]> xenbits.xensource.com Git - pvdrivers/win/xenvif.git/commit
Don't pass MM_DONT_ZERO_ALLOCATION to MmAllocatePagesForMdlEx()...
authorPaul Durrant <pdurrant@amazon.com>
Tue, 16 Jun 2020 12:48:27 +0000 (13:48 +0100)
committerPaul Durrant <pdurrant@amazon.com>
Thu, 18 Jun 2020 14:11:07 +0000 (15:11 +0100)
commit721b0d1b5e39f5ae057bfb836f2bf91fbd3385f0
tree9d9742ef75984f43020d941e5105516a3654f10a
parent0065df612e57f8d6f2bfd7201635299528d909e3
Don't pass MM_DONT_ZERO_ALLOCATION to MmAllocatePagesForMdlEx()...

...in __AllocatePages()

See commit 4f85d004 "Replace uses of MmAllocatePagesForMdlEx in
__AllocatePage" for more background.

In summary, it is to avoid BSOD 139 1e with a stack similar to the following:

nt!KeBugCheckEx
nt!KiBugCheckDispatch+0x69
nt!KiFastFailDispatch+0xd0
nt!KiRaiseSecurityCheckFailure+0x30e
nt!KiAcquireThreadStateLock+0x11fa90
nt!KeSetIdealProcessorThreadEx+0xd0
nt!MiZeroInParallelWorker+0x115016
nt!MiZeroInParallel+0x11c
nt!MiInitializeMdlBatchPages+0x2ae
nt!MiAllocatePagesForMdl+0x192
nt!MmAllocatePartitionNodePagesForMdlEx+0xc9
nt!MmAllocatePagesForMdlEx+0x4d

These bugchecks have been observed in recent updates of Server 2019.

This patch, rather than replacing calls to MmAllocatePagesForMdlEx() with
calls to MmMapLockedPagesSpecifyCache(), just avoids passing
MM_DONT_ZERO_ALLOCATION to work round the bug.

The patch instead passes MM_ALLOCATE_FULLY_REQUIRED, which arguably should
have always been passed for allocations larger than a single page. It also
fixes a formatting issue.

Reported-by: Jan Bakuwel <jan.bakuwel@gmail.com>
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---

This fix will also be propogated to all other PV drivers.
src/xenvif/util.h