No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Eric Biggers d8c7fe9f2a crypto: x86/twofish-3way - Fix %rbp usage
Using %rbp as a temporary register breaks frame pointer convention and
breaks stack traces when unwinding from an interrupt in the crypto code.

In twofish-3way, we can't simply replace %rbp with another register
because there are none available.  Instead, we use the stack to hold the
values that %rbp, %r11, and %r12 were holding previously.  Each of these
values represents the half of the output from the previous Feistel round
that is being passed on unchanged to the following round.  They are only
used once per round, when they are exchanged with %rax, %rbx, and %rcx.

As a result, we free up 3 registers (one per block) and can reassign
them so that %rbp is not used, and additionally %r14 and %r15 are not
used so they do not need to be saved/restored.

There may be a small overhead caused by replacing 'xchg REG, REG' with
the needed sequence 'mov MEM, REG; mov REG, MEM; mov REG, REG' once per
round.  But, counterintuitively, when I tested "ctr-twofish-3way" on a
Haswell processor, the new version was actually about 2% faster.
(Perhaps 'xchg' is not as well optimized as plain moves.)

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-12-28 17:56:44 +11:00
arch crypto: x86/twofish-3way - Fix %rbp usage 2017-12-28 17:56:44 +11:00
block
certs
crypto crypto: tcrypt - add multibuf aead speed test 2017-12-28 17:56:42 +11:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-12-22 20:00:50 +11:00
drivers hwrng: core - Clean up RNG list when last hwrng is unregistered 2017-12-22 20:03:36 +11:00
firmware
fs hpfs: don't bother with the i_version counter or f_version 2017-12-10 12:58:18 -08:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-12-22 20:00:50 +11:00
init
ipc
kernel futex: futex_wake_op, fix sign_extend32 sign bits 2017-12-10 12:50:57 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-12-22 20:00:50 +11:00
mm kmemcheck: rip it out for real 2017-12-08 13:40:17 -08:00
net tcp: evaluate packet losses upon RTT change 2017-12-08 14:14:11 -05:00
samples
scripts
security KEYS: reject NULL restriction string when type is specified 2017-12-08 15:13:29 +00:00
sound
tools kmemcheck: rip it out for real 2017-12-08 13:40:17 -08:00
usr
virt
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-12-22 20:00:50 +11:00
Makefile Linux 4.15-rc3 2017-12-10 17:56:26 -08:00
README

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

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.