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Alexey Brodkin 95aed87b9e ARC: define ARCH_SLAB_MINALIGN = 8 commit `b6835ea777` upstream. The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is "__alignof__(unsigned long long)" which for ARC unexpectedly turns out to be 4. This is not a compiler bug, but as defined by ARC ABI [1] Thus slab allocator would allocate a struct which is 32-bit aligned, which is generally OK even if struct has long long members. There was however potetial problem when it had any atomic64_t which use LLOCKD/SCONDD instructions which are required by ISA to take 64-bit addresses. This is the problem we ran into [ 4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 4.167881] Misaligned Access [ 4.172356] Path: /bin/busybox.nosuid [ 4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1 [ 4.182851] [ 4.182851] [ECR ]: 0x000d0000 => Check Programmer's Manual [ 4.190061] [EFA ]: 0xbeaec3fc [ 4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234 [ 4.190061] [ERET ]: ext4_delete_entry+0x13e/0x234 [ 4.202985] [STAT32]: 0x80080002 : IE K [ 4.207236] BTA: 0x9009329c SP: 0xbe5b1ec4 FP: 0x00000000 [ 4.212790] LPS: 0x9074b118 LPE: 0x9074b120 LPC: 0x00000000 [ 4.218348] r00: 0x00000040 r01: 0x00000021 r02: 0x00000001 ... ... [ 4.270510] Stack Trace: [ 4.274510] ext4_delete_entry+0x13e/0x234 [ 4.278695] ext4_rmdir+0xe0/0x238 [ 4.282187] vfs_rmdir+0x50/0xf0 [ 4.285492] do_rmdir+0x9e/0x154 [ 4.288802] EV_Trap+0x110/0x114 The fix is to make sure slab allocations are 64-bit aligned. Do note that atomic64_t is __attribute__((aligned(8)) which means gcc does generate 64-bit aligned references, relative to beginning of container struct. However the issue is if the container itself is not 64-bit aligned, atomic64_t ends up unaligned which is what this patch ensures. [1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: <stable@vger.kernel.org> # 4.8+ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: reworked changelog, added dependency on LL64+LLSC] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-02-27 10:09:00 +01:00
arch	ARC: define ARCH_SLAB_MINALIGN = 8	2019-02-27 10:09:00 +01:00
block	blk-mq: fix a hung issue when fsync	2019-02-20 10:25:36 +01:00
certs	export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR()	2018-08-22 23:21:44 +09:00
crypto	net: crypto set sk to NULL when af_alg_release.	2019-02-23 09:07:24 +01:00
Documentation	dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string	2019-02-20 10:25:35 +01:00
drivers	RDMA/srp: Rework SCSI device reset handling	2019-02-27 10:09:00 +01:00
firmware	kbuild: remove all dummy assignments to obj-	2017-11-18 11:46:06 +09:00
fs	afs: Fix key refcounting in file locking code	2019-02-27 10:08:56 +01:00
include	KEYS: user: Align the payload buffer	2019-02-27 10:09:00 +01:00
init	kbuild: Disable LD_DEAD_CODE_DATA_ELIMINATION with ftrace & GCC <= 4.7	2019-01-22 21:40:34 +01:00
ipc	ipc/shm.c: use ERR_CAST() for shm_lock() error return	2018-10-05 16:32:04 -07:00
kernel	bpf: zero out build_id for BPF_STACK_BUILD_ID_IP	2019-02-27 10:08:56 +01:00
lib	lib/test_rhashtable: Make test_insert_dup() allocate its hash table dynamically	2019-02-12 19:47:21 +01:00
LICENSES	LICENSES: Remove CC-BY-SA-4.0 license text	2018-10-18 11:28:50 +02:00
mm	numa: change get_mempolicy() to use nr_node_ids instead of MAX_NUMNODES	2019-02-27 10:08:50 +01:00
net	net_sched: fix two more memory leaks in cls_tcindex	2019-02-27 10:08:59 +01:00
samples	samples: mei: use /dev/mei0 instead of /dev/mei	2019-02-15 08:10:11 +01:00
scripts	scripts/gdb: fix lx-version string output	2019-02-12 19:47:20 +01:00
security	KEYS: always initialize keyring_index_key::desc_len	2019-02-27 10:09:00 +01:00
sound	ALSA: hda/realtek: Disable PC beep in passthrough on alc285	2019-02-27 10:08:50 +01:00
tools	selftests: forwarding: Add a test case for externally learned FDB entries	2019-02-27 10:08:57 +01:00
usr	initramfs: move gen_initramfs_list.sh from scripts/ to usr/	2018-08-22 23:21:44 +09:00
virt	kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)	2019-02-12 19:47:25 +01:00
.clang-format	clang-format: Set IndentWrappedFunctionNames false	2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore	Kbuild updates for v4.17 (2nd)	2018-04-15 17:21:30 -07:00
.mailmap	libnvdimm-for-4.19_misc	2018-08-25 18:13:10 -07:00
COPYING	COPYING: use the new text with points to the license files	2018-03-23 12:41:45 -06:00
CREDITS	9p: remove Ron Minnich from MAINTAINERS	2018-08-17 16:20:26 -07:00
Kbuild	Kbuild updates for v4.15	2017-11-17 17:45:29 -08:00
Kconfig	kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt	2018-08-02 08:06:55 +09:00
MAINTAINERS	MAINTAINERS: Add Sasha as a stable branch maintainer	2018-12-01 09:37:25 +01:00
Makefile	Linux 4.19.25	2019-02-23 09:07:27 +01:00
README	Docs: Added a pointer to the formatted docs to README	2018-03-21 09:02:53 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.