user/sven/linux.git/lib, branch v5.4.138

lib/decompress_unlz4.c: correctly handle zero-padding around initrds.

2021-07-20T14:10:46Z

[ Upstream commit 2c484419efc09e7234c667aa72698cb79ba8d8ed ] lz4 compatible decompressor is simple. The format is underspecified and relies on EOF notification to determine when to stop. Initramfs buffer format[1] explicitly states that it can have arbitrary number of zero padding. Thus when operating without a fill function, be extra careful to ensure that sizes less than 4, or apperantly empty chunksizes are treated as EOF. To test this I have created two cpio initrds, first a normal one, main.cpio. And second one with just a single /test-file with content "second" second.cpio. Then i compressed both of them with gzip, and with lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1 count=4). To create four testcase initrds: 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip 2) main.cpio.lz4 + extra.cpio.lz4 = pad0.lz4 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip 4) main.cpio.lz4 + pad4 + extra.cpio.lz4 = pad4.lz4 The pad4 test-cases replicate the initrd load by grub, as it pads and aligns every initrd it loads. All of the above boot, however /test-file was not accessible in the initrd for the testcase #4, as decoding in lz4 decompressor failed. Also an error message printed which usually is harmless. Whith a patched kernel, all of the above testcases now pass, and /test-file is accessible. This fixes lz4 initrd decompress warning on every boot with grub. And more importantly this fixes inability to load multiple lz4 compressed initrds with grub. This patch has been shipping in Ubuntu kernels since January 2021. [1] ./Documentation/driver-api/early-userspace/buffer-format.rst BugLink: https://bugs.launchpad.net/bugs/1835660 Link: https://lore.kernel.org/lkml/20210114200256.196589-1-xnox@ubuntu.com/ # v0 Link: https://lkml.kernel.org/r/20210513104831.432975-1-dimitri.ledkov@canonical.com Signed-off-by: Dimitri John Ledkov Cc: Kyungsik Lee Cc: Yinghai Lu Cc: Bongkyu Kim Cc: Kees Cook Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Rajat Asthana Cc: Nick Terrell Cc: Gao Xiang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

seq_buf: Fix overflow in seq_buf_putmem_hex()

2021-07-19T06:53:16Z

commit d3b16034a24a112bb83aeb669ac5b9b01f744bb7 upstream. There's two variables being increased in that loop (i and j), and i follows the raw data, and j follows what is being written into the buffer. We should compare 'i' to MAX_MEMHEX_BYTES or compare 'j' to HEX_CHARS. Otherwise, if 'j' goes bigger than HEX_CHARS, it will overflow the destination buffer. Link: https://lore.kernel.org/lkml/20210625122453.5e2fe304@oasis.local.home/ Link: https://lkml.kernel.org/r/20210626032156.47889-1-yun.zhou@windriver.com Cc: stable@vger.kernel.org Fixes: 5e3ca0ec76fce ("ftrace: introduce the "hex" output method") Signed-off-by: Yun Zhou Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

lib: vsprintf: Fix handling of number field widths in vsscanf

2021-07-14T14:53:16Z

[ Upstream commit 900fdc4573766dd43b847b4f54bd4a1ee2bc7360 ] The existing code attempted to handle numbers by doing a strto[u]l(), ignoring the field width, and then repeatedly dividing to extract the field out of the full converted value. If the string contains a run of valid digits longer than will fit in a long or long long, this would overflow and no amount of dividing can recover the correct value. This patch fixes vsscanf() to obey number field widths when parsing the number. A new _parse_integer_limit() is added that takes a limit for the number of characters to parse. The number field conversion in vsscanf is changed to use this new function. If a number starts with a radix prefix, the field width must be long enough for at last one digit after the prefix. If not, it will be handled like this: sscanf("0x4", "%1i", &i): i=0, scanning continues with the 'x' sscanf("0x4", "%2i", &i): i=0, scanning continues with the '4' This is consistent with the observed behaviour of userland sscanf. Note that this patch does NOT fix the problem of a single field value overflowing the target type. So for example: sscanf("123456789abcdef", "%x", &i); Will not produce the correct result because the value obviously overflows INT_MAX. But sscanf will report a successful conversion. Note that where a very large number is used to mean "unlimited", the value INT_MAX is used for consistency with the behaviour of vsnprintf(). Signed-off-by: Richard Fitzgerald Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20210514161206.30821-2-rf@opensource.cirrus.com Signed-off-by: Sasha Levin

seq_buf: Make trace_seq_putmem_hex() support data longer than 8

2021-07-14T14:53:08Z

commit 6a2cbc58d6c9d90cd74288cc497c2b45815bc064 upstream. Since the raw memory 'data' does not go forward, it will dump repeated data if the data length is more than 8. If we want to dump longer data blocks, we need to repeatedly call macro SEQ_PUT_HEX_FIELD. I think it is a bit redundant, and multiple function calls also affect the performance. Link: https://lore.kernel.org/lkml/20210625122453.5e2fe304@oasis.local.home/ Link: https://lkml.kernel.org/r/20210626032156.47889-2-yun.zhou@windriver.com Cc: stable@vger.kernel.org Fixes: 6d2289f3faa7 ("tracing: Make trace_seq_putmem_hex() more robust") Signed-off-by: Yun Zhou Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

iov_iter_fault_in_readable() should do nothing in xarray case

2021-07-14T14:53:01Z

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

2021-07-14T14:53:01Z

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

lib/lz4: explicitly support in-place decompression

2021-06-10T11:37:16Z

commit 89b158635ad79574bde8e94d45dad33f8cf09549 upstream. LZ4 final literal copy could be overlapped when doing in-place decompression, so it's unsafe to just use memcpy() on an optimized memcpy approach but memmove() instead. Upstream LZ4 has updated this years ago [1] (and the impact is non-sensible [2] plus only a few bytes remain), this commit just synchronizes LZ4 upstream code to the kernel side as well. It can be observed as EROFS in-place decompression failure on specific files when X86_FEATURE_ERMS is unsupported, memcpy() optimization of commit 59daa706fbec ("x86, mem: Optimize memcpy by avoiding memory false dependece") will be enabled then. Currently most modern x86-CPUs support ERMS, these CPUs just use "rep movsb" approach so no problem at all. However, it can still be verified with forcely disabling ERMS feature... arch/x86/lib/memcpy_64.S: ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \ - "jmp memcpy_erms", X86_FEATURE_ERMS + "jmp memcpy_orig", X86_FEATURE_ERMS We didn't observe any strange on arm64/arm/x86 platform before since most memcpy() would behave in an increasing address order ("copy upwards" [3]) and it's the correct order of in-place decompression but it really needs an update to memmove() for sure considering it's an undefined behavior according to the standard and some unique optimization already exists in the kernel. [1] https://github.com/lz4/lz4/commit/33cb8518ac385835cc17be9a770b27b40cd0e15b [2] https://github.com/lz4/lz4/pull/717#issuecomment-497818921 [3] https://sourceware.org/bugzilla/show_bug.cgi?id=12518 Link: https://lkml.kernel.org/r/20201122030749.2698994-1-hsiangkao@redhat.com Signed-off-by: Gao Xiang Reviewed-by: Nick Terrell Cc: Yann Collet Cc: Miao Xie Cc: Chao Yu Cc: Li Guifu Cc: Guo Xuenan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman

XArray: add xas_split

2021-06-10T11:37:14Z

commit 8fc75643c5e14574c8be59b69182452ece28315a upstream In order to use multi-index entries for huge pages in the page cache, we need to be able to split a multi-index entry (eg if a file is truncated in the middle of a huge page entry). This version does not support splitting more than one level of the tree at a time. This is an acceptable limitation for the page cache as we do not expect to support order-12 pages in the near future. [akpm@linux-foundation.org: export xas_split_alloc() to modules] [willy@infradead.org: fix xarray split] Link: https://lkml.kernel.org/r/20200910175450.GV6583@casper.infradead.org [willy@infradead.org: fix xarray] Link: https://lkml.kernel.org/r/20201001233943.GW20115@casper.infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Cc: "Kirill A . Shutemov" Cc: Qian Cai Cc: Song Liu Link: https://lkml.kernel.org/r/20200903183029.14930-3-willy@infradead.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

XArray: add xa_get_order

2021-06-10T11:37:14Z

commit 57417cebc96b57122a2207fc84a6077d20c84b4b upstream Patch series "Fix read-only THP for non-tmpfs filesystems". As described more verbosely in the [3/3] changelog, we can inadvertently put an order-0 page in the page cache which occupies 512 consecutive entries. Users are running into this if they enable the READ_ONLY_THP_FOR_FS config option; see https://bugzilla.kernel.org/show_bug.cgi?id=206569 and Qian Cai has also reported it here: https://lore.kernel.org/lkml/20200616013309.GB815@lca.pw/ This is a rather intrusive way of fixing the problem, but has the advantage that I've actually been testing it with the THP patches, which means that it sees far more use than it does upstream -- indeed, Song has been entirely unable to reproduce it. It also has the advantage that it removes a few patches from my gargantuan backlog of THP patches. This patch (of 3): This function returns the order of the entry at the index. We need this because there isn't space in the shadow entry to encode its order. [akpm@linux-foundation.org: export xa_get_order to modules] Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Cc: "Kirill A . Shutemov" Cc: Qian Cai Cc: Song Liu Link: https://lkml.kernel.org/r/20200903183029.14930-1-willy@infradead.org Link: https://lkml.kernel.org/r/20200903183029.14930-2-willy@infradead.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib: stackdepot: turn depot_lock spinlock to raw_spinlock

2021-05-22T09:38:30Z

[ Upstream commit 78564b9434878d686c5f88c4488b20cccbcc42bc ] In RT system, the spin_lock will be replaced by sleepable rt_mutex lock, in __call_rcu(), disable interrupts before calling kasan_record_aux_stack(), will trigger this calltrace: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:951 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 19, name: pgdatinit0 Call Trace: ___might_sleep.cold+0x1b2/0x1f1 rt_spin_lock+0x3b/0xb0 stack_depot_save+0x1b9/0x440 kasan_save_stack+0x32/0x40 kasan_record_aux_stack+0xa5/0xb0 __call_rcu+0x117/0x880 __exit_signal+0xafb/0x1180 release_task+0x1d6/0x480 exit_notify+0x303/0x750 do_exit+0x678/0xcf0 kthread+0x364/0x4f0 ret_from_fork+0x22/0x30 Replace spinlock with raw_spinlock. Link: https://lkml.kernel.org/r/20210329084009.27013-1-qiang.zhang@windriver.com Signed-off-by: Zqiang Reported-by: Andrew Halaney Cc: Alexander Potapenko Cc: Gustavo A. R. Silva Cc: Vijayanand Jitta Cc: Vinayak Menon Cc: Yogesh Lal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin