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path: root/drivers/char/hw_random/s390-trng.c
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2022-08-07Merge tag 's390-5.20-1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Rework copy_oldmem_page() callback to take an iov_iter. This includes a few prerequisite updates and fixes to the oldmem reading code. - Rework cpufeature implementation to allow for various CPU feature indications, which is not only limited to hardware capabilities, but also allows CPU facilities. - Use the cpufeature rework to autoload Ultravisor module when CPU facility 158 is available. - Add ELF note type for encrypted CPU state of a protected virtual CPU. The zgetdump tool from s390-tools package will decrypt the CPU state using a Customer Communication Key and overwrite respective notes to make the data accessible for crash and other debugging tools. - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto test. - Fix incorrect recovery of kretprobe modified return address in stacktrace. - Switch the NMI handler to use generic irqentry_nmi_enter() and irqentry_nmi_exit() helper functions. - Rework the cryptographic Adjunct Processors (AP) pass-through design to support dynamic changes to the AP matrix of a running guest as well as to implement more of the AP architecture. - Minor boot code cleanups. - Grammar and typo fixes to hmcdrv and tape drivers. * tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits) Revert "s390/smp: enforce lowcore protection on CPU restart" Revert "s390/smp: rework absolute lowcore access" Revert "s390/smp,ptdump: add absolute lowcore markers" s390/unwind: fix fgraph return address recovery s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit() s390: add ELF note type for encrypted CPU state of a PV VCPU s390/smp,ptdump: add absolute lowcore markers s390/smp: rework absolute lowcore access s390/setup: rearrange absolute lowcore initialization s390/boot: cleanup adjust_to_uv_max() function s390/smp: enforce lowcore protection on CPU restart s390/tape: fix comment typo s390/hmcdrv: fix Kconfig "its" grammar s390/docs: fix warnings for vfio_ap driver doc s390/docs: fix warnings for vfio_ap driver lock usage doc s390/crash: support multi-segment iterators s390/crash: use static swap buffer for copy_to_user_real() s390/crash: move copy_to_user_real() to crash_dump.c s390/zcore: fix race when reading from hardware system area s390/crash: fix incorrect number of bytes to copy to user space ...
2022-07-19s390/cpufeature: rework to allow more than only hwcap bitsHeiko Carstens1-1/+1
Rework cpufeature implementation to allow for various cpu feature indications, which is not only limited to hwcap bits. This is achieved by adding a sequential list of cpu feature numbers, where each of them is mapped to an entry which indicates what this number is about. Each entry contains a type member, which indicates what feature name space to look into (e.g. hwcap, or cpu facility). If wanted this allows also to automatically load modules only in e.g. z/VM configurations. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Link: https://lore.kernel.org/r/20220713125644.16121-2-seiden@linux.ibm.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-18random: remove CONFIG_ARCH_RANDOMJason A. Donenfeld1-9/+0
When RDRAND was introduced, there was much discussion on whether it should be trusted and how the kernel should handle that. Initially, two mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and "nordrand", a boot-time switch. Later the thinking evolved. With a properly designed RNG, using RDRAND values alone won't harm anything, even if the outputs are malicious. Rather, the issue is whether those values are being *trusted* to be good or not. And so a new set of options were introduced as the real ones that people use -- CONFIG_RANDOM_TRUST_CPU and "random.trust_cpu". With these options, RDRAND is used, but it's not always credited. So in the worst case, it does nothing, and in the best case, maybe it helps. Along the way, CONFIG_ARCH_RANDOM's meaning got sort of pulled into the center and became something certain platforms force-select. The old options don't really help with much, and it's a bit odd to have special handling for these instructions when the kernel can deal fine with the existence or untrusted existence or broken existence or non-existence of that CPU capability. Simplify the situation by removing CONFIG_ARCH_RANDOM and using the ordinary asm-generic fallback pattern instead, keeping the two options that are actually used. For now it leaves "nordrand" for now, as the removal of that will take a different route. Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-10-22hwrng: s390 - replace snprintf in show functions with sysfs_emitQing Wang1-2/+2
coccicheck complains about the use of snprintf() in sysfs show functions. Fix the following coccicheck warning: drivers/char/hw_random/s390-trng.c:114:8-16: WARNING: use scnprintf or sprintf. drivers/char/hw_random/s390-trng.c:122:8-16: WARNING: use scnprintf or sprintf. Use sysfs_emit instead of scnprintf or sprintf makes more sense. Signed-off-by: Qing Wang <wangqing@vivo.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-09s390/trng: set quality to 1024Christian Borntraeger1-3/+4
The s390-trng does provide 100% entropy. The quality value is supported to be between 1 and 1024 and not 1..1000. Use 1024 to make this driver the preferred one. If we ever have a better driver that has the same quality but is faster we can change this again when merging the new driver. No need to be conservative. This makes sure that the hw variant is preferred over things like virtio-rng, where the hypervisor has a potential to be misconfigured and thus should have a slightly lower confidence. Cc: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 376Thomas Gleixner1-5/+1
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 version 2 only as published by the free software foundation extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081036.798138318@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-26s390/trng: Introduce s390 TRNG device driver.Harald Freudenberger1-0/+268
This patch introduces a new device driver s390-trng for the s390 platform which exploits the new PRNO TRNG cpacf subfunction. The true-random-number-generator is accessible from userspace, by default visible as /dev/trng. The driver also registers at the kernel build-in hwrng API to feed the hwrng with fresh entropy data. This generic device driver for hardware random data is visible from userspace as /dev/hwrng. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>