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6a8dbd71 |
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12-Mar-2024 |
Herbert Xu <herbert@gondor.apana.org.au> |
Revert "crypto: remove CONFIG_CRYPTO_STATS" This reverts commit 2beb81fbf0c01a62515a1bcef326168494ee2bd0. While removing CONFIG_CRYPTO_STATS is a worthy goal, this also removed unrelated infrastructure such as crypto_comp_alg_common. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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2beb81fb |
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23-Feb-2024 |
Eric Biggers <ebiggers@google.com> |
crypto: remove CONFIG_CRYPTO_STATS Remove support for the "Crypto usage statistics" feature (CONFIG_CRYPTO_STATS). This feature does not appear to have ever been used, and it is harmful because it significantly reduces performance and is a large maintenance burden. Covering each of these points in detail: 1. Feature is not being used Since these generic crypto statistics are only readable using netlink, it's fairly straightforward to look for programs that use them. I'm unable to find any evidence that any such programs exist. For example, Debian Code Search returns no hits except the kernel header and kernel code itself and translations of the kernel header: https://codesearch.debian.net/search?q=CRYPTOCFGA_STAT&literal=1&perpkg=1 The patch series that added this feature in 2018 (https://lore.kernel.org/linux-crypto/1537351855-16618-1-git-send-email-clabbe@baylibre.com/) said "The goal is to have an ifconfig for crypto device." This doesn't appear to have happened. It's not clear that there is real demand for crypto statistics. Just because the kernel provides other types of statistics such as I/O and networking statistics and some people find those useful does not mean that crypto statistics are useful too. Further evidence that programs are not using CONFIG_CRYPTO_STATS is that it was able to be disabled in RHEL and Fedora as a bug fix (https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2947). Even further evidence comes from the fact that there are and have been bugs in how the stats work, but they were never reported. For example, before Linux v6.7 hash stats were double-counted in most cases. There has also never been any documentation for this feature, so it might be hard to use even if someone wanted to. 2. CONFIG_CRYPTO_STATS significantly reduces performance Enabling CONFIG_CRYPTO_STATS significantly reduces the performance of the crypto API, even if no program ever retrieves the statistics. This primarily affects systems with large number of CPUs. For example, https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039576 reported that Lustre client encryption performance improved from 21.7GB/s to 48.2GB/s by disabling CONFIG_CRYPTO_STATS. It can be argued that this means that CONFIG_CRYPTO_STATS should be optimized with per-cpu counters similar to many of the networking counters. But no one has done this in 5+ years. This is consistent with the fact that the feature appears to be unused, so there seems to be little interest in improving it as opposed to just disabling it. It can be argued that because CONFIG_CRYPTO_STATS is off by default, performance doesn't matter. But Linux distros tend to error on the side of enabling options. The option is enabled in Ubuntu and Arch Linux, and until recently was enabled in RHEL and Fedora (see above). So, even just having the option available is harmful to users. 3. CONFIG_CRYPTO_STATS is a large maintenance burden There are over 1000 lines of code associated with CONFIG_CRYPTO_STATS, spread among 32 files. It significantly complicates much of the implementation of the crypto API. After the initial submission, many fixes and refactorings have consumed effort of multiple people to keep this feature "working". We should be spending this effort elsewhere. Cc: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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0a742389 |
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16-Feb-2023 |
Herbert Xu <herbert@gondor.apana.org.au> |
crypto: acomp - Count error stats differently Move all stat code specific to acomp into the acomp code. While we're at it, change the stats so that bytes and counts are always incremented even in case of error. This allows the reference counting to be removed as we can now increment the counters prior to the operation. After the operation we simply increase the error count if necessary. This is safe as errors can only occur synchronously (or rather, the existing code already ignored asynchronous errors which are only visible to the callback function). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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14386d47 |
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24-Nov-2022 |
Herbert Xu <herbert@gondor.apana.org.au> |
crypto: Prepare to move crypto_tfm_ctx The helper crypto_tfm_ctx is only used by the Crypto API algorithm code and should really be in algapi.h. However, for historical reasons many files relied on it to be in crypto.h. This patch changes those files to use algapi.h instead in prepartion for a move. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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c6d633a9 |
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15-Dec-2019 |
Eric Biggers <ebiggers@google.com> |
crypto: algapi - make unregistration functions return void Some of the algorithm unregistration functions return -ENOENT when asked to unregister a non-registered algorithm, while others always return 0 or always return void. But no users check the return value, except for two of the bulk unregistration functions which print a message on error but still always return 0 to their caller, and crypto_del_alg() which calls crypto_unregister_instance() which always returns 0. Since unregistering a non-registered algorithm is always a kernel bug but there isn't anything callers should do to handle this situation at runtime, let's simplify things by making all the unregistration functions return void, and moving the error message into crypto_unregister_alg() and upgrading it to a WARN(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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2874c5fd |
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27-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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14359bd7 |
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20-Dec-2017 |
Zhou Wang <wangzhou1@hisilicon.com> |
crypto: scomp - delete unused comments There are no init and exit callbacks, so delete its comments. Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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3de4f5e1 |
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21-Apr-2017 |
Giovanni Cabiddu <giovanni.cabiddu@intel.com> |
crypto: scomp - allow registration of multiple scomps Add crypto_register_scomps and crypto_unregister_scomps to allow the registration of multiple implementations with one call. Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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1ab53a77 |
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21-Oct-2016 |
Giovanni Cabiddu <giovanni.cabiddu@intel.com> |
crypto: acomp - add driver-side scomp interface Add a synchronous back-end (scomp) to acomp. This allows to easily expose the already present compression algorithms in LKCF via acomp. Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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