linux-stable.git/crypto/Makefile, branch v4.14.331

crypto: aes-generic - fix aes-generic regression on powerpc

2018-09-19T20:43:37+00:00

commit 6e36719fbe90213fbba9f50093fa2d4d69b0e93c upstream.

My last bugfix added -Os on the command line, which unfortunately caused
a build regression on powerpc in some configurations.

I've done some more analysis of the original problem and found slightly
different workaround that avoids this regression and also results in
better performance on gcc-7.0: -fcode-hoisting is an optimization step
that got added in gcc-7 and that for all gcc-7 versions causes worse
performance.

This disables -fcode-hoisting on all compilers that understand the option.
For gcc-7.1 and 7.2 I found the same performance as my previous patch
(using -Os), in gcc-7.0 it was even better. On gcc-8 I could see no
change in performance from this patch. In theory, code hoisting should
not be able make things better for the AES cipher, so leaving it
disabled for gcc-8 only serves to simplify the Makefile change.

Reported-by: kbuild test robot 
Link: https://www.mail-archive.com/linux-crypto@vger.kernel.org/msg30418.html
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83356
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83651
Fixes: 148b974deea9 ("crypto: aes-generic - build with -Os on gcc-7+")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Herbert Xu 
Cc: Horia Geanta 
Signed-off-by: Greg Kroah-Hartman

crypto: aes-generic - build with -Os on gcc-7+

2018-04-12T10:32:20+00:00

[ Upstream commit 148b974deea927f5dbb6c468af2707b488bfa2de ]

While testing other changes, I discovered that gcc-7.2.1 produces badly
optimized code for aes_encrypt/aes_decrypt. This is especially true when
CONFIG_UBSAN_SANITIZE_ALL is enabled, where it leads to extremely
large stack usage that in turn might cause kernel stack overflows:

crypto/aes_generic.c: In function 'aes_encrypt':
crypto/aes_generic.c:1371:1: warning: the frame size of 4880 bytes is larger than 2048 bytes [-Wframe-larger-than=]
crypto/aes_generic.c: In function 'aes_decrypt':
crypto/aes_generic.c:1441:1: warning: the frame size of 4864 bytes is larger than 2048 bytes [-Wframe-larger-than=]

I verified that this problem exists on all architectures that are
supported by gcc-7.2, though arm64 in particular is less affected than
the others. I also found that gcc-7.1 and gcc-8 do not show the extreme
stack usage but still produce worse code than earlier versions for this
file, apparently because of optimization passes that generally provide
a substantial improvement in object code quality but understandably fail
to find any shortcuts in the AES algorithm.

Possible workarounds include

a) disabling -ftree-pre and -ftree-sra optimizations, this was an earlier
   patch I tried, which reliably fixed the stack usage, but caused a
   serious performance regression in some versions, as later testing
   found.

b) disabling UBSAN on this file or all ciphers, as suggested by Ard
   Biesheuvel. This would lead to massively better crypto performance in
   UBSAN-enabled kernels and avoid the stack usage, but there is a concern
   over whether we should exclude arbitrary files from UBSAN at all.

c) Forcing the optimization level in a different way. Similar to a),
   but rather than deselecting specific optimization stages,
   this now uses "gcc -Os" for this file, regardless of the
   CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE/SIZE option. This is a reliable
   workaround for the stack consumption on all architecture, and I've
   retested the performance results now on x86, cycles/byte (lower is
   better) for cbc(aes-generic) with 256 bit keys:

			-O2     -Os
	gcc-6.3.1	14.9	15.1
	gcc-7.0.1	14.7	15.3
	gcc-7.1.1	15.3	14.7
	gcc-7.2.1	16.8	15.9
	gcc-8.0.0	15.5	15.6

This implements the option c) by enabling forcing -Os on all compiler
versions starting with gcc-7.1. As a workaround for PR83356, it would
only be needed for gcc-7.2+ with UBSAN enabled, but since it also shows
better performance on gcc-7.1 without UBSAN, it seems appropriate to
use the faster version here as well.

Side note: during testing, I also played with the AES code in libressl,
which had a similar performance regression from gcc-6 to gcc-7.2,
but was three times slower overall. It might be interesting to
investigate that further and possibly port the Linux implementation
into that.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83356
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83651
Cc: Richard Biener 
Cc: Jakub Jelinek 
Cc: Ard Biesheuvel 
Signed-off-by: Arnd Bergmann 
Acked-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

crypto: ecdh - add privkey generation support

2017-06-10T04:04:35+00:00

Add support for generating ecc private keys.

Generation of ecc private keys is helpful in a user-space to kernel
ecdh offload because the keys are not revealed to user-space. Private
key generation is also helpful to implement forward secrecy.

If the user provides a NULL ecc private key, the kernel will generate it
and further use it for ecdh.

Move ecdh's object files below drbg's. drbg must be present in the kernel
at the time of calling.

Signed-off-by: Tudor Ambarus 
Reviewed-by: Stephan Müller 
Signed-off-by: Herbert Xu

crypto: improve gcc optimization flags for serpent and wp512

2017-02-11T09:52:26+00:00

An ancient gcc bug (first reported in 2003) has apparently resurfaced
on MIPS, where kernelci.org reports an overly large stack frame in the
whirlpool hash algorithm:

crypto/wp512.c:987:1: warning: the frame size of 1112 bytes is larger than 1024 bytes [-Wframe-larger-than=]

With some testing in different configurations, I'm seeing large
variations in stack frames size up to 1500 bytes for what should have
around 300 bytes at most. I also checked the reference implementation,
which is essentially the same code but also comes with some test and
benchmarking infrastructure.

It seems that recent compiler versions on at least arm, arm64 and powerpc
have a partial fix for this problem, but enabling "-fsched-pressure", but
even with that fix they suffer from the issue to a certain degree. Some
testing on arm64 shows that the time needed to hash a given amount of
data is roughly proportional to the stack frame size here, which makes
sense given that the wp512 implementation is doing lots of loads for
table lookups, and the problem with the overly large stack is a result
of doing a lot more loads and stores for spilled registers (as seen from
inspecting the object code).

Disabling -fschedule-insns consistently fixes the problem for wp512,
in my collection of cross-compilers, the results are consistently better
or identical when comparing the stack sizes in this function, though
some architectures (notable x86) have schedule-insns disabled by
default.

The four columns are:
default: -O2
press:	 -O2 -fsched-pressure
nopress: -O2 -fschedule-insns -fno-sched-pressure
nosched: -O2 -no-schedule-insns (disables sched-pressure)

				default	press	nopress	nosched
alpha-linux-gcc-4.9.3		1136	848	1136	176
am33_2.0-linux-gcc-4.9.3	2100	2076	2100	2104
arm-linux-gnueabi-gcc-4.9.3	848	848	1048	352
cris-linux-gcc-4.9.3		272	272	272	272
frv-linux-gcc-4.9.3		1128	1000	1128	280
hppa64-linux-gcc-4.9.3		1128	336	1128	184
hppa-linux-gcc-4.9.3		644	308	644	276
i386-linux-gcc-4.9.3		352	352	352	352
m32r-linux-gcc-4.9.3		720	656	720	268
microblaze-linux-gcc-4.9.3	1108	604	1108	256
mips64-linux-gcc-4.9.3		1328	592	1328	208
mips-linux-gcc-4.9.3		1096	624	1096	240
powerpc64-linux-gcc-4.9.3	1088	432	1088	160
powerpc-linux-gcc-4.9.3		1080	584	1080	224
s390-linux-gcc-4.9.3		456	456	624	360
sh3-linux-gcc-4.9.3		292	292	292	292
sparc64-linux-gcc-4.9.3		992	240	992	208
sparc-linux-gcc-4.9.3		680	592	680	312
x86_64-linux-gcc-4.9.3		224	240	272	224
xtensa-linux-gcc-4.9.3		1152	704	1152	304

aarch64-linux-gcc-7.0.0		224	224	1104	208
arm-linux-gnueabi-gcc-7.0.1	824	824	1048	352
mips-linux-gcc-7.0.0		1120	648	1120	272
x86_64-linux-gcc-7.0.1		240	240	304	240

arm-linux-gnueabi-gcc-4.4.7	840			392
arm-linux-gnueabi-gcc-4.5.4	784	728	784	320
arm-linux-gnueabi-gcc-4.6.4	736	728	736	304
arm-linux-gnueabi-gcc-4.7.4	944	784	944	352
arm-linux-gnueabi-gcc-4.8.5	464	464	760	352
arm-linux-gnueabi-gcc-4.9.3	848	848	1048	352
arm-linux-gnueabi-gcc-5.3.1	824	824	1064	336
arm-linux-gnueabi-gcc-6.1.1	808	808	1056	344
arm-linux-gnueabi-gcc-7.0.1	824	824	1048	352

Trying the same test for serpent-generic, the picture is a bit different,
and while -fno-schedule-insns is generally better here than the default,
-fsched-pressure wins overall, so I picked that instead.

				default	press	nopress	nosched
alpha-linux-gcc-4.9.3		1392	864	1392	960
am33_2.0-linux-gcc-4.9.3	536	524	536	528
arm-linux-gnueabi-gcc-4.9.3	552	552	776	536
cris-linux-gcc-4.9.3		528	528	528	528
frv-linux-gcc-4.9.3		536	400	536	504
hppa64-linux-gcc-4.9.3		524	208	524	480
hppa-linux-gcc-4.9.3		768	472	768	508
i386-linux-gcc-4.9.3		564	564	564	564
m32r-linux-gcc-4.9.3		712	576	712	532
microblaze-linux-gcc-4.9.3	724	392	724	512
mips64-linux-gcc-4.9.3		720	384	720	496
mips-linux-gcc-4.9.3		728	384	728	496
powerpc64-linux-gcc-4.9.3	704	304	704	480
powerpc-linux-gcc-4.9.3		704	296	704	480
s390-linux-gcc-4.9.3		560	560	592	536
sh3-linux-gcc-4.9.3		540	540	540	540
sparc64-linux-gcc-4.9.3		544	352	544	496
sparc-linux-gcc-4.9.3		544	344	544	496
x86_64-linux-gcc-4.9.3		528	536	576	528
xtensa-linux-gcc-4.9.3		752	544	752	544

aarch64-linux-gcc-7.0.0		432	432	656	480
arm-linux-gnueabi-gcc-7.0.1	616	616	808	536
mips-linux-gcc-7.0.0		720	464	720	488
x86_64-linux-gcc-7.0.1		536	528	600	536

arm-linux-gnueabi-gcc-4.4.7	592			440
arm-linux-gnueabi-gcc-4.5.4	776	448	776	544
arm-linux-gnueabi-gcc-4.6.4	776	448	776	544
arm-linux-gnueabi-gcc-4.7.4	768	448	768	544
arm-linux-gnueabi-gcc-4.8.5	488	488	776	544
arm-linux-gnueabi-gcc-4.9.3	552	552	776	536
arm-linux-gnueabi-gcc-5.3.1	552	552	776	536
arm-linux-gnueabi-gcc-6.1.1	560	560	776	536
arm-linux-gnueabi-gcc-7.0.1	616	616	808	536

I did not do any runtime tests with serpent, so it is possible that stack
frame size does not directly correlate with runtime performance here and
it actually makes things worse, but it's more likely to help here, and
the reduced stack frame size is probably enough reason to apply the patch,
especially given that the crypto code is often used in deep call chains.

Link: https://kernelci.org/build/id/58797d7559b5149efdf6c3a9/logs/
Link: http://www.larc.usp.br/~pbarreto/WhirlpoolPage.html
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79149
Cc: Ralf Baechle 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Herbert Xu

crypto: aes - add generic time invariant AES cipher

2017-02-11T09:50:43+00:00

Lookup table based AES is sensitive to timing attacks, which is due to
the fact that such table lookups are data dependent, and the fact that
8 KB worth of tables covers a significant number of cachelines on any
architecture, resulting in an exploitable correlation between the key
and the processing time for known plaintexts.

For network facing algorithms such as CTR, CCM or GCM, this presents a
security risk, which is why arch specific AES ports are typically time
invariant, either through the use of special instructions, or by using
SIMD algorithms that don't rely on table lookups.

For generic code, this is difficult to achieve without losing too much
performance, but we can improve the situation significantly by switching
to an implementation that only needs 256 bytes of table data (the actual
S-box itself), which can be prefetched at the start of each block to
eliminate data dependent latencies.

This code encrypts at ~25 cycles per byte on ARM Cortex-A57 (while the
ordinary generic AES driver manages 18 cycles per byte on this
hardware). Decryption is substantially slower.

Signed-off-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu

Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2016-11-30T11:53:12+00:00

Merge the crypto tree to pull in chelsio chcr fix.

crypto: rsa - Add Makefile dependencies to fix parallel builds

2016-11-30T11:46:45+00:00

Both asn1 headers are included by rsa_helper.c, so rsa_helper.o
should explicitly depend on them.

Signed-off-by: David Michael 
Signed-off-by: Herbert Xu

crypto: simd - Add simd skcipher helper

2016-11-28T13:23:18+00:00

This patch adds the simd skcipher helper which is meant to be
a replacement for ablk helper.  It replaces the underlying blkcipher
interface with skcipher, and also presents the top-level algorithm
as an skcipher.

Signed-off-by: Herbert Xu

crypto: acomp - fix dependency in Makefile

2016-11-01T00:37:15+00:00

Fix dependency between acomp and scomp that appears when acomp is
built as module

Signed-off-by: Giovanni Cabiddu 
Signed-off-by: Herbert Xu