Shared memory segments can be created that are backed by hugetlb pages.
When this happens, the vmas associated with any mappings (shmat) are
marked VM_HUGETLB, yet the vm_ops for such mappings are provided by
ipc/shm (shm_vm_ops). There is a mechanism to call the underlying hugetlb
vm_ops, and this is done for most operations. However, it is not done for
open and close.
This was not an issue until the introduction of the hugetlb vma_lock.
This lock structure is pointed to by vm_private_data and the open/close
vm_ops help maintain this structure. The special hugetlb routine called
at fork took care of structure updates at fork time. However,
vma_splitting is not properly handled for ipc shared memory mappings
backed by hugetlb pages. This can result in a "kernel NULL pointer
dereference" BUG or use after free as two vmas point to the same lock
structure.
Update the shm open and close routines to always call the underlying open
and close routines.
Link: https://lkml.kernel.org/r/20221114210018.49346-1-mike.kravetz@oracle.com
Fixes: 8d9bfb2608 ("hugetlb: add vma based lock for pmd sharing")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Doug Nelson <doug.nelson@intel.com>
Reported-by: <syzbot+83b4134621b7c326d950@syzkaller.appspotmail.com>
Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
These percpu counters are referenced in free_ipcs->freeque, so destroy
them later.
Fixes: 72d1e61108 ("ipc/msg: mitigate the lock contention with percpu counter")
Reported-by: syzbot+96e659d35b9d6b541152@syzkaller.appspotmail.com
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jiebin Sun <jiebin.sun@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Valentin Schneider makes crash-kexec work properly when invoked from
an NMI-time panic.
- ntfs bugfixes from Hawkins Jiawei
- Jiebin Sun improves IPC msg scalability by replacing atomic_t's with
percpu counters.
- nilfs2 cleanups from Minghao Chi
- lots of other single patches all over the tree!
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Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- hfs and hfsplus kmap API modernization (Fabio Francesco)
- make crash-kexec work properly when invoked from an NMI-time panic
(Valentin Schneider)
- ntfs bugfixes (Hawkins Jiawei)
- improve IPC msg scalability by replacing atomic_t's with percpu
counters (Jiebin Sun)
- nilfs2 cleanups (Minghao Chi)
- lots of other single patches all over the tree!
* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
proc: test how it holds up with mapping'less process
mailmap: update Frank Rowand email address
ia64: mca: use strscpy() is more robust and safer
init/Kconfig: fix unmet direct dependencies
ia64: update config files
nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
fork: remove duplicate included header files
init/main.c: remove unnecessary (void*) conversions
proc: mark more files as permanent
nilfs2: remove the unneeded result variable
nilfs2: delete unnecessary checks before brelse()
checkpatch: warn for non-standard fixes tag style
usr/gen_init_cpio.c: remove unnecessary -1 values from int file
ipc/msg: mitigate the lock contention with percpu counter
percpu: add percpu_counter_add_local and percpu_counter_sub_local
fs/ocfs2: fix repeated words in comments
relay: use kvcalloc to alloc page array in relay_alloc_page_array
proc: make config PROC_CHILDREN depend on PROC_FS
fs: uninline inode_maybe_inc_iversion()
...
linux-next for a couple of months without, to my knowledge, any negative
reports (or any positive ones, come to that).
- Also the Maple Tree from Liam R. Howlett. An overlapping range-based
tree for vmas. It it apparently slight more efficient in its own right,
but is mainly targeted at enabling work to reduce mmap_lock contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
(https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
This has yet to be addressed due to Liam's unfortunately timed
vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down to
the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
A fix for a unlikely but possible memory leak.
Hangyu Hua (1):
ipc: mqueue: fix possible memory leak in init_mqueue_fs()
ipc/mqueue.c | 1 +
1 file changed, 1 insertion(+)
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Merge tag 'retire_mq_sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull mqueue fix from Eric Biederman:
"A fix for an unlikely but possible memory leak"
* tag 'retire_mq_sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ipc: mqueue: fix possible memory leak in init_mqueue_fs()
The msg_bytes and msg_hdrs atomic counters are frequently updated when IPC
msg queue is in heavy use, causing heavy cache bounce and overhead.
Change them to percpu_counter greatly improve the performance. Since
there is one percpu struct per namespace, additional memory cost is
minimal. Reading of the count done in msgctl call, which is infrequent.
So the need to sum up the counts in each CPU is infrequent.
Apply the patch and test the pts/stress-ng-1.4.0
-- system v message passing (160 threads).
Score gain: 3.99x
CPU: ICX 8380 x 2 sockets
Core number: 40 x 2 physical cores
Benchmark: pts/stress-ng-1.4.0
-- system v message passing (160 threads)
[akpm@linux-foundation.org: coding-style cleanups]
[jiebin.sun@intel.com: avoid negative value by overflow in msginfo]
Link: https://lkml.kernel.org/r/20220920150809.4014944-1-jiebin.sun@intel.com
[akpm@linux-foundation.org: fix min() warnings]
Link: https://lkml.kernel.org/r/20220913192538.3023708-3-jiebin.sun@intel.com
Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
iput() already handles null and non-null parameters, so there is no need
to use if().
Link: https://lkml.kernel.org/r/20220908185452.76590-1-jingyuwang_vip@163.com
Signed-off-by: Jingyu Wang <jingyuwang_vip@163.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The VMA iterator is faster than the linked llist, and it can be walked
even when VMAs are being removed from the address space, so there's no
need to keep track of 'next'.
Link: https://lkml.kernel.org/r/20220906194824.2110408-46-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
sysvipc_find_ipc() can be simplified further:
- It uses a for() loop to locate the next entry in the idr.
This can be replaced with idr_get_next().
- It receives two parameters (pos - which is actually
an idr index and not a position, and new_pos, which
is really a position).
One parameter is sufficient.
Link: https://lore.kernel.org/all/20210903052020.3265-3-manfred@colorfullife.com/
Link: https://lkml.kernel.org/r/20220805115733.104763-1-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Waiman Long <longman@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
fatfs, autofs, squashfs, procfs, etc.
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Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc updates from Andrew Morton:
"Updates to various subsystems which I help look after. lib, ocfs2,
fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
material this time"
* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
scripts/gdb: ensure the absolute path is generated on initial source
MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
mailmap: add linux.dev alias for Brendan Higgins
mailmap: update Kirill's email
profile: setup_profiling_timer() is moslty not implemented
ocfs2: fix a typo in a comment
ocfs2: use the bitmap API to simplify code
ocfs2: remove some useless functions
lib/mpi: fix typo 'the the' in comment
proc: add some (hopefully) insightful comments
bdi: remove enum wb_congested_state
kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
squashfs: support reading fragments in readahead call
squashfs: implement readahead
squashfs: always build "file direct" version of page actor
Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
fs/ocfs2: Fix spelling typo in comment
ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
proc: fix test for "vsyscall=xonly" boot option
...
commit db7cfc3809 ("ipc: Free mq_sysctls if ipc namespace creation
failed")
Here's a similar memory leak to the one fixed by the patch above.
retire_mq_sysctls need to be called when init_mqueue_fs fails after
setup_mq_sysctls.
Fixes: dc55e35f9e ("ipc: Store mqueue sysctls in the ipc namespace")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lkml.kernel.org/r/20220715062301.19311-1-hbh25y@gmail.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
per ipc namespace. Previously these sysctls depended upon a hack to
simulate being per ipc namespace by looking up the ipc namespace in
read or write. With this set of changes the ipc sysctls are
registered per ipc namespace and open looks up the ipc namespace.
Not only does this series of changes ensure the traditional binding at
open time happens, but it sets a foundation for being able to relax the
permission checks to allow a user namspace root to change the ipc sysctls
for an ipc namespace that the user namespace root requires. To do this
requires the ipc namespace to be known at open time.
These changes were sent for v5.18[1] but were dropped because some
additional cleanups were requested. Linus has given his nod[2] to the
cleanups so I hope enough cleanups are present this time.
[1] https://lkml.kernel.org/r/877d8kfmdp.fsf@email.froward.int.ebiederm.org
[2] https://lkml.kernel.org/r/CAHk-=whi2SzU4XT_FsdTCAuK2qtYmH+-hwi1cbSdG8zu0KXL=g@mail.gmail.com
Alexey Gladkov (6):
ipc: Store mqueue sysctls in the ipc namespace
ipc: Store ipc sysctls in the ipc namespace
ipc: Use the same namespace to modify and validate
ipc: Remove extra1 field abuse to pass ipc namespace
ipc: Check permissions for checkpoint_restart sysctls at open time
ipc: Remove extra braces
include/linux/ipc_namespace.h | 37 +++++++-
ipc/ipc_sysctl.c | 205 +++++++++++++++++++++++++-----------------
ipc/mq_sysctl.c | 121 +++++++++++++------------
ipc/mqueue.c | 10 +--
ipc/namespace.c | 10 +++
5 files changed, 238 insertions(+), 145 deletions(-)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'per-namespace-ipc-sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ipc sysctl namespace updates from Eric Biederman:
"This updates the ipc sysctls so that they are fundamentally per ipc
namespace. Previously these sysctls depended upon a hack to simulate
being per ipc namespace by looking up the ipc namespace in read or
write. With this set of changes the ipc sysctls are registered per ipc
namespace and open looks up the ipc namespace.
Not only does this series of changes ensure the traditional binding at
open time happens, but it sets a foundation for being able to relax
the permission checks to allow a user namspace root to change the ipc
sysctls for an ipc namespace that the user namespace root requires. To
do this requires the ipc namespace to be known at open time"
* tag 'per-namespace-ipc-sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ipc: Remove extra braces
ipc: Check permissions for checkpoint_restart sysctls at open time
ipc: Remove extra1 field abuse to pass ipc namespace
ipc: Use the same namespace to modify and validate
ipc: Store ipc sysctls in the ipc namespace
ipc: Store mqueue sysctls in the ipc namespace
When running the stress-ng clone benchmark with multiple testing threads,
it was found that there were significant spinlock contention in sget_fc().
The contended spinlock was the sb_lock. It is under heavy contention
because the following code in the critcal section of sget_fc():
hlist_for_each_entry(old, &fc->fs_type->fs_supers, s_instances) {
if (test(old, fc))
goto share_extant_sb;
}
After testing with added instrumentation code, it was found that the
benchmark could generate thousands of ipc namespaces with the
corresponding number of entries in the mqueue's fs_supers list where the
namespaces are the key for the search. This leads to excessive time in
scanning the list for a match.
Looking back at the mqueue calling sequence leading to sget_fc():
mq_init_ns()
=> mq_create_mount()
=> fc_mount()
=> vfs_get_tree()
=> mqueue_get_tree()
=> get_tree_keyed()
=> vfs_get_super()
=> sget_fc()
Currently, mq_init_ns() is the only mqueue function that will indirectly
call mqueue_get_tree() with a newly allocated ipc namespace as the key for
searching. As a result, there will never be a match with the exising ipc
namespaces stored in the mqueue's fs_supers list.
So using get_tree_keyed() to do an existing ipc namespace search is just a
waste of time. Instead, we could use get_tree_nodev() to eliminate the
useless search. By doing so, we can greatly reduce the sb_lock hold time
and avoid the spinlock contention problem in case a large number of ipc
namespaces are present.
Of course, if the code is modified in the future to allow
mqueue_get_tree() to be called with an existing ipc namespace instead of a
new one, we will have to use get_tree_keyed() in this case.
The following stress-ng clone benchmark command was run on a 2-socket
48-core Intel system:
./stress-ng --clone 32 --verbose --oomable --metrics-brief -t 20
The "bogo ops/s" increased from 5948.45 before patch to 9137.06 after
patch. This is an increase of 54% in performance.
Link: https://lkml.kernel.org/r/20220121172315.19652-1-longman@redhat.com
Fixes: 935c6912b1 ("ipc: Convert mqueue fs to fs_context")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
semtimedop() should be converted to use hrtimer like it has been done for
most of the system calls with timeouts. This system call already takes a
struct timespec as an argument and can therefore provide finer granularity
timed wait.
Link: https://lkml.kernel.org/r/1651187881-2858-1-git-send-email-prakash.sangappa@oracle.com
Signed-off-by: Prakash Sangappa <prakash.sangappa@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Get rid of redundant assignments which end up in values not being
read either because they are overwritten or the function ends.
Reported by clang-tidy [deadcode.DeadStores]
Link: https://lkml.kernel.org/r/20220409101933.207157-1-michalorzel.eng@gmail.com
Signed-off-by: Michal Orzel <michalorzel.eng@gmail.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().
Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> [ext4]
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ipc sysctls are not available for modification inside the user
namespace. Following the mqueue sysctls, we changed the implementation
to be more userns friendly.
So far, the changes do not provide additional access to files. This
will be done in a future patch.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/be6f9d014276f4dddd0c3aa05a86052856c1c555.1644862280.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Right now, the mqueue sysctls take ipc namespaces into account in a
rather hacky way. This works in most cases, but does not respect the
user namespace.
Within the user namespace, the user cannot change the /proc/sys/fs/mqueue/*
parametres. This poses a problem in the rootless containers.
To solve this I changed the implementation of the mqueue sysctls just
like some other sysctls.
So far, the changes do not provide additional access to files. This will
be done in a future patch.
v3:
* Don't implemenet set_permissions to keep the current behavior.
v2:
* Fixed compilation problem if CONFIG_POSIX_MQUEUE_SYSCTL is not
specified.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/b0ccbb2489119f1f20c737cf1930c3a9c4e4243a.1644862280.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Remove PDE_DATA() completely and replace it with pde_data().
[akpm@linux-foundation.org: fix naming clash in drivers/nubus/proc.c]
[akpm@linux-foundation.org: now fix it properly]
Link: https://lkml.kernel.org/r/20211124081956.87711-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the exit_shm() function not designed to work properly when
task->sysvshm.shm_clist holds shm objects from different IPC namespaces.
This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it
leads to use-after-free (reproducer exists).
This is an attempt to fix the problem by extending exit_shm mechanism to
handle shm's destroy from several IPC ns'es.
To achieve that we do several things:
1. add a namespace (non-refcounted) pointer to the struct shmid_kernel
2. during new shm object creation (newseg()/shmget syscall) we
initialize this pointer by current task IPC ns
3. exit_shm() fully reworked such that it traverses over all shp's in
task->sysvshm.shm_clist and gets IPC namespace not from current task
as it was before but from shp's object itself, then call
shm_destroy(shp, ns).
Note: We need to be really careful here, because as it was said before
(1), our pointer to IPC ns non-refcnt'ed. To be on the safe side we
using special helper get_ipc_ns_not_zero() which allows to get IPC ns
refcounter only if IPC ns not in the "state of destruction".
Q/A
Q: Why can we access shp->ns memory using non-refcounted pointer?
A: Because shp object lifetime is always shorther than IPC namespace
lifetime, so, if we get shp object from the task->sysvshm.shm_clist
while holding task_lock(task) nobody can steal our namespace.
Q: Does this patch change semantics of unshare/setns/clone syscalls?
A: No. It's just fixes non-covered case when process may leave IPC
namespace without getting task->sysvshm.shm_clist list cleaned up.
Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife.com
Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com
Fixes: ab602f7991 ("shm: make exit_shm work proportional to task activity")
Co-developed-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "shm: shm_rmid_forced feature fixes".
Some time ago I met kernel crash after CRIU restore procedure,
fortunately, it was CRIU restore, so, I had dump files and could do
restore many times and crash reproduced easily. After some
investigation I've constructed the minimal reproducer. It was found
that it's use-after-free and it happens only if sysctl
kernel.shm_rmid_forced = 1.
The key of the problem is that the exit_shm() function not handles shp's
object destroy when task->sysvshm.shm_clist contains items from
different IPC namespaces. In most cases this list will contain only
items from one IPC namespace.
How can this list contain object from different namespaces? The
exit_shm() function is designed to clean up this list always when
process leaves IPC namespace. But we made a mistake a long time ago and
did not add a exit_shm() call into the setns() syscall procedures.
The first idea was just to add this call to setns() syscall but it
obviously changes semantics of setns() syscall and that's
userspace-visible change. So, I gave up on this idea.
The first real attempt to address the issue was just to omit forced
destroy if we meet shp object not from current task IPC namespace [1].
But that was not the best idea because task->sysvshm.shm_clist was
protected by rwsem which belongs to current task IPC namespace. It
means that list corruption may occur.
Second approach is just extend exit_shm() to properly handle shp's from
different IPC namespaces [2]. This is really non-trivial thing, I've
put a lot of effort into that but not believed that it's possible to
make it fully safe, clean and clear.
Thanks to the efforts of Manfred Spraul working an elegant solution was
designed. Thanks a lot, Manfred!
Eric also suggested the way to address the issue in ("[RFC][PATCH] shm:
In shm_exit destroy all created and never attached segments") Eric's
idea was to maintain a list of shm_clists one per IPC namespace, use
lock-less lists. But there is some extra memory consumption-related
concerns.
An alternative solution which was suggested by me was implemented in
("shm: reset shm_clist on setns but omit forced shm destroy"). The idea
is pretty simple, we add exit_shm() syscall to setns() but DO NOT
destroy shm segments even if sysctl kernel.shm_rmid_forced = 1, we just
clean up the task->sysvshm.shm_clist list.
This chages semantics of setns() syscall a little bit but in comparision
to the "naive" solution when we just add exit_shm() without any special
exclusions this looks like a safer option.
[1] https://lkml.org/lkml/2021/7/6/1108
[2] https://lkml.org/lkml/2021/7/14/736
This patch (of 2):
Let's produce a warning if we trying to remove non-existing IPC object
from IPC namespace kht/idr structures.
This allows us to catch possible bugs when the ipc_rmid() function was
called with inconsistent struct ipc_ids*, struct kern_ipc_perm*
arguments.
Link: https://lkml.kernel.org/r/20211027224348.611025-1-alexander.mikhalitsyn@virtuozzo.com
Link: https://lkml.kernel.org/r/20211027224348.611025-2-alexander.mikhalitsyn@virtuozzo.com
Co-developed-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Compilation of ipc/ipc_sysctl.c is controlled by
obj-$(CONFIG_SYSVIPC_SYSCTL)
[see ipc/Makefile]
And CONFIG_SYSVIPC_SYSCTL depends on SYSCTL
[see init/Kconfig]
An SYSCTL is selected by PROC_SYSCTL.
[see fs/proc/Kconfig]
Thus: #ifndef CONFIG_PROC_SYSCTL in ipc/ipc_sysctl.c is impossible, the
fallback can be removed.
Link: https://lkml.kernel.org/r/20210918145337.3369-1-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-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>
This commit removes the requirement to be root to modify sem_next_id,
msg_next_id and shm_next_id and checks checkpoint_restore_ns_capable
instead.
Since those files are specific to the IPC namespace, there is no reason
they should require root privileges. This is similar to ns_last_pid,
which also only checks checkpoint_restore_ns_capable.
[akpm@linux-foundation.org: ipc/ipc_sysctl.c needs capability.h for checkpoint_restore_ns_capable()]
Link: https://lkml.kernel.org/r/20210916163717.3179496-1-mclapinski@google.com
Signed-off-by: Michal Clapinski <mclapinski@google.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: 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>
Commit 21a3c273f8 ("mm, hugetlb: add thread name and pid to
SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
but it is not deleted yet.
Mike says he still sees that message in log files on occasion, so maybe we
should preserve this warning.
Also remove hugetlbfs related user_shm_unlock in ipc/shm.c and remove the
user_shm_unlock after out.
Link: https://lkml.kernel.org/r/20211103105857.25041-1-zhangyiru3@huawei.com
Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: wuxu.wu <wuxu.wu@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus proposes to revert an accounting for sops objects in
do_semtimedop() because it's really just a temporary buffer
for a single semtimedop() system call.
This object can consume up to 2 pages, syscall is sleeping
one, size and duration can be controlled by user, and this
allocation can be repeated by many thread at the same time.
However Shakeel Butt pointed that there are much more popular
objects with the same life time and similar memory
consumption, the accounting of which was decided to be
rejected for performance reasons.
Considering at least 2 pages for task_struct and 2 pages for
the kernel stack, a back of the envelope calculation gives a
footprint amplification of <1.5 so this temporal buffer can be
safely ignored.
The factor would IMO be interesting if it was >> 2 (from the
PoV of excessive (ab)use, fine-grained accounting seems to be
currently unfeasible due to performance impact).
Link: https://lore.kernel.org/lkml/90e254df-0dfe-f080-011e-b7c53ee7fd20@virtuozzo.com/
Fixes: 18319498fd ("memcg: enable accounting of ipc resources")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge more updates from Andrew Morton:
"147 patches, based on 7d2a07b769.
Subsystems affected by this patch series: mm (memory-hotplug, rmap,
ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
selftests, ipc, and scripts"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
scripts: check_extable: fix typo in user error message
mm/workingset: correct kernel-doc notations
ipc: replace costly bailout check in sysvipc_find_ipc()
selftests/memfd: remove unused variable
Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
configs: remove the obsolete CONFIG_INPUT_POLLDEV
prctl: allow to setup brk for et_dyn executables
pid: cleanup the stale comment mentioning pidmap_init().
kernel/fork.c: unexport get_{mm,task}_exe_file
coredump: fix memleak in dump_vma_snapshot()
fs/coredump.c: log if a core dump is aborted due to changed file permissions
nilfs2: use refcount_dec_and_lock() to fix potential UAF
nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
nilfs2: fix NULL pointer in nilfs_##name##_attr_release
nilfs2: fix memory leak in nilfs_sysfs_create_device_group
trap: cleanup trap_init()
init: move usermodehelper_enable() to populate_rootfs()
...
sysvipc_find_ipc() was left with a costly way to check if the offset
position fed to it is bigger than the total number of IPC IDs in use. So
much so that the time it takes to iterate over /proc/sysvipc/* files grows
exponentially for a custom benchmark that creates "N" SYSV shm segments
and then times the read of /proc/sysvipc/shm (milliseconds):
12 msecs to read 1024 segs from /proc/sysvipc/shm
18 msecs to read 2048 segs from /proc/sysvipc/shm
65 msecs to read 4096 segs from /proc/sysvipc/shm
325 msecs to read 8192 segs from /proc/sysvipc/shm
1303 msecs to read 16384 segs from /proc/sysvipc/shm
5182 msecs to read 32768 segs from /proc/sysvipc/shm
The root problem lies with the loop that computes the total amount of ids
in use to check if the "pos" feeded to sysvipc_find_ipc() grew bigger than
"ids->in_use". That is a quite inneficient way to get to the maximum
index in the id lookup table, specially when that value is already
provided by struct ipc_ids.max_idx.
This patch follows up on the optimization introduced via commit
15df03c879 ("sysvipc: make get_maxid O(1) again") and gets rid of the
aforementioned costly loop replacing it by a simpler checkpoint based on
ipc_get_maxidx() returned value, which allows for a smooth linear increase
in time complexity for the same custom benchmark:
2 msecs to read 1024 segs from /proc/sysvipc/shm
2 msecs to read 2048 segs from /proc/sysvipc/shm
4 msecs to read 4096 segs from /proc/sysvipc/shm
9 msecs to read 8192 segs from /proc/sysvipc/shm
19 msecs to read 16384 segs from /proc/sysvipc/shm
39 msecs to read 32768 segs from /proc/sysvipc/shm
Link: https://lkml.kernel.org/r/20210809203554.1562989-1-aquini@redhat.com
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Waiman Long <llong@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Container admin can create new namespaces and force kernel to allocate up
to several pages of memory for the namespaces and its associated
structures.
Net and uts namespaces have enabled accounting for such allocations. It
makes sense to account for rest ones to restrict the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/5525bcbf-533e-da27-79b7-158686c64e13@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sys_oabi_semtimedop() is one of the last users of set_fs() on Arm. To
remove this one, expose the internal code of the actual implementation
that operates on a kernel pointer and call it directly after copying.
There should be no measurable impact on the normal execution of this
function, and it makes the overly long function a little shorter, which
may help readability.
While reworking the oabi version, make it behave a little more like
the native one, using kvmalloc_array() and restructure the code
flow in a similar way.
The naming of __do_semtimedop() is not very good, I hope someone can
come up with a better name.
One regression was spotted by kernel test robot <rong.a.chen@intel.com>
and fixed before the first mailing list submission.
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
If semctl(), msgctl() and shmctl() are called with IPC_INFO, SEM_INFO,
MSG_INFO or SHM_INFO, then the return value is the index of the highest
used index in the kernel's internal array recording information about all
SysV objects of the requested type for the current namespace. (This
information can be used with repeated ..._STAT or ..._STAT_ANY operations
to obtain information about all SysV objects on the system.)
There is a cache for this value. But when the cache needs up be updated,
then the highest used index is determined by looping over all possible
values. With the introduction of IPCMNI_EXTEND_SHIFT, this could be a
loop over 16 million entries. And due to /proc/sys/kernel/*next_id, the
index values do not need to be consecutive.
With <write 16000000 to msg_next_id>, msgget(), msgctl(,IPC_RMID) in a
loop, I have observed a performance increase of around factor 13000.
As there is no get_last() function for idr structures: Implement a
"get_last()" using a binary search.
As far as I see, ipc is the only user that needs get_last(), thus
implement it in ipc/util.c and not in a central location.
[akpm@linux-foundation.org: tweak comment, fix typo]
Link: https://lkml.kernel.org/r/20210425075208.11777-2-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patch solves three weaknesses in ipc/sem.c:
1) The initial read of use_global_lock in sem_lock() is an intentional
race. KCSAN detects these accesses and prints a warning.
2) The code assumes that plain C read/writes are not mangled by the CPU
or the compiler.
3) The comment it sysvipc_sem_proc_show() was hard to understand: The
rest of the comments in ipc/sem.c speaks about sem_perm.lock, and
suddenly this function speaks about ipc_lock_object().
To solve 1) and 2), use READ_ONCE()/WRITE_ONCE(). Plain C reads are used
in code that owns sma->sem_perm.lock.
The comment is updated to solve 3)
[manfred@colorfullife.com: use READ_ONCE()/WRITE_ONCE() for use_global_lock]
Link: https://lkml.kernel.org/r/20210627161919.3196-3-manfred@colorfullife.com
Link: https://lkml.kernel.org/r/20210514175319.12195-1-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
msg_queue and shmid_kernel are quite small objects, no need to use
kvmalloc for them. mhocko@: "Both of them are 256B on most 64b systems."
Previously these objects was allocated via ipc_alloc/ipc_rcu_alloc(),
common function for several ipc objects. It had kvmalloc call inside().
Later, this function went away and was finally replaced by direct kvmalloc
call, and now we can use more suitable kmalloc/kfree for them.
Link: https://lkml.kernel.org/r/0d0b6c9b-8af3-29d8-34e2-a565c53780f3@virtuozzo.com
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.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>
Patch series "ipc: allocations cleanup", v2.
Some ipc objects use the wrong allocation functions: small objects can use
kmalloc(), and vice versa, potentially large objects can use kmalloc().
This patch (of 2):
Size of sem_undo can exceed one page and with the maximum possible nsems =
32000 it can grow up to 64Kb. Let's switch its allocation to kvmalloc to
avoid user-triggered disruptive actions like OOM killer in case of
high-order memory shortage.
User triggerable high order allocations are quite a problem on heavily
fragmented systems. They can be a DoS vector.
Link: https://lkml.kernel.org/r/ebc3ac79-3190-520d-81ce-22ad194986ec@virtuozzo.com
Link: https://lkml.kernel.org/r/a6354fd9-2d55-2e63-dd4d-fa7dc1d11134@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull user namespace rlimit handling update from Eric Biederman:
"This is the work mainly by Alexey Gladkov to limit rlimits to the
rlimits of the user that created a user namespace, and to allow users
to have stricter limits on the resources created within a user
namespace."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
cred: add missing return error code when set_cred_ucounts() failed
ucounts: Silence warning in dec_rlimit_ucounts
ucounts: Set ucount_max to the largest positive value the type can hold
kselftests: Add test to check for rlimit changes in different user namespaces
Reimplement RLIMIT_MEMLOCK on top of ucounts
Reimplement RLIMIT_SIGPENDING on top of ucounts
Reimplement RLIMIT_MSGQUEUE on top of ucounts
Reimplement RLIMIT_NPROC on top of ucounts
Use atomic_t for ucounts reference counting
Add a reference to ucounts for each cred
Increase size of ucounts to atomic_long_t
do_mq_timedreceive calls wq_sleep with a stack local address. The
sender (do_mq_timedsend) uses this address to later call pipelined_send.
This leads to a very hard to trigger race where a do_mq_timedreceive
call might return and leave do_mq_timedsend to rely on an invalid
address, causing the following crash:
RIP: 0010:wake_q_add_safe+0x13/0x60
Call Trace:
__x64_sys_mq_timedsend+0x2a9/0x490
do_syscall_64+0x80/0x680
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f5928e40343
The race occurs as:
1. do_mq_timedreceive calls wq_sleep with the address of `struct
ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it
holds a valid `struct ext_wait_queue *` as long as the stack has not
been overwritten.
2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and
do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call
__pipelined_op.
3. Sender calls __pipelined_op::smp_store_release(&this->state,
STATE_READY). Here is where the race window begins. (`this` is
`ewq_addr`.)
4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it
will see `state == STATE_READY` and break.
5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed
to be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's
stack. (Although the address may not get overwritten until another
function happens to touch it, which means it can persist around for an
indefinite time.)
6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a
`struct ext_wait_queue *`, and uses it to find a task_struct to pass to
the wake_q_add_safe call. In the lucky case where nothing has
overwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.
In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a
bogus address as the receiver's task_struct causing the crash.
do_mq_timedsend::__pipelined_op() should not dereference `this` after
setting STATE_READY, as the receiver counterpart is now free to return.
Change __pipelined_op to call wake_q_add_safe on the receiver's
task_struct returned by get_task_struct, instead of dereferencing `this`
which sits on the receiver's stack.
As Manfred pointed out, the race potentially also exists in
ipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare. Fix
those in the same way.
Link: https://lkml.kernel.org/r/20210510102950.12551-1-varad.gautam@suse.com
Fixes: c5b2cbdbda ("ipc/mqueue.c: update/document memory barriers")
Fixes: 8116b54e7e ("ipc/sem.c: document and update memory barriers")
Fixes: 0d97a82ba8 ("ipc/msg.c: update and document memory barriers")
Signed-off-by: Varad Gautam <varad.gautam@suse.com>
Reported-by: Matthias von Faber <matthias.vonfaber@aox-tech.de>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Oleg Nesterov <oleg@redhat.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>
The rlimit counter is tied to uid in the user_namespace. This allows
rlimit values to be specified in userns even if they are already
globally exceeded by the user. However, the value of the previous
user_namespaces cannot be exceeded.
Changelog
v11:
* Fix issue found by lkp robot.
v8:
* Fix issues found by lkp-tests project.
v7:
* Keep only ucounts for RLIMIT_MEMLOCK checks instead of struct cred.
v6:
* Fix bug in hugetlb_file_setup() detected by trinity.
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/970d50c70c71bfd4496e0e8d2a0a32feebebb350.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The rlimit counter is tied to uid in the user_namespace. This allows
rlimit values to be specified in userns even if they are already
globally exceeded by the user. However, the value of the previous
user_namespaces cannot be exceeded.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/2531f42f7884bbfee56a978040b3e0d25cdf6cde.1619094428.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The various vfs_*() helpers are called by filesystems or by the vfs
itself to perform core operations such as create, link, mkdir, mknod, rename,
rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the
inode is accessed through an idmapped mount map it into the
mount's user namespace and pass it down. Afterwards the checks and
operations are identical to non-idmapped mounts. If the initial user
namespace is passed nothing changes so non-idmapped mounts will see
identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-15-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
Rename the callback to reflect that it's not called *on* or *after* split,
but rather some time before the splitting to check if it's possible.
Link: https://lkml.kernel.org/r/20201013013416.390574-5-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull misc fixes from Christian Brauner:
"This contains several fixes which felt worth being combined into a
single branch:
- Use put_nsproxy() instead of open-coding it switch_task_namespaces()
- Kirill's work to unify lifecycle management for all namespaces. The
lifetime counters are used identically for all namespaces types.
Namespaces may of course have additional unrelated counters and
these are not altered. This work allows us to unify the type of the
counters and reduces maintenance cost by moving the counter in one
place and indicating that basic lifetime management is identical
for all namespaces.
- Peilin's fix adding three byte padding to Dmitry's
PTRACE_GET_SYSCALL_INFO uapi struct to prevent an info leak.
- Two smal patches to convert from the /* fall through */ comment
annotation to the fallthrough keyword annotation which I had taken
into my branch and into -next before df561f6688 ("treewide: Use
fallthrough pseudo-keyword") made it upstream which fixed this
tree-wide.
Since I didn't want to invalidate all testing for other commits I
didn't rebase and kept them"
* tag 'fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
nsproxy: use put_nsproxy() in switch_task_namespaces()
sys: Convert to the new fallthrough notation
signal: Convert to the new fallthrough notation
time: Use generic ns_common::count
cgroup: Use generic ns_common::count
mnt: Use generic ns_common::count
user: Use generic ns_common::count
pid: Use generic ns_common::count
ipc: Use generic ns_common::count
uts: Use generic ns_common::count
net: Use generic ns_common::count
ns: Add a common refcount into ns_common
ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info()
Switch over ipc namespaces to use the newly introduced common lifetime
counter.
Currently every namespace type has its own lifetime counter which is stored
in the specific namespace struct. The lifetime counters are used
identically for all namespaces types. Namespaces may of course have
additional unrelated counters and these are not altered.
This introduces a common lifetime counter into struct ns_common. The
ns_common struct encompasses information that all namespaces share. That
should include the lifetime counter since its common for all of them.
It also allows us to unify the type of the counters across all namespaces.
Most of them use refcount_t but one uses atomic_t and at least one uses
kref. Especially the last one doesn't make much sense since it's just a
wrapper around refcount_t since 2016 and actually complicates cleanup
operations by having to use container_of() to cast the correct namespace
struct out of struct ns_common.
Having the lifetime counter for the namespaces in one place reduces
maintenance cost. Not just because after switching all namespaces over we
will have removed more code than we added but also because the logic is
more easily understandable and we indicate to the user that the basic
lifetime requirements for all namespaces are currently identical.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/159644978697.604812.16592754423881032385.stgit@localhost.localdomain
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Remove the superfuous break, as there is a 'return' before it.
Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1594724361-11525-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Two functions are only called via function pointers, don't bother
inlining them.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: http://lkml.kernel.org/r/20200710200312.GA960353@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current split between do_mmap() and do_mmap_pgoff() was introduced in
commit 1fcfd8db7f ("mm, mpx: add "vm_flags_t vm_flags" arg to
do_mmap_pgoff()") to support MPX.
The wrapper function do_mmap_pgoff() always passed 0 as the value of the
vm_flags argument to do_mmap(). However, MPX support has subsequently
been removed from the kernel and there were no more direct callers of
do_mmap(); all calls were going via do_mmap_pgoff().
Simplify the code by removing do_mmap_pgoff() and changing all callers to
directly call do_mmap(), which now no longer takes a vm_flags argument.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200727194109.1371462-1-pcc@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the reason is to avoid a delay caused by the synchronize_rcu() call in
kern_umount() when the mqueue mount is freed.
the code:
#define _GNU_SOURCE
#include <sched.h>
#include <error.h>
#include <errno.h>
#include <stdlib.h>
int main()
{
int i;
for (i = 0; i < 1000; i++)
if (unshare(CLONE_NEWIPC) < 0)
error(EXIT_FAILURE, errno, "unshare");
}
goes from
Command being timed: "./ipc-namespace"
User time (seconds): 0.00
System time (seconds): 0.06
Percent of CPU this job got: 0%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:08.05
to
Command being timed: "./ipc-namespace"
User time (seconds): 0.00
System time (seconds): 0.02
Percent of CPU this job got: 96%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.03
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Link: http://lkml.kernel.org/r/20200225145419.527994-1-gscrivan@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
Augusto von Dentz.
2) Add GSO partial support to igc, from Sasha Neftin.
3) Several cleanups and improvements to r8169 from Heiner Kallweit.
4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
device self-test. From Andrew Lunn.
5) Start moving away from custom driver versions, use the globally
defined kernel version instead, from Leon Romanovsky.
6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.
7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.
8) Add sriov and vf support to hinic, from Luo bin.
9) Support Media Redundancy Protocol (MRP) in the bridging code, from
Horatiu Vultur.
10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.
11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
Dubroca. Also add ipv6 support for espintcp.
12) Lots of ReST conversions of the networking documentation, from Mauro
Carvalho Chehab.
13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
from Doug Berger.
14) Allow to dump cgroup id and filter by it in inet_diag code, from
Dmitry Yakunin.
15) Add infrastructure to export netlink attribute policies to
userspace, from Johannes Berg.
16) Several optimizations to sch_fq scheduler, from Eric Dumazet.
17) Fallback to the default qdisc if qdisc init fails because otherwise
a packet scheduler init failure will make a device inoperative. From
Jesper Dangaard Brouer.
18) Several RISCV bpf jit optimizations, from Luke Nelson.
19) Correct the return type of the ->ndo_start_xmit() method in several
drivers, it's netdev_tx_t but many drivers were using
'int'. From Yunjian Wang.
20) Add an ethtool interface for PHY master/slave config, from Oleksij
Rempel.
21) Add BPF iterators, from Yonghang Song.
22) Add cable test infrastructure, including ethool interfaces, from
Andrew Lunn. Marvell PHY driver is the first to support this
facility.
23) Remove zero-length arrays all over, from Gustavo A. R. Silva.
24) Calculate and maintain an explicit frame size in XDP, from Jesper
Dangaard Brouer.
25) Add CAP_BPF, from Alexei Starovoitov.
26) Support terse dumps in the packet scheduler, from Vlad Buslov.
27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.
28) Add devm_register_netdev(), from Bartosz Golaszewski.
29) Minimize qdisc resets, from Cong Wang.
30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
eliminate set_fs/get_fs calls. From Christoph Hellwig.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
selftests: net: ip_defrag: ignore EPERM
net_failover: fixed rollback in net_failover_open()
Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
vmxnet3: allow rx flow hash ops only when rss is enabled
hinic: add set_channels ethtool_ops support
selftests/bpf: Add a default $(CXX) value
tools/bpf: Don't use $(COMPILE.c)
bpf, selftests: Use bpf_probe_read_kernel
s390/bpf: Use bcr 0,%0 as tail call nop filler
s390/bpf: Maintain 8-byte stack alignment
selftests/bpf: Fix verifier test
selftests/bpf: Fix sample_cnt shared between two threads
bpf, selftests: Adapt cls_redirect to call csum_level helper
bpf: Add csum_level helper for fixing up csum levels
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
crypto/chtls: IPv6 support for inline TLS
Crypto/chcr: Fixes a coccinile check error
Crypto/chcr: Fixes compilations warnings
...
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Merge tag 'threads-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull thread updates from Christian Brauner:
"We have been discussing using pidfds to attach to namespaces for quite
a while and the patches have in one form or another already existed
for about a year. But I wanted to wait to see how the general api
would be received and adopted.
This contains the changes to make it possible to use pidfds to attach
to the namespaces of a process, i.e. they can be passed as the first
argument to the setns() syscall.
When only a single namespace type is specified the semantics are
equivalent to passing an nsfd. That means setns(nsfd, CLONE_NEWNET)
equals setns(pidfd, CLONE_NEWNET).
However, when a pidfd is passed, multiple namespace flags can be
specified in the second setns() argument and setns() will attach the
caller to all the specified namespaces all at once or to none of them.
Specifying 0 is not valid together with a pidfd. Here are just two
obvious examples:
setns(pidfd, CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWNET);
setns(pidfd, CLONE_NEWUSER);
Allowing to also attach subsets of namespaces supports various
use-cases where callers setns to a subset of namespaces to retain
privilege, perform an action and then re-attach another subset of
namespaces.
Apart from significantly reducing the number of syscalls needed to
attach to all currently supported namespaces (eight "open+setns"
sequences vs just a single "setns()"), this also allows atomic setns
to a set of namespaces, i.e. either attaching to all namespaces
succeeds or we fail without having changed anything.
This is centered around a new internal struct nsset which holds all
information necessary for a task to switch to a new set of namespaces
atomically. Fwiw, with this change a pidfd becomes the only token
needed to interact with a container. I'm expecting this to be
picked-up by util-linux for nsenter rather soon.
Associated with this change is a shiny new test-suite dedicated to
setns() (for pidfds and nsfds alike)"
* tag 'threads-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
selftests/pidfd: add pidfd setns tests
nsproxy: attach to namespaces via pidfds
nsproxy: add struct nsset
Move the bpf verifier trace check into the new switch statement in
HEAD.
Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a simple struct nsset. It holds all necessary pieces to switch to a new
set of namespaces without leaving a task in a half-switched state which we
will make use of in the next patch. This patch switches the existing setns
logic over without causing a change in setns() behavior. This brings
setns() closer to how unshare() works(). The prepare_ns() function is
responsible to prepare all necessary information. This has two reasons.
First it minimizes dependencies between individual namespaces, i.e. all
install handler can expect that all fields are properly initialized
independent in what order they are called in. Second, this makes the code
easier to maintain and easier to follow if it needs to be changed.
The prepare_ns() helper will only be switched over to use a flags argument
in the next patch. Here it will still use nstype as a simple integer
argument which was argued would be clearer. I'm not particularly
opinionated about this if it really helps or not. The struct nsset itself
already contains the flags field since its name already indicates that it
can contain information required by different namespaces. None of this
should have functional consequences.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Jann Horn <jannh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20200505140432.181565-2-christian.brauner@ubuntu.com
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following sparse warning:
ipc/shm.c:1335:6: warning: symbol 'compat_ksys_shmctl' was not declared.
Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200403063933.24785-1-yanaijie@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that "struct proc_ops" exist we can start putting there stuff which
could not fly with VFS "struct file_operations"...
Most of fs/proc/inode.c file is dedicated to make open/read/.../close
reliable in the event of disappearing /proc entries which usually happens
if module is getting removed. Files like /proc/cpuinfo which never
disappear simply do not need such protection.
Save 2 atomic ops, 1 allocation, 1 free per open/read/close sequence for such
"permanent" files.
Enable "permanent" flag for
/proc/cpuinfo
/proc/kmsg
/proc/modules
/proc/slabinfo
/proc/stat
/proc/sysvipc/*
/proc/swaps
More will come once I figure out foolproof way to prevent out module
authors from marking their stuff "permanent" for performance reasons
when it is not.
This should help with scalability: benchmark is "read /proc/cpuinfo R times
by N threads scattered over the system".
N R t, s (before) t, s (after)
-----------------------------------------------------
64 4096 1.582458 1.530502 -3.2%
256 4096 6.371926 6.125168 -3.9%
1024 4096 25.64888 24.47528 -4.6%
Benchmark source:
#include <chrono>
#include <iostream>
#include <thread>
#include <vector>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
const int NR_CPUS = sysconf(_SC_NPROCESSORS_ONLN);
int N;
const char *filename;
int R;
int xxx = 0;
int glue(int n)
{
cpu_set_t m;
CPU_ZERO(&m);
CPU_SET(n, &m);
return sched_setaffinity(0, sizeof(cpu_set_t), &m);
}
void f(int n)
{
glue(n % NR_CPUS);
while (*(volatile int *)&xxx == 0) {
}
for (int i = 0; i < R; i++) {
int fd = open(filename, O_RDONLY);
char buf[4096];
ssize_t rv = read(fd, buf, sizeof(buf));
asm volatile ("" :: "g" (rv));
close(fd);
}
}
int main(int argc, char *argv[])
{
if (argc < 4) {
std::cerr << "usage: " << argv[0] << ' ' << "N /proc/filename R
";
return 1;
}
N = atoi(argv[1]);
filename = argv[2];
R = atoi(argv[3]);
for (int i = 0; i < NR_CPUS; i++) {
if (glue(i) == 0)
break;
}
std::vector<std::thread> T;
T.reserve(N);
for (int i = 0; i < N; i++) {
T.emplace_back(f, i);
}
auto t0 = std::chrono::system_clock::now();
{
*(volatile int *)&xxx = 1;
for (auto& t: T) {
t.join();
}
}
auto t1 = std::chrono::system_clock::now();
std::chrono::duration<double> dt = t1 - t0;
std::cout << dt.count() << '
';
return 0;
}
P.S.:
Explicit randomization marker is added because adding non-function pointer
will silently disable structure layout randomization.
[akpm@linux-foundation.org: coding style fixes]
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200222201539.GA22576@avx2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit a979558448.
Commit a979558448 ("ipc,sem: remove uneeded sem_undo_list lock usage
in exit_sem()") removes a lock that is needed. This leads to a process
looping infinitely in exit_sem() and can also lead to a crash. There is
a reproducer available in [1] and with the commit reverted the issue
does not reproduce anymore.
Using the reproducer found in [1] is fairly easy to reach a point where
one of the child processes is looping infinitely in exit_sem between
for(;;) and if (semid == -1) block, while it's trying to free its last
sem_undo structure which has already been freed by freeary().
Each sem_undo struct is on two lists: one per semaphore set (list_id)
and one per process (list_proc). The list_id list tracks undos by
semaphore set, and the list_proc by process.
Undo structures are removed either by freeary() or by exit_sem(). The
freeary function is invoked when the user invokes a syscall to remove a
semaphore set. During this operation freeary() traverses the list_id
associated with the semaphore set and removes the undo structures from
both the list_id and list_proc lists.
For this case, exit_sem() is called at process exit. Each process
contains a struct sem_undo_list (referred to as "ulp") which contains
the head for the list_proc list. When the process exits, exit_sem()
traverses this list to remove each sem_undo struct. As in freeary(),
whenever a sem_undo struct is removed from list_proc, it is also removed
from the list_id list.
Removing elements from list_id is safe for both exit_sem() and freeary()
due to sem_lock(). Removing elements from list_proc is not safe;
freeary() locks &un->ulp->lock when it performs
list_del_rcu(&un->list_proc) but exit_sem() does not (locking was
removed by commit a979558448 ("ipc,sem: remove uneeded sem_undo_list
lock usage in exit_sem()").
This can result in the following situation while executing the
reproducer [1] : Consider a child process in exit_sem() and the parent
in freeary() (because of semctl(sid[i], NSEM, IPC_RMID)).
- The list_proc for the child contains the last two undo structs A and
B (the rest have been removed either by exit_sem() or freeary()).
- The semid for A is 1 and semid for B is 2.
- exit_sem() removes A and at the same time freeary() removes B.
- Since A and B have different semid sem_lock() will acquire different
locks for each process and both can proceed.
The bug is that they remove A and B from the same list_proc at the same
time because only freeary() acquires the ulp lock. When exit_sem()
removes A it makes ulp->list_proc.next to point at B and at the same
time freeary() removes B setting B->semid=-1.
At the next iteration of for(;;) loop exit_sem() will try to remove B.
The only way to break from for(;;) is for (&un->list_proc ==
&ulp->list_proc) to be true which is not. Then exit_sem() will check if
B->semid=-1 which is and will continue looping in for(;;) until the
memory for B is reallocated and the value at B->semid is changed.
At that point, exit_sem() will crash attempting to unlink B from the
lists (this can be easily triggered by running the reproducer [1] a
second time).
To prove this scenario instrumentation was added to keep information
about each sem_undo (un) struct that is removed per process and per
semaphore set (sma).
CPU0 CPU1
[caller holds sem_lock(sma for A)] ...
freeary() exit_sem()
... ...
... sem_lock(sma for B)
spin_lock(A->ulp->lock) ...
list_del_rcu(un_A->list_proc) list_del_rcu(un_B->list_proc)
Undo structures A and B have different semid and sem_lock() operations
proceed. However they belong to the same list_proc list and they are
removed at the same time. This results into ulp->list_proc.next
pointing to the address of B which is already removed.
After reverting commit a979558448 ("ipc,sem: remove uneeded
sem_undo_list lock usage in exit_sem()") the issue was no longer
reproducible.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1694779
Link: http://lkml.kernel.org/r/20191211191318.11860-1-ioanna-maria.alifieraki@canonical.com
Fixes: a979558448 ("ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()")
Signed-off-by: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Herton R. Krzesinski <herton@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: <malat@debian.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jay Vosburgh <jay.vosburgh@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Document and update the memory barriers in ipc/sem.c:
- Add smp_store_release() to wake_up_sem_queue_prepare() and
document why it is needed.
- Read q->status using READ_ONCE+smp_acquire__after_ctrl_dep().
as the pair for the barrier inside wake_up_sem_queue_prepare().
- Add comments to all barriers, and mention the rules in the block
regarding locking.
- Switch to using wake_q_add_safe().
Link: http://lkml.kernel.org/r/20191020123305.14715-6-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Transfer findings from ipc/mqueue.c:
- A control barrier was missing for the lockless receive case So in
theory, not yet initialized data may have been copied to user space -
obviously only for architectures where control barriers are not NOP.
- use smp_store_release(). In theory, the refount may have been
decreased to 0 already when wake_q_add() tries to get a reference.
Link: http://lkml.kernel.org/r/20191020123305.14715-5-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update and document memory barriers for mqueue.c:
- ewp->state is read without any locks, thus READ_ONCE is required.
- add smp_aquire__after_ctrl_dep() after the READ_ONCE, we need
acquire semantics if the value is STATE_READY.
- use wake_q_add_safe()
- document why __set_current_state() may be used:
Reading task->state cannot happen before the wake_q_add() call,
which happens while holding info->lock. Thus the spin_unlock()
is the RELEASE, and the spin_lock() is the ACQUIRE.
For completeness: there is also a 3 CPU scenario, if the to be woken
up task is already on another wake_q.
Then:
- CPU1: spin_unlock() of the task that goes to sleep is the RELEASE
- CPU2: the spin_lock() of the waker is the ACQUIRE
- CPU2: smp_mb__before_atomic inside wake_q_add() is the RELEASE
- CPU3: smp_mb__after_spinlock() inside try_to_wake_up() is the ACQUIRE
Link: http://lkml.kernel.org/r/20191020123305.14715-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Waiman Long <longman@redhat.com>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().
This patch is generated using following script:
EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"
git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do
if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net
CONFIG_PROVE_RCU_LIST requires list_for_each_entry_rcu() to pass a lockdep
expression if using srcu or locking for protection. It can only check
regular RCU protection, all other protection needs to be passed as lockdep
expression.
Link: http://lkml.kernel.org/r/20190830231817.76862-2-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Jonathan Derrick <jonathan.derrick@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Null pointers were assigned to local variables in a few cases as exception
handling. The jump target “out” was used where no meaningful data
processing actions should eventually be performed by branches of an if
statement then. Use an additional jump target for calling dev_kfree_skb()
directly.
Return also directly after error conditions were detected when no extra
clean-up is needed by this function implementation.
Link: http://lkml.kernel.org/r/592ef10e-0b69-72d0-9789-fc48f638fdfd@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
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>
dev_kfree_skb() input parameter validation, thus the test around the call
is not needed.
This issue was detected by using the Coccinelle software.
Link: http://lkml.kernel.org/r/07477187-63e5-cc80-34c1-32dd16b38e12@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
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>
Pull vfs mount API infrastructure updates from Al Viro:
"Infrastructure bits of mount API conversions.
The rest is more of per-filesystem updates and that will happen
in separate pull requests"
* 'work.mount-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
mtd: Provide fs_context-aware mount_mtd() replacement
vfs: Create fs_context-aware mount_bdev() replacement
new helper: get_tree_keyed()
vfs: set fs_context::user_ns for reconfigure
Matt bisected a sparc64 specific issue with semctl, shmctl and msgctl
to a commit from my y2038 series in linux-5.1, as I missed the custom
sys_ipc() wrapper that sparc64 uses in place of the generic version that
I patched.
The problem is that the sys_{sem,shm,msg}ctl() functions in the kernel
now do not allow being called with the IPC_64 flag any more, resulting
in a -EINVAL error when they don't recognize the command.
Instead, the correct way to do this now is to call the internal
ksys_old_{sem,shm,msg}ctl() functions to select the API version.
As we generally move towards these functions anyway, change all of
sparc_ipc() to consistently use those in place of the sys_*() versions,
and move the required ksys_*() declarations into linux/syscalls.h
The IS_ENABLED(CONFIG_SYSVIPC) check is required to avoid link
errors when ipc is disabled.
Reported-by: Matt Turner <mattst88@gmail.com>
Fixes: 275f22148e ("ipc: rename old-style shmctl/semctl/msgctl syscalls")
Cc: stable@vger.kernel.org
Tested-by: Matt Turner <mattst88@gmail.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range. This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.
On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.
The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:
$ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
248
Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.
This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:
# scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
Data old new delta
sysctl_vals - 12 +12
__kstrtab_sysctl_vals - 12 +12
max 14 10 -4
int_max 16 - -16
one 68 - -68
zero 128 28 -100
Total: Before=20583249, After=20583085, chg -0.00%
[mcroce@redhat.com: tipc: remove two unused variables]
Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andreas Christoforou reported:
UBSAN: Undefined behaviour in ipc/mqueue.c:414:49 signed integer overflow:
9 * 2305843009213693951 cannot be represented in type 'long int'
...
Call Trace:
mqueue_evict_inode+0x8e7/0xa10 ipc/mqueue.c:414
evict+0x472/0x8c0 fs/inode.c:558
iput_final fs/inode.c:1547 [inline]
iput+0x51d/0x8c0 fs/inode.c:1573
mqueue_get_inode+0x8eb/0x1070 ipc/mqueue.c:320
mqueue_create_attr+0x198/0x440 ipc/mqueue.c:459
vfs_mkobj+0x39e/0x580 fs/namei.c:2892
prepare_open ipc/mqueue.c:731 [inline]
do_mq_open+0x6da/0x8e0 ipc/mqueue.c:771
Which could be triggered by:
struct mq_attr attr = {
.mq_flags = 0,
.mq_maxmsg = 9,
.mq_msgsize = 0x1fffffffffffffff,
.mq_curmsgs = 0,
};
if (mq_open("/testing", 0x40, 3, &attr) == (mqd_t) -1)
perror("mq_open");
mqueue_get_inode() was correctly rejecting the giant mq_msgsize, and
preparing to return -EINVAL. During the cleanup, it calls
mqueue_evict_inode() which performed resource usage tracking math for
updating "user", before checking if there was a valid "user" at all
(which would indicate that the calculations would be sane). Instead,
delay this check to after seeing a valid "user".
The overflow was real, but the results went unused, so while the flaw is
harmless, it's noisy for kernel fuzzers, so just fix it by moving the
calculation under the non-NULL "user" where it actually gets used.
Link: http://lkml.kernel.org/r/201906072207.ECB65450@keescook
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Andreas Christoforou <andreaschristofo@gmail.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
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>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this file is released under gnu general public licence version 2 or
at your option any later version see the file copying for more
details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071857.941092988@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For ipcmni_extend mode, the sequence number space is only 7 bits. So
the chance of id reuse is relatively high compared with the non-extended
mode.
To alleviate this id reuse problem, this patch enables cyclic allocation
for the index to the radix tree (idx). The disadvantage is that this
can cause a slight slow-down of the fast path, as the radix tree could
be higher than necessary.
To limit the radix tree height, I have chosen the following limits:
1) The cycling is done over in_use*1.5.
2) At least, the cycling is done over
"normal" ipcnmi mode: RADIX_TREE_MAP_SIZE elements
"ipcmni_extended": 4096 elements
Result:
- for normal mode:
No change for <= 42 active ipc elements. With more than 42
active ipc elements, a 2nd level would be added to the radix
tree.
Without cyclic allocation, a 2nd level would be added only with
more than 63 active elements.
- for extended mode:
Cycling creates always at least a 2-level radix tree.
With more than 2730 active objects, a 3rd level would be
added, instead of > 4095 active objects until the 3rd level
is added without cyclic allocation.
For a 2-level radix tree compared to a 1-level radix tree, I have
observed < 1% performance impact.
Notes:
1) Normal "x=semget();y=semget();" is unaffected: Then the idx
is e.g. a and a+1, regardless if idr_alloc() or idr_alloc_cyclic()
is used.
2) The -1% happens in a microbenchmark after this situation:
x=semget();
for(i=0;i<4000;i++) {t=semget();semctl(t,0,IPC_RMID);}
y=semget();
Now perform semget calls on x and y that do not sleep.
3) The worst-case reuse cycle time is unfortunately unaffected:
If you have 2^24-1 ipc objects allocated, and get/remove the last
possible element in a loop, then the id is reused after 128
get/remove pairs.
Performance check:
A microbenchmark that performes no-op semop() randomly on two IDs,
with only these two IDs allocated.
The IDs were set using /proc/sys/kernel/sem_next_id.
The test was run 5 times, averages are shown.
1 & 2: Base (6.22 seconds for 10.000.000 semops)
1 & 40: -0.2%
1 & 3348: - 0.8%
1 & 27348: - 1.6%
1 & 15777204: - 3.2%
Or: ~12.6 cpu cycles per additional radix tree level.
The cpu is an Intel I3-5010U. ~1300 cpu cycles/syscall is slower
than what I remember (spectre impact?).
V2 of the patch:
- use "min" and "max"
- use RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE instead of
(2<<12).
[akpm@linux-foundation.org: fix max() warning]
Link: http://lkml.kernel.org/r/20190329204930.21620-3-longman@redhat.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Waiman Long <longman@redhat.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rewrite, based on the patch from Waiman Long:
The mixing in of a sequence number into the IPC IDs is probably to avoid
ID reuse in userspace as much as possible. With ipcmni_extend mode, the
number of usable sequence numbers is greatly reduced leading to higher
chance of ID reuse.
To address this issue, we need to conserve the sequence number space as
much as possible. Right now, the sequence number is incremented for
every new ID created. In reality, we only need to increment the
sequence number when new allocated ID is not greater than the last one
allocated. It is in such case that the new ID may collide with an
existing one. This is being done irrespective of the ipcmni mode.
In order to avoid any races, the index is first allocated and then the
pointer is replaced.
Changes compared to the initial patch:
- Handle failures from idr_alloc().
- Avoid that concurrent operations can see the wrong sequence number.
(This is achieved by using idr_replace()).
- IPCMNI_SEQ_SHIFT is not a constant, thus renamed to
ipcmni_seq_shift().
- IPCMNI_SEQ_MAX is not a constant, thus renamed to ipcmni_seq_max().
Link: http://lkml.kernel.org/r/20190329204930.21620-2-longman@redhat.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The maximum number of unique System V IPC identifiers was limited to
32k. That limit should be big enough for most use cases.
However, there are some users out there requesting for more, especially
those that are migrating from Solaris which uses 24 bits for unique
identifiers. To satisfy the need of those users, a new boot time kernel
option "ipcmni_extend" is added to extend the IPCMNI value to 16M. This
is a 512X increase which should be big enough for users out there that
need a large number of unique IPC identifier.
The use of this new option will change the pattern of the IPC
identifiers returned by functions like shmget(2). An application that
depends on such pattern may not work properly. So it should only be
used if the users really need more than 32k of unique IPC numbers.
This new option does have the side effect of reducing the maximum number
of unique sequence numbers from 64k down to 128. So it is a trade-off.
The computation of a new IPC id is not done in the performance critical
path. So a little bit of additional overhead shouldn't have any real
performance impact.
Link: http://lkml.kernel.org/r/20190329204930.21620-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Our msg priorities became an rbtree as of d6629859b3 ("ipc/mqueue:
improve performance of send/recv"). However, consuming a msg in
msg_get() remains logarithmic (still being better than the case before
of course). By applying well known techniques to cache pointers we can
have the node with the highest priority in O(1), which is specially nice
for the rt cases. Furthermore, some callers can call msg_get() in a
loop.
A new msg_tree_erase() helper is also added to encapsulate the tree
removal and node_cache game. Passes ltp mq testcases.
Link: http://lkml.kernel.org/r/20190321190216.1719-2-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>
