commit 0047d57e6c91177bb731bed5ada6c211868bc27c
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon May 30 09:24:09 2022 +0200
Linux 5.18.1
Link: https://lore.kernel.org/r/20220527084801.223648383@linuxfoundation.org
Tested-by: Ronald Warsow <rwarsow@gmx.de
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
Tested-by: Ron Economos <re@w6rz.net>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Rudi Heitbaum <rudi@heitbaum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 80213405895162c448b30d28623f1f95337f9b3e
Author: Edward Matijevic <motolav@gmail.com>
Date: Fri May 20 23:45:15 2022 -0500
ALSA: ctxfi: Add SB046x PCI ID
commit 1b073ebb174d0c7109b438e0a5eb4495137803ec upstream.
Adds the PCI ID for X-Fi cards sold under the Platnum and XtremeMusic names
Before: snd_ctxfi 0000:05:05.0: chip 20K1 model Unknown (1102:0021) is found
After: snd_ctxfi 0000:05:05.0: chip 20K1 model SB046x (1102:0021) is found
[ This is only about defining the model name string, and the rest is
handled just like before, as a default unknown device.
Edward confirmed that the stuff has been working fine -- tiwai ]
Signed-off-by: Edward Matijevic <motolav@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/cae7d1a4-8bd9-7dfe-7427-db7e766f7272@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 453f8156652106e335176db8bfff05333e248498
Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Date: Thu Apr 7 11:51:20 2022 +0100
ACPI: sysfs: Fix BERT error region memory mapping
commit 1bbc21785b7336619fb6a67f1fff5afdaf229acc upstream.
Currently the sysfs interface maps the BERT error region as "memory"
(through acpi_os_map_memory()) in order to copy the error records into
memory buffers through memory operations (eg memory_read_from_buffer()).
The OS system cannot detect whether the BERT error region is part of
system RAM or it is "device memory" (eg BMC memory) and therefore it
cannot detect which memory attributes the bus to memory support (and
corresponding kernel mapping, unless firmware provides the required
information).
The acpi_os_map_memory() arch backend implementation determines the
mapping attributes. On arm64, if the BERT error region is not present in
the EFI memory map, the error region is mapped as device-nGnRnE; this
triggers alignment faults since memcpy unaligned accesses are not
allowed in device-nGnRnE regions.
The ACPI sysfs code cannot therefore map by default the BERT error
region with memory semantics but should use a safer default.
Change the sysfs code to map the BERT error region as MMIO (through
acpi_os_map_iomem()) and use the memcpy_fromio() interface to read the
error region into the kernel buffer.
Link: https://lore.kernel.org/linux-arm-kernel/31ffe8fc-f5ee-2858-26c5-0fd8bdd68702@arm.com
Link: https://lore.kernel.org/linux-acpi/CAJZ5v0g+OVbhuUUDrLUCfX_mVqY_e8ubgLTU98=jfjTeb4t+Pw@mail.gmail.com
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Veronika Kabatova <vkabatov@redhat.com>
Tested-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 068108f53811d99b5a470eafe5b0ddd523ed2c79
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sun May 22 22:25:41 2022 +0200
random: check for signals after page of pool writes
commit 1ce6c8d68f8ac587f54d0a271ac594d3d51f3efb upstream.
get_random_bytes_user() checks for signals after producing a PAGE_SIZE
worth of output, just like /dev/zero does. write_pool() is doing
basically the same work (actually, slightly more expensive), and so
should stop to check for signals in the same way. Let's also name it
write_pool_user() to match get_random_bytes_user(), so this won't be
misused in the future.
Before this patch, massive writes to /dev/urandom would tie up the
process for an extremely long time and make it unterminatable. After, it
can be successfully interrupted. The following test program can be used
to see this works as intended:
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
static unsigned char x[~0U];
static void handle(int) { }
int main(int argc, char *argv[])
{
pid_t pid = getpid(), child;
int fd;
signal(SIGUSR1, handle);
if (!(child = fork())) {
for (;;)
kill(pid, SIGUSR1);
}
fd = open("/dev/urandom", O_WRONLY);
pause();
printf("interrupted after writing %zd bytes\n", write(fd, x, sizeof(x)));
close(fd);
kill(child, SIGTERM);
return 0;
}
Result before: "interrupted after writing 2147479552 bytes"
Result after: "interrupted after writing 4096 bytes"
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 08467db994c0cf6c16e347a99e374a432e6c3509
Author: Jens Axboe <axboe@kernel.dk>
Date: Thu May 19 17:31:37 2022 -0600
random: wire up fops->splice_{read,write}_iter()
commit 79025e727a846be6fd215ae9cdb654368ac3f9a6 upstream.
Now that random/urandom is using {read,write}_iter, we can wire it up to
using the generic splice handlers.
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Jason: added the splice_write path. Note that sendfile() and such still
does not work for read, though it does for write, because of a file
type restriction in splice_direct_to_actor(), which I'll address
separately.]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fdb1b354e301dd2aa56df862b9d4894b79039c40
Author: Jens Axboe <axboe@kernel.dk>
Date: Thu May 19 17:43:15 2022 -0600
random: convert to using fops->write_iter()
commit 22b0a222af4df8ee9bb8e07013ab44da9511b047 upstream.
Now that the read side has been converted to fix a regression with
splice, convert the write side as well to have some symmetry in the
interface used (and help deprecate ->write()).
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Jason: cleaned up random_ioctl a bit, require full writes in
RNDADDENTROPY since it's crediting entropy, simplify control flow of
write_pool(), and incorporate suggestions from Al.]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 09ea8bc7276aead310e5faa21ae29ceeecea87c9
Author: Jens Axboe <axboe@kernel.dk>
Date: Thu May 19 17:31:36 2022 -0600
random: convert to using fops->read_iter()
commit 1b388e7765f2eaa137cf5d92b47ef5925ad83ced upstream.
This is a pre-requisite to wiring up splice() again for the random
and urandom drivers. It also allows us to remove the INT_MAX check in
getrandom(), because import_single_range() applies capping internally.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Jason: rewrote get_random_bytes_user() to simplify and also incorporate
additional suggestions from Al.]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 806afdc6d97fe17a9b96a8d6964f7d2da610ee58
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sun May 15 00:22:05 2022 +0200
random: unify batched entropy implementations
commit 3092adcef3ffd2ef59634998297ca8358461ebce upstream.
There are currently two separate batched entropy implementations, for
u32 and u64, with nearly identical code, with the goal of avoiding
unaligned memory accesses and letting the buffers be used more
efficiently. Having to maintain these two functions independently is a
bit of a hassle though, considering that they always need to be kept in
sync.
This commit factors them out into a type-generic macro, so that the
expansion produces the same code as before, such that diffing the
assembly shows no differences. This will also make it easier in the
future to add u16 and u8 batches.
This was initially tested using an always_inline function and letting
gcc constant fold the type size in, but the code gen was less efficient,
and in general it was more verbose and harder to follow. So this patch
goes with the boring macro solution, similar to what's already done for
the _wait functions in random.h.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 463ebd6f8707e57847680541a05c910947a2518a
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat May 14 13:59:30 2022 +0200
random: move randomize_page() into mm where it belongs
commit 5ad7dd882e45d7fe432c32e896e2aaa0b21746ea upstream.
randomize_page is an mm function. It is documented like one. It contains
the history of one. It has the naming convention of one. It looks
just like another very similar function in mm, randomize_stack_top().
And it has always been maintained and updated by mm people. There is no
need for it to be in random.c. In the "which shape does not look like
the other ones" test, pointing to randomize_page() is correct.
So move randomize_page() into mm/util.c, right next to the similar
randomize_stack_top() function.
This commit contains no actual code changes.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4f276d40e6032bcc19b341185e335dee65a431aa
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 13 16:17:12 2022 +0200
random: move initialization functions out of hot pages
commit 560181c27b582557d633ecb608110075433383af upstream.
Much of random.c is devoted to initializing the rng and accounting for
when a sufficient amount of entropy has been added. In a perfect world,
this would all happen during init, and so we could mark these functions
as __init. But in reality, this isn't the case: sometimes the rng only
finishes initializing some seconds after system init is finished.
For this reason, at the moment, a whole host of functions that are only
used relatively close to system init and then never again are intermixed
with functions that are used in hot code all the time. This creates more
cache misses than necessary.
In order to pack the hot code closer together, this commit moves the
initialization functions that can't be marked as __init into
.text.unlikely by way of the __cold attribute.
Of particular note is moving credit_init_bits() into a macro wrapper
that inlines the crng_ready() static branch check. This avoids a
function call to a nop+ret, and most notably prevents extra entropy
arithmetic from being computed in mix_interrupt_randomness().
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6fd3ff02dadcf6eacf6efd2e0840e75506d15905
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 13 13:18:46 2022 +0200
random: make consistent use of buf and len
commit a19402634c435a4eae226df53c141cdbb9922e7b upstream.
The current code was a mix of "nbytes", "count", "size", "buffer", "in",
and so forth. Instead, let's clean this up by naming input parameters
"buf" (or "ubuf") and "len", so that you always understand that you're
reading this variety of function argument.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit da71481fefa21c7511244b66d000590704bd21ba
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 13 12:32:23 2022 +0200
random: use proper return types on get_random_{int,long}_wait()
commit 7c3a8a1db5e03d02cc0abb3357a84b8b326dfac3 upstream.
Before these were returning signed values, but the API is intended to be
used with unsigned values.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4df97cbda270c1254fd866a9ec80bbd4bab868a8
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 13 12:29:38 2022 +0200
random: remove extern from functions in header
commit 7782cfeca7d420e8bb707613d4cfb0f7ff29bb3a upstream.
Accoriding to the kernel style guide, having `extern` on functions in
headers is old school and deprecated, and doesn't add anything. So remove
them from random.h, and tidy up the file a little bit too.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 05daffcd83dae217daedfa17577bbf8dc91f48fd
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue May 3 15:30:45 2022 +0200
random: use static branch for crng_ready()
commit f5bda35fba615ace70a656d4700423fa6c9bebee upstream.
Since crng_ready() is only false briefly during initialization and then
forever after becomes true, we don't need to evaluate it after, making
it a prime candidate for a static branch.
One complication, however, is that it changes state in a particular call
to credit_init_bits(), which might be made from atomic context, which
means we must kick off a workqueue to change the static key. Further
complicating things, credit_init_bits() may be called sufficiently early
on in system initialization such that system_wq is NULL.
Fortunately, there exists the nice function execute_in_process_context(),
which will immediately execute the function if !in_interrupt(), and
otherwise defer it to a workqueue. During early init, before workqueues
are available, in_interrupt() is always false, because interrupts
haven't even been enabled yet, which means the function in that case
executes immediately. Later on, after workqueues are available,
in_interrupt() might be true, but in that case, the work is queued in
system_wq and all goes well.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 91657c81fc3d0401189060acf54cddc201464645
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Thu May 12 15:32:26 2022 +0200
random: credit architectural init the exact amount
commit 12e45a2a6308105469968951e6d563e8f4fea187 upstream.
RDRAND and RDSEED can fail sometimes, which is fine. We currently
initialize the RNG with 512 bits of RDRAND/RDSEED. We only need 256 bits
of those to succeed in order to initialize the RNG. Instead of the
current "all or nothing" approach, actually credit these contributions
the amount that is actually contributed.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d9394ac04eeb2d60518566e78835e952ed395166
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Thu May 5 02:20:22 2022 +0200
random: handle latent entropy and command line from random_init()
commit 2f14062bb14b0fcfcc21e6dc7d5b5c0d25966164 upstream.
Currently, start_kernel() adds latent entropy and the command line to
the entropy bool *after* the RNG has been initialized, deferring when
it's actually used by things like stack canaries until the next time
the pool is seeded. This surely is not intended.
Rather than splitting up which entropy gets added where and when between
start_kernel() and random_init(), just do everything in random_init(),
which should eliminate these kinds of bugs in the future.
While we're at it, rename the awkwardly titled "rand_initialize()" to
the more standard "random_init()" nomenclature.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68f784cbb1757f82061a74c3d22b6781348ba04d
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue May 10 15:20:42 2022 +0200
random: use proper jiffies comparison macro
commit 8a5b8a4a4ceb353b4dd5bafd09e2b15751bcdb51 upstream.
This expands to exactly the same code that it replaces, but makes things
consistent by using the same macro for jiffy comparisons throughout.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 443a7b15c858ec799ae7ba5146316c4d30c778d6
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Mon May 9 16:13:18 2022 +0200
random: remove ratelimiting for in-kernel unseeded randomness
commit cc1e127bfa95b5fb2f9307e7168bf8b2b45b4c5e upstream.
The CONFIG_WARN_ALL_UNSEEDED_RANDOM debug option controls whether the
kernel warns about all unseeded randomness or just the first instance.
There's some complicated rate limiting and comparison to the previous
caller, such that even with CONFIG_WARN_ALL_UNSEEDED_RANDOM enabled,
developers still don't see all the messages or even an accurate count of
how many were missed. This is the result of basically parallel
mechanisms aimed at accomplishing more or less the same thing, added at
different points in random.c history, which sort of compete with the
first-instance-only limiting we have now.
It turns out, however, that nobody cares about the first unseeded
randomness instance of in-kernel users. The same first user has been
there for ages now, and nobody is doing anything about it. It isn't even
clear that anybody _can_ do anything about it. Most places that can do
something about it have switched over to using get_random_bytes_wait()
or wait_for_random_bytes(), which is the right thing to do, but there is
still much code that needs randomness sometimes during init, and as a
geeneral rule, if you're not using one of the _wait functions or the
readiness notifier callback, you're bound to be doing it wrong just
based on that fact alone.
So warning about this same first user that can't easily change is simply
not an effective mechanism for anything at all. Users can't do anything
about it, as the Kconfig text points out -- the problem isn't in
userspace code -- and kernel developers don't or more often can't react
to it.
Instead, show the warning for all instances when CONFIG_WARN_ALL_UNSEEDED_RANDOM
is set, so that developers can debug things need be, or if it isn't set,
don't show a warning at all.
At the same time, CONFIG_WARN_ALL_UNSEEDED_RANDOM now implies setting
random.ratelimit_disable=1 on by default, since if you care about one
you probably care about the other too. And we can clean up usage around
the related urandom_warning ratelimiter as well (whose behavior isn't
changing), so that it properly counts missed messages after the 10
message threshold is reached.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d77c5dc80264c0b9d9d4799d2afa8024e23a64f
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Mon May 9 13:53:24 2022 +0200
random: move initialization out of reseeding hot path
commit 68c9c8b192c6dae9be6278e98ee44029d5da2d31 upstream.
Initialization happens once -- by way of credit_init_bits() -- and then
it never happens again. Therefore, it doesn't need to be in
crng_reseed(), which is a hot path that is called multiple times. It
also doesn't make sense to have there, as initialization activity is
better associated with initialization routines.
After the prior commit, crng_reseed() now won't be called by multiple
concurrent callers, which means that we can safely move the
"finialize_init" logic into crng_init_bits() unconditionally.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e84123f90491618c6d0095495502e566bc5b41c4
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Mon May 9 13:40:55 2022 +0200
random: avoid initializing twice in credit race
commit fed7ef061686cc813b1f3d8d0edc6c35b4d3537b upstream.
Since all changes of crng_init now go through credit_init_bits(), we can
fix a long standing race in which two concurrent callers of
credit_init_bits() have the new bit count >= some threshold, but are
doing so with crng_init as a lower threshold, checked outside of a lock,
resulting in crng_reseed() or similar being called twice.
In order to fix this, we can use the original cmpxchg value of the bit
count, and only change crng_init when the bit count transitions from
below a threshold to meeting the threshold.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a199b1cf0d53b2da8994b084cd25a84f26cb462a
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sun May 8 13:20:30 2022 +0200
random: use symbolic constants for crng_init states
commit e3d2c5e79a999aa4e7d6f0127e16d3da5a4ff70d upstream.
crng_init represents a state machine, with three states, and various
rules for transitions. For the longest time, we've been managing these
with "0", "1", and "2", and expecting people to figure it out. To make
the code more obvious, replace these with proper enum values
representing the transition, and then redocument what each of these
states mean.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 65419736ad67ae4d42647eecdde4f71770dbf50c
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat May 7 14:03:46 2022 +0200
siphash: use one source of truth for siphash permutations
commit e73aaae2fa9024832e1f42e30c787c7baf61d014 upstream.
The SipHash family of permutations is currently used in three places:
- siphash.c itself, used in the ordinary way it was intended.
- random32.c, in a construction from an anonymous contributor.
- random.c, as part of its fast_mix function.
Each one of these places reinvents the wheel with the same C code, same
rotation constants, and same symmetry-breaking constants.
This commit tidies things up a bit by placing macros for the
permutations and constants into siphash.h, where each of the three .c
users can access them. It also leaves a note dissuading more users of
them from emerging.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3cac6963de9f3014c9b980caede71f2344d47daa
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 6 23:19:43 2022 +0200
random: help compiler out with fast_mix() by using simpler arguments
commit 791332b3cbb080510954a4c152ce02af8832eac9 upstream.
Now that fast_mix() has more than one caller, gcc no longer inlines it.
That's fine. But it also doesn't handle the compound literal argument we
pass it very efficiently, nor does it handle the loop as well as it
could. So just expand the code to spell out this function so that it
generates the same code as it did before. Performance-wise, this now
behaves as it did before the last commit. The difference in actual code
size on x86 is 45 bytes, which is less than a cache line.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e34e244a3727c13c7f8858c42c3d82bc3d1d818
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 6 18:30:51 2022 +0200
random: do not use input pool from hard IRQs
commit e3e33fc2ea7fcefd0d761db9d6219f83b4248f5c upstream.
Years ago, a separate fast pool was added for interrupts, so that the
cost associated with taking the input pool spinlocks and mixing into it
would be avoided in places where latency is critical. However, one
oversight was that add_input_randomness() and add_disk_randomness()
still sometimes are called directly from the interrupt handler, rather
than being deferred to a thread. This means that some unlucky interrupts
will be caught doing a blake2s_compress() call and potentially spinning
on input_pool.lock, which can also be taken by unprivileged users by
writing into /dev/urandom.
In order to fix this, add_timer_randomness() now checks whether it is
being called from a hard IRQ and if so, just mixes into the per-cpu IRQ
fast pool using fast_mix(), which is much faster and can be done
lock-free. A nice consequence of this, as well, is that it means hard
IRQ context FPU support is likely no longer useful.
The entropy estimation algorithm used by add_timer_randomness() is also
somewhat different than the one used for add_interrupt_randomness(). The
former looks at deltas of deltas of deltas, while the latter just waits
for 64 interrupts for one bit or for one second since the last bit. In
order to bridge these, and since add_interrupt_randomness() runs after
an add_timer_randomness() that's called from hard IRQ, we add to the
fast pool credit the related amount, and then subtract one to account
for add_interrupt_randomness()'s contribution.
A downside of this, however, is that the num argument is potentially
attacker controlled, which puts a bit more pressure on the fast_mix()
sponge to do more than it's really intended to do. As a mitigating
factor, the first 96 bits of input aren't attacker controlled (a cycle
counter followed by zeros), which means it's essentially two rounds of
siphash rather than one, which is somewhat better. It's also not that
much different from add_interrupt_randomness()'s use of the irq stack
instruction pointer register.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Filipe Manana <fdmanana@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 157edd57d51f5945e8aa207dc64cc10560ffc582
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri May 6 18:27:38 2022 +0200
random: order timer entropy functions below interrupt functions
commit a4b5c26b79ffdfcfb816c198f2fc2b1e7b5b580f upstream.
There are no code changes here; this is just a reordering of functions,
so that in subsequent commits, the timer entropy functions can call into
the interrupt ones.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0e4944c9c11ebb207355d6edab0ac5b5a958e9a6
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 30 22:03:29 2022 +0200
random: do not pretend to handle premature next security model
commit e85c0fc1d94c52483a603651748d4c76d6aa1c6b upstream.
Per the thread linked below, "premature next" is not considered to be a
realistic threat model, and leads to more serious security problems.
"Premature next" is the scenario in which:
- Attacker compromises the current state of a fully initialized RNG via
some kind of infoleak.
- New bits of entropy are added directly to the key used to generate the
/dev/urandom stream, without any buffering or pooling.
- Attacker then, somehow having read access to /dev/urandom, samples RNG
output and brute forces the individual new bits that were added.
- Result: the RNG never "recovers" from the initial compromise, a
so-called violation of what academics term "post-compromise security".
The usual solutions to this involve some form of delaying when entropy
gets mixed into the crng. With Fortuna, this involves multiple input
buckets. With what the Linux RNG was trying to do prior, this involves
entropy estimation.
However, by delaying when entropy gets mixed in, it also means that RNG
compromises are extremely dangerous during the window of time before
the RNG has gathered enough entropy, during which time nonces may become
predictable (or repeated), ephemeral keys may not be secret, and so
forth. Moreover, it's unclear how realistic "premature next" is from an
attack perspective, if these attacks even make sense in practice.
Put together -- and discussed in more detail in the thread below --
these constitute grounds for just doing away with the current code that
pretends to handle premature next. I say "pretends" because it wasn't
doing an especially great job at it either; should we change our mind
about this direction, we would probably implement Fortuna to "fix" the
"problem", in which case, removing the pretend solution still makes
sense.
This also reduces the crng reseed period from 5 minutes down to 1
minute. The rationale from the thread might lead us toward reducing that
even further in the future (or even eliminating it), but that remains a
topic of a future commit.
At a high level, this patch changes semantics from:
Before: Seed for the first time after 256 "bits" of estimated
entropy have been accumulated since the system booted. Thereafter,
reseed once every five minutes, but only if 256 new "bits" have been
accumulated since the last reseeding.
After: Seed for the first time after 256 "bits" of estimated entropy
have been accumulated since the system booted. Thereafter, reseed
once every minute.
Most of this patch is renaming and removing: POOL_MIN_BITS becomes
POOL_INIT_BITS, credit_entropy_bits() becomes credit_init_bits(),
crng_reseed() loses its "force" parameter since it's now always true,
the drain_entropy() function no longer has any use so it's removed,
entropy estimation is skipped if we've already init'd, the various
notifiers for "low on entropy" are now only active prior to init, and
finally, some documentation comments are cleaned up here and there.
Link: https://lore.kernel.org/lkml/YmlMGx6+uigkGiZ0@zx2c4.com/
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Nadia Heninger <nadiah@cs.ucsd.edu>
Cc: Tom Ristenpart <ristenpart@cornell.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7176e96d798807e536bf4e76b8767a5e94a301f6
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 30 15:08:20 2022 +0200
random: use first 128 bits of input as fast init
commit 5c3b747ef54fa2a7318776777f6044540d99f721 upstream.
Before, the first 64 bytes of input, regardless of how entropic it was,
would be used to mutate the crng base key directly, and none of those
bytes would be credited as having entropy. Then 256 bits of credited
input would be accumulated, and only then would the rng transition from
the earlier "fast init" phase into being actually initialized.
The thinking was that by mixing and matching fast init and real init, an
attacker who compromised the fast init state, considered easy to do
given how little entropy might be in those first 64 bytes, would then be
able to bruteforce bits from the actual initialization. By keeping these
separate, bruteforcing became impossible.
However, by not crediting potentially creditable bits from those first 64
bytes of input, we delay initialization, and actually make the problem
worse, because it means the user is drawing worse random numbers for a
longer period of time.
Instead, we can take the first 128 bits as fast init, and allow them to
be credited, and then hold off on the next 128 bits until they've
accumulated. This is still a wide enough margin to prevent bruteforcing
the rng state, while still initializing much faster.
Then, rather than trying to piecemeal inject into the base crng key at
various points, instead just extract from the pool when we need it, for
the crng_init==0 phase. Performance may even be better for the various
inputs here, since there are likely more calls to mix_pool_bytes() then
there are to get_random_bytes() during this phase of system execution.
Since the preinit injection code is gone, bootloader randomness can then
do something significantly more straight forward, removing the weird
system_wq hack in hwgenerator randomness.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f0cb03957175452e8dfc18f3f7d8dd2698553bd4
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue May 3 14:14:32 2022 +0200
random: do not use batches when !crng_ready()
commit cbe89e5a375a51bbb952929b93fa973416fea74e upstream.
It's too hard to keep the batches synchronized, and pointless anyway,
since in !crng_ready(), we're updating the base_crng key really often,
where batching only hurts. So instead, if the crng isn't ready, just
call into get_random_bytes(). At this stage nothing is performance
critical anyhow.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8f4d6e33b53405de6696a92caea2d71a5b7c15e0
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue Apr 12 19:59:57 2022 +0200
random: insist on random_get_entropy() existing in order to simplify
commit 4b758eda851eb9336ca86a0041a4d3da55f66511 upstream.
All platforms are now guaranteed to provide some value for
random_get_entropy(). In case some bug leads to this not being so, we
print a warning, because that indicates that something is really very
wrong (and likely other things are impacted too). This should never be
hit, but it's a good and cheap way of finding out if something ever is
problematic.
Since we now have viable fallback code for random_get_entropy() on all
platforms, which is, in the worst case, not worse than jiffies, we can
count on getting the best possible value out of it. That means there's
no longer a use for using jiffies as entropy input. It also means we no
longer have a reason for doing the round-robin register flow in the IRQ
handler, which was always of fairly dubious value.
Instead we can greatly simplify the IRQ handler inputs and also unify
the construction between 64-bits and 32-bits. We now collect the cycle
counter and the return address, since those are the two things that
matter. Because the return address and the irq number are likely
related, to the extent we mix in the irq number, we can just xor it into
the top unchanging bytes of the return address, rather than the bottom
changing bytes of the cycle counter as before. Then, we can do a fixed 2
rounds of SipHash/HSipHash. Finally, we use the same construction of
hashing only half of the [H]SipHash state on 32-bit and 64-bit. We're
not actually discarding any entropy, since that entropy is carried
through until the next time. And more importantly, it lets us do the
same sponge-like construction everywhere.
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7ebcfba533435b50a80096064e374a3cc08aabbb
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
xtensa: use fallback for random_get_entropy() instead of zero
commit e10e2f58030c5c211d49042a8c2a1b93d40b2ffb upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 32a177ccb3884717251e2394750f283ef3b6c916
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
sparc: use fallback for random_get_entropy() instead of zero
commit ac9756c79797bb98972736b13cfb239fd2cffb79 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d161ede79be763eabaa2a617eae0c9892f3869b6
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
um: use fallback for random_get_entropy() instead of zero
commit 9f13fb0cd11ed2327abff69f6501a2c124c88b5a upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c37981032472f827d920dd37d59b9c248fbe0b8c
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
x86/tsc: Use fallback for random_get_entropy() instead of zero
commit 3bd4abc07a267e6a8b33d7f8717136e18f921c53 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is suboptimal. Instead, fallback
to calling random_get_entropy_fallback(), which isn't extremely high
precision or guaranteed to be entropic, but is certainly better than
returning zero all the time.
If CONFIG_X86_TSC=n, then it's possible for the kernel to run on systems
without RDTSC, such as 486 and certain 586, so the fallback code is only
required for that case.
As well, fix up both the new function and the get_cycles() function from
which it was derived to use cpu_feature_enabled() rather than
boot_cpu_has(), and use !IS_ENABLED() instead of #ifndef.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cca2a7ad060e5abae5d12f4b58de64679d59fa81
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
nios2: use fallback for random_get_entropy() instead of zero
commit c04e72700f2293013dab40208e809369378f224c upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a9ebafbe00f5086a8149d2b9eebe6033dce509d5
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
arm: use fallback for random_get_entropy() instead of zero
commit ff8a8f59c99f6a7c656387addc4d9f2247d75077 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9d3ee85be180b174fb3a28668e067d37c93c6ae5
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
mips: use fallback for random_get_entropy() instead of just c0 random
commit 1c99c6a7c3c599a68321b01b9ec243215ede5a68 upstream.
For situations in which we don't have a c0 counter register available,
we've been falling back to reading the c0 "random" register, which is
usually bounded by the amount of TLB entries and changes every other
cycle or so. This means it wraps extremely often. We can do better by
combining this fast-changing counter with a potentially slower-changing
counter from random_get_entropy_fallback() in the more significant bits.
This commit combines the two, taking into account that the changing bits
are in a different bit position depending on the CPU model. In addition,
we previously were falling back to 0 for ancient CPUs that Linux does
not support anyway; remove that dead path entirely.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f4e9fe58d4af645cf92a889d54a842ff79969a53
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
riscv: use fallback for random_get_entropy() instead of zero
commit 6d01238623faa9425f820353d2066baf6c9dc872 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 955a870ebdf691c84baa09ea27fd0e80135d0ad7
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri Apr 8 18:03:13 2022 +0200
m68k: use fallback for random_get_entropy() instead of zero
commit 0f392c95391f2d708b12971a07edaa7973f9eece upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7a5a2e2ccfd9496dcc9290c2e8799da612270607
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sun Apr 10 16:49:50 2022 +0200
timekeeping: Add raw clock fallback for random_get_entropy()
commit 1366992e16bddd5e2d9a561687f367f9f802e2e4 upstream.
The addition of random_get_entropy_fallback() provides access to
whichever time source has the highest frequency, which is useful for
gathering entropy on platforms without available cycle counters. It's
not necessarily as good as being able to quickly access a cycle counter
that the CPU has, but it's still something, even when it falls back to
being jiffies-based.
In the event that a given arch does not define get_cycles(), falling
back to the get_cycles() default implementation that returns 0 is really
not the best we can do. Instead, at least calling
random_get_entropy_fallback() would be preferable, because that always
needs to return _something_, even falling back to jiffies eventually.
It's not as though random_get_entropy_fallback() is super high precision
or guaranteed to be entropic, but basically anything that's not zero all
the time is better than returning zero all the time.
Finally, since random_get_entropy_fallback() is used during extremely
early boot when randomizing freelists in mm_init(), it can be called
before timekeeping has been initialized. In that case there really is
nothing we can do; jiffies hasn't even started ticking yet. So just give
up and return 0.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 62d1c104c7f6ee38d4f2717b1539a0dd54f71ff9
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 23 21:11:41 2022 +0200
powerpc: define get_cycles macro for arch-override
commit 408835832158df0357e18e96da7f2d1ed6b80e7f upstream.
PowerPC defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@ozlabs.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d0d24c89d88505011b09eec0dec43bec1c617bef
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 23 21:11:41 2022 +0200
alpha: define get_cycles macro for arch-override
commit 1097710bc9660e1e588cf2186a35db3d95c4d258 upstream.
Alpha defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a51867dc50cdc4df16200d8897bced7f243aaab
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 23 21:11:41 2022 +0200
parisc: define get_cycles macro for arch-override
commit 8865bbe6ba1120e67f72201b7003a16202cd42be upstream.
PA-RISC defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f11c51290d0f854f83632d79a03af9605ca2c32a
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 23 21:11:41 2022 +0200
s390: define get_cycles macro for arch-override
commit 2e3df523256cb9836de8441e9c791a796759bb3c upstream.
S390x defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9d923d15fc4b99d55a4cf0f8b1336ed7b8af218e
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Sat Apr 23 21:11:41 2022 +0200
ia64: define get_cycles macro for arch-override
commit 57c0900b91d8891ab43f0e6b464d059fda51d102 upstream.
Itanium defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a27dffcb938836affc211846a44e6dfa306582f7
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Thu May 5 02:20:22 2022 +0200
init: call time_init() before rand_initialize()
commit fe222a6ca2d53c38433cba5d3be62a39099e708e upstream.
Currently time_init() is called after rand_initialize(), but
rand_initialize() makes use of the timer on various platforms, and
sometimes this timer needs to be initialized by time_init() first. In
order for random_get_entropy() to not return zero during early boot when
it's potentially used as an entropy source, reverse the order of these
two calls. The block doing random initialization was right before
time_init() before, so changing the order shouldn't have any complicated
effects.
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3162bd8ac0530d5488a6e861f91871a2002ae416
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue May 3 21:43:58 2022 +0200
random: fix sysctl documentation nits
commit 069c4ea6871c18bd368f27756e0f91ffb524a788 upstream.
A semicolon was missing, and the almost-alphabetical-but-not ordering
was confusing, so regroup these by category instead.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8c37b3bc825d4ce567d01533782224cdec8337a5
Author: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Date: Mon May 9 18:50:20 2022 +0530
HID: amd_sfh: Add support for sensor discovery
commit b5d7f43e97dabfa04a4be5ff027ce7da119332be upstream.
Sensor discovery status fails in case of broken sensors or
platform not supported. Hence disable driver on failure
of sensor discovery.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Mario Limonciello <Mario.Limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit eca56bf0066ef2f1e7be0e3fa7564b85a309872c
Author: Daniel Thompson <daniel.thompson@linaro.org>
Date: Mon May 23 19:11:02 2022 +0100
lockdown: also lock down previous kgdb use
commit eadb2f47a3ced5c64b23b90fd2a3463f63726066 upstream.
KGDB and KDB allow read and write access to kernel memory, and thus
should be restricted during lockdown. An attacker with access to a
serial port (for example, via a hypervisor console, which some cloud
vendors provide over the network) could trigger the debugger so it is
important that the debugger respect the lockdown mode when/if it is
triggered.
Fix this by integrating lockdown into kdb's existing permissions
mechanism. Unfortunately kgdb does not have any permissions mechanism
(although it certainly could be added later) so, for now, kgdb is simply
and brutally disabled by immediately exiting the gdb stub without taking
any action.
For lockdowns established early in the boot (e.g. the normal case) then
this should be fine but on systems where kgdb has set breakpoints before
the lockdown is enacted than "bad things" will happen.
CVE: CVE-2022-21499
Co-developed-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>