Lorenzo Stoakes (Oracle)
3a6455d56b
mm: convert do_brk_flags() to use vma_flags_t
...
In order to be able to do this, we need to change VM_DATA_DEFAULT_FLAGS
and friends and update the architecture-specific definitions also.
We then have to update some KSM logic to handle VMA flags, and introduce
VMA_STACK_FLAGS to define the vma_flags_t equivalent of VM_STACK_FLAGS.
We also introduce two helper functions for use during the time we are
converting legacy flags to vma_flags_t values - vma_flags_to_legacy() and
legacy_to_vma_flags().
This enables us to iteratively make changes to break these changes up into
separate parts.
We use these explicitly here to keep VM_STACK_FLAGS around for certain
users which need to maintain the legacy vm_flags_t values for the time
being.
We are no longer able to rely on the simple VM_xxx being set to zero if
the feature is not enabled, so in the case of VM_DROPPABLE we introduce
VMA_DROPPABLE as the vma_flags_t equivalent, which is set to
EMPTY_VMA_FLAGS if the droppable flag is not available.
While we're here, we make the description of do_brk_flags() into a kdoc
comment, as it almost was already.
We use vma_flags_to_legacy() to not need to update the vm_get_page_prot()
logic as this time.
Note that in create_init_stack_vma() we have to replace the BUILD_BUG_ON()
with a VM_WARN_ON_ONCE() as the tested values are no longer build time
available.
We also update mprotect_fixup() to use VMA flags where possible, though we
have to live with a little duplication between vm_flags_t and vma_flags_t
values for the time being until further conversions are made.
While we're here, update VM_SPECIAL to be defined in terms of
VMA_SPECIAL_FLAGS now we have vma_flags_to_legacy().
Finally, we update the VMA tests to reflect these changes.
Link: https://lkml.kernel.org/r/d02e3e45d9a33d7904b149f5604904089fd640ae.1774034900.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org >
Acked-by: Paul Moore <paul@paul-moore.com > [SELinux]
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org >
Cc: Albert Ou <aou@eecs.berkeley.edu >
Cc: Alexander Gordeev <agordeev@linux.ibm.com >
Cc: Alexandre Ghiti <alex@ghiti.fr >
Cc: Al Viro <viro@zeniv.linux.org.uk >
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com >
Cc: "Borislav Petkov (AMD)" <bp@alien8.de >
Cc: Catalin Marinas <catalin.marinas@arm.com >
Cc: Chengming Zhou <chengming.zhou@linux.dev >
Cc: Christian Borntraeger <borntraeger@linux.ibm.com >
Cc: Christian Brauner <brauner@kernel.org >
Cc: David Hildenbrand <david@kernel.org >
Cc: Dinh Nguyen <dinguyen@kernel.org >
Cc: Heiko Carstens <hca@linux.ibm.com >
Cc: "H. Peter Anvin" <hpa@zytor.com >
Cc: Huacai Chen <chenhuacai@kernel.org >
Cc: Ingo Molnar <mingo@redhat.com >
Cc: Jan Kara <jack@suse.cz >
Cc: Jann Horn <jannh@google.com >
Cc: Johannes Berg <johannes@sipsolutions.net >
Cc: Kees Cook <kees@kernel.org >
Cc: Liam Howlett <liam.howlett@oracle.com >
Cc: Madhavan Srinivasan <maddy@linux.ibm.com >
Cc: Michael Ellerman <mpe@ellerman.id.au >
Cc: Michal Hocko <mhocko@suse.com >
Cc: Mike Rapoport <rppt@kernel.org >
Cc: Nicholas Piggin <npiggin@gmail.com >
Cc: Ondrej Mosnacek <omosnace@redhat.com >
Cc: Palmer Dabbelt <palmer@dabbelt.com >
Cc: Pedro Falcato <pfalcato@suse.de >
Cc: Richard Weinberger <richard@nod.at >
Cc: Russell King <linux@armlinux.org.uk >
Cc: Stephen Smalley <stephen.smalley.work@gmail.com >
Cc: Suren Baghdasaryan <surenb@google.com >
Cc: Sven Schnelle <svens@linux.ibm.com >
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de >
Cc: Vasily Gorbik <gor@linux.ibm.com >
Cc: Vineet Gupta <vgupta@kernel.org >
Cc: WANG Xuerui <kernel@xen0n.name >
Cc: Will Deacon <will@kernel.org >
Cc: xu xin <xu.xin16@zte.com.cn >
Signed-off-by: Andrew Morton <akpm@linux-foundation.org >
2026-04-05 13:53:40 -07:00
Anthony Yznaga
d239462787
mm: prevent droppable mappings from being locked
...
Droppable mappings must not be lockable. There is a check for VMAs with
VM_DROPPABLE set in mlock_fixup() along with checks for other types of
unlockable VMAs which ensures this when calling mlock()/mlock2().
For mlockall(MCL_FUTURE), the check for unlockable VMAs is different. In
apply_mlockall_flags(), if the flags parameter has MCL_FUTURE set, the
current task's mm's default VMA flag field mm->def_flags has VM_LOCKED
applied to it. VM_LOCKONFAULT is also applied if MCL_ONFAULT is also set.
When these flags are set as default in this manner they are cleared in
__mmap_complete() for new mappings that do not support mlock. A check for
VM_DROPPABLE in __mmap_complete() is missing resulting in droppable
mappings created with VM_LOCKED set. To fix this and reduce that chance
of similar bugs in the future, introduce and use vma_supports_mlock().
Link: https://lkml.kernel.org/r/20260310155821.17869-1-anthony.yznaga@oracle.com
Fixes: 9651fcedf7anthony.yznaga@oracle.com >
Suggested-by: David Hildenbrand <david@kernel.org >
Acked-by: David Hildenbrand (Arm) <david@kernel.org >
Reviewed-by: Pedro Falcato <pfalcato@suse.de >
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org >
Tested-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org >
Cc: Jann Horn <jannh@google.com >
Cc: Jason A. Donenfeld <jason@zx2c4.com >
Cc: Liam Howlett <liam.howlett@oracle.com >
Cc: Michal Hocko <mhocko@suse.com >
Cc: Mike Rapoport <rppt@kernel.org >
Cc: Shuah Khan <shuah@kernel.org >
Cc: Suren Baghdasaryan <surenb@google.com >
Cc: Vlastimil Babka <vbabka@kernel.org >
Cc: <stable@vger.kernel.org >
Signed-off-by: Andrew Morton <akpm@linux-foundation.org >
2026-04-05 13:53:25 -07:00
Lorenzo Stoakes
a1f0dacaab
tools/testing/vma: separate out vma_internal.h into logical headers
...
The vma_internal.h file is becoming entirely unmanageable. It combines
duplicated kernel implementation logic that needs to be kept in-sync with
the kernel, stubbed out declarations that we simply ignore for testing
purposes and custom logic added to aid testing.
If we separate each of the three things into separate headers it makes
things far more manageable, so do so:
* include/stubs.h contains the stubbed declarations,
* include/dup.h contains the duplicated kernel declarations, and
* include/custom.h contains declarations customised for testing.
[lorenzo.stoakes@oracle.com: avoid a duplicate struct define]
Link: https://lkml.kernel.org/r/1e032732-61c3-485c-9aa7-6a09016fefc1@lucifer.local
Link: https://lkml.kernel.org/r/dd57baf5b5986cb96a167150ac712cbe804b63ee.1769097829.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com >
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com >
Cc: Baolin Wang <baolin.wang@linux.alibaba.com >
Cc: Barry Song <baohua@kernel.org >
Cc: David Hildenbrand <david@kernel.org >
Cc: Dev Jain <dev.jain@arm.com >
Cc: Jason Gunthorpe <jgg@nvidia.com >
Cc: Suren Baghdasaryan <surenb@google.com >
Cc: Vlastimil Babka <vbabka@suse.cz >
Cc: Zi Yan <ziy@nvidia.com >
Cc: Damien Le Moal <dlemoal@kernel.org >
Cc: "Darrick J. Wong" <djwong@kernel.org >
Cc: Jarkko Sakkinen <jarkko@kernel.org >
Cc: Yury Norov <ynorov@nvidia.com >
Cc: Chris Mason <clm@fb.com >
Cc: Pedro Falcato <pfalcato@suse.de >
Signed-off-by: Andrew Morton <akpm@linux-foundation.org >
2026-02-12 15:42:59 -08:00
