kernel/linux.git/lib/iov_iter.c, branch v5.12.18

iov_iter_fault_in_readable() should do nothing in xarray case

2021-07-14T14:59:03+00:00

commit 0e8f0d67401589a141950856902c7d0ec8d9c985 upstream. ... and actually should just check it's given an iovec-backed iterator in the first place. Cc: stable@vger.kernel.org Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

copy_page_to_iter(): fix ITER_DISCARD case

2021-07-14T14:59:03+00:00

commit a506abc7b644d71966a75337d5a534f531b3cdc4 upstream. we need to advance the iterator... Cc: stable@vger.kernel.org Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

Merge branch 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2021-03-01T19:24:18+00:00

Pull kmap conversion updates from David Sterba: "This contains changes regarding kmap API use and eg conversion from kmap_atomic to kmap_local_page. The API belongs to memory management but to save cross-tree dependency headaches we've agreed to take it through the btrfs tree because there are some trivial conversions possible, while the rest will need some time and getting the easy cases out of the way would be convenient. The changes can be grouped: - function exports, new helpers - new VM_BUG_ON for additional verification; it's been discussed if it should be VM_BUG_ON or BUG_ON, the former was chosen due to performance reasons - code replaced by relevant helpers" [ This is an updated version of a request that originally came in during the merge window, but I asked for some updates: https://lore.kernel.org/lkml/cover.1614090658.git.dsterba@suse.com/ which is why this got merge after the merge window closed. - Linus ] * 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: use copy_highpage() instead of 2 kmaps() btrfs: use memcpy_[to|from]_page() and kmap_local_page() mm/highmem: Add VM_BUG_ON() to mem*_page() calls mm/highmem: Introduce memcpy_page(), memmove_page(), and memset_page() mm/highmem: Convert memcpy_[to|from]_page() to kmap_local_page() mm/highmem: Lift memcpy_[to|from]_page to core

Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

2021-02-21T19:02:48+00:00

Pull core block updates from Jens Axboe: "Another nice round of removing more code than what is added, mostly due to Christoph's relentless pursuit of tech debt removal/cleanups. This pull request contains: - Two series of BFQ improvements (Paolo, Jan, Jia) - Block iov_iter improvements (Pavel) - bsg error path fix (Pan) - blk-mq scheduler improvements (Jan) - -EBUSY discard fix (Jan) - bvec allocation improvements (Ming, Christoph) - bio allocation and init improvements (Christoph) - Store bdev pointer in bio instead of gendisk + partno (Christoph) - Block trace point cleanups (Christoph) - hard read-only vs read-only split (Christoph) - Block based swap cleanups (Christoph) - Zoned write granularity support (Damien) - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)" * tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits) mm: simplify swapdev_block sd_zbc: clear zone resources for non-zoned case block: introduce blk_queue_clear_zone_settings() zonefs: use zone write granularity as block size block: introduce zone_write_granularity limit block: use blk_queue_set_zoned in add_partition() nullb: use blk_queue_set_zoned() to setup zoned devices nvme: cleanup zone information initialization block: document zone_append_max_bytes attribute block: use bi_max_vecs to find the bvec pool md/raid10: remove dead code in reshape_request block: mark the bio as cloned in bio_iov_bvec_set block: set BIO_NO_PAGE_REF in bio_iov_bvec_set block: remove a layer of indentation in bio_iov_iter_get_pages block: turn the nr_iovecs argument to bio_alloc* into an unsigned short block: remove the 1 and 4 vec bvec_slabs entries block: streamline bvec_alloc block: factor out a bvec_alloc_gfp helper block: move struct biovec_slab to bio.c block: reuse BIO_INLINE_VECS for integrity bvecs ...

mm/highmem: Lift memcpy_[to|from]_page to core

2021-02-11T18:54:43+00:00

Working through a conversion to a call kmap_local_page() instead of kmap() revealed many places where the pattern kmap/memcpy/kunmap occurred. Eric Biggers, Matthew Wilcox, Christoph Hellwig, Dan Williams, and Al Viro all suggested putting this code into helper functions. Al Viro further pointed out that these functions already existed in the iov_iter code.[1] Various locations for the lifted functions were considered. Headers like mm.h or string.h seem ok but don't really portray the functionality well. pagemap.h made some sense but is for page cache functionality.[2] Another alternative would be to create a new header for the promoted memcpy functions, but it masks the fact that these are designed to copy to/from pages using the kernel direct mappings and complicates matters with a new header. Placing these functions in 'highmem.h' is suboptimal especially with the changes being proposed in the functionality of kmap. From a caller perspective including/using 'highmem.h' implies that the functions defined in that header are only required when highmem is in use which is increasingly not the case with modern processors. However, highmem.h is where all the current functions like this reside (zero_user(), clear_highpage(), clear_user_highpage(), copy_user_highpage(), and copy_highpage()). So it makes the most sense even though it is distasteful for some.[3] Lift memcpy_to_page() and memcpy_from_page() to pagemap.h. [1] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/ https://lore.kernel.org/lkml/20201013112544.GA5249@infradead.org/ [2] https://lore.kernel.org/lkml/20201208122316.GH7338@casper.infradead.org/ [3] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/#t https://lore.kernel.org/lkml/20201208163814.GN1563847@iweiny-DESK2.sc.intel.com/ Cc: Boris Pismenny Cc: Or Gerlitz Cc: Dave Hansen Suggested-by: Matthew Wilcox Suggested-by: Christoph Hellwig Suggested-by: Dan Williams Suggested-by: Al Viro Suggested-by: Eric Biggers Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Signed-off-by: David Sterba

udp: fix skb_copy_and_csum_datagram with odd segment sizes

2021-02-05T02:56:56+00:00

When iteratively computing a checksum with csum_block_add, track the offset "pos" to correctly rotate in csum_block_add when offset is odd. The open coded implementation of skb_copy_and_csum_datagram did this. With the switch to __skb_datagram_iter calling csum_and_copy_to_iter, pos was reinitialized to 0 on each call. Bring back the pos by passing it along with the csum to the callback. Changes v1->v2 - pass csum value, instead of csump pointer (Alexander Duyck) Link: https://lore.kernel.org/netdev/20210128152353.GB27281@optiplex/ Fixes: 950fcaecd5cc ("datagram: consolidate datagram copy to iter helpers") Reported-by: Oliver Graute Signed-off-by: Willem de Bruijn Reviewed-by: Alexander Duyck Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20210203192952.1849843-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

iov_iter: optimise bvec iov_iter_advance()

2021-01-25T15:58:24+00:00

iov_iter_advance() is heavily used, but implemented through generic means. For bvecs there is a specifically crafted function for that, so use bvec_iter_advance() instead, it's faster and slimmer. Reviewed-by: Christoph Hellwig Signed-off-by: Pavel Begunkov Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

bvec/iter: disallow zero-length segment bvecs

2021-01-25T15:58:24+00:00

zero-length bvec segments are allowed in general, but not handled by bio and down the block layer so filtered out. This inconsistency may be confusing and prevent from optimisations. As zero-length segments are useless and places that were generating them are patched, declare them not allowed. Reviewed-by: Christoph Hellwig Signed-off-by: Pavel Begunkov Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

iov_iter: fix the uaccess area in copy_compat_iovec_from_user

2021-01-16T03:51:42+00:00

sizeof needs to be called on the compat pointer, not the native one. Fixes: 89cd35c58bc2 ("iov_iter: transparently handle compat iovecs in import_iovec") Reported-by: David Laight Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

lib, uaccess: add failure injection to usercopy functions

2020-10-16T18:11:22+00:00

To test fault-tolerance of user memory access functions, introduce fault injection to usercopy functions. If a failure is expected return either -EFAULT or the total amount of bytes that were not copied. Signed-off-by: Albert van der Linde Signed-off-by: Andrew Morton Reviewed-by: Akinobu Mita Reviewed-by: Alexander Potapenko Cc: Al Viro Cc: Andrey Konovalov Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Dmitry Vyukov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Marco Elver Cc: Peter Zijlstra (Intel) Cc: Thomas Gleixner Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20200831171733.955393-3-alinde@google.com Signed-off-by: Linus Torvalds