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* | ipc/shm: properly return EIDRM in shm_lock()Davidlohr Bueso2018-09-051-0/+1
|/ | | | | | | | | | | | | | | | When getting rid of the general ipc_lock(), this was missed furthermore, making the comment around the ipc object validity check bogus. Under EIDRM conditions, callers will in turn not see the error and continue with the operation. Link: http://lkml.kernel.org/r/20180824030920.GD3677@linux-r8p5 Link: http://lkml.kernel.org/r/20180823024051.GC13343@shao2-debian Fixes: 82061c57ce9 ("ipc: drop ipc_lock()") Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: kernel test robot <rong.a.chen@intel.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/util.c: update return value of ipc_getref from int to boolManfred Spraul2018-08-222-2/+2
| | | | | | | | | | | | | | | | | | | | | | ipc_getref has still a return value of type "int", matching the atomic_t interface of atomic_inc_not_zero()/atomic_add_unless(). ipc_getref now uses refcount_inc_not_zero, which has a return value of type "bool". Therefore, update the return code to avoid implicit conversions. Link: http://lkml.kernel.org/r/20180712185241.4017-13-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/util.c: further variable name cleanupsManfred Spraul2018-08-225-26/+26
| | | | | | | | | | | | | | | | | | | | | | | | The varable names got a mess, thus standardize them again: id: user space id. Called semid, shmid, msgid if the type is known. Most functions use "id" already. idx: "index" for the idr lookup Right now, some functions use lid, ipc_addid() already uses idx as the variable name. seq: sequence number, to avoid quick collisions of the user space id key: user space key, used for the rhash tree Link: http://lkml.kernel.org/r/20180712185241.4017-12-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: simplify ipc initializationDavidlohr Bueso2018-08-226-54/+30
| | | | | | | | | | | | | | | | | Now that we know that rhashtable_init() will not fail, we can get rid of a lot of the unnecessary cleanup paths when the call errored out. [manfred@colorfullife.com: variable name added to util.h to resolve checkpatch warning] Link: http://lkml.kernel.org/r/20180712185241.4017-11-manfred@colorfullife.com Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: get rid of ids->tables_initialized hackDavidlohr Bueso2018-08-221-15/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In sysvipc we have an ids->tables_initialized regarding the rhashtable, introduced in 0cfb6aee70bd ("ipc: optimize semget/shmget/msgget for lots of keys") It's there, specifically, to prevent nil pointer dereferences, from using an uninitialized api. Considering how rhashtable_init() can fail (probably due to ENOMEM, if anything), this made the overall ipc initialization capable of failure as well. That alone is ugly, but fine, however I've spotted a few issues regarding the semantics of tables_initialized (however unlikely they may be): - There is inconsistency in what we return to userspace: ipc_addid() returns ENOSPC which is certainly _wrong_, while ipc_obtain_object_idr() returns EINVAL. - After we started using rhashtables, ipc_findkey() can return nil upon !tables_initialized, but the caller expects nil for when the ipc structure isn't found, and can therefore call into ipcget() callbacks. Now that rhashtable initialization cannot fail, we can properly get rid of the hack altogether. [manfred@colorfullife.com: commit id extended to 12 digits] Link: http://lkml.kernel.org/r/20180712185241.4017-10-manfred@colorfullife.com Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: drop ipc_lock()Davidlohr Bueso2018-08-223-43/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ipc/util.c contains multiple functions to get the ipc object pointer given an id number. There are two sets of function: One set verifies the sequence counter part of the id number, other functions do not check the sequence counter. The standard for function names in ipc/util.c is - ..._check() functions verify the sequence counter - ..._idr() functions do not verify the sequence counter ipc_lock() is an exception: It does not verify the sequence counter value, but this is not obvious from the function name. Furthermore, shm.c is the only user of this helper. Thus, we can simply move the logic into shm_lock() and get rid of the function altogether. [manfred@colorfullife.com: most of changelog] Link: http://lkml.kernel.org/r/20180712185241.4017-7-manfred@colorfullife.com Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/util.c: correct comment in ipc_obtain_object_checkManfred Spraul2018-08-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | The comment that explains ipc_obtain_object_check is wrong: The function checks the sequence number, not the reference counter. Note that checking the reference counter would be meaningless: The reference counter is decreased without holding any locks, thus an object with kern_ipc_perm.deleted=true may disappear at the end of the next rcu grace period. Link: http://lkml.kernel.org/r/20180712185241.4017-6-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: rename ipcctl_pre_down_nolock()Manfred Spraul2018-08-225-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | Both the comment and the name of ipcctl_pre_down_nolock() are misleading: The function must be called while holdling the rw semaphore. Therefore the patch renames the function to ipcctl_obtain_check(): This name matches the other names used in util.c: - "obtain" function look up a pointer in the idr, without acquiring the object lock. - The caller is responsible for locking. - _check means that the sequence number is checked. Link: http://lkml.kernel.org/r/20180712185241.4017-5-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()Manfred Spraul2018-08-224-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ipc_addid() is impossible to use: - for certain failures, the caller must not use ipc_rcu_putref(), because the reference counter is not yet initialized. - for other failures, the caller must use ipc_rcu_putref(), because parallel operations could be ongoing already. The patch cleans that up, by initializing the refcount early, and by modifying all callers. The issues is related to the finding of syzbot+2827ef6b3385deb07eaf@syzkaller.appspotmail.com: syzbot found an issue with reading kern_ipc_perm.seq, here both read and write to already released memory could happen. Link: http://lkml.kernel.org/r/20180712185241.4017-4-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: reorganize initialization of kern_ipc_perm.seqManfred Spraul2018-08-221-43/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ipc_addid() initializes kern_ipc_perm.seq after having called idr_alloc() (within ipc_idr_alloc()). Thus a parallel semop() or msgrcv() that uses ipc_obtain_object_check() may see an uninitialized value. The patch moves the initialization of kern_ipc_perm.seq before the calls of idr_alloc(). Notes: 1) This patch has a user space visible side effect: If /proc/sys/kernel/*_next_id is used (i.e.: checkpoint/restore) and if semget()/msgget()/shmget() fails in the final step of adding the id to the rhash tree, then .._next_id is cleared. Before the patch, is remained unmodified. There is no change of the behavior after a successful ..get() call: It always clears .._next_id, there is no impact to non checkpoint/restore code as that code does not use .._next_id. 2) The patch correctly documents that after a call to ipc_idr_alloc(), the full tear-down sequence must be used. The callers of ipc_addid() do not fullfill that, i.e. more bugfixes are required. The patch is a squash of a patch from Dmitry and my own changes. Link: http://lkml.kernel.org/r/20180712185241.4017-3-manfred@colorfullife.com Reported-by: syzbot+2827ef6b3385deb07eaf@syzkaller.appspotmail.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: compute kern_ipc_perm.id under the ipc lockManfred Spraul2018-08-223-15/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | ipc_addid() initializes kern_ipc_perm.id after having called ipc_idr_alloc(). Thus a parallel semctl() or msgctl() that uses e.g. MSG_STAT may use this unitialized value as the return code. The patch moves all accesses to kern_ipc_perm.id under the spin_lock(). The issues is related to the finding of syzbot+2827ef6b3385deb07eaf@syzkaller.appspotmail.com: syzbot found an issue with kern_ipc_perm.seq Link: http://lkml.kernel.org/r/20180712185241.4017-2-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2018-08-164-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Highlights: - Gustavo A. R. Silva keeps working on the implicit switch fallthru changes. - Support 802.11ax High-Efficiency wireless in cfg80211 et al, From Luca Coelho. - Re-enable ASPM in r8169, from Kai-Heng Feng. - Add virtual XFRM interfaces, which avoids all of the limitations of existing IPSEC tunnels. From Steffen Klassert. - Convert GRO over to use a hash table, so that when we have many flows active we don't traverse a long list during accumluation. - Many new self tests for routing, TC, tunnels, etc. Too many contributors to mention them all, but I'm really happy to keep seeing this stuff. - Hardware timestamping support for dpaa_eth/fsl-fman from Yangbo Lu. - Lots of cleanups and fixes in L2TP code from Guillaume Nault. - Add IPSEC offload support to netdevsim, from Shannon Nelson. - Add support for slotting with non-uniform distribution to netem packet scheduler, from Yousuk Seung. - Add UDP GSO support to mlx5e, from Boris Pismenny. - Support offloading of Team LAG in NFP, from John Hurley. - Allow to configure TX queue selection based upon RX queue, from Amritha Nambiar. - Support ethtool ring size configuration in aquantia, from Anton Mikaev. - Support DSCP and flowlabel per-transport in SCTP, from Xin Long. - Support list based batching and stack traversal of SKBs, this is very exciting work. From Edward Cree. - Busyloop optimizations in vhost_net, from Toshiaki Makita. - Introduce the ETF qdisc, which allows time based transmissions. IGB can offload this in hardware. From Vinicius Costa Gomes. - Add parameter support to devlink, from Moshe Shemesh. - Several multiplication and division optimizations for BPF JIT in nfp driver, from Jiong Wang. - Lots of prepatory work to make more of the packet scheduler layer lockless, when possible, from Vlad Buslov. - Add ACK filter and NAT awareness to sch_cake packet scheduler, from Toke Høiland-Jørgensen. - Support regions and region snapshots in devlink, from Alex Vesker. - Allow to attach XDP programs to both HW and SW at the same time on a given device, with initial support in nfp. From Jakub Kicinski. - Add TLS RX offload and support in mlx5, from Ilya Lesokhin. - Use PHYLIB in r8169 driver, from Heiner Kallweit. - All sorts of changes to support Spectrum 2 in mlxsw driver, from Ido Schimmel. - PTP support in mv88e6xxx DSA driver, from Andrew Lunn. - Make TCP_USER_TIMEOUT socket option more accurate, from Jon Maxwell. - Support for templates in packet scheduler classifier, from Jiri Pirko. - IPV6 support in RDS, from Ka-Cheong Poon. - Native tproxy support in nf_tables, from Máté Eckl. - Maintain IP fragment queue in an rbtree, but optimize properly for in-order frags. From Peter Oskolkov. - Improvde handling of ACKs on hole repairs, from Yuchung Cheng" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1996 commits) bpf: test: fix spelling mistake "REUSEEPORT" -> "REUSEPORT" hv/netvsc: Fix NULL dereference at single queue mode fallback net: filter: mark expected switch fall-through xen-netfront: fix warn message as irq device name has '/' cxgb4: Add new T5 PCI device ids 0x50af and 0x50b0 net: dsa: mv88e6xxx: missing unlock on error path rds: fix building with IPV6=m inet/connection_sock: prefer _THIS_IP_ to current_text_addr net: dsa: mv88e6xxx: bitwise vs logical bug net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd() ieee802154: hwsim: using right kind of iteration net: hns3: Add vlan filter setting by ethtool command -K net: hns3: Set tx ring' tc info when netdev is up net: hns3: Remove tx ring BD len register in hns3_enet net: hns3: Fix desc num set to default when setting channel net: hns3: Fix for phy link issue when using marvell phy driver net: hns3: Fix for information of phydev lost problem when down/up net: hns3: Fix for command format parsing error in hclge_is_all_function_id_zero net: hns3: Add support for serdes loopback selftest bnxt_en: take coredump_record structure off stack ...
| * Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-08-051-0/+12
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lots of overlapping changes, mostly trivial in nature. The mlxsw conflict was resolving using the example resolution at: https://github.com/jpirko/linux_mlxsw/blob/combined_queue/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c Signed-off-by: David S. Miller <davem@davemloft.net>
| * \ Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-08-021-1/+1
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The BTF conflicts were simple overlapping changes. The virtio_net conflict was an overlap of a fix of statistics counter, happening alongisde a move over to a bonafide statistics structure rather than counting value on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | rhashtable: split rhashtable.hNeilBrown2018-06-224-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to the use of rhashtables in net namespaces, rhashtable.h is included in lots of the kernel, so a small changes can required a large recompilation. This makes development painful. This patch splits out rhashtable-types.h which just includes the major type declarations, and does not include (non-trivial) inline code. rhashtable.h is no longer included by anything in the include/ directory. Common include files only include rhashtable-types.h so a large recompilation is only triggered when that changes. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | Merge branch 'work.open3' of ↵Linus Torvalds2018-08-141-24/+21
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs open-related updates from Al Viro: - "do we need fput() or put_filp()" rules are gone - it's always fput() now. We keep track of that state where it belongs - in ->f_mode. - int *opened mess killed - in finish_open(), in ->atomic_open() instances and in fs/namei.c code around do_last()/lookup_open()/atomic_open(). - alloc_file() wrappers with saner calling conventions are introduced (alloc_file_clone() and alloc_file_pseudo()); callers converted, with much simplification. - while we are at it, saner calling conventions for path_init() and link_path_walk(), simplifying things inside fs/namei.c (both on open-related paths and elsewhere). * 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) few more cleanups of link_path_walk() callers allow link_path_walk() to take ERR_PTR() make path_init() unconditionally paired with terminate_walk() document alloc_file() changes make alloc_file() static do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone() new helper: alloc_file_clone() create_pipe_files(): switch the first allocation to alloc_file_pseudo() anon_inode_getfile(): switch to alloc_file_pseudo() hugetlb_file_setup(): switch to alloc_file_pseudo() ocxlflash_getfile(): switch to alloc_file_pseudo() cxl_getfile(): switch to alloc_file_pseudo() ... and switch shmem_file_setup() to alloc_file_pseudo() __shmem_file_setup(): reorder allocations new wrapper: alloc_file_pseudo() kill FILE_{CREATED,OPENED} switch atomic_open() and lookup_open() to returning 0 in all success cases document ->atomic_open() changes ->atomic_open(): return 0 in all success cases get rid of 'opened' in path_openat() and the helpers downstream ...
| * | | do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone()Al Viro2018-07-121-21/+18
| | | | | | | | | | | | | | | | | | | | Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | alloc_file(): switch to passing O_... flags instead of FMODE_... modeAl Viro2018-07-121-4/+4
| |/ / | | | | | | | | | | | | | | | | | | ... so that it could set both ->f_flags and ->f_mode, without callers having to set ->f_flags manually. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | / ipc/shm.c add ->pagesize function to shm_vm_opsJane Chu2018-08-031-0/+12
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 05ea88608d4e ("mm, hugetlbfs: introduce ->pagesize() to vm_operations_struct") adds a new ->pagesize() function to hugetlb_vm_ops, intended to cover all hugetlbfs backed files. With System V shared memory model, if "huge page" is specified, the "shared memory" is backed by hugetlbfs files, but the mappings initiated via shmget/shmat have their original vm_ops overwritten with shm_vm_ops, so we need to add a ->pagesize function to shm_vm_ops. Otherwise, vma_kernel_pagesize() returns PAGE_SIZE given a hugetlbfs backed vma, result in below BUG: fs/hugetlbfs/inode.c 443 if (unlikely(page_mapped(page))) { 444 BUG_ON(truncate_op); resulting in hugetlbfs: oracle (4592): Using mlock ulimits for SHM_HUGETLB is deprecated ------------[ cut here ]------------ kernel BUG at fs/hugetlbfs/inode.c:444! Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 ... CPU: 35 PID: 5583 Comm: oracle_5583_sbt Not tainted 4.14.35-1829.el7uek.x86_64 #2 RIP: 0010:remove_inode_hugepages+0x3db/0x3e2 .... Call Trace: hugetlbfs_evict_inode+0x1e/0x3e evict+0xdb/0x1af iput+0x1a2/0x1f7 dentry_unlink_inode+0xc6/0xf0 __dentry_kill+0xd8/0x18d dput+0x1b5/0x1ed __fput+0x18b/0x216 ____fput+0xe/0x10 task_work_run+0x90/0xa7 exit_to_usermode_loop+0xdd/0x116 do_syscall_64+0x187/0x1ae entry_SYSCALL_64_after_hwframe+0x150/0x0 [jane.chu@oracle.com: relocate comment] Link: http://lkml.kernel.org/r/20180731044831.26036-1-jane.chu@oracle.com Link: http://lkml.kernel.org/r/20180727211727.5020-1-jane.chu@oracle.com Fixes: 05ea88608d4e13 ("mm, hugetlbfs: introduce ->pagesize() to vm_operations_struct") Signed-off-by: Jane Chu <jane.chu@oracle.com> Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | ipc/sem.c: prevent queue.status tearing in semopDavidlohr Bueso2018-07-271-1/+1
|/ | | | | | | | | | | | | In order for load/store tearing prevention to work, _all_ accesses to the variable in question need to be done around READ and WRITE_ONCE() macros. Ensure everyone does so for q->status variable for semtimedop(). Link: http://lkml.kernel.org/r/20180717052654.676-1-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: use new return type vm_fault_tSouptick Joarder2018-06-151-1/+1
| | | | | | | | | | | | | | | | | | | Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Commit 1c8f422059ae ("mm: change return type to vm_fault_t") Link: http://lkml.kernel.org/r/20180425043413.GA21467@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysvipc/sem: mitigate semnum index against spectre v1Davidlohr Bueso2018-06-151-4/+14
| | | | | | | | | | | | | | | | | | | | | | Both smatch and coverity are reporting potential issues with spectre variant 1 with the 'semnum' index within the sma->sems array, ie: ipc/sem.c:388 sem_lock() warn: potential spectre issue 'sma->sems' ipc/sem.c:641 perform_atomic_semop_slow() warn: potential spectre issue 'sma->sems' ipc/sem.c:721 perform_atomic_semop() warn: potential spectre issue 'sma->sems' Avoid any possible speculation by using array_index_nospec() thus ensuring the semnum value is bounded to [0, sma->sem_nsems). With the exception of sem_lock() all of these are slowpaths. Link: http://lkml.kernel.org/r/20180423171131.njs4rfm2yzyeg6do@linux-n805 Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* treewide: kvmalloc() -> kvmalloc_array()Kees Cook2018-06-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kvmalloc() function has a 2-factor argument form, kvmalloc_array(). This patch replaces cases of: kvmalloc(a * b, gfp) with: kvmalloc_array(a * b, gfp) as well as handling cases of: kvmalloc(a * b * c, gfp) with: kvmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kvmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kvmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kvmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kvmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kvmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kvmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kvmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kvmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kvmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kvmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kvmalloc( - sizeof(char) * COUNT + COUNT , ...) | kvmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kvmalloc + kvmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kvmalloc + kvmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kvmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kvmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kvmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kvmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kvmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kvmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kvmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kvmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kvmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kvmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kvmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kvmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kvmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kvmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kvmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kvmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kvmalloc(C1 * C2 * C3, ...) | kvmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kvmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kvmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kvmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kvmalloc(sizeof(THING) * C2, ...) | kvmalloc(sizeof(TYPE) * C2, ...) | kvmalloc(C1 * C2 * C3, ...) | kvmalloc(C1 * C2, ...) | - kvmalloc + kvmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kvmalloc + kvmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kvmalloc + kvmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kvmalloc + kvmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kvmalloc + kvmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
* Merge branch 'timers-2038-for-linus' of ↵Linus Torvalds2018-06-056-65/+99
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull time/Y2038 updates from Thomas Gleixner: - Consolidate SySV IPC UAPI headers - Convert SySV IPC to the new COMPAT_32BIT_TIME mechanism - Cleanup the core interfaces and standardize on the ktime_get_* naming convention. - Convert the X86 platform ops to timespec64 - Remove the ugly temporary timespec64 hack * 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86: Convert x86_platform_ops to timespec64 timekeeping: Add more coarse clocktai/boottime interfaces timekeeping: Add ktime_get_coarse_with_offset timekeeping: Standardize on ktime_get_*() naming timekeeping: Clean up ktime_get_real_ts64 timekeeping: Remove timespec64 hack y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop y2038: ipc: Enable COMPAT_32BIT_TIME y2038: ipc: Use __kernel_timespec y2038: ipc: Report long times to user space y2038: ipc: Use ktime_get_real_seconds consistently y2038: xtensa: Extend sysvipc data structures y2038: powerpc: Extend sysvipc data structures y2038: sparc: Extend sysvipc data structures y2038: parisc: Extend sysvipc data structures y2038: mips: Extend sysvipc data structures y2038: arm64: Extend sysvipc compat data structures y2038: s390: Remove unneeded ipc uapi header files y2038: ia64: Remove unneeded ipc uapi header files y2038: alpha: Remove unneeded ipc uapi header files ...
| * y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedopArnd Bergmann2018-04-201-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 32-bit architectures implementing 64BIT_TIME and COMPAT_32BIT_TIME need to have the traditional semtimedop() behavior with 32-bit timestamps for sys_ipc() by calling compat_ksys_semtimedop(), while those that are not yet converted need to keep using ksys_semtimedop() like 64-bit architectures do. Note that I chose to not implement a new SEMTIMEDOP64 function that corresponds to the new sys_semtimedop() with 64-bit timeouts. The reason here is that sys_ipc() should no longer be used for new system calls, and libc should just call the semtimedop syscall directly. One open question remain to whether we want to completely avoid the sys_ipc() system call for architectures that do not yet have all the individual calls as they get converted to 64-bit time_t. Doing that would require adding several extra system calls on m68k, mips, powerpc, s390, sh, sparc, and x86-32. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
| * y2038: ipc: Enable COMPAT_32BIT_TIMEArnd Bergmann2018-04-203-41/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | Three ipc syscalls (mq_timedsend, mq_timedreceive and and semtimedop) take a timespec argument. After we move 32-bit architectures over to useing 64-bit time_t based syscalls, we need seperate entry points for the old 32-bit based interfaces. This changes the #ifdef guards for the existing 32-bit compat syscalls to check for CONFIG_COMPAT_32BIT_TIME instead, which will then be enabled on all existing 32-bit architectures. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
| * y2038: ipc: Use __kernel_timespecArnd Bergmann2018-04-203-6/+6
| | | | | | | | | | | | | | | | | | | | | | This is a preparatation for changing over __kernel_timespec to 64-bit times, which involves assigning new system call numbers for mq_timedsend(), mq_timedreceive() and semtimedop() for compatibility with future y2038 proof user space. The existing ABIs will remain available through compat code. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
| * y2038: ipc: Report long times to user spaceArnd Bergmann2018-04-203-9/+33
| | | | | | | | | | | | | | | | | | | | | | | | The shmid64_ds/semid64_ds/msqid64_ds data structures have been extended to contain extra fields for storing the upper bits of the time stamps, this patch does the other half of the job and and fills the new fields on 32-bit architectures as well as 32-bit tasks running on a 64-bit kernel in compat mode. There should be no change for native 64-bit tasks. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
| * y2038: ipc: Use ktime_get_real_seconds consistentlyArnd Bergmann2018-04-202-6/+6
| | | | | | | | | | | | | | | | | | | | In some places, we still used get_seconds() instead of ktime_get_real_seconds(), and I'm changing the remaining ones now to all use ktime_get_real_seconds() so we use the full available range for timestamps instead of overflowing the 'unsigned long' return value in year 2106 on 32-bit kernels. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* | ipc/shm: fix shmat() nil address after round-down when remappingDavidlohr Bueso2018-05-261-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | shmat()'s SHM_REMAP option forbids passing a nil address for; this is in fact the very first thing we check for. Andrea reported that for SHM_RND|SHM_REMAP cases we can end up bypassing the initial addr check, but we need to check again if the address was rounded down to nil. As of this patch, such cases will return -EINVAL. Link: http://lkml.kernel.org/r/20180503204934.kk63josdu6u53fbd@linux-n805 Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Revert "ipc/shm: Fix shmat mmap nil-page protection"Davidlohr Bueso2018-05-261-7/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "ipc/shm: shmat() fixes around nil-page". These patches fix two issues reported[1] a while back by Joe and Andrea around how shmat(2) behaves with nil-page. The first reverts a commit that it was incorrectly thought that mapping nil-page (address=0) was a no no with MAP_FIXED. This is not the case, with the exception of SHM_REMAP; which is address in the second patch. I chose two patches because it is easier to backport and it explicitly reverts bogus behaviour. Both patches ought to be in -stable and ltp testcases need updated (the added testcase around the cve can be modified to just test for SHM_RND|SHM_REMAP). [1] lkml.kernel.org/r/20180430172152.nfa564pvgpk3ut7p@linux-n805 This patch (of 2): Commit 95e91b831f87 ("ipc/shm: Fix shmat mmap nil-page protection") worked on the idea that we should not be mapping as root addr=0 and MAP_FIXED. However, it was reported that this scenario is in fact valid, thus making the patch both bogus and breaks userspace as well. For example X11's libint10.so relies on shmat(1, SHM_RND) for lowmem initialization[1]. [1] https://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/os-support/linux/int10/linux.c#n347 Link: http://lkml.kernel.org/r/20180503203243.15045-2-dave@stgolabs.net Fixes: 95e91b831f87 ("ipc/shm: Fix shmat mmap nil-page protection") Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/shm: fix use-after-free of shm file via remap_file_pages()Eric Biggers2018-04-141-3/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot reported a use-after-free of shm_file_data(file)->file->f_op in shm_get_unmapped_area(), called via sys_remap_file_pages(). Unfortunately it couldn't generate a reproducer, but I found a bug which I think caused it. When remap_file_pages() is passed a full System V shared memory segment, the memory is first unmapped, then a new map is created using the ->vm_file. Between these steps, the shm ID can be removed and reused for a new shm segment. But, shm_mmap() only checks whether the ID is currently valid before calling the underlying file's ->mmap(); it doesn't check whether it was reused. Thus it can use the wrong underlying file, one that was already freed. Fix this by making the "outer" shm file (the one that gets put in ->vm_file) hold a reference to the real shm file, and by making __shm_open() require that the file associated with the shm ID matches the one associated with the "outer" file. Taking the reference to the real shm file is needed to fully solve the problem, since otherwise sfd->file could point to a freed file, which then could be reallocated for the reused shm ID, causing the wrong shm segment to be mapped (and without the required permission checks). Commit 1ac0b6dec656 ("ipc/shm: handle removed segments gracefully in shm_mmap()") almost fixed this bug, but it didn't go far enough because it didn't consider the case where the shm ID is reused. The following program usually reproduces this bug: #include <stdlib.h> #include <sys/shm.h> #include <sys/syscall.h> #include <unistd.h> int main() { int is_parent = (fork() != 0); srand(getpid()); for (;;) { int id = shmget(0xF00F, 4096, IPC_CREAT|0700); if (is_parent) { void *addr = shmat(id, NULL, 0); usleep(rand() % 50); while (!syscall(__NR_remap_file_pages, addr, 4096, 0, 0, 0)); } else { usleep(rand() % 50); shmctl(id, IPC_RMID, NULL); } } } It causes the following NULL pointer dereference due to a 'struct file' being used while it's being freed. (I couldn't actually get a KASAN use-after-free splat like in the syzbot report. But I think it's possible with this bug; it would just take a more extraordinary race...) BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 9 PID: 258 Comm: syz_ipc Not tainted 4.16.0-05140-gf8cf2f16a7c95 #189 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014 RIP: 0010:d_inode include/linux/dcache.h:519 [inline] RIP: 0010:touch_atime+0x25/0xd0 fs/inode.c:1724 [...] Call Trace: file_accessed include/linux/fs.h:2063 [inline] shmem_mmap+0x25/0x40 mm/shmem.c:2149 call_mmap include/linux/fs.h:1789 [inline] shm_mmap+0x34/0x80 ipc/shm.c:465 call_mmap include/linux/fs.h:1789 [inline] mmap_region+0x309/0x5b0 mm/mmap.c:1712 do_mmap+0x294/0x4a0 mm/mmap.c:1483 do_mmap_pgoff include/linux/mm.h:2235 [inline] SYSC_remap_file_pages mm/mmap.c:2853 [inline] SyS_remap_file_pages+0x232/0x310 mm/mmap.c:2769 do_syscall_64+0x64/0x1a0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ebiggers@google.com: add comment] Link: http://lkml.kernel.org/r/20180410192850.235835-1-ebiggers3@gmail.com Link: http://lkml.kernel.org/r/20180409043039.28915-1-ebiggers3@gmail.com Reported-by: syzbot+d11f321e7f1923157eac80aa990b446596f46439@syzkaller.appspotmail.com Fixes: c8d78c1823f4 ("mm: replace remap_file_pages() syscall with emulation") Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/shm.c: shm_split(): remove unneeded test for NULL shm_file_data.vm_opsAndrew Morton2018-04-111-1/+1
| | | | | | | | | | | | | | This was added by the recent "ipc/shm.c: add split function to shm_vm_ops", but it is not necessary. Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/msg: introduce msgctl(MSG_STAT_ANY)Davidlohr Bueso2018-04-111-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a permission discrepancy when consulting msq ipc object metadata between /proc/sysvipc/msg (0444) and the MSG_STAT shmctl command. The later does permission checks for the object vs S_IRUGO. As such there can be cases where EACCESS is returned via syscall but the info is displayed anyways in the procfs files. While this might have security implications via info leaking (albeit no writing to the msq metadata), this behavior goes way back and showing all the objects regardless of the permissions was most likely an overlook - so we are stuck with it. Furthermore, modifying either the syscall or the procfs file can cause userspace programs to break (ie ipcs). Some applications require getting the procfs info (without root privileges) and can be rather slow in comparison with a syscall -- up to 500x in some reported cases for shm. This patch introduces a new MSG_STAT_ANY command such that the msq ipc object permissions are ignored, and only audited instead. In addition, I've left the lsm security hook checks in place, as if some policy can block the call, then the user has no other choice than just parsing the procfs file. Link: http://lkml.kernel.org/r/20180215162458.10059-4-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Robert Kettler <robert.kettler@outlook.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/sem: introduce semctl(SEM_STAT_ANY)Davidlohr Bueso2018-04-111-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a permission discrepancy when consulting shm ipc object metadata between /proc/sysvipc/sem (0444) and the SEM_STAT semctl command. The later does permission checks for the object vs S_IRUGO. As such there can be cases where EACCESS is returned via syscall but the info is displayed anyways in the procfs files. While this might have security implications via info leaking (albeit no writing to the sma metadata), this behavior goes way back and showing all the objects regardless of the permissions was most likely an overlook - so we are stuck with it. Furthermore, modifying either the syscall or the procfs file can cause userspace programs to break (ie ipcs). Some applications require getting the procfs info (without root privileges) and can be rather slow in comparison with a syscall -- up to 500x in some reported cases for shm. This patch introduces a new SEM_STAT_ANY command such that the sem ipc object permissions are ignored, and only audited instead. In addition, I've left the lsm security hook checks in place, as if some policy can block the call, then the user has no other choice than just parsing the procfs file. Link: http://lkml.kernel.org/r/20180215162458.10059-3-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reported-by: Robert Kettler <robert.kettler@outlook.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/shm: introduce shmctl(SHM_STAT_ANY)Davidlohr Bueso2018-04-111-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "sysvipc: introduce STAT_ANY commands", v2. The following patches adds the discussed (see [1]) new command for shm as well as for sems and msq as they are subject to the same discrepancies for ipc object permission checks between the syscall and via procfs. These new commands are justified in that (1) we are stuck with this semantics as changing syscall and procfs can break userland; and (2) some users can benefit from performance (for large amounts of shm segments, for example) from not having to parse the procfs interface. Once merged, I will submit the necesary manpage updates. But I'm thinking something like: : diff --git a/man2/shmctl.2 b/man2/shmctl.2 : index 7bb503999941..bb00bbe21a57 100644 : --- a/man2/shmctl.2 : +++ b/man2/shmctl.2 : @@ -41,6 +41,7 @@ : .\" 2005-04-25, mtk -- noted aberrant Linux behavior w.r.t. new : .\" attaches to a segment that has already been marked for deletion. : .\" 2005-08-02, mtk: Added IPC_INFO, SHM_INFO, SHM_STAT descriptions. : +.\" 2018-02-13, dbueso: Added SHM_STAT_ANY description. : .\" : .TH SHMCTL 2 2017-09-15 "Linux" "Linux Programmer's Manual" : .SH NAME : @@ -242,6 +243,18 @@ However, the : argument is not a segment identifier, but instead an index into : the kernel's internal array that maintains information about : all shared memory segments on the system. : +.TP : +.BR SHM_STAT_ANY " (Linux-specific)" : +Return a : +.I shmid_ds : +structure as for : +.BR SHM_STAT . : +However, the : +.I shm_perm.mode : +is not checked for read access for : +.IR shmid , : +resembing the behaviour of : +/proc/sysvipc/shm. : .PP : The caller can prevent or allow swapping of a shared : memory segment with the following \fIcmd\fP values: : @@ -287,7 +300,7 @@ operation returns the index of the highest used entry in the : kernel's internal array recording information about all : shared memory segments. : (This information can be used with repeated : -.B SHM_STAT : +.B SHM_STAT/SHM_STAT_ANY : operations to obtain information about all shared memory segments : on the system.) : A successful : @@ -328,7 +341,7 @@ isn't accessible. : \fIshmid\fP is not a valid identifier, or \fIcmd\fP : is not a valid command. : Or: for a : -.B SHM_STAT : +.B SHM_STAT/SHM_STAT_ANY : operation, the index value specified in : .I shmid : referred to an array slot that is currently unused. This patch (of 3): There is a permission discrepancy when consulting shm ipc object metadata between /proc/sysvipc/shm (0444) and the SHM_STAT shmctl command. The later does permission checks for the object vs S_IRUGO. As such there can be cases where EACCESS is returned via syscall but the info is displayed anyways in the procfs files. While this might have security implications via info leaking (albeit no writing to the shm metadata), this behavior goes way back and showing all the objects regardless of the permissions was most likely an overlook - so we are stuck with it. Furthermore, modifying either the syscall or the procfs file can cause userspace programs to break (ie ipcs). Some applications require getting the procfs info (without root privileges) and can be rather slow in comparison with a syscall -- up to 500x in some reported cases. This patch introduces a new SHM_STAT_ANY command such that the shm ipc object permissions are ignored, and only audited instead. In addition, I've left the lsm security hook checks in place, as if some policy can block the call, then the user has no other choice than just parsing the procfs file. [1] https://lkml.org/lkml/2017/12/19/220 Link: http://lkml.kernel.org/r/20180215162458.10059-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Robert Kettler <robert.kettler@outlook.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: move /proc/sysvipc creation to where it belongsAlexey Dobriyan2018-04-111-0/+1
| | | | | | | | | | | | | | Move the proc_mkdir() call within the sysvipc subsystem such that we avoid polluting proc_root_init() with petty cpp. [dave@stgolabs.net: contributed changelog] Link: http://lkml.kernel.org/r/20180216161732.GA10297@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'userns-linus' of ↵Linus Torvalds2018-04-045-80/+152
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "There was a lot of work this cycle fixing bugs that were discovered after the merge window and getting everything ready where we can reasonably support fully unprivileged fuse. The bug fixes you already have and much of the unprivileged fuse work is coming in via other trees. Still left for fully unprivileged fuse is figuring out how to cleanly handle .set_acl and .get_acl in the legacy case, and properly handling of evm xattrs on unprivileged mounts. Included in the tree is a cleanup from Alexely that replaced a linked list with a statically allocated fix sized array for the pid caches, which simplifies and speeds things up. Then there is are some cleanups and fixes for the ipc namespace. The motivation was that in reviewing other code it was discovered that access ipc objects from different pid namespaces recorded pids in such a way that when asked the wrong pids were returned. In the worst case there has been a measured 30% performance impact for sysvipc semaphores. Other test cases showed no measurable performance impact. Manfred Spraul and Davidlohr Bueso who tend to work on sysvipc performance both gave the nod that this is good enough. Casey Schaufler and James Morris have given their approval to the LSM side of the changes. I simplified the types and the code dealing with sysvipc to pass just kern_ipc_perm for all three types of ipc. Which reduced the header dependencies throughout the kernel and simplified the lsm code. Which let me work on the pid fixes without having to worry about trivial changes causing complete kernel recompiles" * 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ipc/shm: Fix pid freeing. ipc/shm: fix up for struct file no longer being available in shm.h ipc/smack: Tidy up from the change in type of the ipc security hooks ipc: Directly call the security hook in ipc_ops.associate ipc/sem: Fix semctl(..., GETPID, ...) between pid namespaces ipc/msg: Fix msgctl(..., IPC_STAT, ...) between pid namespaces ipc/shm: Fix shmctl(..., IPC_STAT, ...) between pid namespaces. ipc/util: Helpers for making the sysvipc operations pid namespace aware ipc: Move IPCMNI from include/ipc.h into ipc/util.h msg: Move struct msg_queue into ipc/msg.c shm: Move struct shmid_kernel into ipc/shm.c sem: Move struct sem and struct sem_array into ipc/sem.c msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooks shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks pidns: simpler allocation of pid_* caches
| * ipc/shm: Fix pid freeing.Eric W. Biederman2018-03-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 0day kernel test build report reported an oops: > > IP: put_pid+0x22/0x5c > PGD 19efa067 P4D 19efa067 PUD 0 > Oops: 0000 [#1] > CPU: 0 PID: 727 Comm: trinity Not tainted 4.16.0-rc2-00010-g98f929b #1 > RIP: 0010:put_pid+0x22/0x5c > RSP: 0018:ffff986719f73e48 EFLAGS: 00010202 > RAX: 00000006d765f710 RBX: ffff98671a4fa4d0 RCX: ffff986719f73d40 > RDX: 000000006f6e6125 RSI: 0000000000000000 RDI: ffffffffa01e6d21 > RBP: ffffffffa0955fe0 R08: 0000000000000020 R09: 0000000000000000 > R10: 0000000000000078 R11: ffff986719f73e76 R12: 0000000000001000 > R13: 00000000ffffffea R14: 0000000054000fb0 R15: 0000000000000000 > FS: 00000000028c2880(0000) GS:ffffffffa06ad000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000677846439 CR3: 0000000019fc1005 CR4: 00000000000606b0 > Call Trace: > ? ipc_update_pid+0x36/0x3e > ? newseg+0x34c/0x3a6 > ? ipcget+0x5d/0x528 > ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 > ? SyS_shmget+0x5a/0x84 > ? do_syscall_64+0x194/0x1b3 > ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 > Code: ff 05 e7 20 9b 03 58 c9 c3 48 ff 05 85 21 9b 03 48 85 ff 74 4f 8b 47 04 8b 17 48 ff 05 7c 21 9b 03 48 83 c0 03 48 c1 e0 04 ff ca <48> 8b 44 07 08 74 1f 48 ff 05 6c 21 9b 03 ff 0f 0f 94 c2 48 ff > RIP: put_pid+0x22/0x5c RSP: ffff986719f73e48 > CR2: 0000000677846439 > ---[ end trace ab8c5cb4389d37c5 ]--- > Kernel panic - not syncing: Fatal exception In newseg when changing shm_cprid and shm_lprid from pid_t to struct pid* I misread the kvmalloc as kvzalloc and thought shp was initialized to 0. As that is not the case it is not safe to for the error handling to address shm_cprid and shm_lprid before they are initialized. Therefore move the cleanup of shm_cprid and shm_lprid from the no_file error cleanup path to the no_id error cleanup path. Ensuring that an early error exit won't cause the oops above. Reported-by: kernel test robot <fengguang.wu@intel.com> Reviewed-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * ipc: Directly call the security hook in ipc_ops.associateEric W. Biederman2018-03-273-27/+3
| | | | | | | | | | | | | | | | | | After the last round of cleanups the shm, sem, and msg associate operations just became trivial wrappers around the appropriate security method. Simplify things further by just calling the security method directly. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * ipc/sem: Fix semctl(..., GETPID, ...) between pid namespacesEric W. Biederman2018-03-271-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today the last process to update a semaphore is remembered and reported in the pid namespace of that process. If there are processes in any other pid namespace querying that process id with GETPID the result will be unusable nonsense as it does not make any sense in your own pid namespace. Due to ipc_update_pid I don't think you will be able to get System V ipc semaphores into a troublesome cache line ping-pong. Using struct pids from separate process are not a problem because they do not share a cache line. Using struct pid from different threads of the same process are unlikely to be a problem as the reference count update can be avoided. Further linux futexes are a much better tool for the job of mutual exclusion between processes than System V semaphores. So I expect programs that are performance limited by their interprocess mutual exclusion primitive will be using futexes. So while it is possible that enhancing the storage of the last rocess of a System V semaphore from an integer to a struct pid will cause a performance regression because of the effect of frequently updating the pid reference count. I don't expect that to happen in practice. This change updates semctl(..., GETPID, ...) to return the process id of the last process to update a semphore inthe pid namespace of the calling process. Fixes: b488893a390e ("pid namespaces: changes to show virtual ids to user") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * ipc/msg: Fix msgctl(..., IPC_STAT, ...) between pid namespacesEric W. Biederman2018-03-271-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today msg_lspid and msg_lrpid are remembered in the pid namespace of the creator and the processes that last send or received a sysvipc message. If you have processes in multiple pid namespaces that is just wrong. The process ids reported will not make the least bit of sense. This fix is slightly more susceptible to a performance problem than the related fix for System V shared memory. By definition the pids are updated by msgsnd and msgrcv, the fast path of System V message queues. The only concern over the previous implementation is the incrementing and decrementing of the pid reference count. As that is the only difference and multiple updates by of the task_tgid by threads in the same process have been shown in af_unix sockets to create a cache line ping-pong between cpus of the same processor. In this case I don't expect cache lines holding pid reference counts to ping pong between cpus. As senders and receivers update different pids there is a natural separation there. Further if multiple threads of the same process either send or receive messages the pid will be updated to the same value and ipc_update_pid will avoid the reference count update. Which means in the common case I expect msg_lspid and msg_lrpid to remain constant, and reference counts not to be updated when messages are sent. In rare cases it may be possible to trigger the issue which was observed for af_unix sockets, but it will require multiple processes with multiple threads to be either sending or receiving messages. It just does not feel likely that anyone would do that in practice. This change updates msgctl(..., IPC_STAT, ...) to return msg_lspid and msg_lrpid in the pid namespace of the process calling stat. This change also updates cat /proc/sysvipc/msg to return print msg_lspid and msg_lrpid in the pid namespace of the process that opened the proc file. Fixes: b488893a390e ("pid namespaces: changes to show virtual ids to user") Reviewed-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * ipc/shm: Fix shmctl(..., IPC_STAT, ...) between pid namespaces.Eric W. Biederman2018-03-271-10/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today shm_cpid and shm_lpid are remembered in the pid namespace of the creator and the processes that last touched a sysvipc shared memory segment. If you have processes in multiple pid namespaces that is just wrong, and I don't know how this has been over-looked for so long. As only creation and shared memory attach and shared memory detach update the pids I do not expect there to be a repeat of the issues when struct pid was attached to each af_unix skb, which in some notable cases cut the performance in half. The problem was threads of the same process updating same struct pid from different cpus causing the cache line to be highly contended and bounce between cpus. As creation, attach, and detach are expected to be rare operations for sysvipc shared memory segments I do not expect that kind of cache line ping pong to cause probems. In addition because the pid is at a fixed location in the structure instead of being dynamic on a skb, the reference count of the pid does not need to be updated on each operation if the pid is the same. This ability to simply skip the pid reference count changes if the pid is unchanging further reduces the likelihood of the a cache line holding a pid reference count ping-ponging between cpus. Fixes: b488893a390e ("pid namespaces: changes to show virtual ids to user") Reviewed-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * ipc/util: Helpers for making the sysvipc operations pid namespace awareEric W. Biederman2018-03-242-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Capture the pid namespace when /proc/sysvipc/msg /proc/sysvipc/shm and /proc/sysvipc/sem are opened, and make it available through the new helper ipc_seq_pid_ns. This makes it possible to report the pids in these files in the pid namespace of the opener of the files. Implement ipc_update_pid. A simple impline helper that will only update a struct pid pointer if the new value does not equal the old value. This removes the need for wordy code sequences like: old = object->pid; object->pid = new; put_pid(old); and old = object->pid; if (old != new) { object->pid = new; put_pid(old); } Allowing the following to be written instead: ipc_update_pid(&object->pid, new); Which is easier to read and ensures that the pid reference count is not touched the old and the new values are the same. Not touching the reference count in this case is important to help avoid issues like af_unix experienced, where multiple threads of the same process managed to bounce the struct pid between cpu cache lines, but updating the pids reference count. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * ipc: Move IPCMNI from include/ipc.h into ipc/util.hEric W. Biederman2018-03-241-0/+1
| | | | | | | | | | | | | | | | The definition IPCMNI is only used in ipc/util.h and ipc/util.c. So there is no reason to keep it in a header file that the whole kernel can see. Move it into util.h to simplify future maintenance. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * msg: Move struct msg_queue into ipc/msg.cEric W. Biederman2018-03-241-0/+17
| | | | | | | | | | | | | | | | All of the users are now in ipc/msg.c so make the definition local to that file to make code maintenance easier. AKA to prevent rebuilding the entire kernel when struct msg_queue changes. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * shm: Move struct shmid_kernel into ipc/shm.cEric W. Biederman2018-03-241-0/+22
| | | | | | | | | | | | | | | | All of the users are now in ipc/shm.c so make the definition local to that file to make code maintenance easier. AKA to prevent rebuilding the entire kernel when struct shmid_kernel changes. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * sem: Move struct sem and struct sem_array into ipc/sem.cEric W. Biederman2018-03-231-0/+34
| | | | | | | | | | | | | | | | | | All of the users are now in ipc/sem.c so make the definitions local to that file to make code maintenance easier. AKA to prevent rebuilding the entire kernel when one of these files is changed. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooksEric W. Biederman2018-03-231-10/+8
| | | | | | | | | | | | | | | | | | | | | | | | All of the implementations of security hooks that take msg_queue only access q_perm the struct kern_ipc_perm member. This means the dependencies of the msg_queue security hooks can be simplified by passing the kern_ipc_perm member of msg_queue. Making this change will allow struct msg_queue to become private to ipc/msg.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| * shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooksEric W. Biederman2018-03-231-10/+7
| | | | | | | | | | | | | | | | | | | | | | All of the implementations of security hooks that take shmid_kernel only access shm_perm the struct kern_ipc_perm member. This means the dependencies of the shm security hooks can be simplified by passing the kern_ipc_perm member of shmid_kernel.. Making this change will allow struct shmid_kernel to become private to ipc/shm.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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