powerpc: drop dependency on <asm/machdep.h> in archrandom.h

archrandom.h includes <asm/machdep.h> to refer ppc_md. This causes
circular header dependency, if generic nodemask.h includes random.h:

powerpc: drop dependency on <asm/machdep.h> in archrandom.h

archrandom.h includes <asm/machdep.h> to refer ppc_md. This causes
circular header dependency, if generic nodemask.h includes random.h:

In file included from include/linux/cred.h:16,
from include/linux/seq_file.h:13,
from arch/powerpc/include/asm/machdep.h:6,
from arch/powerpc/include/asm/archrandom.h:5,
from include/linux/random.h:109,
from include/linux/nodemask.h:97,
from include/linux/list_lru.h:12,
from include/linux/fs.h:13,
from include/linux/compat.h:17,
from arch/powerpc/kernel/asm-offsets.c:12:
include/linux/sched.h:1203:9: error: unknown type name 'nodemask_t'
1203 | nodemask_t mems_allowed;
| ^~~~~~~~~~

Fix it by removing <asm/machdep.h> dependency from archrandom.h

Now as arch_get_random_seed_long() moved to c-file, and not exported,
it's not available for modules. As Michael Ellerman says:

I think we actually don't need it exported to modules, I think it's
a private detail of the RNG <-> architecture interface, not something
that modules should be calling.

CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Michael Ellerman <mpe@ellerman.id.au>
CC: Paul Mackerras <paulus@samba.org>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
CC: linuxppc-dev@lists.ozlabs.org
Suggested-by: Michael Ellerman <mpe@ellerman.id.au> (for non-exporting)
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

show more ...

powerpc/powernv: rename remaining rng powernv_ functions to pnv_

The preferred nomenclature is pnv_, not powernv_, but rng.c used
powernv_ for some reason, which isn't consistent with the rest. A re

powerpc/powernv: rename remaining rng powernv_ functions to pnv_

The preferred nomenclature is pnv_, not powernv_, but rng.c used
powernv_ for some reason, which isn't consistent with the rest. A recent
commit added a few pnv_ functions to rng.c, making the file a bit of a
mishmash. This commit just replaces the rest of them.

Fixes: f3eac426657d ("powerpc/powernv: wire up rng during setup_arch")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
[mpe: Reorder after bug fix commits]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220727143219.2684192-3-mpe@ellerman.id.au

show more ...

powerpc/powernv/kvm: Use darn for H_RANDOM on Power9

The existing logic in KVM to support guests calling H_RANDOM only works
on Power8, because it looks for an RNG in the device tree, but on Power9

powerpc/powernv/kvm: Use darn for H_RANDOM on Power9

The existing logic in KVM to support guests calling H_RANDOM only works
on Power8, because it looks for an RNG in the device tree, but on Power9
we just use darn.

In addition the existing code needs to work in real mode, so we have the
special cased powernv_get_random_real_mode() to deal with that.

Instead just have KVM call ppc_md.get_random_seed(), and do the real
mode check inside of there, that way we use whatever RNG is available,
including darn on Power9.

Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.")
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
[mpe: Rebase on previous commit, update change log appropriately]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220727143219.2684192-2-mpe@ellerman.id.au

show more ...

random: handle archrandom with multiple longs

The archrandom interface was originally designed for x86, which supplies
RDRAND/RDSEED for receiving random words into registers, resulting in
one funct

random: handle archrandom with multiple longs

The archrandom interface was originally designed for x86, which supplies
RDRAND/RDSEED for receiving random words into registers, resulting in
one function to generate an int and another to generate a long. However,
other architectures don't follow this.

On arm64, the SMCCC TRNG interface can return between one and three
longs. On s390, the CPACF TRNG interface can return arbitrary amounts,
with four longs having the same cost as one. On UML, the os_getrandom()
interface can return arbitrary amounts.

So change the api signature to take a "max_longs" parameter designating
the maximum number of longs requested, and then return the number of
longs generated.

Since callers need to check this return value and loop anyway, each arch
implementation does not bother implementing its own loop to try again to
fill the maximum number of longs. Additionally, all existing callers
pass in a constant max_longs parameter. Taken together, these two things
mean that the codegen doesn't really change much for one-word-at-a-time
platforms, while performance is greatly improved on platforms such as
s390.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

show more ...

random: remove CONFIG_ARCH_RANDOM

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, C

random: remove CONFIG_ARCH_RANDOM

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>

show more ...

powerpc/powernv/kvm: Use darn for H_RANDOM on Power9

[ Upstream commit 7ef3d06f1bc4a5e62273726f3dc2bd258ae1c71f ]

The existing logic in KVM to support guests calling H_RANDOM only works
on Power8,

powerpc/powernv/kvm: Use darn for H_RANDOM on Power9

[ Upstream commit 7ef3d06f1bc4a5e62273726f3dc2bd258ae1c71f ]

The existing logic in KVM to support guests calling H_RANDOM only works
on Power8, because it looks for an RNG in the device tree, but on Power9
we just use darn.

In addition the existing code needs to work in real mode, so we have the
special cased powernv_get_random_real_mode() to deal with that.

Instead just have KVM call ppc_md.get_random_seed(), and do the real
mode check inside of there, that way we use whatever RNG is available,
including darn on Power9.

Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.")
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
[mpe: Rebase on previous commit, update change log appropriately]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220727143219.2684192-2-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

powerpc: Mark archrandom.h functions __must_check

We must not use the pointer output without validating the
success of the random read.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by:

powerpc: Mark archrandom.h functions __must_check

We must not use the pointer output without validating the
success of the random read.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-10-broonie@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

powerpc: Use bool in archrandom.h

The generic interface uses bool not int; match that.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by

powerpc: Use bool in archrandom.h

The generic interface uses bool not int; match that.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-9-broonie@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

powerpc: Remove arch_has_random, arch_has_random_seed

These symbols are currently part of the generic archrandom.h
interface, but are currently unused and can be removed.

Signed-off-by: Richard Hen

powerpc: Remove arch_has_random, arch_has_random_seed

These symbols are currently part of the generic archrandom.h
interface, but are currently unused and can be removed.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-3-broonie@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

powerpc/archrandom: fix arch_get_random_seed_int()

Commit 01c9348c7620ec65

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

updated arch_get_random_[int|long]() to be N

powerpc/archrandom: fix arch_get_random_seed_int()

Commit 01c9348c7620ec65

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

updated arch_get_random_[int|long]() to be NOPs, and moved the hardware
RNG backing to arch_get_random_seed_[int|long]() instead. However, it
failed to take into account that arch_get_random_int() was implemented
in terms of arch_get_random_long(), and so we ended up with a version
of the former that is essentially a NOP as well.

Fix this by calling arch_get_random_seed_long() from
arch_get_random_seed_int() instead.

Fixes: 01c9348c7620ec65 ("powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191204115015.18015-1-ardb@kernel.org

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

The hardware RNG on POWER8 and POWER7+ can be relatively slow, since
it can only supply one 64-bit value per microsecond.

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

The hardware RNG on POWER8 and POWER7+ can be relatively slow, since
it can only supply one 64-bit value per microsecond. Currently we
read it in arch_get_random_long(), but that slows down reading from
/dev/urandom since the code in random.c calls arch_get_random_long()
for every longword read from /dev/urandom.

Since the hardware RNG supplies high-quality entropy on every read, it
matches the semantics of arch_get_random_seed_long() better than those
of arch_get_random_long(). Therefore this commit makes the code use
the POWER8/7+ hardware RNG only for arch_get_random_seed_{long,int}
and not for arch_get_random_{long,int}.

This won't affect any other PowerPC-based platforms because none of
them currently support a hardware RNG. To make it clear that the
ppc_md function pointer is used for arch_get_random_seed_*, we rename
it from get_random_long to get_random_seed.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

show more ...

KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.

Some PowerNV systems include a hardware random-number generator.
This HWRNG is present on POWER7+ and POWER8 chips and is capable of

KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.

Some PowerNV systems include a hardware random-number generator.
This HWRNG is present on POWER7+ and POWER8 chips and is capable of
generating one 64-bit random number every microsecond. The random
numbers are produced by sampling a set of 64 unstable high-frequency
oscillators and are almost completely entropic.

PAPR defines an H_RANDOM hypercall which guests can use to obtain one
64-bit random sample from the HWRNG. This adds a real-mode
implementation of the H_RANDOM hypercall. This hypercall was
implemented in real mode because the latency of reading the HWRNG is
generally small compared to the latency of a guest exit and entry for
all the threads in the same virtual core.

Userspace can detect the presence of the HWRNG and the H_RANDOM
implementation by querying the KVM_CAP_PPC_HWRNG capability. The
H_RANDOM hypercall implementation will only be invoked when the guest
does an H_RANDOM hypercall if userspace first enables the in-kernel
H_RANDOM implementation using the KVM_CAP_PPC_ENABLE_HCALL capability.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

show more ...

random: Add arch_has_random[_seed]()

Add predicate functions for having arch_get_random[_seed]*(). The
only current use is to avoid the loop in arch_random_refill() when
arch_get_random_seed_long()

random: Add arch_has_random[_seed]()

Add predicate functions for having arch_get_random[_seed]*(). The
only current use is to avoid the loop in arch_random_refill() when
arch_get_random_seed_long() is unavailable.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

x86, random: Enable the RDSEED instruction

Upcoming Intel silicon adds a new RDSEED instruction, which is similar
to RDRAND but provides a stronger guarantee: unlike RDRAND, RDSEED
will always resee

x86, random: Enable the RDSEED instruction

Upcoming Intel silicon adds a new RDSEED instruction, which is similar
to RDRAND but provides a stronger guarantee: unlike RDRAND, RDSEED
will always reseed the PRNG from the true random number source between
each read. Thus, the output of RDSEED is guaranteed to be 100%
entropic, unlike RDRAND which is only architecturally guaranteed to be
1/512 entropic (although in practice is much more.)

The RDSEED instruction takes the same time to execute as RDRAND, but
RDSEED unlike RDRAND can legitimately return failure (CF=0) due to
entropy exhaustion if too many threads on too many cores are hammering
the RDSEED instruction at the same time. Therefore, we have to be
more conservative and only use it in places where we can tolerate
failures.

This patch introduces the primitives arch_get_random_seed_{int,long}()
but does not use it yet.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

powerpc: Implement arch_get_random_long/int() for powernv

Add the plumbing to implement arch_get_random_long/int(). It didn't seem
worth adding an extra ppc_md hook for int, so we reuse the one for

powerpc: Implement arch_get_random_long/int() for powernv

Add the plumbing to implement arch_get_random_long/int(). It didn't seem
worth adding an extra ppc_md hook for int, so we reuse the one for long.

Add an implementation for powernv based on the hwrng found in power7+
systems. We whiten the output of the hwrng, and the result passes all
the dieharder tests.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc: Mark archrandom.h functions __must_check

We must not use the pointer output without validating the
success of the random read.

Acked-by: Michael Ellerman <mpe@ellerman.

powerpc: Mark archrandom.h functions __must_check

We must not use the pointer output without validating the
success of the random read.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-10-broonie@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

powerpc: Use bool in archrandom.h

The generic interface uses bool not int; match that.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddl

powerpc: Use bool in archrandom.h

The generic interface uses bool not int; match that.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-9-broonie@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

powerpc: Remove arch_has_random, arch_has_random_seed

These symbols are currently part of the generic archrandom.h
interface, but are currently unused and can be removed.

Signed

powerpc: Remove arch_has_random, arch_has_random_seed

These symbols are currently part of the generic archrandom.h
interface, but are currently unused and can be removed.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200110145422.49141-3-broonie@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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powerpc/archrandom: fix arch_get_random_seed_int()

Commit 01c9348c7620ec65

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

updated arch_get_ran

powerpc/archrandom: fix arch_get_random_seed_int()

Commit 01c9348c7620ec65

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

updated arch_get_random_[int|long]() to be NOPs, and moved the hardware
RNG backing to arch_get_random_seed_[int|long]() instead. However, it
failed to take into account that arch_get_random_int() was implemented
in terms of arch_get_random_long(), and so we ended up with a version
of the former that is essentially a NOP as well.

Fix this by calling arch_get_random_seed_long() from
arch_get_random_seed_int() instead.

Fixes: 01c9348c7620ec65 ("powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191204115015.18015-1-ardb@kernel.org

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

The hardware RNG on POWER8 and POWER7+ can be relatively slow, since
it can only supply one 64-bit value per mi

powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_*

The hardware RNG on POWER8 and POWER7+ can be relatively slow, since
it can only supply one 64-bit value per microsecond. Currently we
read it in arch_get_random_long(), but that slows down reading from
/dev/urandom since the code in random.c calls arch_get_random_long()
for every longword read from /dev/urandom.

Since the hardware RNG supplies high-quality entropy on every read, it
matches the semantics of arch_get_random_seed_long() better than those
of arch_get_random_long(). Therefore this commit makes the code use
the POWER8/7+ hardware RNG only for arch_get_random_seed_{long,int}
and not for arch_get_random_{long,int}.

This won't affect any other PowerPC-based platforms because none of
them currently support a hardware RNG. To make it clear that the
ppc_md function pointer is used for arch_get_random_seed_*, we rename
it from get_random_long to get_random_seed.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.

Some PowerNV systems include a hardware random-number generator.
This HWRNG is present on POWER7+ and POWER8 chips and is

KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.

Some PowerNV systems include a hardware random-number generator.
This HWRNG is present on POWER7+ and POWER8 chips and is capable of
generating one 64-bit random number every microsecond. The random
numbers are produced by sampling a set of 64 unstable high-frequency
oscillators and are almost completely entropic.

PAPR defines an H_RANDOM hypercall which guests can use to obtain one
64-bit random sample from the HWRNG. This adds a real-mode
implementation of the H_RANDOM hypercall. This hypercall was
implemented in real mode because the latency of reading the HWRNG is
generally small compared to the latency of a guest exit and entry for
all the threads in the same virtual core.

Userspace can detect the presence of the HWRNG and the H_RANDOM
implementation by querying the KVM_CAP_PPC_HWRNG capability. The
H_RANDOM hypercall implementation will only be invoked when the guest
does an H_RANDOM hypercall if userspace first enables the in-kernel
H_RANDOM implementation using the KVM_CAP_PPC_ENABLE_HCALL capability.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

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random: Add arch_has_random[_seed]()

Add predicate functions for having arch_get_random[_seed]*(). The
only current use is to avoid the loop in arch_random_refill() when
arch_get_ra

random: Add arch_has_random[_seed]()

Add predicate functions for having arch_get_random[_seed]*(). The
only current use is to avoid the loop in arch_random_refill() when
arch_get_random_seed_long() is unavailable.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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x86, random: Enable the RDSEED instruction

Upcoming Intel silicon adds a new RDSEED instruction, which is similar
to RDRAND but provides a stronger guarantee: unlike RDRAND, RDSEED
w

x86, random: Enable the RDSEED instruction

Upcoming Intel silicon adds a new RDSEED instruction, which is similar
to RDRAND but provides a stronger guarantee: unlike RDRAND, RDSEED
will always reseed the PRNG from the true random number source between
each read. Thus, the output of RDSEED is guaranteed to be 100%
entropic, unlike RDRAND which is only architecturally guaranteed to be
1/512 entropic (although in practice is much more.)

The RDSEED instruction takes the same time to execute as RDRAND, but
RDSEED unlike RDRAND can legitimately return failure (CF=0) due to
entropy exhaustion if too many threads on too many cores are hammering
the RDSEED instruction at the same time. Therefore, we have to be
more conservative and only use it in places where we can tolerate
failures.

This patch introduces the primitives arch_get_random_seed_{int,long}()
but does not use it yet.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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