Kernel for Galaxy S24, rebased on CLO sources (WIP)
Go to file
Eric Biggers f05ccf6a6a crypto: testmgr - fix RNG performance in fuzz tests
commit f900fde28883602b6c5e1027a6c912b673382aaf upstream.

The performance of the crypto fuzz tests has greatly regressed since
v5.18.  When booting a kernel on an arm64 dev board with all software
crypto algorithms and CONFIG_CRYPTO_MANAGER_EXTRA_TESTS enabled, the
fuzz tests now take about 200 seconds to run, or about 325 seconds with
lockdep enabled, compared to about 5 seconds before.

The root cause is that the random number generation has become much
slower due to commit d4150779e6 ("random32: use real rng for
non-deterministic randomness").  On my same arm64 dev board, at the time
the fuzz tests are run, get_random_u8() is about 345x slower than
prandom_u32_state(), or about 469x if lockdep is enabled.

Lockdep makes a big difference, but much of the rest comes from the
get_random_*() functions taking a *very* slow path when the CRNG is not
yet initialized.  Since the crypto self-tests run early during boot,
even having a hardware RNG driver enabled (CONFIG_CRYPTO_DEV_QCOM_RNG in
my case) doesn't prevent this.  x86 systems don't have this issue, but
they still see a significant regression if lockdep is enabled.

Converting the "Fully random bytes" case in generate_random_bytes() to
use get_random_bytes() helps significantly, improving the test time to
about 27 seconds.  But that's still over 5x slower than before.

This is all a bit silly, though, since the fuzz tests don't actually
need cryptographically secure random numbers.  So let's just make them
use a non-cryptographically-secure RNG as they did before.  The original
prandom_u32() is gone now, so let's use prandom_u32_state() instead,
with an explicitly managed state, like various other self-tests in the
kernel source tree (rbtree_test.c, test_scanf.c, etc.) already do.  This
also has the benefit that no locking is required anymore, so performance
should be even better than the original version that used prandom_u32().

Fixes: d4150779e6 ("random32: use real rng for non-deterministic randomness")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-24 17:32:53 +01:00
arch rethook, fprobe: do not trace rethook related functions 2023-05-24 17:32:53 +01:00
block block, bfq: Fix division by zero error on zero wsum 2023-05-24 17:32:38 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: testmgr - fix RNG performance in fuzz tests 2023-05-24 17:32:53 +01:00
Documentation dt-bindings: ata: ahci-ceva: Cover all 4 iommus entries 2023-05-24 17:32:52 +01:00
drivers remoteproc: imx_dsp_rproc: Fix kernel test robot sparse warning 2023-05-24 17:32:53 +01:00
fs nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode() 2023-05-24 17:32:52 +01:00
include SUNRPC: always free ctxt when freeing deferred request 2023-05-24 17:32:45 +01:00
init gcc: disable '-Warray-bounds' for gcc-13 too 2023-04-26 14:28:43 +02:00
io_uring io_uring/rsrc: use nospec'ed indexes 2023-05-11 23:03:24 +09:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler 2023-05-24 17:32:52 +01:00
lib maple_tree: make maple state reusable after mas_empty_area() 2023-05-24 17:32:51 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: fix zswap writeback race condition 2023-05-24 17:32:51 +01:00
net can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag 2023-05-24 17:32:49 +01:00
rust rust: kernel: Mark rust_fmt_argument as extern "C" 2023-04-26 14:28:38 +02:00
samples samples/bpf: Fix fout leak in hbm's run_bpf_prog 2023-05-24 17:32:38 +01:00
scripts recordmcount: Fix memory leaks in the uwrite function 2023-05-24 17:32:41 +01:00
security selinux: ensure av_permissions.h is built when needed 2023-05-11 23:03:06 +09:00
sound ALSA: hda/realtek: Fix mute and micmute LEDs for yet another HP laptop 2023-05-24 17:32:49 +01:00
tools net: selftests: Fix optstring 2023-05-24 17:32:48 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Fix vcpu_array[0] races 2023-05-24 17:32:50 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS platform/x86: Move existing HP drivers to a new hp subdir 2023-05-24 17:32:42 +01:00
Makefile Linux 6.1.29 2023-05-17 11:54:00 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.