kernel/linux.git/lib, branch v4.4.4

lib: sw842: select crc32

2016-03-03T23:07:24+00:00

commit 5b57167749274961baf15ed1f05a4996b3ab0487 upstream. The sw842 library code was merged in linux-4.1 and causes a very rare randconfig failure when CONFIG_CRC32 is not set: lib/built-in.o: In function `sw842_compress': oid_registry.c:(.text+0x12ddc): undefined reference to `crc32_be' lib/built-in.o: In function `sw842_decompress': oid_registry.c:(.text+0x137e4): undefined reference to `crc32_be' This adds an explict 'select CRC32' statement, similar to what the other users of the crc32 code have. In practice, CRC32 is always enabled anyway because over 100 other symbols select it. Signed-off-by: Arnd Bergmann Fixes: 2da572c959dd ("lib: add software 842 compression/decompression") Acked-by: Dan Streetman Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

lib/ucs2_string: Correct ucs2 -> utf8 conversion

2016-03-03T23:07:09+00:00

commit a68075908a37850918ad96b056acc9ac4ce1bd90 upstream. The comparisons should be >= since 0x800 and 0x80 require an additional bit to store. For the 3 byte case, the existing shift would drop off 2 more bits than intended. For the 2 byte case, there should be 5 bits bits in byte 1, and 6 bits in byte 2. Signed-off-by: Jason Andryuk Reviewed-by: Laszlo Ersek Cc: Peter Jones Cc: Matthew Garrett Cc: "Lee, Chun-Yi" Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

lib/ucs2_string: Add ucs2 -> utf8 helper functions

2016-03-03T23:07:08+00:00

commit 73500267c930baadadb0d02284909731baf151f7 upstream. This adds ucs2_utf8size(), which tells us how big our ucs2 string is in bytes, and ucs2_as_utf8, which translates from ucs2 to utf8.. Signed-off-by: Peter Jones Tested-by: Lee, Chun-Yi Acked-by: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

dump_stack: avoid potential deadlocks

2016-02-25T20:01:23+00:00

commit d7ce36924344ace0dbdc855b1206cacc46b36d45 upstream. Some servers experienced fatal deadlocks because of a combination of bugs, leading to multiple cpus calling dump_stack(). The checksumming bug was fixed in commit 34ae6a1aa054 ("ipv6: update skb->csum when CE mark is propagated"). The second problem is a faulty locking in dump_stack() CPU1 runs in process context and calls dump_stack(), grabs dump_lock. CPU2 receives a TCP packet under softirq, grabs socket spinlock, and call dump_stack() from netdev_rx_csum_fault(). dump_stack() spins on atomic_cmpxchg(&dump_lock, -1, 2), since dump_lock is owned by CPU1 While dumping its stack, CPU1 is interrupted by a softirq, and happens to process a packet for the TCP socket locked by CPU2. CPU1 spins forever in spin_lock() : deadlock Stack trace on CPU1 looked like : NMI backtrace for cpu 1 RIP: _raw_spin_lock+0x25/0x30 ... Call Trace: tcp_v6_rcv+0x243/0x620 ip6_input_finish+0x11f/0x330 ip6_input+0x38/0x40 ip6_rcv_finish+0x3c/0x90 ipv6_rcv+0x2a9/0x500 process_backlog+0x461/0xaa0 net_rx_action+0x147/0x430 __do_softirq+0x167/0x2d0 call_softirq+0x1c/0x30 do_softirq+0x3f/0x80 irq_exit+0x6e/0xc0 smp_call_function_single_interrupt+0x35/0x40 call_function_single_interrupt+0x6a/0x70 printk+0x4d/0x4f printk_address+0x31/0x33 print_trace_address+0x33/0x3c print_context_stack+0x7f/0x119 dump_trace+0x26b/0x28e show_trace_log_lvl+0x4f/0x5c show_stack_log_lvl+0x104/0x113 show_stack+0x42/0x44 dump_stack+0x46/0x58 netdev_rx_csum_fault+0x38/0x3c __skb_checksum_complete_head+0x6e/0x80 __skb_checksum_complete+0x11/0x20 tcp_rcv_established+0x2bd5/0x2fd0 tcp_v6_do_rcv+0x13c/0x620 sk_backlog_rcv+0x15/0x30 release_sock+0xd2/0x150 tcp_recvmsg+0x1c1/0xfc0 inet_recvmsg+0x7d/0x90 sock_recvmsg+0xaf/0xe0 ___sys_recvmsg+0x111/0x3b0 SyS_recvmsg+0x5c/0xb0 system_call_fastpath+0x16/0x1b Fixes: b58d977432c8 ("dump_stack: serialize the output from dump_stack()") Signed-off-by: Eric Dumazet Cc: Alex Thorlton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

radix-tree: fix race in gang lookup

2016-02-25T20:01:23+00:00

commit 46437f9a554fbe3e110580ca08ab703b59f2f95a upstream. If the indirect_ptr bit is set on a slot, that indicates we need to redo the lookup. Introduce a new function radix_tree_iter_retry() which forces the loop to retry the lookup by setting 'slot' to NULL and turning the iterator back to point at the problematic entry. This is a pretty rare problem to hit at the moment; the lookup has to race with a grow of the radix tree from a height of 0. The consequences of hitting this race are that gang lookup could return a pointer to a radix_tree_node instead of a pointer to whatever the user had inserted in the tree. Fixes: cebbd29e1c2f ("radix-tree: rewrite gang lookup using iterator") Signed-off-by: Matthew Wilcox Cc: Hugh Dickins Cc: Ohad Ben-Cohen Cc: Konstantin Khlebnikov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

dma-debug: switch check from _text to _stext

2016-02-25T20:01:22+00:00

commit ea535e418c01837d07b6c94e817540f50bfdadb0 upstream. In include/asm-generic/sections.h: /* * Usage guidelines: * _text, _data: architecture specific, don't use them in * arch-independent code * [_stext, _etext]: contains .text.* sections, may also contain * .rodata.* * and/or .init.* sections _text is not guaranteed across architectures. Architectures such as ARM may reuse parts which are not actually text and erroneously trigger a bug. Switch to using _stext which is guaranteed to contain text sections. Came out of https://lkml.kernel.org/g/<567B1176.4000106@redhat.com> Signed-off-by: Laura Abbott Reviewed-by: Kees Cook Cc: Russell King Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

string_helpers: fix precision loss for some inputs

2016-02-25T20:01:21+00:00

commit 564b026fbd0d28e9f70fb3831293d2922bb7855b upstream. It was noticed that we lose precision in the final calculation for some inputs. The most egregious example is size=3000 blk_size=1900 in units of 10 should yield 5.70 MB but in fact yields 3.00 MB (oops). This is because the current algorithm doesn't correctly account for all the remainders in the logarithms. Fix this by doing a correct calculation in the remainders based on napier's algorithm. Additionally, now we have the correct result, we have to account for arithmetic rounding because we're printing 3 digits of precision. This means that if the fourth digit is five or greater, we have to round up, so add a section to ensure correct rounding. Finally account for all possible inputs correctly, including zero for block size. Fixes: b9f28d863594c429e1df35a0474d2663ca28b307 Signed-off-by: James Bottomley Reported-by: Vitaly Kuznetsov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

klist: fix starting point removed bug in klist iterators

2016-02-25T20:01:16+00:00

commit 00cd29b799e3449f0c68b1cc77cd4a5f95b42d17 upstream. The starting node for a klist iteration is often passed in from somewhere way above the klist infrastructure, meaning there's no guarantee the node is still on the list. We've seen this in SCSI where we use bus_find_device() to iterate through a list of devices. In the face of heavy hotplug activity, the last device returned by bus_find_device() can be removed before the next call. This leads to Dec 3 13:22:02 localhost kernel: WARNING: CPU: 2 PID: 28073 at include/linux/kref.h:47 klist_iter_init_node+0x3d/0x50() Dec 3 13:22:02 localhost kernel: Modules linked in: scsi_debug x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel joydev iTCO_wdt dcdbas ipmi_devintf acpi_power_meter iTCO_vendor_support ipmi_si imsghandler pcspkr wmi acpi_cpufreq tpm_tis tpm shpchp lpc_ich mfd_core nfsd nfs_acl lockd grace sunrpc tg3 ptp pps_core Dec 3 13:22:02 localhost kernel: CPU: 2 PID: 28073 Comm: cat Not tainted 4.4.0-rc1+ #2 Dec 3 13:22:02 localhost kernel: Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013 Dec 3 13:22:02 localhost kernel: ffffffff81a20e77 ffff880613acfd18 ffffffff81321eef 0000000000000000 Dec 3 13:22:02 localhost kernel: ffff880613acfd50 ffffffff8107ca52 ffff88061176b198 0000000000000000 Dec 3 13:22:02 localhost kernel: ffffffff814542b0 ffff880610cfb100 ffff88061176b198 ffff880613acfd60 Dec 3 13:22:02 localhost kernel: Call Trace: Dec 3 13:22:02 localhost kernel: [] dump_stack+0x44/0x55 Dec 3 13:22:02 localhost kernel: [] warn_slowpath_common+0x82/0xc0 Dec 3 13:22:02 localhost kernel: [] ? proc_scsi_show+0x20/0x20 Dec 3 13:22:02 localhost kernel: [] warn_slowpath_null+0x1a/0x20 Dec 3 13:22:02 localhost kernel: [] klist_iter_init_node+0x3d/0x50 Dec 3 13:22:02 localhost kernel: [] bus_find_device+0x51/0xb0 Dec 3 13:22:02 localhost kernel: [] scsi_seq_next+0x2d/0x40 [...] And an eventual crash. It can actually occur in any hotplug system which has a device finder and a starting device. We can fix this globally by making sure the starting node for klist_iter_init_node() is actually a member of the list before using it (and by starting from the beginning if it isn't). Reported-by: Ewan D. Milne Tested-by: Ewan D. Milne Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman

crypto: crc32c - Fix crc32c soft dependency

2016-02-17T20:31:04+00:00

commit fd7f6727102a1ccf6b4c1dfcc631f9b546526b26 upstream. I don't think it makes sense for a module to have a soft dependency on itself. This seems quite cyclic by nature and I can't see what purpose it could serve. OTOH libcrc32c calls crypto_alloc_shash("crc32c", 0, 0) so it pretty much assumes that some incarnation of the "crc32c" hash algorithm has been loaded. Therefore it makes sense to have the soft dependency there (as crc-t10dif does.) Cc: Tim Chen Cc: "David S. Miller" Signed-off-by: Jean Delvare Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

rhashtable: Kill harmless RCU warning in rhashtable_walk_init

2015-12-19T04:44:18+00:00

The commit c6ff5268293ef98e48a99597e765ffc417e39fa5 ("rhashtable: Fix walker list corruption") causes a suspicious RCU usage warning because we no longer hold ht->mutex when we dereference ht->tbl. However, this is a false positive because we now hold ht->lock which also guarantees that ht->tbl won't disppear from under us. This patch kills the warning by using rcu_dereference_protected. Reported-by: kernel test robot Signed-off-by: Herbert Xu Signed-off-by: David S. Miller