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Robert Elliott a76bd86a85 crypto: testmgr - don't generate WARN for missing modules
This userspace command:
    modprobe tcrypt
or
    modprobe tcrypt mode=0

runs all the tcrypt test cases numbered <200 (i.e., all the
test cases calling tcrypt_test() and returning return values).

Tests are sparsely numbered from 0 to 1000. For example:
    modprobe tcrypt mode=12
tests sha512, and
    modprobe tcrypt mode=152
tests rfc4543(gcm(aes))) - AES-GCM as GMAC

The test manager generates WARNING crashdumps every time it attempts
a test using an algorithm that is not available (not built-in to the
kernel or available as a module):

    alg: skcipher: failed to allocate transform for ecb(arc4): -2
    ------------[ cut here ]-----------
    alg: self-tests for ecb(arc4) (ecb(arc4)) failed (rc=-2)
    WARNING: CPU: 9 PID: 4618 at crypto/testmgr.c:5777
alg_test+0x30b/0x510
    [50 more lines....]

    ---[ end trace 0000000000000000 ]---

If the kernel is compiled with CRYPTO_USER_API_ENABLE_OBSOLETE
disabled (the default), then these algorithms are not compiled into
the kernel or made into modules and trigger WARNINGs:
    arc4 tea xtea khazad anubis xeta seed

Additionally, any other algorithms that are not enabled in .config
will generate WARNINGs. In RHEL 9.0, for example, the default
selection of algorithms leads to 16 WARNING dumps.

One attempt to fix this was by modifying tcrypt_test() to check
crypto_has_alg() and immediately return 0 if crypto_has_alg() fails,
rather than proceed and return a non-zero error value that causes
the caller (alg_test() in crypto/testmgr.c) to invoke WARN().
That knocks out too many algorithms, though; some combinations
like ctr(des3_ede) would work.

Instead, change the condition on the WARN to ignore a return
value is ENOENT, which is the value returned when the algorithm
or combination of algorithms doesn't exist. Add a pr_warn to
communicate that information in case the WARN is skipped.

This approach allows algorithm tests to work that are combinations,
not provided by one driver, like ctr(blowfish).

Result - no more WARNINGs:
modprobe tcrypt
[  115.541765] tcrypt: testing md5
[  115.556415] tcrypt: testing sha1
[  115.570463] tcrypt: testing ecb(des)
[  115.585303] cryptomgr: alg: skcipher: failed to allocate transform for ecb(des): -2
[  115.593037] cryptomgr: alg: self-tests for ecb(des) using ecb(des) failed (rc=-2)
[  115.593038] tcrypt: testing cbc(des)
[  115.610641] cryptomgr: alg: skcipher: failed to allocate transform for cbc(des): -2
[  115.618359] cryptomgr: alg: self-tests for cbc(des) using cbc(des) failed (rc=-2)
...

Signed-off-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-08-19 18:39:39 +08:00
Documentation xen: branch for v6.0-rc1b 2022-08-14 09:28:54 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch crypto: x86/sha512 - load based on CPU features 2022-08-19 18:39:39 +08:00
block block-6.0-2022-08-12 2022-08-13 13:37:36 -07:00
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: testmgr - don't generate WARN for missing modules 2022-08-19 18:39:39 +08:00
drivers crypto: hisilicon/qm - remove unneeded hardware cache write back 2022-08-19 18:39:38 +08:00
fs take care to handle NULL ->proc_lseek() 2022-08-14 15:16:18 -04:00
include hwrng: core - let sleep be interrupted when unregistering hwrng 2022-08-19 18:39:34 +08:00
init Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
io_uring io_uring-6.0-2022-08-13 2022-08-13 13:28:54 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel xen: branch for v6.0-rc1b 2022-08-14 09:28:54 -07:00
lib crypto: lib - remove __HAVE_ARCH_CRYPTO_MEMNEQ 2022-08-19 18:39:34 +08:00
mm - hugetlb_vmemmap cleanups from Muchun Song 2022-08-10 11:18:00 -07:00
net Including fixes from bluetooth, bpf, can and netfilter. 2022-08-11 13:45:37 -07:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts RISC-V Patches for the 5.20 Merge Window, Part 2 2022-08-12 18:39:43 -07:00
security + Features 2022-08-10 10:53:22 -07:00
sound sound fixes for 6.0-rc1 2022-08-12 09:55:32 -07:00
tools perf tools changes for v6.0: 2nd batch 2022-08-14 09:22:11 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Actually create debugfs in kvm_create_vm() 2022-08-10 15:08:28 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS xen: branch for v6.0-rc1b 2022-08-14 09:28:54 -07:00
Makefile Linux 6.0-rc1 2022-08-14 15:50:18 -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.