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* Merge tag 'v6.5/vfs.misc' of ↵Linus Torvalds2023-06-261-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Miscellaneous features, cleanups, and fixes for vfs and individual fs Features: - Use mode 0600 for file created by cachefilesd so it can be run by unprivileged users. This aligns them with directories which are already created with mode 0700 by cachefilesd - Reorder a few members in struct file to prevent some false sharing scenarios - Indicate that an eventfd is used a semaphore in the eventfd's fdinfo procfs file - Add a missing uapi header for eventfd exposing relevant uapi defines - Let the VFS protect transitions of a superblock from read-only to read-write in addition to the protection it already provides for transitions from read-write to read-only. Protecting read-only to read-write transitions allows filesystems such as ext4 to perform internal writes, keeping writers away until the transition is completed Cleanups: - Arnd removed the architecture specific arch_report_meminfo() prototypes and added a generic one into procfs.h. Note, we got a report about a warning in amdpgpu codepaths that suggested this was bisectable to this change but we concluded it was a false positive - Remove unused parameters from split_fs_names() - Rename put_and_unmap_page() to unmap_and_put_page() to let the name reflect the order of the cleanup operation that has to unmap before the actual put - Unexport buffer_check_dirty_writeback() as it is not used outside of block device aops - Stop allocating aio rings from highmem - Protecting read-{only,write} transitions in the VFS used open-coded barriers in various places. Replace them with proper little helpers and document both the helpers and all barrier interactions involved when transitioning between read-{only,write} states - Use flexible array members in old readdir codepaths Fixes: - Use the correct type __poll_t for epoll and eventfd - Replace all deprecated strlcpy() invocations, whose return value isn't checked with an equivalent strscpy() call - Fix some kernel-doc warnings in fs/open.c - Reduce the stack usage in jffs2's xattr codepaths finally getting rid of this: fs/jffs2/xattr.c:887:1: error: the frame size of 1088 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] royally annoying compilation warning - Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY where an int and not fmode_t is required to avoid fmode_t to integer degradation warnings - Create coredumps with O_WRONLY instead of O_RDWR. There's a long explanation in that commit how O_RDWR is actually a bug which we found out with the help of Linus and git archeology - Fix "no previous prototype" warnings in the pipe codepaths - Add overflow calculations for remap_verify_area() as a signed addition overflow could be triggered in xfstests - Fix a null pointer dereference in sysv - Use an unsigned variable for length calculations in jfs avoiding compilation warnings with gcc 13 - Fix a dangling pipe pointer in the watch queue codepath - The legacy mount option parser provided as a fallback by the VFS for filesystems not yet converted to the new mount api did prefix the generated mount option string with a leading ',' causing issues for some filesystems - Fix a repeated word in a comment in fs.h - autofs: Update the ctime when mtime is updated as mandated by POSIX" * tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits) readdir: Replace one-element arrays with flexible-array members fs: Provide helpers for manipulating sb->s_readonly_remount fs: Protect reconfiguration of sb read-write from racing writes eventfd: add a uapi header for eventfd userspace APIs autofs: set ctime as well when mtime changes on a dir eventfd: show the EFD_SEMAPHORE flag in fdinfo fs/aio: Stop allocating aio rings from HIGHMEM fs: Fix comment typo fs: unexport buffer_check_dirty_writeback fs: avoid empty option when generating legacy mount string watch_queue: prevent dangling pipe pointer fs.h: Optimize file struct to prevent false sharing highmem: Rename put_and_unmap_page() to unmap_and_put_page() cachefiles: Allow the cache to be non-root init: remove unused names parameter in split_fs_names() jfs: Use unsigned variable for length calculations fs/sysv: Null check to prevent null-ptr-deref bug fs: use UB-safe check for signed addition overflow in remap_verify_area procfs: consolidate arch_report_meminfo declaration fs: pipe: reveal missing function protoypes ...
| * coredump: require O_WRONLY instead of O_RDWRVladimir Sementsov-Ogievskiy2023-05-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The motivation for this patch has been to enable using a stricter apparmor profile to prevent programs from reading any coredump in the system. However, this became something else. The following details are based on Christian's and Linus' archeology into the history of the number "2" in the coredump handling code. To make sure we're not accidently introducing some subtle behavioral change into the coredump code we set out on a voyage into the depths of history.git to figure out why this was O_RDWR in the first place. Coredump handling was introduced over 30 years ago in commit ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)"). The original code used O_WRONLY: open_namei("core",O_CREAT | O_WRONLY | O_TRUNC,0600,&inode,NULL) However, this changed in 1993 and starting with commit 9cb9f18b5d26 ("[PATCH] Linux-0.99.10 (June 7, 1993)") the coredump code suddenly used the constant "2": open_namei("core",O_CREAT | 2 | O_TRUNC,0600,&inode,NULL) This was curious as in the same commit the kernel switched from constants to proper defines in other places such as KERNEL_DS and USER_DS and O_RDWR did already exist. So why was "2" used? It turns out that open_namei() - an early version of what later turned into filp_open() - didn't accept O_RDWR. A semantic quirk of the open() uapi is the definition of the O_RDONLY flag. It would seem natural to define: #define O_RDWR (O_RDONLY | O_WRONLY) but that isn't possible because: #define O_RDONLY 0 This makes O_RDONLY effectively meaningless when passed to the kernel. In other words, there has never been a way - until O_PATH at least - to open a file without any permission; O_RDONLY was always implied on the uapi side while the kernel does in fact allow opening files without permissions. The trouble comes when trying to map the uapi flags onto the corresponding file mode flags FMODE_{READ,WRITE}. This mapping still happens today and is causing issues to this day (We ran into this during additions for openat2() for example.). So the special value "3" was used to indicate that the file was opened for special access: f->f_flags = flag = flags; f->f_mode = (flag+1) & O_ACCMODE; if (f->f_mode) flag++; This allowed the file mode to be set to FMODE_READ | FMODE_WRITE mapping the O_{RDONLY,WRONLY,RDWR} flags into the FMODE_{READ,WRITE} flags. The special access then required read-write permissions and 0 was used to access symlinks. But back when ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") added coredump handling open_namei() took the FMODE_{READ,WRITE} flags as an argument. So the coredump handling introduced in ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") was buggy because O_WRONLY shouldn't have been passed. Since O_WRONLY is 1 but open_namei() took FMODE_{READ,WRITE} it was passed FMODE_READ on accident. So 9cb9f18b5d26 ("[PATCH] Linux-0.99.10 (June 7, 1993)") was a bugfix for this and the 2 didn't really mean O_RDWR, it meant FMODE_WRITE which was correct. The clue is that FMODE_{READ,WRITE} didn't exist yet and thus a raw "2" value was passed. Fast forward 5 years when around 2.2.4pre4 (February 16, 1999) this code was changed to: - dentry = open_namei(corefile,O_CREAT | 2 | O_TRUNC | O_NOFOLLOW, 0600); ... + file = filp_open(corefile,O_CREAT | 2 | O_TRUNC | O_NOFOLLOW, 0600); At this point the raw "2" should have become O_WRONLY again as filp_open() didn't take FMODE_{READ,WRITE} but O_{RDONLY,WRONLY,RDWR}. Another 17 years later, the code was changed again cementing the mistake and making it almost impossible to detect when commit 378c6520e7d2 ("fs/coredump: prevent fsuid=0 dumps into user-controlled directories") replaced the raw "2" with O_RDWR. And now, here we are with this patch that sent us on a quest to answer the big questions in life such as "Why are coredump files opened with O_RDWR?" and "Is it safe to just use O_WRONLY?". So with this commit we're reintroducing O_WRONLY again and bringing this code back to its original state when it was first introduced in commit ddc733f452e0 ("[PATCH] Linux-0.97 (August 1, 1992)") over 30 years ago. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20230420120409.602576-1-vsementsov@yandex-team.ru> [brauner@kernel.org: completely rewritten commit message] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
* | fork, vhost: Use CLONE_THREAD to fix freezer/ps regressionMike Christie2023-06-011-1/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When switching from kthreads to vhost_tasks two bugs were added: 1. The vhost worker tasks's now show up as processes so scripts doing ps or ps a would not incorrectly detect the vhost task as another process. 2. kthreads disabled freeze by setting PF_NOFREEZE, but vhost tasks's didn't disable or add support for them. To fix both bugs, this switches the vhost task to be thread in the process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that SIGKILL/STOP support is required because CLONE_THREAD requires CLONE_SIGHAND which requires those 2 signals to be supported. This is a modified version of the patch written by Mike Christie <michael.christie@oracle.com> which was a modified version of patch originally written by Linus. Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER. Including ignoring signals, setting up the register state, and having get_signal return instead of calling do_group_exit. Tidied up the vhost_task abstraction so that the definition of vhost_task only needs to be visible inside of vhost_task.c. Making it easier to review the code and tell what needs to be done where. As part of this the main loop has been moved from vhost_worker into vhost_task_fn. vhost_worker now returns true if work was done. The main loop has been updated to call get_signal which handles SIGSTOP, freezing, and collects the message that tells the thread to exit as part of process exit. This collection clears __fatal_signal_pending. This collection is not guaranteed to clear signal_pending() so clear that explicitly so the schedule() sleeps. For now the vhost thread continues to exist and run work until the last file descriptor is closed and the release function is called as part of freeing struct file. To avoid hangs in the coredump rendezvous and when killing threads in a multi-threaded exec. The coredump code and de_thread have been modified to ignore vhost threads. Remvoing the special case for exec appears to require teaching vhost_dev_flush how to directly complete transactions in case the vhost thread is no longer running. Removing the special case for coredump rendezvous requires either the above fix needed for exec or moving the coredump rendezvous into get_signal. Fixes: 6e890c5d5021 ("vhost: use vhost_tasks for worker threads") Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Co-developed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: hwpoison: coredump: support recovery from dump_user_range()Kefeng Wang2023-05-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dump_user_range() is used to copy the user page to a coredump file, but if a hardware memory error occurred during copy, which called from __kernel_write_iter() in dump_user_range(), it crashes, CPU: 112 PID: 7014 Comm: mca-recover Not tainted 6.3.0-rc2 #425 pc : __memcpy+0x110/0x260 lr : _copy_from_iter+0x3bc/0x4c8 ... Call trace: __memcpy+0x110/0x260 copy_page_from_iter+0xcc/0x130 pipe_write+0x164/0x6d8 __kernel_write_iter+0x9c/0x210 dump_user_range+0xc8/0x1d8 elf_core_dump+0x308/0x368 do_coredump+0x2e8/0xa40 get_signal+0x59c/0x788 do_signal+0x118/0x1f8 do_notify_resume+0xf0/0x280 el0_da+0x130/0x138 el0t_64_sync_handler+0x68/0xc0 el0t_64_sync+0x188/0x190 Generally, the '->write_iter' of file ops will use copy_page_from_iter() and copy_page_from_iter_atomic(), change memcpy() to copy_mc_to_kernel() in both of them to handle #MC during source read, which stop coredump processing and kill the task instead of kernel panic, but the source address may not always a user address, so introduce a new copy_mc flag in struct iov_iter{} to indicate that the iter could do a safe memory copy, also introduce the helpers to set/cleck the flag, for now, it's only used in coredump's dump_user_range(), but it could expand to any other scenarios to fix the similar issue. Link: https://lkml.kernel.org/r/20230417045323.11054-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Tong Tiangen <tongtiangen@huawei.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'mm-stable-2023-02-20-13-37' of ↵Linus Torvalds2023-02-231-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
| * coredump: convert to vma iteratorLiam R. Howlett2023-02-091-4/+4
| | | | | | | | | | | | | | | | | | Use the vma iterator so that the iterator can be invalidated or updated to avoid each caller doing so. Link: https://lkml.kernel.org/r/20230120162650.984577-20-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linuxLinus Torvalds2023-02-201-5/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block updates from Jens Axboe: - NVMe updates via Christoph: - Small improvements to the logging functionality (Amit Engel) - Authentication cleanups (Hannes Reinecke) - Cleanup and optimize the DMA mapping cod in the PCIe driver (Keith Busch) - Work around the command effects for Format NVM (Keith Busch) - Misc cleanups (Keith Busch, Christoph Hellwig) - Fix and cleanup freeing single sgl (Keith Busch) - MD updates via Song: - Fix a rare crash during the takeover process - Don't update recovery_cp when curr_resync is ACTIVE - Free writes_pending in md_stop - Change active_io to percpu - Updates to drbd, inching us closer to unifying the out-of-tree driver with the in-tree one (Andreas, Christoph, Lars, Robert) - BFQ update adding support for multi-actuator drives (Paolo, Federico, Davide) - Make brd compliant with REQ_NOWAIT (me) - Fix for IOPOLL and queue entering, fixing stalled IO waiting on timeouts (me) - Fix for REQ_NOWAIT with multiple bios (me) - Fix memory leak in blktrace cleanup (Greg) - Clean up sbitmap and fix a potential hang (Kemeng) - Clean up some bits in BFQ, and fix a bug in the request injection (Kemeng) - Clean up the request allocation and issue code, and fix some bugs related to that (Kemeng) - ublk updates and fixes: - Add support for unprivileged ublk (Ming) - Improve device deletion handling (Ming) - Misc (Liu, Ziyang) - s390 dasd fixes (Alexander, Qiheng) - Improve utility of request caching and fixes (Anuj, Xiao) - zoned cleanups (Pankaj) - More constification for kobjs (Thomas) - blk-iocost cleanups (Yu) - Remove bio splitting from drivers that don't need it (Christoph) - Switch blk-cgroups to use struct gendisk. Some of this is now incomplete as select late reverts were done. (Christoph) - Add bvec initialization helpers, and convert callers to use that rather than open-coding it (Christoph) - Misc fixes and cleanups (Jinke, Keith, Arnd, Bart, Li, Martin, Matthew, Ulf, Zhong) * tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux: (169 commits) brd: use radix_tree_maybe_preload instead of radix_tree_preload block: use proper return value from bio_failfast() block: bio-integrity: Copy flags when bio_integrity_payload is cloned block: Fix io statistics for cgroup in throttle path brd: mark as nowait compatible brd: check for REQ_NOWAIT and set correct page allocation mask brd: return 0/-error from brd_insert_page() block: sync mixed merged request's failfast with 1st bio's Revert "blk-cgroup: pin the gendisk in struct blkcg_gq" Revert "blk-cgroup: pass a gendisk to blkg_lookup" Revert "blk-cgroup: delay blk-cgroup initialization until add_disk" Revert "blk-cgroup: delay calling blkcg_exit_disk until disk_release" Revert "blk-cgroup: move the cgroup information to struct gendisk" nvme-pci: remove iod use_sgls nvme-pci: fix freeing single sgl block: ublk: check IO buffer based on flag need_get_data s390/dasd: Fix potential memleak in dasd_eckd_init() s390/dasd: sort out physical vs virtual pointers usage block: Remove the ALLOC_CACHE_SLACK constant block: make kobj_type structures constant ...
| * | coredump: use bvec_set_page to initialize a bvecChristoph Hellwig2023-02-031-5/+2
| |/ | | | | | | | | | | | | | | Use the bvec_set_page helper to initialize a bvec. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230203150634.3199647-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge tag 'fs.idmapped.v6.3' of ↵Linus Torvalds2023-02-201-4/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping Pull vfs idmapping updates from Christian Brauner: - Last cycle we introduced the dedicated struct mnt_idmap type for mount idmapping and the required infrastucture in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). As promised in last cycle's pull request message this converts everything to rely on struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevant on the mount level. Especially for non-vfs developers without detailed knowledge in this area this was a potential source for bugs. This finishes the conversion. Instead of passing the plain namespace around this updates all places that currently take a pointer to a mnt_userns with a pointer to struct mnt_idmap. Now that the conversion is done all helpers down to the really low-level helpers only accept a struct mnt_idmap argument instead of two namespace arguments. Conflating mount and other idmappings will now cause the compiler to complain loudly thus eliminating the possibility of any bugs. This makes it impossible for filesystem developers to mix up mount and filesystem idmappings as they are two distinct types and require distinct helpers that cannot be used interchangeably. Everything associated with struct mnt_idmap is moved into a single separate file. With that change no code can poke around in struct mnt_idmap. It can only be interacted with through dedicated helpers. That means all filesystems are and all of the vfs is completely oblivious to the actual implementation of idmappings. We are now also able to extend struct mnt_idmap as we see fit. For example, we can decouple it completely from namespaces for users that don't require or don't want to use them at all. We can also extend the concept of idmappings so we can cover filesystem specific requirements. In combination with the vfs{g,u}id_t work we finished in v6.2 this makes this feature substantially more robust and thus difficult to implement wrong by a given filesystem and also protects the vfs. - Enable idmapped mounts for tmpfs and fulfill a longstanding request. A long-standing request from users had been to make it possible to create idmapped mounts for tmpfs. For example, to share the host's tmpfs mount between multiple sandboxes. This is a prerequisite for some advanced Kubernetes cases. Systemd also has a range of use-cases to increase service isolation. And there are more users of this. However, with all of the other work going on this was way down on the priority list but luckily someone other than ourselves picked this up. As usual the patch is tiny as all the infrastructure work had been done multiple kernel releases ago. In addition to all the tests that we already have I requested that Rodrigo add a dedicated tmpfs testsuite for idmapped mounts to xfstests. It is to be included into xfstests during the v6.3 development cycle. This should add a slew of additional tests. * tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits) shmem: support idmapped mounts for tmpfs fs: move mnt_idmap fs: port vfs{g,u}id helpers to mnt_idmap fs: port fs{g,u}id helpers to mnt_idmap fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap fs: port i_{g,u}id_{needs_}update() to mnt_idmap quota: port to mnt_idmap fs: port privilege checking helpers to mnt_idmap fs: port inode_owner_or_capable() to mnt_idmap fs: port inode_init_owner() to mnt_idmap fs: port acl to mnt_idmap fs: port xattr to mnt_idmap fs: port ->permission() to pass mnt_idmap fs: port ->fileattr_set() to pass mnt_idmap fs: port ->set_acl() to pass mnt_idmap fs: port ->get_acl() to pass mnt_idmap fs: port ->tmpfile() to pass mnt_idmap fs: port ->rename() to pass mnt_idmap fs: port ->mknod() to pass mnt_idmap fs: port ->mkdir() to pass mnt_idmap ...
| * | fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmapChristian Brauner2023-01-191-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert to struct mnt_idmap. Remove legacy file_mnt_user_ns() and mnt_user_ns(). Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
| * | fs: port vfs_*() helpers to struct mnt_idmapChristian Brauner2023-01-181-2/+4
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
* / coredump: Move dump_emit_page() to kill unused warningGeert Uytterhoeven2023-01-101-24/+24
|/ | | | | | | | | | | | | | | If CONFIG_ELF_CORE is not set: fs/coredump.c:835:12: error: ‘dump_emit_page’ defined but not used [-Werror=unused-function] 835 | static int dump_emit_page(struct coredump_params *cprm, struct page *page) | ^~~~~~~~~~~~~~ Fix this by moving dump_emit_page() inside the existing section protected by #ifdef CONFIG_ELF_CORE. Fixes: 06bbaa6dc53cb720 ("[coredump] don't use __kernel_write() on kmap_local_page()") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'hardening-v6.2-rc1' of ↵Linus Torvalds2022-12-141-2/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kernel hardening updates from Kees Cook: - Convert flexible array members, fix -Wstringop-overflow warnings, and fix KCFI function type mismatches that went ignored by maintainers (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook) - Remove the remaining side-effect users of ksize() by converting dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add more __alloc_size attributes, and introduce full testing of all allocator functions. Finally remove the ksize() side-effect so that each allocation-aware checker can finally behave without exceptions - Introduce oops_limit (default 10,000) and warn_limit (default off) to provide greater granularity of control for panic_on_oops and panic_on_warn (Jann Horn, Kees Cook) - Introduce overflows_type() and castable_to_type() helpers for cleaner overflow checking - Improve code generation for strscpy() and update str*() kern-doc - Convert strscpy and sigphash tests to KUnit, and expand memcpy tests - Always use a non-NULL argument for prepare_kernel_cred() - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell) - Adjust orphan linker section checking to respect CONFIG_WERROR (Xin Li) - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu) - Fix um vs FORTIFY warnings for always-NULL arguments * tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits) ksmbd: replace one-element arrays with flexible-array members hpet: Replace one-element array with flexible-array member um: virt-pci: Avoid GCC non-NULL warning signal: Initialize the info in ksignal lib: fortify_kunit: build without structleak plugin panic: Expose "warn_count" to sysfs panic: Introduce warn_limit panic: Consolidate open-coded panic_on_warn checks exit: Allow oops_limit to be disabled exit: Expose "oops_count" to sysfs exit: Put an upper limit on how often we can oops panic: Separate sysctl logic from CONFIG_SMP mm/pgtable: Fix multiple -Wstringop-overflow warnings mm: Make ksize() a reporting-only function kunit/fortify: Validate __alloc_size attribute results drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid() drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid() driver core: Add __alloc_size hint to devm allocators overflow: Introduce overflows_type() and castable_to_type() coredump: Proactively round up to kmalloc bucket size ...
| * coredump: Proactively round up to kmalloc bucket sizeKees Cook2022-11-011-2/+5
| | | | | | | | | | | | | | | | | | | | | | Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* | Merge tag 'fs.vfsuid.conversion.v6.2' of ↵Linus Torvalds2022-12-121-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping Pull vfsuid updates from Christian Brauner: "Last cycle we introduced the vfs{g,u}id_t types and associated helpers to gain type safety when dealing with idmapped mounts. That initial work already converted a lot of places over but there were still some left, This converts all remaining places that still make use of non-type safe idmapping helpers to rely on the new type safe vfs{g,u}id based helpers. Afterwards it removes all the old non-type safe helpers" * tag 'fs.vfsuid.conversion.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: fs: remove unused idmapping helpers ovl: port to vfs{g,u}id_t and associated helpers fuse: port to vfs{g,u}id_t and associated helpers ima: use type safe idmapping helpers apparmor: use type safe idmapping helpers caps: use type safe idmapping helpers fs: use type safe idmapping helpers mnt_idmapping: add missing helpers
| * | fs: use type safe idmapping helpersChristian Brauner2022-10-261-2/+2
| |/ | | | | | | | | | | | | | | | | | | We already ported most parts and filesystems over for v6.0 to the new vfs{g,u}id_t type and associated helpers for v6.0. Convert the remaining places so we can remove all the old helpers. This is a non-functional change. Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
* | Merge tag 'pull-iov_iter' of ↵Linus Torvalds2022-12-121-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull iov_iter updates from Al Viro: "iov_iter work; most of that is about getting rid of direction misannotations and (hopefully) preventing more of the same for the future" * tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: use less confusing names for iov_iter direction initializers iov_iter: saner checks for attempt to copy to/from iterator [xen] fix "direction" argument of iov_iter_kvec() [vhost] fix 'direction' argument of iov_iter_{init,bvec}() [target] fix iov_iter_bvec() "direction" argument [s390] memcpy_real(): WRITE is "data source", not destination... [s390] zcore: WRITE is "data source", not destination... [infiniband] READ is "data destination", not source... [fsi] WRITE is "data source", not destination... [s390] copy_oldmem_kernel() - WRITE is "data source", not destination csum_and_copy_to_iter(): handle ITER_DISCARD get rid of unlikely() on page_copy_sane() calls
| * | use less confusing names for iov_iter direction initializersAl Viro2022-11-251-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'pull-elfcore' of ↵Linus Torvalds2022-12-121-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull elf coredumping updates from Al Viro: "Unification of regset and non-regset sides of ELF coredump handling. Collecting per-thread register values is the only thing that needs to be ifdefed there..." * tag 'pull-elfcore' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [elf] get rid of get_note_info_size() [elf] unify regset and non-regset cases [elf][non-regset] use elf_core_copy_task_regs() for dumper as well [elf][non-regset] uninline elf_core_copy_task_fpregs() (and lose pt_regs argument) elf_core_copy_task_regs(): task_pt_regs is defined everywhere [elf][regset] simplify thread list handling in fill_note_info() [elf][regset] clean fill_note_info() a bit kill extern of vsyscall32_sysctl kill coredump_params->regs kill signal_pt_regs()
| * | kill coredump_params->regsAl Viro2022-10-231-1/+0
| | | | | | | | | | | | | | | | | | it's always task_pt_regs(current) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | kill signal_pt_regs()Al Viro2022-10-231-1/+1
| |/ | | | | | | | | | | | | | | | | Once upon at it was used on hot paths, but that had not been true since 2013. IOW, there's no point for arch-optimized equivalent of task_pt_regs(current) - remaining two users are not worth bothering with. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / core_pattern: add CPU specifierOleksandr Natalenko2022-11-181-0/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Statistically, in a large deployment regular segfaults may indicate a CPU issue. Currently, it is not possible to find out what CPU the segfault happened on. There are at least two attempts to improve segfault logging with this regard, but they do not help in case the logs rotate. Hence, lets make sure it is possible to permanently record a CPU the task ran on using a new core_pattern specifier. Link: https://lkml.kernel.org/r/20220903064330.20772-1-oleksandr@redhat.com Signed-off-by: Oleksandr Natalenko <oleksandr@redhat.com> Suggested-by: Renaud Métrich <rmetrich@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Grzegorz Halat <ghalat@redhat.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Joel Savitz <jsavitz@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Stephen Kitt <steve@sk2.org> Cc: Will Deacon <will@kernel.org> Cc: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds2022-10-101-22/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * coredump: remove vma linked list walkMatthew Wilcox (Oracle)2022-09-261-22/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the Maple Tree iterator instead. This is too complicated for the VMA iterator to handle, so let's open-code it for now. If this turns out to be a common pattern, we can migrate it to common code. Link: https://lkml.kernel.org/r/20220906194824.2110408-41-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>
* | Merge tag 'sched-core-2022-10-07' of ↵Linus Torvalds2022-10-101-4/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Debuggability: - Change most occurances of BUG_ON() to WARN_ON_ONCE() - Reorganize & fix TASK_ state comparisons, turn it into a bitmap - Update/fix misc scheduler debugging facilities Load-balancing & regular scheduling: - Improve the behavior of the scheduler in presence of lot of SCHED_IDLE tasks - in particular they should not impact other scheduling classes. - Optimize task load tracking, cleanups & fixes - Clean up & simplify misc load-balancing code Freezer: - Rewrite the core freezer to behave better wrt thawing and be simpler in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting all the fallout. Deadline scheduler: - Fix the DL capacity-aware code - Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period() - Relax/optimize locking in task_non_contending() Cleanups: - Factor out the update_current_exec_runtime() helper - Various cleanups, simplifications" * tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) sched: Fix more TASK_state comparisons sched: Fix TASK_state comparisons sched/fair: Move call to list_last_entry() in detach_tasks sched/fair: Cleanup loop_max and loop_break sched/fair: Make sure to try to detach at least one movable task sched: Show PF_flag holes freezer,sched: Rewrite core freezer logic sched: Widen TAKS_state literals sched/wait: Add wait_event_state() sched/completion: Add wait_for_completion_state() sched: Add TASK_ANY for wait_task_inactive() sched: Change wait_task_inactive()s match_state freezer,umh: Clean up freezer/initrd interaction freezer: Have {,un}lock_system_sleep() save/restore flags sched: Rename task_running() to task_on_cpu() sched/fair: Cleanup for SIS_PROP sched/fair: Default to false in test_idle_cores() sched/fair: Remove useless check in select_idle_core() sched/fair: Avoid double search on same cpu sched/fair: Remove redundant check in select_idle_smt() ...
| * | freezer,sched: Rewrite core freezer logicPeter Zijlstra2022-09-071-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite the core freezer to behave better wrt thawing and be simpler in general. By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is ensured frozen tasks stay frozen until thawed and don't randomly wake up early, as is currently possible. As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up two PF_flags (yay!). Specifically; the current scheme works a little like: freezer_do_not_count(); schedule(); freezer_count(); And either the task is blocked, or it lands in try_to_freezer() through freezer_count(). Now, when it is blocked, the freezer considers it frozen and continues. However, on thawing, once pm_freezing is cleared, freezer_count() stops working, and any random/spurious wakeup will let a task run before its time. That is, thawing tries to thaw things in explicit order; kernel threads and workqueues before doing bringing SMP back before userspace etc.. However due to the above mentioned races it is entirely possible for userspace tasks to thaw (by accident) before SMP is back. This can be a fatal problem in asymmetric ISA architectures (eg ARMv9) where the userspace task requires a special CPU to run. As said; replace this with a special task state TASK_FROZEN and add the following state transitions: TASK_FREEZABLE -> TASK_FROZEN __TASK_STOPPED -> TASK_FROZEN __TASK_TRACED -> TASK_FROZEN The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL (IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state is already required to deal with spurious wakeups and the freezer causes one such when thawing the task (since the original state is lost). The special __TASK_{STOPPED,TRACED} states *can* be restored since their canonical state is in ->jobctl. With this, frozen tasks need an explicit TASK_FROZEN wakeup and are free of undue (early / spurious) wakeups. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
| * | sched: Add TASK_ANY for wait_task_inactive()Peter Zijlstra2022-09-071-1/+1
| |/ | | | | | | | | | | | | | | | | | | Now that wait_task_inactive()'s @match_state argument is a mask (like ttwu()) it is possible to replace the special !match_state case with an 'all-states' value such that any blocked state will match. Suggested-by: Ingo Molnar (mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YxhkzfuFTvRnpUaH@hirez.programming.kicks-ass.net
* | Merge tag 'signal-for-v5.20' of ↵Linus Torvalds2022-10-091-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace update from Eric Biederman: "ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT Recently I had a conversation where it was pointed out to me that SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite difficult for a tracer to handle. Keeping SIGKILL working after the process has been killed is pain from an implementation point of view. So since the debuggers don't want this behavior let's see if we can remove this wart for the userspace API If a regression is detected it should only need to be the last change that is the reverted. The other two are just general cleanups that make the last patch simpler" * tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: signal: Drop signals received after a fatal signal has been processed signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
| * | signal: Drop signals received after a fatal signal has been processedEric W. Biederman2022-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 403bad72b67d ("coredump: only SIGKILL should interrupt the coredumping task") Oleg modified the kernel to drop all signals that come in during a coredump except SIGKILL, and suggested that it might be a good idea to generalize that to other cases after the process has received a fatal signal. Semantically it does not make sense to perform any signal delivery after the process has already been killed. When a signal is sent while a process is dying today the signal is placed in the signal queue by __send_signal and a single task of the process is woken up with signal_wake_up, if there are any tasks that have not set PF_EXITING. Take things one step farther and have prepare_signal report that all signals that come after a process has been killed should be ignored. While retaining the historical exception of allowing SIGKILL to interrupt coredumps. Update the comment in fs/coredump.c to make it clear coredumps are special in being able to receive SIGKILL. This changes things so that a process stopped in PTRACE_EVENT_EXIT can not be made to escape it's ptracer and finish exiting by sending it SIGKILL. That a process can be made to leave PTRACE_EVENT_EXIT and escape it's tracer by sending the process a SIGKILL has been complicating tracer's for no apparent advantage. If the process needs to be made to leave PTRACE_EVENT_EXIT all that needs to happen is to kill the proceses's tracer. This differs from the coredump code where there is no other mechanism besides honoring SIGKILL to expedite the end of coredumping. Link: https://lkml.kernel.org/r/875yksd4s9.fsf_-_@email.froward.int.ebiederm.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | [brown paperbag] fix coredump breakageAl Viro2022-10-031-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let me count the ways in which I'd screwed up: * when emitting a page, handling of gaps in coredump should happen before fetching the current file position. * fix for a problem that occurs on rather uncommon setups (and hadn't been observed in the wild) had been sent very late in the cycle. * ... with badly insufficient testing, introducing an easily reproducible breakage. Without giving it time to soak in -next. Fucked-up-by: Al Viro <viro@zeniv.linux.org.uk> Reported-by: "J. R. Okajima" <hooanon05g@gmail.com> Tested-by: "J. R. Okajima" <hooanon05g@gmail.com> Fixes: 06bbaa6dc53c "[coredump] don't use __kernel_write() on kmap_local_page()" Cc: stable@kernel.org # v6.0-only Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | [coredump] don't use __kernel_write() on kmap_local_page()Al Viro2022-09-281-5/+33
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | passing kmap_local_page() result to __kernel_write() is unsafe - random ->write_iter() might (and 9p one does) get unhappy when passed ITER_KVEC with pointer that came from kmap_local_page(). Fix by providing a variant of __kernel_write() that takes an iov_iter from caller (__kernel_write() becomes a trivial wrapper) and adding dump_emit_page() that parallels dump_emit(), except that instead of __kernel_write() it uses __kernel_write_iter() with ITER_BVEC source. Fixes: 3159ed57792b "fs/coredump: use kmap_local_page()" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | fs: do not compare against ->llseekJason A. Donenfeld2022-07-161-2/+2
|/ | | | | | | | | | | | | Now vfs_llseek() can simply check for FMODE_LSEEK; if it's set, we know that ->llseek() won't be NULL and if it's not we should just fail with -ESPIPE. A couple of other places where we used to check for special values of ->llseek() (somewhat inconsistently) switched to checking FMODE_LSEEK. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'ptrace-cleanups-for-v5.18' of ↵Linus Torvalds2022-03-281-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace cleanups from Eric Biederman: "This set of changes removes tracehook.h, moves modification of all of the ptrace fields inside of siglock to remove races, adds a missing permission check to ptrace.c The removal of tracehook.h is quite significant as it has been a major source of confusion in recent years. Much of that confusion was around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the semantics clearer). For people who don't know tracehook.h is a vestiage of an attempt to implement uprobes like functionality that was never fully merged, and was later superseeded by uprobes when uprobes was merged. For many years now we have been removing what tracehook functionaly a little bit at a time. To the point where anything left in tracehook.h was some weird strange thing that was difficult to understand" * tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ptrace: Remove duplicated include in ptrace.c ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE ptrace: Return the signal to continue with from ptrace_stop ptrace: Move setting/clearing ptrace_message into ptrace_stop tracehook: Remove tracehook.h resume_user_mode: Move to resume_user_mode.h resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume signal: Move set_notify_signal and clear_notify_signal into sched/signal.h task_work: Decouple TIF_NOTIFY_SIGNAL and task_work task_work: Call tracehook_notify_signal from get_signal on all architectures task_work: Introduce task_work_pending task_work: Remove unnecessary include from posix_timers.h ptrace: Remove tracehook_signal_handler ptrace: Remove arch_syscall_{enter,exit}_tracehook ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h ptrace/arm: Rename tracehook_report_syscall report_syscall ptrace: Move ptrace_report_syscall into ptrace.h
| * tracehook: Remove tracehook.hEric W. Biederman2022-03-101-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that all of the definitions have moved out of tracehook.h into ptrace.h, sched/signal.h, resume_user_mode.h there is nothing left in tracehook.h so remove it. Update the few files that were depending upon tracehook.h to bring in definitions to use the headers they need directly. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-13-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | coredump: Use the vma snapshot in fill_files_noteEric W. Biederman2022-03-081-1/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Matthew Wilcox reported that there is a missing mmap_lock in file_files_note that could possibly lead to a user after free. Solve this by using the existing vma snapshot for consistency and to avoid the need to take the mmap_lock anywhere in the coredump code except for dump_vma_snapshot. Update the dump_vma_snapshot to capture vm_pgoff and vm_file that are neeeded by fill_files_note. Add free_vma_snapshot to free the captured values of vm_file. Reported-by: Matthew Wilcox <willy@infradead.org> Link: https://lkml.kernel.org/r/20220131153740.2396974-1-willy@infradead.org Cc: stable@vger.kernel.org Fixes: a07279c9a8cd ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Fixes: 2aa362c49c31 ("coredump: extend core dump note section to contain file names of mapped files") Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | coredump: Remove the WARN_ON in dump_vma_snapshotEric W. Biederman2022-03-081-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The condition is impossible and to the best of my knowledge has never triggered. We are in deep trouble if that conditions happens and we walk past the end of our allocated array. So delete the WARN_ON and the code that makes it look like the kernel can handle the case of walking past the end of it's vma_meta array. Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | coredump: Snapshot the vmas in do_coredumpEric W. Biederman2022-03-081-18/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the call of dump_vma_snapshot and kvfree(vma_meta) out of the individual coredump routines into do_coredump itself. This makes the code less error prone and easier to maintain. Make the vma snapshot available to the coredump routines in struct coredump_params. This makes it easier to change and update what is captures in the vma snapshot and will be needed for fixing fill_file_notes. Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | coredump: Also dump first pages of non-executable ELF librariesJann Horn2022-03-011-5/+34
|/ | | | | | | | | | | | | | | | | | | | | | When I rewrote the VMA dumping logic for coredumps, I changed it to recognize ELF library mappings based on the file being executable instead of the mapping having an ELF header. But turns out, distros ship many ELF libraries as non-executable, so the heuristic goes wrong... Restore the old behavior where FILTER(ELF_HEADERS) dumps the first page of any offset-0 readable mapping that starts with the ELF magic. This fix is technically layer-breaking a bit, because it checks for something ELF-specific in fs/coredump.c; but since we probably want to share this between standard ELF and FDPIC ELF anyway, I guess it's fine? And this also keeps the change small for backporting. Cc: stable@vger.kernel.org Fixes: 429a22e776a2 ("coredump: rework elf/elf_fdpic vma_dump_size() into common helper") Reported-by: Bill Messmer <wmessmer@microsoft.com> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220126025739.2014888-1-jannh@google.com
* fs/coredump: move coredump sysctls into its own fileXiaoming Ni2022-01-221-5/+61
| | | | | | | | | | | | | | | | | | | | | | | This moves the fs/coredump.c respective sysctls to its own file. Link: https://lkml.kernel.org/r/20211129211943.640266-6-mcgrof@kernel.org Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Antti Palosaari <crope@iki.fi> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Lukas Middendorf <kernel@tuxforce.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Stephen Kitt <steve@sk2.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signal: Remove the helper signal_group_exitEric W. Biederman2022-01-081-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This helper is misleading. It tests for an ongoing exec as well as the process having received a fatal signal. Sometimes it is appropriate to treat an on-going exec differently than a process that is shutting down due to a fatal signal. In particular taking the fast path out of exit_signals instead of retargeting signals is not appropriate during exec, and not changing the the exit code in do_group_exit during exec. Removing the helper makes it more obvious what is going on as both cases must be coded for explicitly. While removing the helper fix the two cases where I have observed using signal_group_exit resulted in the wrong result. In exit_signals only test for SIGNAL_GROUP_EXIT so that signals are retargetted during an exec. In do_group_exit use 0 as the exit code during an exec as de_thread does not set group_exit_code. As best as I can determine group_exit_code has been is set to 0 most of the time during de_thread. During a thread group stop group_exit_code is set to the stop signal and when the thread group receives SIGCONT group_exit_code is reset to 0. Link: https://lkml.kernel.org/r/20211213225350.27481-8-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* coredump: Stop setting signal->group_exit_taskEric W. Biederman2022-01-081-2/+0
| | | | | | | | | | Currently the coredump code sets group_exit_task so that signal_group_exit() will return true during a coredump. Now that the coredump code always sets SIGNAL_GROUP_EXIT there is no longer a need to set signal->group_exit_task. Link: https://lkml.kernel.org/r/20211213225350.27481-6-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* signal: Remove SIGNAL_GROUP_COREDUMPEric W. Biederman2022-01-081-2/+1
| | | | | | | | | | | | | | | | | | | | After the previous cleanups "signal->core_state" is set whenever SIGNAL_GROUP_COREDUMP is set and "signal->core_state" is tested whenver the code wants to know if a coredump is in progress. The remaining tests of SIGNAL_GROUP_COREDUMP also test to see if SIGNAL_GROUP_EXIT is set. Similarly the only place that sets SIGNAL_GROUP_COREDUMP also sets SIGNAL_GROUP_EXIT. Which makes SIGNAL_GROUP_COREDUMP unecessary and redundant. So stop setting SIGNAL_GROUP_COREDUMP, stop testing SIGNAL_GROUP_COREDUMP, and remove it's definition. With the setting of SIGNAL_GROUP_COREDUMP gone, coredump_finish no longer needs to clear SIGNAL_GROUP_COREDUMP out of signal->flags by setting SIGNAL_GROUP_EXIT. Link: https://lkml.kernel.org/r/20211213225350.27481-5-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* signal: During coredumps set SIGNAL_GROUP_EXIT in zap_processEric W. Biederman2022-01-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | There are only a few places that test SIGNAL_GROUP_EXIT and are not also already testing SIGNAL_GROUP_COREDUMP. This will not affect the callers of signal_group_exit as zap_process also sets group_exit_task so signal_group_exit will continue to return true at the same times. This does not affect wait_task_zombie as the none of the threads wind up in EXIT_ZOMBIE state during a coredump. This does not affect oom_kill.c:__task_will_free_mem as sig->core_state is tested and handled before SIGNAL_GROUP_EXIT is tested for. This does not affect complete_signal as signal->core_state is tested for to ensure the coredump case is handled appropriately. Link: https://lkml.kernel.org/r/20211213225350.27481-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* coredump: Limit coredumps to a single thread groupEric W. Biederman2021-10-081-75/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today when a signal is delivered with a handler of SIG_DFL whose default behavior is to generate a core dump not only that process but every process that shares the mm is killed. In the case of vfork this looks like a real world problem. Consider the following well defined sequence. if (vfork() == 0) { execve(...); _exit(EXIT_FAILURE); } If a signal that generates a core dump is received after vfork but before the execve changes the mm the process that called vfork will also be killed (as the mm is shared). Similarly if the execve fails after the point of no return the kernel delivers SIGSEGV which will kill both the exec'ing process and because the mm is shared the process that called vfork as well. As far as I can tell this behavior is a violation of people's reasonable expectations, POSIX, and is unnecessarily fragile when the system is low on memory. Solve this by making a userspace visible change to only kill a single process/thread group. This is possible because Jann Horn recently modified[1] the coredump code so that the mm can safely be modified while the coredump is happening. With LinuxThreads long gone I don't expect anyone to have a notice this behavior change in practice. To accomplish this move the core_state pointer from mm_struct to signal_struct, which allows different thread groups to coredump simultatenously. In zap_threads remove the work to kill anything except for the current thread group. v2: Remove core_state from the VM_BUG_ON_MM print to fix compile failure when CONFIG_DEBUG_VM is enabled. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> [1] a07279c9a8cd ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot") Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3") History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133 Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* coredump: Don't perform any cleanups before dumping coreEric W. Biederman2021-10-061-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename coredump_exit_mm to coredump_task_exit and call it from do_exit before PTRACE_EVENT_EXIT, and before any cleanup work for a task happens. This ensures that an accurate copy of the process can be captured in the coredump as no cleanup for the process happens before the coredump completes. This also ensures that PTRACE_EVENT_EXIT will not be visited by any thread until the coredump is complete. Add a new flag PF_POSTCOREDUMP so that tasks that have passed through coredump_task_exit can be recognized and ignored in zap_process. Now that all of the coredumping happens before exit_mm remove code to test for a coredump in progress from mm_release. Replace "may_ptrace_stop()" with a simple test of "current->ptrace". The other tests in may_ptrace_stop all concern avoiding stopping during a coredump. These tests are no longer necessary as it is now guaranteed that fatal_signal_pending will be set if the code enters ptrace_stop during a coredump. The code in ptrace_stop is guaranteed not to stop if fatal_signal_pending returns true. Until this change "ptrace_event(PTRACE_EVENT_EXIT)" could call ptrace_stop without fatal_signal_pending being true, as signals are dequeued in get_signal before calling do_exit. This is no longer an issue as "ptrace_event(PTRACE_EVENT_EXIT)" is no longer reached until after the coredump completes. Link: https://lkml.kernel.org/r/874kaax26c.fsf@disp2133 Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* exit: Factor coredump_exit_mm out of exit_mmEric W. Biederman2021-10-061-3/+3
| | | | | | | | | | Separate the coredump logic from the ordinary exit_mm logic by moving the coredump logic out of exit_mm into it's own function coredump_exit_mm. Link: https://lkml.kernel.org/r/87a6k2x277.fsf@disp2133 Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* coredump: fix memleak in dump_vma_snapshot()QiuXi2021-09-081-1/+3
| | | | | | | | | | | | | | 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: a07279c9a8cd7 ("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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/coredump.c: log if a core dump is aborted due to changed file permissionsDavid Oberhollenzer2021-09-081-2/+9
| | | | | | | | | | | | | | | | | | | | | 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.at Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'work.namei' of ↵Linus Torvalds2021-07-031-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs name lookup updates from Al Viro: "Small namei.c patch series, mostly to simplify the rules for nameidata state. It's actually from the previous cycle - but I didn't post it for review in time... Changes visible outside of fs/namei.c: file_open_root() calling conventions change, some freed bits in LOOKUP_... space" * 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: namei: make sure nd->depth is always valid teach set_nameidata() to handle setting the root as well take LOOKUP_{ROOT,ROOT_GRABBED,JUMPED} out of LOOKUP_... space switch file_open_root() to struct path
| * switch file_open_root() to struct pathAl Viro2021-04-071-2/+2
| | | | | | | | | | | | ... and provide file_open_root_mnt(), using the root of given mount. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>