1783,12 @@ HostIF_WaitForFreePages(unsigned int tim
 static uint64
 HostIFReadUptimeWork(unsigned long *j)  // OUT: current jiffies 
 {
-   struct timeval tv;
    uint64 monotime, uptime, upBase, monoBase;
    int64 diff;
    uint32 version;
    unsigned long jifs, jifBase;
    unsigned int attempts = 0;
 
-   /* Assert that HostIF_InitUptime has been called. */
-   ASSERT(uptimeState.timer.function);
-
  retry:
    do {
       version  = VersionedAtomic_BeginTryRead(&uptimeState.version);
@@ -1710,13 +1797,12 @@ HostIFReadUptimeWork(unsigned long *j)
       monoBase = uptimeState.monotimeBase;
    } while (!VersionedAtomic_EndTryRead(&uptimeState.version, version));
 
-   do_gettimeofday(&tv);
+   uptime = HostIFGetTime();
    upBase = Atomic_Read64(&uptimeState.uptimeBase);
    
    monotime = (uint64)(jifs - jifBase) * (UPTIME_FREQ / HZ);
    monotime += monoBase;
 
-   uptime = tv.tv_usec * (UPTIME_FREQ / 1000000) + tv.tv_sec * UPTIME_FREQ;
    uptime += upBase;
    
    /* 
@@ -1767,7 +1853,7 @@ HostIFReadUptimeWork(unsigned long *j)
  */
 
 static void
-HostIFUptimeResyncMono(unsigned long data)  // IN: ignored
+HostIFUptimeResyncMono(struct timer_list *timer)  // IN: ignored
 {
    unsigned long jifs;
    uintptr_t flags;
@@ -1821,16 +1907,19 @@ HostIFUptimeResyncMono(unsigned long dat
 void
 HostIF_InitUptime(void)
 {
-   struct timeval tv;
+   uint64 tm;
 
    uptimeState.jiffiesBase = jiffies;
-   do_gettimeofday(&tv);
-   Atomic_Write64(&uptimeState.uptimeBase, 
-                  -(tv.tv_usec * (UPTIME_FREQ / 1000000) + 
-                    tv.tv_sec * UPTIME_FREQ));
+   tm = HostIFGetTime();
+   Atomic_Write64(&uptimeState.uptimeBase, -tm);
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0) && !defined(timer_setup)
    init_timer(&uptimeState.timer);
-   uptimeState.timer.function = HostIFUptimeResyncMono;
+   uptimeState.timer.function = (void *)HostIFUptimeResyncMono;
+   uptimeState.timer.data = (unsigned long)&uptimeState.timer;
+#else
+   timer_setup(&uptimeState.timer, HostIFUptimeResyncMono, 0);
+#endif
    mod_timer(&uptimeState.timer, jiffies + HZ);
 }
 
@@ -2246,16 +2335,22 @@ HostIF_VMLockIsHeld(VMDriver *vm) // IN
 static Bool
 isVAReadable(VA r)  // IN:
 {
-   mm_segment_t old_fs;
    uint32 dummy;
    int ret;
    
+#ifdef HAVE_GET_KERNEL_NOFAULT
+   ret = get_kernel_nofault(dummy, (void *)r);
+#else
+   {
+   mm_segment_t old_fs;
+ 
    old_fs = get_fs();
-   set_fs(get_ds());
+   set_fs(KERNEL_DS);
    r = APICR_TO_ADDR(r, APICR_VERSION);
    ret = HostIF_CopyFromUser(&dummy, (void*)r, sizeof(dummy));
    set_fs(old_fs);
-
+   }
+#endif
    return ret == 0;
 }
 
@@ -2284,7 +2379,7 @@ SetVMAPICAddr(VMDriver *vm, // IN/OUT: d
    volatile void *hostapic;
 
    ASSERT_ON_COMPILE(APICR_SIZE <= PAGE_SIZE);
-   hostapic = (volatile void *) ioremap_nocache(ma, PAGE_SIZE);
+   hostapic = (volatile void *) ioremap(ma, PAGE_SIZE);
    if (hostapic) {
       if ((APIC_VERSIONREG(hostapic) & 0xF0) == 0x10) {
 	 vm->hostAPIC.base = (volatile uint32 (*)[4]) hostapic;
@@ -2440,7 +2535,6 @@ HostIF_SemaphoreWait(VMDriver *vm,   //
                      uint64 *args)   // IN:
 {
    struct file *file;
-   mm_segment_t old_fs;
    int res;
    int waitFD = args[0];
    int timeoutms = args[2];
@@ -2451,9 +2545,6 @@ HostIF_SemaphoreWait(VMDriver *vm,   //
       return MX_WAITERROR;
    }
 
-   old_fs = get_fs();
-   set_fs(get_ds());
-
    {
       struct poll_wqueues table;
       unsigned int mask;
@@ -2475,9 +2566,11 @@ HostIF_SemaphoreWait(VMDriver *vm,   //
     * the code to happily deal with a pipe or an eventfd. We only care about
     * reading no bytes (EAGAIN - non blocking fd) or sizeof(uint64).
     */
-
-   res = file->f_op->read(file, (char *) &value, sizeof value, &file->f_pos);
-
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 14, 0)
+   res = kernel_read(file, file->f_pos, (char *)&value, sizeof value);
+#else
+   res = kernel_read(file, &value, sizeof value, &file->f_pos);
+#endif
    if (res == sizeof value) {
       res = MX_WAITNORMAL;
    } else {
@@ -2486,7 +2579,6 @@ HostIF_SemaphoreWait(VMDriver *vm,   //
       }
    }
 
-   set_fs(old_fs);
    fput(file);
 
    /*
@@ -2569,8 +2661,8 @@ HostIF_SemaphoreForceWakeup(VMDriver *vm
 int
 HostIF_SemaphoreSignal(uint64 *args)  // IN:
 {
+   struct eventfd_ctx *eventfd;
    struct file *file;
-   mm_segment_t old_fs;
    int res;
    int signalFD = args[1];
    uint64 value = 1;  // make an eventfd happy should it be there
@@ -2580,22 +2672,32 @@ HostIF_SemaphoreSignal(uint64 *args)  //
       return MX_WAITERROR;
    }
 
-   old_fs = get_fs();
-   set_fs(get_ds());
+   /*
+    * If it's eventfd, use specific eventfd interface as kernel writes
+    * to eventfd may not be allowed in kernel 5.10 and later.
+    */
+   eventfd = eventfd_ctx_fileget(file);
+   if (!IS_ERR(eventfd)) {
+      eventfd_signal(eventfd, 1);
+      fput(file);
+      return MX_WAITNORMAL;
+   }
 
    /*
     * Always write sizeof(uint64) bytes. This works fine for eventfd and
     * pipes. The data written is formatted to make an eventfd happy should
     * it be present.
     */
-
-   res = file->f_op->write(file, (char *) &value, sizeof value, &file->f_pos);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 14, 0)
+   res = kernel_write(file, (char *)&value, sizeof value, file->f_pos);
+#else
+   res = kernel_write(file, &value, sizeof value, &file->f_pos);
+#endif
 
    if (res == sizeof value) {
       res = MX_WAITNORMAL;
    }
 
-   set_fs(old_fs);
    fput(file);
 
    /*
@@ -3364,12 +3466,9 @@ HostIFFastClockThread(void *data)  // IN
 {
    struct file *filp = (struct file *) data;
    int res;
-   mm_segment_t oldFS;
    unsigned int rate = 0;
    unsigned int prevRate = 0;
 
-   oldFS = get_fs();
-   set_fs(KERNEL_DS);
    allow_signal(SIGKILL);
    set_user_nice(current, linuxState.fastClockPriority);
 
@@ -3403,8 +3502,6 @@ HostIFFastClockThread(void *data)  // IN
 
  out:
    LinuxDriverWakeUp(TRUE);
-   set_fs(oldFS);
-
    /*
     * Do not exit thread until we are told to do so.
     */
@@ -3524,7 +3621,6 @@ HostIF_SetFastClockRate(unsigned int rat
       }
    } else {
       if (linuxState.fastClockThread) {
-         force_sig(SIGKILL, linuxState.fastClockThread);
          kthread_stop(linuxState.fastClockThread);
 	 close_rtc(linuxState.fastClockFile, current->files);
 
@@ -3572,7 +3668,12 @@ HostIF_MapUserMem(VA addr,
 
    ASSERT(handle);
 
-   if (!access_ok(VERIFY_WRITE, p, size)) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
+   if (!access_ok(VERIFY_WRITE, p, size))
+#else
+   if (!access_ok(p, size))
+#endif
+   {
       printk(KERN_ERR "%s: Couldn't verify write to uva 0x%p with size %"
              FMTSZ"u\n", __func__, p, size);