Revision e700898fa075c69b3ae02b702ab57fb75e1a82ec authored by Mike Kravetz on 12 December 2022, 23:50:41 UTC, committed by Andrew Morton on 21 December 2022, 22:31:52 UTC
Commit bbff39cc6cbc ("hugetlb: allocate vma lock for all sharable vmas")
removed the pmd sharable checks in the vma lock helper routines.  However,
it left the functional version of helper routines behind #ifdef
CONFIG_ARCH_WANT_HUGE_PMD_SHARE.  Therefore, the vma lock is not being
used for sharable vmas on architectures that do not support pmd sharing. 
On these architectures, a potential fault/truncation race is exposed that
could leave pages in a hugetlb file past i_size until the file is removed.

Move the functional vma lock helpers outside the ifdef, and remove the
non-functional stubs.  Since the vma lock is not just for pmd sharing,
rename the routine __vma_shareable_flags_pmd.

Link: https://lkml.kernel.org/r/20221212235042.178355-1-mike.kravetz@oracle.com
Fixes: bbff39cc6cbc ("hugetlb: allocate vma lock for all sharable vmas")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1 parent 7ba594d
Raw File
Kconfig
# SPDX-License-Identifier: GPL-2.0
menu "Android"

config ANDROID_BINDER_IPC
	bool "Android Binder IPC Driver"
	depends on MMU
	default n
	help
	  Binder is used in Android for both communication between processes,
	  and remote method invocation.

	  This means one Android process can call a method/routine in another
	  Android process, using Binder to identify, invoke and pass arguments
	  between said processes.

config ANDROID_BINDERFS
	bool "Android Binderfs filesystem"
	depends on ANDROID_BINDER_IPC
	default n
	help
	  Binderfs is a pseudo-filesystem for the Android Binder IPC driver
	  which can be mounted per-ipc namespace allowing to run multiple
	  instances of Android.
	  Each binderfs mount initially only contains a binder-control device.
	  It can be used to dynamically allocate new binder IPC devices via
	  ioctls.

config ANDROID_BINDER_DEVICES
	string "Android Binder devices"
	depends on ANDROID_BINDER_IPC
	default "binder,hwbinder,vndbinder"
	help
	  Default value for the binder.devices parameter.

	  The binder.devices parameter is a comma-separated list of strings
	  that specifies the names of the binder device nodes that will be
	  created. Each binder device has its own context manager, and is
	  therefore logically separated from the other devices.

config ANDROID_BINDER_IPC_SELFTEST
	bool "Android Binder IPC Driver Selftest"
	depends on ANDROID_BINDER_IPC
	help
	  This feature allows binder selftest to run.

	  Binder selftest checks the allocation and free of binder buffers
	  exhaustively with combinations of various buffer sizes and
	  alignments.

endmenu
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