- 08 Sep, 2021 40 commits
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Arnd Bergmann authored
All users of compat_alloc_user_space() and copy_in_user() have been removed from the kernel, only a few functions in sparc remain that can be changed to calling arch_copy_in_user() instead. Link: https://lkml.kernel.org/r/20210727144859.4150043-7-arnd@kernel.orgSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Reviewed-by:
Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> 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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Arnd Bergmann authored
These are all handled correctly when calling the native system call entry point, so remove the special cases. Link: https://lkml.kernel.org/r/20210727144859.4150043-6-arnd@kernel.orgSigned-off-by:
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Arnd Bergmann authored
The compat implementations for mbind, get_mempolicy, set_mempolicy and migrate_pages are just there to handle the subtly different layout of bitmaps on 32-bit hosts. The compat implementation however lacks some of the checks that are present in the native one, in particular for checking that the extra bits are all zero when user space has a larger mask size than the kernel. Worse, those extra bits do not get cleared when copying in or out of the kernel, which can lead to incorrect data as well. Unify the implementation to handle the compat bitmap layout directly in the get_nodes() and copy_nodes_to_user() helpers. Splitting out the get_bitmap() helper from get_nodes() also helps readability of the native case. On x86, two additional problems are addressed by this: compat tasks can pass a bitmap at the end of a mapping, causing a fault when reading across the page boundary for a 64-bit word. x32 tasks might also run into problems with get_mempolicy corrupting data when an odd number of 32-bit words gets passed. On parisc the migrate_pages() system call apparently had the wrong calling convention, as big-endian architectures expect the words inside of a bitmap to be swapped. This is not a problem though since parisc has no NUMA support. [arnd@arndb.de: fix mempolicy crash] Link: https://lkml.kernel.org/r/20210730143417.3700653-1-arnd@kernel.org Link: https://lore.kernel.org/lkml/YQPLG20V3dmOfq3a@osiris/ Link: https://lkml.kernel.org/r/20210727144859.4150043-5-arnd@kernel.orgSigned-off-by:
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Arnd Bergmann authored
The compat move_pages() implementation uses compat_alloc_user_space() for converting the pointer array. Moving the compat handling into the function itself is a bit simpler and lets us avoid the compat_alloc_user_space() call. Link: https://lkml.kernel.org/r/20210727144859.4150043-4-arnd@kernel.orgSigned-off-by:
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Arnd Bergmann authored
kimage_alloc_init() expects a __user pointer, so compat_sys_kexec_load() uses compat_alloc_user_space() to convert the layout and put it back onto the user space caller stack. Moving the user space access into the syscall handler directly actually makes the code simpler, as the conversion for compat mode can now be done on kernel memory. Link: https://lkml.kernel.org/r/20210727144859.4150043-3-arnd@kernel.org Link: https://lore.kernel.org/lkml/YPbtsU4GX6PL7%2F42@infradead.org/ Link: https://lore.kernel.org/lkml/m1y2cbzmnw.fsf@fess.ebiederm.org/Signed-off-by:
Eric Biederman <ebiederm@xmission.com> Co-developed-by:
Christoph Hellwig <hch@infradead.org> Acked-by:
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Arnd Bergmann authored
Patch series "compat: remove compat_alloc_user_space", v5. Going through compat_alloc_user_space() to convert indirect system call arguments tends to add complexity compared to handling the native and compat logic in the same code. This patch (of 6): The locking is the same between the native and compat version of sys_kexec_load(), so it can be done in the common implementation to reduce duplication. Link: https://lkml.kernel.org/r/20210727144859.4150043-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20210727144859.4150043-2-arnd@kernel.orgSigned-off-by:
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Baolin Wang authored
Change to use bool type for 'page_was_mapped' variable making it more readable. Link: https://lkml.kernel.org/r/ce1279df18d2c163998c403e0b5ec6d3f6f90f7a.1629447552.git.baolin.wang@linux.alibaba.comSigned-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by:
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Baolin Wang authored
since commit a98a2f0c ("mm/rmap: split migration into its own function"), the migration ptes establishment has been split into a separate try_to_migrate() function, thus update the related comments. Link: https://lkml.kernel.org/r/5b824bad6183259c916ae6cf42f81d14c6118b06.1629447552.git.baolin.wang@linux.alibaba.comSigned-off-by:
Alistair Popple <apopple@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by:
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Baolin Wang authored
Use thp_nr_pages() instead of compound_nr() to get the number of pages for THP page, meanwhile introducing a local variable 'nr_pages' to avoid getting the number of pages repeatedly. Link: https://lkml.kernel.org/r/a8e331ac04392ee230c79186330fb05e86a2aa77.1629447552.git.baolin.wang@linux.alibaba.comSigned-off-by:
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Ingo Molnar authored
Disable preemption on -RT for the vmstat code. On vanila the code runs in IRQ-off regions while on -RT it may not when stats are updated under a local_lock. "preempt_disable" ensures that the same resources is not updated in parallel due to preemption. This patch differs from the preempt-rt version where __count_vm_event and __count_vm_events are also protected. The counters are explicitly "allowed to be to be racy" so there is no need to protect them from preemption. Only the accurate page stats that are updated by a read-modify-write need protection. This patch also differs in that a preempt_[en|dis]able_rt helper is not used. As vmstat is the only user of the helper, it was suggested that it be open-coded in vmstat.c instead of risking the helper being used in unnecessary contexts. Link: https://lkml.kernel.org/r/20210805160019.1137-2-mgorman@techsingularity.netSigned-off-by:
Ingo Molnar <mingo@elte.hu> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Mel Gorman <mgorman@techsingularity.net> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
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Linus Torvalds authored
Merge more updates from Andrew Morton: "147 patches, based on 7d2a07b7. 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() ...
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git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linuxLinus Torvalds authored
Pull SLUB updates from Vlastimil Babka: "SLUB: reduce irq disabled scope and make it RT compatible This series was initially inspired by Mel's pcplist local_lock rewrite, and also interest to better understand SLUB's locking and the new primitives and RT variants and implications. It makes SLUB compatible with PREEMPT_RT and generally more preemption-friendly, apparently without significant regressions, as the fast paths are not affected. The main changes to SLUB by this series: - irq disabling is now only done for minimum amount of time needed to protect the strict kmem_cache_cpu fields, and as part of spin lock, local lock and bit lock operations to make them irq-safe - SLUB is fully PREEMPT_RT compatible The series should now be sufficiently tested in both RT and !RT configs, mainly thanks to Mike. The RFC/v1 version also got basic performance screening by Mel that didn't show major regressions. Mike's testing with hackbench of v2 on !RT reported negligible differences [6]: virgin(ish) tip 5.13.0.g60ab3ed-tip 7,320.67 msec task-clock # 7.792 CPUs utilized ( +- 0.31% ) 221,215 context-switches # 0.030 M/sec ( +- 3.97% ) 16,234 cpu-migrations # 0.002 M/sec ( +- 4.07% ) 13,233 page-faults # 0.002 M/sec ( +- 0.91% ) 27,592,205,252 cycles # 3.769 GHz ( +- 0.32% ) 8,309,495,040 instructions # 0.30 insn per cycle ( +- 0.37% ) 1,555,210,607 branches # 212.441 M/sec ( +- 0.42% ) 5,484,209 branch-misses # 0.35% of all branches ( +- 2.13% ) 0.93949 +- 0.00423 seconds time elapsed ( +- 0.45% ) 0.94608 +- 0.00384 seconds time elapsed ( +- 0.41% ) (repeat) 0.94422 +- 0.00410 seconds time elapsed ( +- 0.43% ) 5.13.0.g60ab3ed-tip +slub-local-lock-v2r3 7,343.57 msec task-clock # 7.776 CPUs utilized ( +- 0.44% ) 223,044 context-switches # 0.030 M/sec ( +- 3.02% ) 16,057 cpu-migrations # 0.002 M/sec ( +- 4.03% ) 13,164 page-faults # 0.002 M/sec ( +- 0.97% ) 27,684,906,017 cycles # 3.770 GHz ( +- 0.45% ) 8,323,273,871 instructions # 0.30 insn per cycle ( +- 0.28% ) 1,556,106,680 branches # 211.901 M/sec ( +- 0.31% ) 5,463,468 branch-misses # 0.35% of all branches ( +- 1.33% ) 0.94440 +- 0.00352 seconds time elapsed ( +- 0.37% ) 0.94830 +- 0.00228 seconds time elapsed ( +- 0.24% ) (repeat) 0.93813 +- 0.00440 seconds time elapsed ( +- 0.47% ) (repeat) RT configs showed some throughput regressions, but that's expected tradeoff for the preemption improvements through the RT mutex. It didn't prevent the v2 to be incorporated to the 5.13 RT tree [7], leading to testing exposure and bugfixes. Before the series, SLUB is lockless in both allocation and free fast paths, but elsewhere, it's disabling irqs for considerable periods of time - especially in allocation slowpath and the bulk allocation, where IRQs are re-enabled only when a new page from the page allocator is needed, and the context allows blocking. The irq disabled sections can then include deactivate_slab() which walks a full freelist and frees the slab back to page allocator or unfreeze_partials() going through a list of percpu partial slabs. The RT tree currently has some patches mitigating these, but we can do much better in mainline too. Patches 1-6 are straightforward improvements or cleanups that could exist outside of this series too, but are prerequsities. Patches 7-9 are also preparatory code changes without functional changes, but not so useful without the rest of the series. Patch 10 simplifies the fast paths on systems with preemption, based on (hopefully correct) observation that the current loops to verify tid are unnecessary. Patches 11-20 focus on reducing irq disabled scope in the allocation slowpath: - patch 11 moves disabling of irqs into ___slab_alloc() from its callers, which are the allocation slowpath, and bulk allocation. Instead these callers only disable preemption to stabilize the cpu. - The following patches then gradually reduce the scope of disabled irqs in ___slab_alloc() and the functions called from there. As of patch 14, the re-enabling of irqs based on gfp flags before calling the page allocator is removed from allocate_slab(). As of patch 17, it's possible to reach the page allocator (in case of existing slabs depleted) without disabling and re-enabling irqs a single time. Pathces 21-26 reduce the scope of disabled irqs in functions related to unfreezing percpu partial slab. Patch 27 is preparatory. Patch 28 is adopted from the RT tree and converts the flushing of percpu slabs on all cpus from using IPI to workqueue, so that the processing isn't happening with irqs disabled in the IPI handler. The flushing is not performance critical so it should be acceptable. Patch 29 also comes from RT tree and makes object_map_lock RT compatible. Patch 30 make slab_lock irq-safe on RT where we cannot rely on having irq disabled from the list_lock spin lock usage. Patch 31 changes kmem_cache_cpu->partial handling in put_cpu_partial() from cmpxchg loop to a short irq disabled section, which is used by all other code modifying the field. This addresses a theoretical race scenario pointed out by Jann, and makes the critical section safe wrt with RT local_lock semantics after the conversion in patch 35. Patch 32 changes preempt disable to migrate disable, so that the nested list_lock spinlock is safe to take on RT. Because migrate_disable() is a function call even on !RT, a small set of private wrappers is introduced to keep using the cheaper preempt_disable() on !PREEMPT_RT configurations. As of this patch, SLUB should be already compatible with RT's lock semantics. Finally, patch 33 changes irq disabled sections that protect kmem_cache_cpu fields in the slow paths, with a local lock. However on PREEMPT_RT it means the lockless fast paths can now preempt slow paths which don't expect that, so the local lock has to be taken also in the fast paths and they are no longer lockless. RT folks seem to not mind this tradeoff. The patch also updates the locking documentation in the file's comment" Mike Galbraith and Mel Gorman verified that their earlier testing observations still hold for the final series: Link: https://lore.kernel.org/lkml/89ba4f783114520c167cc915ba949ad2c04d6790.camel@gmx.de/ Link: https://lore.kernel.org/lkml/20210907082010.GB3959@techsingularity.net/ * tag 'mm-slub-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux: (33 commits) mm, slub: convert kmem_cpu_slab protection to local_lock mm, slub: use migrate_disable() on PREEMPT_RT mm, slub: protect put_cpu_partial() with disabled irqs instead of cmpxchg mm, slub: make slab_lock() disable irqs with PREEMPT_RT mm: slub: make object_map_lock a raw_spinlock_t mm: slub: move flush_cpu_slab() invocations __free_slab() invocations out of IRQ context mm, slab: split out the cpu offline variant of flush_slab() mm, slub: don't disable irqs in slub_cpu_dead() mm, slub: only disable irq with spin_lock in __unfreeze_partials() mm, slub: separate detaching of partial list in unfreeze_partials() from unfreezing mm, slub: detach whole partial list at once in unfreeze_partials() mm, slub: discard slabs in unfreeze_partials() without irqs disabled mm, slub: move irq control into unfreeze_partials() mm, slub: call deactivate_slab() without disabling irqs mm, slub: make locking in deactivate_slab() irq-safe mm, slub: move reset of c->page and freelist out of deactivate_slab() mm, slub: stop disabling irqs around get_partial() mm, slub: check new pages with restored irqs mm, slub: validate slab from partial list or page allocator before making it cpu slab mm, slub: restore irqs around calling new_slab() ... -
Randy Dunlap authored
Fix typo ("and" should be "an") in an error message. Link: https://lkml.kernel.org/r/20210727002943.29774-1-rdunlap@infradead.orgSigned-off-by:Randy Dunlap <rdunlap@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by:
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Randy Dunlap authored
Use the documented kernel-doc format to prevent kernel-doc warnings. mm/workingset.c:256: warning: No description found for return value of 'workingset_eviction' mm/workingset.c:285: warning: Function parameter or member 'folio' not described in 'workingset_refault' mm/workingset.c:285: warning: Excess function parameter 'page' description in 'workingset_refault' Link: https://lkml.kernel.org/r/20210808203153.10678-1-rdunlap@infradead.orgSigned-off-by:
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Rafael Aquini authored
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 15df03c8 ("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.comSigned-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:
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Greg Thelen authored
Commit 54402986 ("selftests/memfd: add tests for F_SEAL_FUTURE_WRITE seal") added an unused variable to mfd_assert_reopen_fd(). Delete the unused variable. Link: https://lkml.kernel.org/r/20210702045509.1517643-1-gthelen@google.com Fixes: 54402986 ("selftests/memfd: add tests for F_SEAL_FUTURE_WRITE seal") Signed-off-by:
Greg Thelen <gthelen@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org> Signed-off-by:
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Lukas Bulwahn authored
Commit 05a4a952 ("kernel/watchdog: split up config options") adds a new config HARDLOCKUP_DETECTOR, which selects the non-existing config HARDLOCKUP_DETECTOR_ARCH. Hence, ./scripts/checkkconfigsymbols.py warns: HARDLOCKUP_DETECTOR_ARCH Referencing files: lib/Kconfig.debug Simply drop selecting the non-existing HARDLOCKUP_DETECTOR_ARCH. Link: https://lkml.kernel.org/r/20210806115618.22088-1-lukas.bulwahn@gmail.com Fixes: 05a4a952 ("kernel/watchdog: split up config options") Signed-off-by:
Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Babu Moger <babu.moger@oracle.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Zenghui Yu authored
This CONFIG option was removed in commit 278b13ce ("Input: remove input_polled_dev implementation") so there's no point to keep it in defconfigs any longer. Get rid of the leftover for all arches. Link: https://lkml.kernel.org/r/20210726074741.1062-1-yuzenghui@huawei.comSigned-off-by:
Zenghui Yu <yuzenghui@huawei.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by:
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Cyrill Gorcunov authored
Keno Fischer reported that when a binray loaded via ld-linux-x the prctl(PR_SET_MM_MAP) doesn't allow to setup brk value because it lays before mm:end_data. For example a test program shows | # ~/t | | start_code 401000 | end_code 401a15 | start_stack 7ffce4577dd0 | start_data 403e10 | end_data 40408c | start_brk b5b000 | sbrk(0) b5b000 and when executed via ld-linux | # /lib64/ld-linux-x86-64.so.2 ~/t | | start_code 7fc25b0a4000 | end_code 7fc25b0c4524 | start_stack 7fffcc6b2400 | start_data 7fc25b0ce4c0 | end_data 7fc25b0cff98 | start_brk 55555710c000 | sbrk(0) 55555710c000 This of course prevent criu from restoring such programs. Looking into how kernel operates with brk/start_brk inside brk() syscall I don't see any problem if we allow to setup brk/start_brk without checking for end_data. Even if someone pass some weird address here on a purpose then the worst possible result will be an unexpected unmapping of existing vma (own vma, since prctl works with the callers memory) but test for RLIMIT_DATA is still valid and a user won't be able to gain more memory in case of expanding VMAs via new values shipped with prctl call. Link: https://lkml.kernel.org/r/20210121221207.GB2174@grain Fixes: bbdc6076 ("binfmt_elf: move brk out of mmap when doing direct loader exec") Signed-off-by:
Cyrill Gorcunov <gorcunov@gmail.com> Reported-by:
Keno Fischer <keno@juliacomputing.com> Acked-by:
Andrey Vagin <avagin@gmail.com> Tested-by:
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Takahiro Itazuri authored
pidmap_init() has already been replaced with pid_idr_init() in the commit 95846ecf ("pid: replace pid bitmap implementation with IDR API"). Cleanup the stale comment which still mentions it. Link: https://lkml.kernel.org/r/20210714120713.19825-1-itazur@amazon.comSigned-off-by:
Takahiro Itazuri <itazur@amazon.com> Cc: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by:
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Christoph Hellwig authored
Only used by core code and the tomoyo which can't be a module either. Link: https://lkml.kernel.org/r/20210820095430.445242-1-hch@lst.deSigned-off-by:
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QiuXi authored
dump_vma_snapshot() allocs memory for *vma_meta, when dump_vma_snapshot() returns -EFAULT, the memory will be leaked, so we free it correctly. Link: https://lkml.kernel.org/r/20210810020441.62806-1-qiuxi1@huawei.com Fixes: a07279c9 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Signed-off-by:
QiuXi <qiuxi1@huawei.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jann Horn <jannh@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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David Oberhollenzer authored
For obvious security reasons, a core dump is aborted if the filesystem cannot preserve ownership or permissions of the dump file. This affects filesystems like e.g. vfat, but also something like a 9pfs share in a Qemu test setup, running as a regular user, depending on the security model used. In those cases, the result is an empty core file and a confused user. To hopefully save other people a lot of time figuring out the cause, this patch adds a simple log message for those specific cases. [akpm@linux-foundation.org: s/|%s/%s/ in printk text] Link: https://lkml.kernel.org/r/20210701233151.102720-1-david.oberhollenzer@sigma-star.atSigned-off-by:
David Oberhollenzer <david.oberhollenzer@sigma-star.at> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Zhen Lei authored
When the refcount is decreased to 0, the resource reclamation branch is entered. Before CPU0 reaches the race point (1), CPU1 may obtain the spinlock and traverse the rbtree to find 'root', see nilfs_lookup_root(). Although CPU1 will call refcount_inc() to increase the refcount, it is obviously too late. CPU0 will release 'root' directly, CPU1 then accesses 'root' and triggers UAF. Use refcount_dec_and_lock() to ensure that both the operations of decrease refcount to 0 and link deletion are lock protected eliminates this risk. CPU0 CPU1 nilfs_put_root(): <-------- (1) spin_lock(&nilfs->ns_cptree_lock); rb_erase(&root->rb_node, &nilfs->ns_cptree); spin_unlock(&nilfs->ns_cptree_lock); kfree(root); <-------- use-after-free refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \ refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28 Modules linked in: CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28 ... ... Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795 nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline] nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812 nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467 generic_shutdown_super+0xcd/0x1f0 fs/super.c:464 kill_block_super+0x4a/0x90 fs/super.c:1446 deactivate_locked_super+0x6a/0xb0 fs/super.c:335 deactivate_super+0x85/0x90 fs/super.c:366 cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118 __cleanup_mnt+0x15/0x20 fs/namespace.c:1125 task_work_run+0x8e/0x110 kernel/task_work.c:151 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:164 [inline] exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xa9 There is no reproduction program, and the above is only theoretical analysis. Link: https://lkml.kernel.org/r/1629859428-5906-1-git-send-email-konishi.ryusuke@gmail.com Fixes: ba65ae47 ("nilfs2: add checkpoint tree to nilfs object") Link: https://lkml.kernel.org/r/20210723012317.4146-1-thunder.leizhen@huawei.comSigned-off-by:Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by:
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Nanyong Sun authored
kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del(). See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-7-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-7-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:
Nanyong Sun <sunnanyong@huawei.com> Signed-off-by:
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Nanyong Sun authored
If kobject_init_and_add returns with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-6-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-6-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:
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Nanyong Sun authored
The kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del. See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-5-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-5-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:
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Nanyong Sun authored
If kobject_init_and_add return with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-4-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-4-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:
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Nanyong Sun authored
In nilfs_##name##_attr_release, kobj->parent should not be referenced because it is a NULL pointer. The release() method of kobject is always called in kobject_put(kobj), in the implementation of kobject_put(), the kobj->parent will be assigned as NULL before call the release() method. So just use kobj to get the subgroups, which is more efficient and can fix a NULL pointer reference problem. Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@gmail.comSigned-off-by:
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Nanyong Sun authored
Patch series "nilfs2: fix incorrect usage of kobject". This patchset from Nanyong Sun fixes memory leak issues and a NULL pointer dereference issue caused by incorrect usage of kboject in nilfs2 sysfs implementation. This patch (of 6): Reported by syzkaller: BUG: memory leak unreferenced object 0xffff888100ca8988 (size 8): comm "syz-executor.1", pid 1930, jiffies 4294745569 (age 18.052s) hex dump (first 8 bytes): 6c 6f 6f 70 31 00 ff ff loop1... backtrace: kstrdup+0x36/0x70 mm/util.c:60 kstrdup_const+0x35/0x60 mm/util.c:83 kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48 kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xc9/0x150 lib/kobject.c:473 nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986 init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637 nilfs_fill_super fs/nilfs2/super.c:1046 [inline] nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316 legacy_get_tree+0x105/0x210 fs/fs_context.c:592 vfs_get_tree+0x8e/0x2d0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0xf9b/0x1990 fs/namespace.c:3235 do_mount+0xea/0x100 fs/namespace.c:3248 __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount fs/namespace.c:3433 [inline] __x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae If kobject_init_and_add return with error, then the cleanup of kobject is needed because memory may be allocated in kobject_init_and_add without freeing. And the place of cleanup_dev_kobject should use kobject_put to free the memory associated with the kobject. As the section "Kobject removal" of "Documentation/core-api/kobject.rst" says, kobject_del() just makes the kobject "invisible", but it is not cleaned up. And no more cleanup will do after cleanup_dev_kobject, so kobject_put is needed here. Link: https://lkml.kernel.org/r/1625651306-10829-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/1625651306-10829-2-git-send-email-konishi.ryusuke@gmail.comReported-by:Hulk Robot <hulkci@huawei.com> Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.comSigned-off-by:
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Kefeng Wang authored
There are some empty trap_init() definitions in different ARCHs, Introduce a new weak trap_init() function to clean them up. Link: https://lkml.kernel.org/r/20210812123602.76356-1-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm32] Acked-by: Vineet Gupta [arc] Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <palmerdabbelt@google.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by:
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Rasmus Villemoes authored
Currently, usermodehelper is enabled right before PID1 starts going through the initcalls. However, any call of a usermodehelper from a pure_, core_, postcore_, arch_, subsys_ or fs_ initcall is futile, as there is no filesystem contents yet. Up until commit e7cb072e ("init/initramfs.c: do unpacking asynchronously"), such calls, whether via some request_module(), a legacy uevent "/sbin/hotplug" notification or something else, would just fail silently with (presumably) -ENOENT from kernel_execve(). However, that commit introduced the wait_for_initramfs() synchronization hook which must be called from the usermodehelper exec path right before the kernel_execve, in order that request_module() et al done from *after* rootfs_initcall() time (i.e. device_ and late_ initcalls) would continue to find a populated initramfs as they used to. Any call of wait_for_initramfs() done before the unpacking has been scheduled (i.e. before rootfs_initcall time) must just return immediately [and let the caller find an empty file system] in order not to deadlock the machine. I mistakenly thought, and my limited testing confirmed, that there were no such calls, so I added a pr_warn_once() in wait_for_initramfs(). It turns out that one can indeed hit request_module() as well as kobject_uevent_env() during those early init calls, leading to a user-visible warning in the kernel log emitted consistently for certain configurations. We could just remove the pr_warn_once(), but I think it's better to postpone enabling the usermodehelper framework until there is at least some chance of finding the executable. That is also a little more efficient in that a lot of work done in umh.c will be elided. However, it does change the error seen by those early callers from -ENOENT to -EBUSY, so there is a risk of a regression if any caller care about the exact error value. Link: https://lkml.kernel.org/r/20210728134638.329060-1-linux@rasmusvillemoes.dk Fixes: e7cb072e ("init/initramfs.c: do unpacking asynchronously") Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Reported-by:
Alexander Egorenkov <egorenar@linux.ibm.com> Reported-by:
Bruno Goncalves <bgoncalv@redhat.com> Reported-by:
Heiner Kallweit <hkallweit1@gmail.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by:
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Nicholas Piggin authored
This counter tracks the number of watches a user has, to compare against the 'max_user_watches' limit. This causes a scalability bottleneck on SPECjbb2015 on large systems as there is only one user. Changing to a per-cpu counter increases throughput of the benchmark by about 30% on a 16-socket, > 1000 thread system. [rdunlap@infradead.org: fix build errors in kernel/user.c when CONFIG_EPOLL=n] [npiggin@gmail.com: move ifdefs into wrapper functions, slightly improve panic message] Link: https://lkml.kernel.org/r/1628051945.fens3r99ox.astroid@bobo.none [akpm@linux-foundation.org: tweak user_epoll_alloc(), per Guenter] Link: https://lkml.kernel.org/r/20210804191421.GA1900577@roeck-us.net Link: https://lkml.kernel.org/r/20210802032013.2751916-1-npiggin@gmail.comSigned-off-by:
Nicholas Piggin <npiggin@gmail.com> Reported-by:
Anton Blanchard <anton@ozlabs.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Joe Perches authored
The preferred git commit id reference has the form commit <SHA-1> ("Title line") where SHA-1 is the commit hex hash with a minimum lenth of 12 and ("Title line") is the complete title line of the commit with a (" prefix and ") suffix. The current tests fail when the "Title line" has one or more embedded double quotes. Improve the test that finds the commit SHA-1 hex hash then ("Title line") by using $balanced_parens for a maximum of 3 consecutive lines. [akpm@linux-foundation.org: add missing &&] Link: https://lkml.kernel.org/r/976c6cdd680db4b55ae31b5fc2d1779da5c0dc66.camel@perches.comSigned-off-by:Joe Perches <joe@perches.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Denis Efremov <efremov@linux.com> Signed-off-by:
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Mimi Zohar authored
Instead of checkpatch requiring the patch author to exactly match the signed-off-by tag, commit 48ca2d8a ("checkpatch: add new warnings to author signoff checks.") safely relaxed this requirement. Although the local-part of an email address (local-part@domain), may be case sensitive, exploiting the case sensitivity of mailbox local-parts impedes interoperability and is discouraged. Mailbox domains follow normal DNS rules and are hence not case sensitive. (Refer to https://datatracker.ietf.org/doc/html/rfc5321#section-2.4.) Further relax the patch author and signed-off-by tag comparison by making the email address check case insensitive. Link: https://lkml.kernel.org/r/20210816112725.173206-1-zohar@linux.ibm.comSigned-off-by:
Mimi Zohar <zohar@linux.ibm.com> Acked-by:
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Joe Perches authored
Allow prefixing typical strings with L for wide strings and u for unicode strings. Link: https://lkml.kernel.org/r/20210801170733.1.I3f9784fd3c1007d08ec2e70b151d137687575495@changeidSigned-off-by:
Simon Glass <sjg@chromium.org> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by:
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Andy Shevchenko authored
Rename bitmap_alloc() to bitmap_zalloc() in tools to follow the bitmap API in the kernel. No functional changes intended. Link: https://lkml.kernel.org/r/20210814211713.180533-14-yury.norov@gmail.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Yury Norov <yury.norov@gmail.com> Suggested-by:
Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by:
Jiri Olsa <jolsa@redhat.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexey Klimov <aklimov@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Will Deacon <will@kernel.org> Signed-off-by:
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Randy Dunlap authored
Fix all kernel-doc warnings in lib/iov_iter.c: lib/iov_iter.c:695: warning: Function parameter or member 'i' not described in '_copy_mc_to_iter' lib/iov_iter.c:695: warning: Excess function parameter 'iter' description in '_copy_mc_to_iter' lib/iov_iter.c:695: warning: No description found for return value of '_copy_mc_to_iter' lib/iov_iter.c:758: warning: Function parameter or member 'i' not described in '_copy_from_iter_flushcache' lib/iov_iter.c:758: warning: Excess function parameter 'iter' description in '_copy_from_iter_flushcache' lib/iov_iter.c:758: warning: No description found for return value of '_copy_from_iter_flushcache' Link: https://lkml.kernel.org/r/20210809051053.6531-1-rdunlap@infradead.orgSigned-off-by:
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Randy Dunlap authored
Fix kernel-doc warnings in dump_stack.c: lib/dump_stack.c:97: warning: Function parameter or member 'log_lvl' not described in 'dump_stack_lvl' lib/dump_stack.c:97: warning: expecting prototype for dump_stack(). Prototype was for dump_stack_lvl() instead Link: https://lkml.kernel.org/r/20210809051643.17567-1-rdunlap@infradead.orgSigned-off-by:
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Daniel Latypov authored
This follows up commit ebd09577 ("lib/test: convert lib/test_list_sort.c to use KUnit"). Converting this test to KUnit makes the test a bit shorter, standardizes how it reports pass/fail, and adds an easier way to run the test [1]. Like ebd09577, this leaves the file and Kconfig option name the same, but slightly changes their dependencies (needs CONFIG_KUNIT). [1] Can be run via $ ./tools/testing/kunit/kunit.py run --kunitconfig /dev/stdin <<EOF CONFIG_KUNIT=y CONFIG_TEST_SORT=y EOF [11:30:27] Starting KUnit Kernel ... [11:30:30] ============================================================ [11:30:30] ======== [PASSED] lib_sort ======== [11:30:30] [PASSED] test_sort [11:30:30] ============================================================ [11:30:30] Testing complete. 1 tests run. 0 failed. 0 crashed. 0 skipped. [11:30:30] Elapsed time: 37.032s total, 0.001s configuring, 34.090s building, 0.000s running Note: this is the time it took after a `make mrproper`. With an incremental rebuild, this looks more like: [11:38:58] Elapsed time: 6.444s total, 0.001s configuring, 3.416s building, 0.000s running Since the test has no dependencies, it can also be run (with some other tests) with just: $ ./tools/testing/kunit/kunit.py run Link: https://lkml.kernel.org/r/20210715232441.1380885-1-dlatypov@google.comSigned-off-by:
Daniel Latypov <dlatypov@google.com> Cc: Pravin Shedge <pravin.shedge4linux@gmail.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: David Gow <davidgow@google.com> Signed-off-by:
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