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Linus Torvalds ab9bb6318b Partially revert "kfifo: fix kfifo_alloc() and kfifo_init()"
Commit dfe2a77fd2 ("kfifo: fix kfifo_alloc() and kfifo_init()") made
the kfifo code round the number of elements up.  That was good for
__kfifo_alloc(), but it's actually wrong for __kfifo_init().

The difference? __kfifo_alloc() will allocate the rounded-up number of
elements, but __kfifo_init() uses an allocation done by the caller.  We
can't just say "use more elements than the caller allocated", and have
to round down.

The good news? All the normal cases will be using power-of-two arrays
anyway, and most users of kfifo's don't use kfifo_init() at all, but one
of the helper macros to declare a KFIFO that enforce the proper
power-of-two behavior.  But it looks like at least ibmvscsis might be
affected.

The bad news? Will Deacon refers to an old thread and points points out
that the memory ordering in kfifo's is questionable.  See

  https://lore.kernel.org/lkml/20181211034032.32338-1-yuleixzhang@tencent.com/

for more.

Fixes: dfe2a77fd2 ("kfifo: fix kfifo_alloc() and kfifo_init()")
Reported-by: laokz <laokz@foxmail.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-30 18:47:15 -07:00
Documentation ARC updates for 5.3-rc7 2019-08-27 10:50:27 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch Three fixes for ARM this time around: 2019-08-30 11:58:02 -07:00
block block: remove REQ_NOWAIT_INLINE 2019-08-15 11:09:16 -06:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
drivers ARM: SoC fixes 2019-08-30 10:53:12 -07:00
fs a few small SMB3 fixes, and a larger one to fix various older string handling functions 2019-08-29 17:51:23 -07:00
include ARM: SoC fixes 2019-08-30 10:53:12 -07:00
init Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
ipc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
kernel arm64 fixes for -rc7 2019-08-28 10:37:21 -07:00
lib Partially revert "kfifo: fix kfifo_alloc() and kfifo_init()" 2019-08-30 18:47:15 -07:00
mm mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y 2019-08-24 19:48:42 -07:00
net A fix for a -rc1 regression in rbd and a trivial static checker fix. 2019-08-30 09:09:54 -07:00
samples auxdisplay: Fix a typo in cfag12864b-example.c 2019-08-08 20:00:18 +02:00
scripts SPDX fixes for 5.3-rc5 2019-08-18 09:26:16 -07:00
security keys: ensure that ->match_free() is called in request_key_and_link() 2019-08-30 11:10:55 -07:00
sound sound fixes for 5.3-rc7 2019-08-27 10:42:03 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-08-27 10:12:48 -07:00
usr kbuild: enable arch/s390/include/uapi/asm/zcrypt.h for uapi header test 2019-07-23 10:45:46 +02:00
virt arm64 fixes for -rc7 2019-08-28 10:37:21 -07:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: Add compilation database file 2019-07-27 12:18:19 +09:00
.mailmap A single patch to change my MAINTAINERS address 2019-08-29 17:29:09 +02:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Remove references to dead website. 2019-07-19 12:22:04 -07:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS ARM: SoC fixes 2019-08-30 10:53:12 -07:00
Makefile Linux 5.3-rc6 2019-08-25 12:01:23 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.