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path: root/include/crypto/acompress.h
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2024-04-02crypto: remove CONFIG_CRYPTO_STATSEric Biggers
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 a 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. Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-03-13crypto: introduce: acomp_is_async to expose if comp drivers might sleepBarry Song
acomp's users might want to know if acomp is really async to optimize themselves. One typical user which can benefit from exposed async stat is zswap. In zswap, zsmalloc is the most commonly used allocator for (and perhaps the only one). For zsmalloc, we cannot sleep while we map the compressed memory, so we copy it to a temporary buffer. By knowing the alg won't sleep can help zswap to avoid the need for a buffer. This shows noticeable improvement in load/store latency of zswap. Link: https://lkml.kernel.org/r/20240222081135.173040-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Chris Li <chrisl@kernel.org> Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: David S. Miller <davem@davemloft.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-14crypto: acomp - Count error stats differentlyHerbert Xu
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>
2023-03-10crypto: acomp - Be more careful with request flagsHerbert Xu
The request flags for acompress is split into two parts. Part of it may be set by the user while the other part (ALLOC_OUTPUT) is managed by the API. This patch makes the split more explicit by not touching the other bits at all in the two "set" functions that let the user modify the flags. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-12-09crypto: acomp - define max size for destinationGiovanni Cabiddu
The acomp API allows to send requests with a NULL destination buffer. In this case, the algorithm implementation needs to allocate the destination scatter list, perform the operation and return the buffer to the user. For decompression, data is likely to expand and be bigger than the allocated buffer. Define the maximum size (128KB) that acomp implementations will allocate for decompression operations as destination buffer when they receive a request with a NULL destination buffer. Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-13crypto: api - check for ERR pointers in crypto_destroy_tfm()Ard Biesheuvel
Given that crypto_alloc_tfm() may return ERR pointers, and to avoid crashes on obscure error paths where such pointers are presented to crypto_destroy_tfm() (such as [0]), add an ERR_PTR check there before dereferencing the second argument as a struct crypto_tfm pointer. [0] https://lore.kernel.org/linux-crypto/000000000000de949705bc59e0f6@google.com/ Reported-by: syzbot+12cf5fbfdeba210a89dd@syzkaller.appspotmail.com Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-09crypto: api - permit users to specify numa node of acomp hardwareBarry Song
For a Linux server with NUMA, there are possibly multiple (de)compressors which are either local or remote to some NUMA node. Some drivers will automatically use the (de)compressor near the CPU calling acomp_alloc(). However, it is not necessarily correct because users who send acomp_req could be from different NUMA node with the CPU which allocates acomp. Just like kernel has kmalloc() and kmalloc_node(), here crypto can have same support. Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-05-08crypto: acomp - search acomp with scomp backend in crypto_has_acompBarry Song
users may call crypto_has_acomp to confirm the existence of acomp before using crypto_acomp APIs. Right now, many acomp have scomp backend, for example, lz4, lzo, deflate etc. crypto_has_acomp will return false for them even though they support acomp APIs. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
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>
2018-12-07crypto: user - fix use_after_free of struct xxx_requestCorentin Labbe
All crypto_stats functions use the struct xxx_request for feeding stats, but in some case this structure could already be freed. For fixing this, the needed parameters (len and alg) will be stored before the request being executed. Fixes: cac5818c25d0 ("crypto: user - Implement a generic crypto statistics") Reported-by: syzbot <syzbot+6939a606a5305e9e9799@syzkaller.appspotmail.com> Signed-off-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-12-07crypto: user - convert all stats from u32 to u64Corentin Labbe
All the 32-bit fields need to be 64-bit. In some cases, UINT32_MAX crypto operations can be done in seconds. Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-28crypto: user - Implement a generic crypto statisticsCorentin Labbe
This patch implement a generic way to get statistics about all crypto usages. Signed-off-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-10-25crypto: acomp - add driver-side scomp interfaceGiovanni Cabiddu
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>
2016-10-25crypto: acomp - add asynchronous compression apiGiovanni Cabiddu
Add acomp, an asynchronous compression api that uses scatterlist buffers. Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>