[NTOSKRNL] Drop the MmPagingFile spin lock in favor of a guarded mutex

This commit is contained in:
Pierre Schweitzer 2018-08-16 12:39:24 +02:00
parent 891a6eeeb9
commit 315867d4ff
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GPG key ID: 7545556C3D585B0B

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@ -44,7 +44,7 @@
PMMPAGING_FILE MmPagingFile[MAX_PAGING_FILES];
/* Lock for examining the list of paging files */
static KSPIN_LOCK PagingFileListLock;
KGUARDED_MUTEX MmPageFileCreationLock;
/* Number of paging files */
ULONG MmNumberOfPagingFiles;
@ -258,7 +258,7 @@ MmInitPagingFile(VOID)
{
ULONG i;
KeInitializeSpinLock(&PagingFileListLock);
KeInitializeGuardedMutex(&MmPageFileCreationLock);
MiFreeSwapPages = 0;
MiUsedSwapPages = 0;
@ -277,13 +277,12 @@ MmFreeSwapPage(SWAPENTRY Entry)
{
ULONG i;
ULONG_PTR off;
KIRQL oldIrql;
PMMPAGING_FILE PagingFile;
i = FILE_FROM_ENTRY(Entry);
off = OFFSET_FROM_ENTRY(Entry) - 1;
KeAcquireSpinLock(&PagingFileListLock, &oldIrql);
KeAcquireGuardedMutex(&MmPageFileCreationLock);
PagingFile = MmPagingFile[i];
if (PagingFile == NULL)
@ -299,23 +298,22 @@ MmFreeSwapPage(SWAPENTRY Entry)
MiFreeSwapPages++;
MiUsedSwapPages--;
KeReleaseSpinLock(&PagingFileListLock, oldIrql);
KeReleaseGuardedMutex(&MmPageFileCreationLock);
}
SWAPENTRY
NTAPI
MmAllocSwapPage(VOID)
{
KIRQL oldIrql;
ULONG i;
ULONG off;
SWAPENTRY entry;
KeAcquireSpinLock(&PagingFileListLock, &oldIrql);
KeAcquireGuardedMutex(&MmPageFileCreationLock);
if (MiFreeSwapPages == 0)
{
KeReleaseSpinLock(&PagingFileListLock, oldIrql);
KeReleaseGuardedMutex(&MmPageFileCreationLock);
return(0);
}
@ -328,19 +326,19 @@ MmAllocSwapPage(VOID)
if (off == 0xFFFFFFFF)
{
KeBugCheck(MEMORY_MANAGEMENT);
KeReleaseSpinLock(&PagingFileListLock, oldIrql);
KeReleaseGuardedMutex(&MmPageFileCreationLock);
return(STATUS_UNSUCCESSFUL);
}
MiUsedSwapPages++;
MiFreeSwapPages--;
KeReleaseSpinLock(&PagingFileListLock, oldIrql);
KeReleaseGuardedMutex(&MmPageFileCreationLock);
entry = ENTRY_FROM_FILE_OFFSET(i, off + 1);
return(entry);
}
}
KeReleaseSpinLock(&PagingFileListLock, oldIrql);
KeReleaseGuardedMutex(&MmPageFileCreationLock);
KeBugCheck(MEMORY_MANAGEMENT);
return(0);
}
@ -357,7 +355,6 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
IO_STATUS_BLOCK IoStatus;
PFILE_OBJECT FileObject;
PMMPAGING_FILE PagingFile;
KIRQL oldIrql;
ULONG AllocMapSize;
ULONG Count;
KPROCESSOR_MODE PreviousMode;
@ -371,6 +368,8 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
DPRINT("NtCreatePagingFile(FileName %wZ, InitialSize %I64d)\n",
FileName, InitialSize->QuadPart);
PAGED_CODE();
if (MmNumberOfPagingFiles >= MAX_PAGING_FILES)
{
return STATUS_TOO_MANY_PAGING_FILES;
@ -602,6 +601,11 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
/* Find if it matches a previous page file */
PagingFile = NULL;
/* FIXME: should be calling unsafe instead,
* we should already be in a guarded region
*/
KeAcquireGuardedMutex(&MmPageFileCreationLock);
if (MmNumberOfPagingFiles > 0)
{
i = 0;
@ -622,6 +626,7 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
/* If we didn't find the page file, fail */
if (PagingFile == NULL)
{
KeReleaseGuardedMutex(&MmPageFileCreationLock);
ObDereferenceObject(FileObject);
ZwClose(FileHandle);
ExFreePoolWithTag(Dacl, 'lcaD');
@ -632,6 +637,7 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
/* FIXME: implement parameters checking and page file extension */
UNIMPLEMENTED;
KeReleaseGuardedMutex(&MmPageFileCreationLock);
ObDereferenceObject(FileObject);
ZwClose(FileHandle);
ExFreePoolWithTag(Dacl, 'lcaD');
@ -737,12 +743,15 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
(ULONG)(PagingFile->FreePages));
RtlClearAllBits(PagingFile->AllocMap);
KeAcquireSpinLock(&PagingFileListLock, &oldIrql);
/* FIXME: should be calling unsafe instead,
* we should already be in a guarded region
*/
KeAcquireGuardedMutex(&MmPageFileCreationLock);
ASSERT(MmPagingFile[MmNumberOfPagingFiles] == NULL);
MmPagingFile[MmNumberOfPagingFiles] = PagingFile;
MmNumberOfPagingFiles++;
MiFreeSwapPages = MiFreeSwapPages + PagingFile->FreePages;
KeReleaseSpinLock(&PagingFileListLock, oldIrql);
KeReleaseGuardedMutex(&MmPageFileCreationLock);
MmSwapSpaceMessage = FALSE;