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>
random: credit architectural init the exact amount
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>
random: handle latent entropy and command line from random_init()
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>
random: remove ratelimiting for in-kernel unseeded randomness
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>
random: move initialization out of reseeding hot path
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>
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>
random: use symbolic constants for crng_init states
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>
random32: use real rng for non-deterministic randomness
random32.c has two random number generators in it: one that is meant to
be used deterministically, with some predefined seed, and one that does
the same exact thing as random.c, except does it poorly. The first one
has some use cases. The second one no longer does and can be replaced
with calls to random.c's proper random number generator.
The relatively recent siphash-based bad random32.c code was added in
response to concerns that the prior random32.c was too deterministic.
Out of fears that random.c was (at the time) too slow, this code was
anonymously contributed. Then out of that emerged a kind of shadow
entropy gathering system, with its own tentacles throughout various net
code, added willy nilly.
Stop👏making👏bespoke👏random👏number👏generators👏.
Fortunately, recent advances in random.c mean that we can stop playing
with this sketchiness, and just use get_random_u32(), which is now fast
enough. In micro benchmarks using RDPMC, I'm seeing the same median
cycle count between the two functions, with the mean being _slightly_
higher due to batches refilling (which we can optimize further need be).
However, when doing *real* benchmarks of the net functions that actually
use these random numbers, the mean cycles actually *decreased* slightly
(with the median still staying the same), likely because the additional
prandom code means icache misses and complexity, whereas random.c is
generally already being used by something else nearby.
The biggest benefit of this is that there are many users of prandom who
probably should be using cryptographically secure random numbers. This
makes all of those accidental cases become secure by just flipping a
switch. Later on, we can do a tree-wide cleanup to remove the static
inline wrapper functions that this commit adds.
There are also some low-ish hanging fruits for making this even faster
in the future: a get_random_u16() function for use in the networking
stack will give a 2x performance boost there, using SIMD for ChaCha20
will let us compute 4 or 8 or 16 blocks of output in parallel, instead
of just one, giving us large buffers for cheap, and introducing a
get_random_*_bh() function that assumes irqs are already disabled will
shave off a few cycles for ordinary calls. These are things we can chip
away at down the road.
Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
siphash: use one source of truth for siphash permutations
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>
random: help compiler out with fast_mix() by using simpler arguments
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>
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>
random: order timer entropy functions below interrupt functions
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>
random: do not pretend to handle premature next security model
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>
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>
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>
random: mix in timestamps and reseed on system restore
Since the RNG loses freshness with system suspend/hibernation, when we
resume, immediately reseed using whatever data we can, which for this
particular case is the various timestamps regarding system suspend time,
in addition to more generally the RDSEED/RDRAND/RDTSC values that happen
whenever the crng reseeds.
On systems that suspend and resume automatically all the time -- such as
Android -- we skip the reseeding on suspend resumption, since that could
wind up being far too busy. This is the same trade-off made in
WireGuard.
In addition to reseeding upon resumption always mix into the pool these
various stamps on every power notification event.
Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
random: vary jitter iterations based on cycle counter speed
Currently, we do the jitter dance if two consecutive reads to the cycle
counter return different values. If they do, then we consider the cycle
counter to be fast enough that one trip through the scheduler will yield
one "bit" of credited entropy. If those two reads return the same value,
then we assume the cycle counter is too slow to show meaningful
differences.
This methodology is flawed for a variety of reasons, one of which Eric
posted a patch to fix in [1]. The issue that patch solves is that on a
system with a slow counter, you might be [un]lucky and read the counter
_just_ before it changes, so that the second cycle counter you read
differs from the first, even though there's usually quite a large period
of time in between the two. For example:
If we read the counter at (a) and compare it to (b), we might be fooled
into thinking that it's a fast counter, when in reality it is not. The
solution in [1] is to also compare counter (b) to counter (c), on the
theory that if the counter is _actually_ slow, and (a)!=(b), then
certainly (b)==(c).
This helps solve this particular issue, in one sense, but in another
sense, it mostly functions to disallow jitter entropy on these systems,
rather than simply taking more samples in that case.
Instead, this patch takes a different approach. Right now we assume that
a difference in one set of consecutive samples means one "bit" of
credited entropy per scheduler trip. We can extend this so that a
difference in two sets of consecutive samples means one "bit" of
credited entropy per /two/ scheduler trips, and three for three, and
four for four. In other words, we can increase the amount of jitter
"work" we require for each "bit", depending on how slow the cycle
counter is.
So this patch takes whole bunch of samples, sees how many of them are
different, and divides to find the amount of work required per "bit",
and also requires that at least some minimum of them are different in
order to attempt any jitter entropy.
Note that this approach is still far from perfect. It's not a real
statistical estimate on how much these samples vary; it's not a
real-time analysis of the relevant input data. That remains a project
for another time. However, it makes the same (partly flawed) assumptions
as the code that's there now, so it's probably not worse than the status
quo, and it handles the issue Eric mentioned in [1]. But, again, it's
probably a far cry from whatever a really robust version of this would
be.
random: insist on random_get_entropy() existing in order to simplify
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>
xtensa: use fallback for random_get_entropy() instead of zero
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>
sparc: use fallback for random_get_entropy() instead of zero
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>
um: use fallback for random_get_entropy() instead of zero
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>
x86/tsc: Use fallback for random_get_entropy() instead of zero
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
nios2: use fallback for random_get_entropy() instead of zero
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>
arm: use fallback for random_get_entropy() instead of zero
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>
mips: use fallback for random_get_entropy() instead of just c0 random
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>
riscv: use fallback for random_get_entropy() instead of zero
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>
m68k: use fallback for random_get_entropy() instead of zero
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>
timekeeping: Add raw clock fallback for random_get_entropy()
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>
In order to measure the boot process, the timer should be switched on as
early in boot as possible. As well, the commit defines the get_cycles
macro, like the previous patches in this series, so that generic code is
aware that it's implemented by the platform, as is done on other archs.
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Acked-by: Stafford Horne <shorne@gmail.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
powerpc: define get_cycles macro for arch-override
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>
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>
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>
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>
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>
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>
Linus Torvalds [Sun, 8 May 2022 19:42:05 +0000 (12:42 -0700)]
Merge tag 'for-5.18/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc architecture fixes from Helge Deller:
"Some reverts of existing patches, which were necessary because of boot
issues due to wrong CPU clock handling and cache issues which led to
userspace segfaults with 32bit kernels. Dave has a whole bunch of
upcoming cache fixes which I then plan to push in the next merge
window.
Other than that just small updates and fixes, e.g. defconfig updates,
spelling fixes, a clocksource fix, boot topology fixes and a fix for
/proc/cpuinfo output to satisfy lscpu"
* tag 'for-5.18/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
Revert "parisc: Increase parisc_cache_flush_threshold setting"
parisc: Mark cr16 clock unstable on all SMP machines
parisc: Fix typos in comments
parisc: Change MAX_ADDRESS to become unsigned long long
parisc: Merge model and model name into one line in /proc/cpuinfo
parisc: Re-enable GENERIC_CPU_DEVICES for !SMP
parisc: Update 32- and 64-bit defconfigs
parisc: Only list existing CPUs in cpu_possible_mask
Revert "parisc: Fix patch code locking and flushing"
Revert "parisc: Mark sched_clock unstable only if clocks are not syncronized"
Revert "parisc: Mark cr16 CPU clocksource unstable on all SMP machines"
Linus Torvalds [Sun, 8 May 2022 18:38:23 +0000 (11:38 -0700)]
Merge tag 'powerpc-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix the DWARF CFI in our VDSO time functions, allowing gdb to
backtrace through them correctly.
- Fix a buffer overflow in the papr_scm driver, only triggerable by
hypervisor input.
- A fix in the recently added QoS handling for VAS (used for
communicating with coprocessors).
Thanks to Alan Modra, Haren Myneni, Kajol Jain, and Segher Boessenkool.
* tag 'powerpc-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE
powerpc/vdso: Fix incorrect CFI in gettimeofday.S
powerpc/pseries/vas: Use QoS credits from the userspace
Linus Torvalds [Sun, 8 May 2022 18:21:54 +0000 (11:21 -0700)]
Merge tag 'x86-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Thomas Gleixner:
"A fix and an email address update:
- Prevent FPU state corruption.
The condition in irq_fpu_usable() grants FPU usage when the FPU is
not used in the kernel. That's just wrong as it does not take the
fpregs_lock()'ed regions into account. If FPU usage happens within
such a region from interrupt context, then the FPU state gets
corrupted.
That's a long standing bug, which got unearthed by the recent
changes to the random code.
- Josh wants to use his kernel.org email address"
* tag 'x86-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Prevent FPU state corruption
MAINTAINERS: Update Josh Poimboeuf's email address
Linus Torvalds [Sun, 8 May 2022 18:18:11 +0000 (11:18 -0700)]
Merge tag 'timers-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A fix and an email address update:
- Mark the NMI safe time accessors notrace to prevent tracer
recursion when they are selected as trace clocks.
- John Stultz has a new email address"
* tag 'timers-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Mark NMI safe time accessors as notrace
MAINTAINERS: Update email address for John Stultz
Linus Torvalds [Sun, 8 May 2022 18:10:17 +0000 (11:10 -0700)]
Merge tag 'irq-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner:
"A fix for the threaded interrupt core.
A quick sequence of request/free_irq() can result in a hang because
the interrupt thread did not reach the thread function and got stopped
in the kthread core already. That leaves a state active counter
arround which makes a invocation of synchronized_irq() on that
interrupt hang forever.
Ensure that the thread reached the thread function in request_irq() to
prevent that"
* tag 'irq-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Synchronize interrupt thread startup
Helge Deller [Sun, 8 May 2022 16:25:00 +0000 (18:25 +0200)]
parisc: Mark cr16 clock unstable on all SMP machines
The cr16 interval timers are not synchronized across CPUs, even with just
one dual-core CPU. This becomes visible if the machines have a longer
uptime.
parisc: Change MAX_ADDRESS to become unsigned long long
Dave noticed that for the 32-bit kernel MAX_ADDRESS should be a ULL,
otherwise this define would become 0:
MAX_ADDRESS (1UL << MAX_ADDRBITS)
It has no real effect on the kernel.
Signed-off-by: Helge Deller <deller@gmx.de> Noticed-by: John David Anglin <dave.anglin@bell.net>
parisc: Merge model and model name into one line in /proc/cpuinfo
The Linux tool "lscpu" shows the double amount of CPUs if we have
"model" and "model name" in two different lines in /proc/cpuinfo.
This change combines the model and the model name into one line.
In commit 8f439e87d94e ("parisc: Switch from GENERIC_CPU_DEVICES to
GENERIC_ARCH_TOPOLOGY") GENERIC_CPU_DEVICES was unconditionally turned
off, but this triggers a warning in topology_add_dev(). Turning it back
on for the !SMP case avoids this warning.
Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Fixes: 8f439e87d94e ("parisc: Switch from GENERIC_CPU_DEVICES to GENERIC_ARCH_TOPOLOGY") Signed-off-by: Helge Deller <deller@gmx.de>
Linus Torvalds [Sun, 8 May 2022 17:28:22 +0000 (10:28 -0700)]
Merge tag 'core-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull PASID fix from Thomas Gleixner:
"A single bugfix for the PASID management code, which freed the PASID
too early. The PASID needs to be tied to the mm lifetime, not to the
address space lifetime"
* tag 'core-urgent-2022-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm: Fix PASID use-after-free issue
Linus Torvalds [Sun, 8 May 2022 17:10:51 +0000 (10:10 -0700)]
Merge tag 'sound-5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"This became slightly larger as I've been off in the last weeks.
The majority of changes here is about ASoC, fixes for dmaengine
and for addressing issues reported by CI, as well as other
device-specific small fixes.
Also, fixes for FireWire core stack and the usual HD-audio quirks
are included"
* tag 'sound-5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (23 commits)
ASoC: SOF: Fix NULL pointer exception in sof_pci_probe callback
ASoC: ops: Validate input values in snd_soc_put_volsw_range()
ASoC: dmaengine: Restore NULL prepare_slave_config() callback
ASoC: atmel: mchp-pdmc: set prepare_slave_config
ASoC: max98090: Generate notifications on changes for custom control
ASoC: max98090: Reject invalid values in custom control put()
ALSA: fireworks: fix wrong return count shorter than expected by 4 bytes
ALSA: hda/realtek: Add quirk for Yoga Duet 7 13ITL6 speakers
firewire: core: extend card->lock in fw_core_handle_bus_reset
firewire: remove check of list iterator against head past the loop body
firewire: fix potential uaf in outbound_phy_packet_callback()
ASoC: rt9120: Correct the reg 0x09 size to one byte
ALSA: hda/realtek: Enable mute/micmute LEDs support for HP Laptops
ALSA: hda/realtek: Fix mute led issue on thinkpad with cs35l41 s-codec
ASoC: meson: axg-card: Fix nonatomic links
ASoC: meson: axg-tdm-interface: Fix formatters in trigger"
ASoC: soc-ops: fix error handling
ASoC: meson: Fix event generation for G12A tohdmi mux
ASoC: meson: Fix event generation for AUI CODEC mux
ASoC: meson: Fix event generation for AUI ACODEC mux
...
Willy Tarreau [Sun, 8 May 2022 09:37:08 +0000 (11:37 +0200)]
ataflop: use a statically allocated error counters
This is the last driver making use of fd_request->error_count, which is
easy to get wrong as was shown in floppy.c. We don't need to keep it
there, it can be moved to the atari_floppy_struct instead, so let's do
this.
Willy Tarreau [Sun, 8 May 2022 09:37:07 +0000 (11:37 +0200)]
floppy: use a statically allocated error counter
Interrupt handler bad_flp_intr() may cause a UAF on the recently freed
request just to increment the error count. There's no point keeping
that one in the request anyway, and since the interrupt handler uses a
static pointer to the error which cannot be kept in sync with the
pending request, better make it use a static error counter that's reset
for each new request. This reset now happens when entering
redo_fd_request() for a new request via set_next_request().
One initial concern about a single error counter was that errors on one
floppy drive could be reported on another one, but this problem is not
real given that the driver uses a single drive at a time, as that
PC-compatible controllers also have this limitation by using shared
signals. As such the error count is always for the "current" drive.
Takashi Iwai [Sun, 8 May 2022 08:49:25 +0000 (10:49 +0200)]
Merge tag 'asoc-fix-v5.18-rc4' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v5.18
A larger collection of fixes than I'd like, mainly because mixer-test
is making it's way into the CI systems and turning up issues on a wider
range of systems. The most substantial thing though is a revert and an
alternative fix for a dmaengine issue where the fix caused disruption
for some other configurations, the core fix is backed out an a driver
specific thing done instead.
Linus Torvalds [Sat, 7 May 2022 18:02:02 +0000 (11:02 -0700)]
Merge tag 'gpio-fixes-for-v5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
- fix the bounds check for the 'gpio-reserved-ranges' device property
in gpiolib-of
- drop the assignment of the pwm base number in gpio-mvebu (this was
missed by the patch doing it globally for all pwm drivers)
- fix the fwnode assignment (use own fwnode, not the parent's one) for
the GPIO irqchip in gpio-visconti
- update the irq_stat field before checking the trigger field in
gpio-pca953x
- update GPIO entry in MAINTAINERS
* tag 'gpio-fixes-for-v5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpio: pca953x: fix irq_stat not updated when irq is disabled (irq_mask not set)
gpio: visconti: Fix fwnode of GPIO IRQ
MAINTAINERS: update the GPIO git tree entry
gpio: mvebu: drop pwm base assignment
gpiolib: of: fix bounds check for 'gpio-reserved-ranges'
Linus Torvalds [Sat, 7 May 2022 17:47:51 +0000 (10:47 -0700)]
Merge tag 'block-5.18-2022-05-06' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A single revert for a change that isn't needed in 5.18, and a small
series for s390/dasd"
* tag 'block-5.18-2022-05-06' of git://git.kernel.dk/linux-block:
s390/dasd: Use kzalloc instead of kmalloc/memset
s390/dasd: Fix read inconsistency for ESE DASD devices
s390/dasd: Fix read for ESE with blksize < 4k
s390/dasd: prevent double format of tracks for ESE devices
s390/dasd: fix data corruption for ESE devices
Revert "block: release rq qos structures for queue without disk"
Linus Torvalds [Fri, 6 May 2022 21:32:16 +0000 (14:32 -0700)]
Merge tag 'for-5.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Regression fixes in zone activation:
- move a loop invariant out of the loop to avoid checking space
status
- properly handle unlimited activation
Other fixes:
- for subpage, force the free space v2 mount to avoid a warning and
make it easy to switch a filesystem on different page size systems
- export sysfs status of exclusive operation 'balance paused', so the
user space tools can recognize it and allow adding a device with
paused balance
- fix assertion failure when logging directory key range item"
* tag 'for-5.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: sysfs: export the balance paused state of exclusive operation
btrfs: fix assertion failure when logging directory key range item
btrfs: zoned: activate block group properly on unlimited active zone device
btrfs: zoned: move non-changing condition check out of the loop
btrfs: force v2 space cache usage for subpage mount
Linus Torvalds [Fri, 6 May 2022 20:19:11 +0000 (13:19 -0700)]
Merge tag 'nfs-for-5.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client fixes from Trond Myklebust:
"Highlights include:
Stable fixes:
- Fix a socket leak when setting up an AF_LOCAL RPC client
- Ensure that knfsd connects to the gss-proxy daemon on setup
Bugfixes:
- Fix a refcount leak when migrating a task off an offlined transport
- Don't gratuitously invalidate inode attributes on delegation return
- Don't leak sockets in xs_local_connect()
- Ensure timely close of disconnected AF_LOCAL sockets"
* tag 'nfs-for-5.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
Revert "SUNRPC: attempt AF_LOCAL connect on setup"
SUNRPC: Ensure gss-proxy connects on setup
SUNRPC: Ensure timely close of disconnected AF_LOCAL sockets
SUNRPC: Don't leak sockets in xs_local_connect()
NFSv4: Don't invalidate inode attributes on delegation return
SUNRPC release the transport of a relocated task with an assigned transport
Linus Torvalds [Fri, 6 May 2022 18:42:58 +0000 (11:42 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"x86:
- Account for family 17h event renumberings in AMD PMU emulation
- Remove CPUID leaf 0xA on AMD processors
- Fix lockdep issue with locking all vCPUs
- Fix loss of A/D bits in SPTEs
- Fix syzkaller issue with invalid guest state"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: VMX: Exit to userspace if vCPU has injected exception and invalid state
KVM: SEV: Mark nested locking of vcpu->lock
kvm: x86/cpuid: Only provide CPUID leaf 0xA if host has architectural PMU
KVM: x86/svm: Account for family 17h event renumberings in amd_pmc_perf_hw_id
KVM: x86/mmu: Use atomic XCHG to write TDP MMU SPTEs with volatile bits
KVM: x86/mmu: Move shadow-present check out of spte_has_volatile_bits()
KVM: x86/mmu: Don't treat fully writable SPTEs as volatile (modulo A/D)
KVM: VMX: Exit to userspace if vCPU has injected exception and invalid state
Exit to userspace with an emulation error if KVM encounters an injected
exception with invalid guest state, in addition to the existing check of
bailing if there's a pending exception (KVM doesn't support emulating
exceptions except when emulating real mode via vm86).
In theory, KVM should never get to such a situation as KVM is supposed to
exit to userspace before injecting an exception with invalid guest state.
But in practice, userspace can intervene and manually inject an exception
and/or stuff registers to force invalid guest state while a previously
injected exception is awaiting reinjection.
Fixes: 17f4efdc00dd ("KVM: VMX: Reject KVM_RUN if emulation is required with pending exception") Reported-by: syzbot+cfafed3bb76d3e37581b@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220502221850.131873-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Peter Gonda [Mon, 2 May 2022 16:58:07 +0000 (09:58 -0700)]
KVM: SEV: Mark nested locking of vcpu->lock
svm_vm_migrate_from() uses sev_lock_vcpus_for_migration() to lock all
source and target vcpu->locks. Unfortunately there is an 8 subclass
limit, so a new subclass cannot be used for each vCPU. Instead maintain
ownership of the first vcpu's mutex.dep_map using a role specific
subclass: source vs target. Release the other vcpu's mutex.dep_maps.
Fixes: 0f9a534d193e6 ("KVM: SEV: Add support for SEV intra host migration") Reported-by: John Sperbeck<jsperbeck@google.com> Suggested-by: David Rientjes <rientjes@google.com> Suggested-by: Sean Christopherson <seanjc@google.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Peter Gonda <pgonda@google.com>
Message-Id: <20220502165807.529624-1-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linus Torvalds [Fri, 6 May 2022 16:50:25 +0000 (09:50 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull rdma fixes from Jason Gunthorpe:
"A few recent regressions in rxe's multicast code, and some old driver
bugs:
- Error case unwind bug in rxe for rkeys
- Dot not call netdev functions under a spinlock in rxe multicast
code
- Use the proper BH lock type in rxe multicast code
- Fix idrma deadlock and crash
- Add a missing flush to drain irdma QPs when in error
- Fix high userspace latency in irdma during destroy due to
synchronize_rcu()
- Rare race in siw MPA processing"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
RDMA/rxe: Change mcg_lock to a _bh lock
RDMA/rxe: Do not call dev_mc_add/del() under a spinlock
RDMA/siw: Fix a condition race issue in MPA request processing
RDMA/irdma: Fix possible crash due to NULL netdev in notifier
RDMA/irdma: Reduce iWARP QP destroy time
RDMA/irdma: Flush iWARP QP if modified to ERR from RTR state
RDMA/rxe: Recheck the MR in when generating a READ reply
RDMA/irdma: Fix deadlock in irdma_cleanup_cm_core()
RDMA/rxe: Fix "Replace mr by rkey in responder resources"
Linus Torvalds [Fri, 6 May 2022 16:33:28 +0000 (09:33 -0700)]
Merge tag 'drm-fixes-2022-05-06' of git://anongit.freedesktop.org/drm/drm
Pull drm fixes from Dave Airlie:
"A pretty quiet week, one fbdev, msm, kconfig, and two amdgpu fixes,
about what I'd expect for rc6.
fbdev:
- hotunplugging fix
amdgpu:
- Fix a xen dom0 regression on APUs
- Fix a potential array overflow if a receiver were to send an
erroneous audio channel count
msm:
- lockdep fix.
it6505:
- kconfig fix"
* tag 'drm-fixes-2022-05-06' of git://anongit.freedesktop.org/drm/drm:
drm/amd/display: Avoid reading audio pattern past AUDIO_CHANNELS_COUNT
drm/amdgpu: do not use passthrough mode in Xen dom0
drm/bridge: ite-it6505: add missing Kconfig option select
fbdev: Make fb_release() return -ENODEV if fbdev was unregistered
drm/msm/dp: remove fail safe mode related code
Puyou Lu [Fri, 6 May 2022 08:06:30 +0000 (16:06 +0800)]
gpio: pca953x: fix irq_stat not updated when irq is disabled (irq_mask not set)
When one port's input state get inverted (eg. from low to hight) after
pca953x_irq_setup but before setting irq_mask (by some other driver such as
"gpio-keys"), the next inversion of this port (eg. from hight to low) will not
be triggered any more (because irq_stat is not updated at the first time). Issue
should be fixed after this commit.
Kajol Jain [Thu, 5 May 2022 15:34:51 +0000 (21:04 +0530)]
powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE
With CONFIG_FORTIFY_SOURCE enabled, string functions will also perform
dynamic checks for string size which can panic the kernel, like incase
of overflow detection.
In papr_scm, papr_scm_pmu_check_events function uses stat->stat_id with
string operations, to populate the nvdimm_events_map array. Since
stat_id variable is not NULL terminated, the kernel panics with
CONFIG_FORTIFY_SOURCE enabled at boot time.
Below are the logs of kernel panic:
detected buffer overflow in __fortify_strlen
------------[ cut here ]------------
kernel BUG at lib/string_helpers.c:980!
Oops: Exception in kernel mode, sig: 5 [#1]
NIP [c00000000077dad0] fortify_panic+0x28/0x38
LR [c00000000077dacc] fortify_panic+0x24/0x38
Call Trace:
[c0000022d77836e0] [c00000000077dacc] fortify_panic+0x24/0x38 (unreliable)
[c00800000deb2660] papr_scm_pmu_check_events.constprop.0+0x118/0x220 [papr_scm]
[c00800000deb2cb0] papr_scm_probe+0x288/0x62c [papr_scm]
[c0000000009b46a8] platform_probe+0x98/0x150
Fix this issue by using kmemdup_nul() to copy the content of
stat->stat_id directly to the nvdimm_events_map array.
mpe: stat->stat_id comes from the hypervisor, not userspace, so there is
no security exposure.
Jan Höppner [Thu, 5 May 2022 14:17:32 +0000 (16:17 +0200)]
s390/dasd: Fix read inconsistency for ESE DASD devices
Read requests that return with NRF error are partially completed in
dasd_eckd_ese_read(). The function keeps track of the amount of
processed bytes and the driver will eventually return this information
back to the block layer for further processing via __dasd_cleanup_cqr()
when the request is in the final stage of processing (from the driver's
perspective).
For this, blk_update_request() is used which requires the number of
bytes to complete the request. As per documentation the nr_bytes
parameter is described as follows:
"number of bytes to complete for @req".
This was mistakenly interpreted as "number of bytes _left_ for @req"
leading to new requests with incorrect data length. The consequence are
inconsistent and completely wrong read requests as data from random
memory areas are read back.
Fix this by correctly specifying the amount of bytes that should be used
to complete the request.
Fixes: a156a5edb36f ("s390/dasd: fix data corruption for thin provisioned devices") Cc: stable@vger.kernel.org # 5.3+ Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Link: https://lore.kernel.org/r/20220505141733.1989450-5-sth@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Höppner [Thu, 5 May 2022 14:17:31 +0000 (16:17 +0200)]
s390/dasd: Fix read for ESE with blksize < 4k
When reading unformatted tracks on ESE devices, the corresponding memory
areas are simply set to zero for each segment. This is done incorrectly
for blocksizes < 4096.
There are two problems. First, the increment of dst is done using the
counter of the loop (off), which is increased by blksize every
iteration. This leads to a much bigger increment for dst as actually
intended. Second, the increment of dst is done before the memory area
is set to 0, skipping a significant amount of bytes of memory.
This leads to illegal overwriting of memory and ultimately to a kernel
panic.
This is not a problem with 4k blocksize because
blk_queue_max_segment_size is set to PAGE_SIZE, always resulting in a
single iteration for the inner segment loop (bv.bv_len == blksize). The
incorrectly used 'off' value to increment dst is 0 and the correct
memory area is used.
In order to fix this for blksize < 4k, increment dst correctly using the
blksize and only do it at the end of the loop.
Fixes: 4fb6bf848fbc ("s390/dasd: Add dynamic formatting support for ESE volumes") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Link: https://lore.kernel.org/r/20220505141733.1989450-4-sth@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
s390/dasd: prevent double format of tracks for ESE devices
For ESE devices we get an error for write operations on an unformatted
track. Afterwards the track will be formatted and the IO operation
restarted.
When using alias devices a track might be accessed by multiple requests
simultaneously and there is a race window that a track gets formatted
twice resulting in data loss.
Prevent this by remembering the amount of formatted tracks when starting
a request and comparing this number before actually formatting a track
on the fly. If the number has changed there is a chance that the current
track was finally formatted in between. As a result do not format the
track and restart the current IO to check.
The number of formatted tracks does not match the overall number of
formatted tracks on the device and it might wrap around but this is no
problem. It is only needed to recognize that a track has been formatted at
all in between.
Fixes: 4fb6bf848fbc ("s390/dasd: Add dynamic formatting support for ESE volumes") Cc: stable@vger.kernel.org # 5.3+ Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Link: https://lore.kernel.org/r/20220505141733.1989450-3-sth@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
For ESE devices we get an error when accessing an unformatted track.
The handling of this error will return zero data for read requests and
format the track on demand before writing to it. To do this the code needs
to distinguish between read and write requests. This is done with data from
the blocklayer request. A pointer to the blocklayer request is stored in
the CQR.
If there is an error on the device an ERP request is built to do error
recovery. While the ERP request is mostly a copy of the original CQR the
pointer to the blocklayer request is not copied to not accidentally pass
it back to the blocklayer without cleanup.
This leads to the error that during ESE handling after an ERP request was
built it is not possible to determine the IO direction. This leads to the
formatting of a track for read requests which might in turn lead to data
corruption.
Fixes: 4fb6bf848fbc ("s390/dasd: Add dynamic formatting support for ESE volumes") Cc: stable@vger.kernel.org # 5.3+ Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Link: https://lore.kernel.org/r/20220505141733.1989450-2-sth@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linus Torvalds [Thu, 5 May 2022 23:52:15 +0000 (16:52 -0700)]
Merge tag 'folio-5.18f' of git://git.infradead.org/users/willy/pagecache
Pull folio fixes from Matthew Wilcox:
"Two folio fixes for 5.18.
Darrick and Brian have done amazing work debugging the race I created
in the folio BIO iterator. The readahead problem was deterministic, so
easy to fix.
- Fix a race when we were calling folio_next() in the BIO folio iter
without holding a reference, meaning the folio could be split or
freed, and we'd jump to the next page instead of the intended next
folio.
- Fix readahead creating single-page folios instead of the intended
large folios when doing reads that are not a power of two in size"
* tag 'folio-5.18f' of git://git.infradead.org/users/willy/pagecache:
mm/readahead: Fix readahead with large folios
block: Do not call folio_next() on an unreferenced folio
Linus Torvalds [Thu, 5 May 2022 22:50:27 +0000 (15:50 -0700)]
Merge tag 'devicetree-fixes-for-5.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree fixes from Rob Herring:
- Drop unused 'max-link-speed' in Apple PCIe
- More redundant 'maxItems/minItems' schema fixes
- Support values for pinctrl 'drive-push-pull' and 'drive-open-drain'
- Fix redundant 'unevaluatedProperties' in MT6360 LEDs binding
- Add missing 'power-domains' property to Cadence UFSHC
* tag 'devicetree-fixes-for-5.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: pci: apple,pcie: Drop max-link-speed from example
dt-bindings: Drop redundant 'maxItems/minItems' in if/then schemas
dt-bindings: pinctrl: Allow values for drive-push-pull and drive-open-drain
dt-bindings: leds-mt6360: Drop redundant 'unevaluatedProperties'
dt-bindings: ufs: cdns,ufshc: Add power-domains
Filipe Manana [Tue, 3 May 2022 10:57:02 +0000 (11:57 +0100)]
btrfs: fix assertion failure when logging directory key range item
When inserting a key range item (BTRFS_DIR_LOG_INDEX_KEY) while logging
a directory, we don't expect the insertion to fail with -EEXIST, because
we are holding the directory's log_mutex and we have dropped all existing
BTRFS_DIR_LOG_INDEX_KEY keys from the log tree before we started to log
the directory. However it's possible that during the logging we attempt
to insert the same BTRFS_DIR_LOG_INDEX_KEY key twice, but for this to
happen we need to race with insertions of items from other inodes in the
subvolume's tree while we are logging a directory. Here's how this can
happen:
1) We are logging a directory with inode number 1000 that has its items
spread across 3 leaves in the subvolume's tree:
leaf A - has index keys from the range 2 to 20 for example. The last
item in the leaf corresponds to a dir item for index number 20. All
these dir items were created in a past transaction.
leaf B - has index keys from the range 22 to 100 for example. It has
no keys from other inodes, all its keys are dir index keys for our
directory inode number 1000. Its first key is for the dir item with
a sequence number of 22. All these dir items were also created in a
past transaction.
leaf C - has index keys for our directory for the range 101 to 120 for
example. This leaf also has items from other inodes, and its first
item corresponds to the dir item for index number 101 for our directory
with inode number 1000;
2) When we finish processing the items from leaf A at log_dir_items(),
we log a BTRFS_DIR_LOG_INDEX_KEY key with an offset of 21 and a last
offset of 21, meaning the log is authoritative for the index range
from 21 to 21 (a single sequence number). At this point leaf B was
not yet modified in the current transaction;
3) When we return from log_dir_items() we have released our read lock on
leaf B, and have set *last_offset_ret to 21 (index number of the first
item on leaf B minus 1);
4) Some other task inserts an item for other inode (inode number 1001 for
example) into leaf C. That resulted in pushing some items from leaf C
into leaf B, in order to make room for the new item, so now leaf B
has dir index keys for the sequence number range from 22 to 102 and
leaf C has the dir items for the sequence number range 103 to 120;
5) At log_directory_changes() we call log_dir_items() again, passing it
a 'min_offset' / 'min_key' value of 22 (*last_offset_ret from step 3
plus 1, so 21 + 1). Then btrfs_search_forward() leaves us at slot 0
of leaf B, since leaf B was modified in the current transaction.
We have also initialized 'last_old_dentry_offset' to 20 after calling
btrfs_previous_item() at log_dir_items(), as it left us at the last
item of leaf A, which refers to the dir item with sequence number 20;
6) We then call process_dir_items_leaf() to process the dir items of
leaf B, and when we process the first item, corresponding to slot 0,
sequence number 22, we notice the dir item was created in a past
transaction and its sequence number is greater than the value of
*last_old_dentry_offset + 1 (20 + 1), so we decide to log again a
BTRFS_DIR_LOG_INDEX_KEY key with an offset of 21 and an end range
of 21 (key.offset - 1 == 22 - 1 == 21), which results in an -EEXIST
error from insert_dir_log_key(), as we have already inserted that
key at step 2, triggering the assertion at process_dir_items_leaf().
The trace produced in dmesg is like the following:
Fix this by treating -EEXIST as expected at insert_dir_log_key() and have
it update the item with an end offset corresponding to the maximum between
the previously logged end offset and the new requested end offset. The end
offsets may be different due to dir index key deletions that happened as
part of unlink operations while we are logging a directory (triggered when
fsyncing some other inode parented by the directory) or during renames
which always attempt to log a single dir index deletion.
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Link: https://lore.kernel.org/linux-btrfs/YmyefE9mc2xl5ZMz@hungrycats.org/ Fixes: 0b11e702bb3f6d ("btrfs: stop copying old dir items when logging a directory") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 3 May 2022 21:10:05 +0000 (14:10 -0700)]
btrfs: zoned: activate block group properly on unlimited active zone device
btrfs_zone_activate() checks if it activated all the underlying zones in
the loop. However, that check never hit on an unlimited activate zone
device (max_active_zones == 0).
Fortunately, it still works without ENOSPC because btrfs_zone_activate()
returns true in the end, even if block_group->zone_is_active == 0. But, it
is confusing to have non zone_is_active block group still usable for
allocation. Also, we are wasting CPU time to iterate the loop every time
btrfs_zone_activate() is called for the blog groups.
Since error case in the loop is handled by out_unlock, we can just set
zone_is_active and do the list stuff after the loop.
Fixes: 87e2c6e56182 ("btrfs: zoned: make zone activation multi stripe capable") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 3 May 2022 21:10:04 +0000 (14:10 -0700)]
btrfs: zoned: move non-changing condition check out of the loop
btrfs_zone_activate() checks if block_group->alloc_offset ==
block_group->zone_capacity every time it iterates the loop. But, it is
not depending on the index. Move out the check and do it only once.
Fixes: 87e2c6e56182 ("btrfs: zoned: make zone activation multi stripe capable") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: force v2 space cache usage for subpage mount
[BUG]
For a 4K sector sized btrfs with v1 cache enabled and only mounted on
systems with 4K page size, if it's mounted on subpage (64K page size)
systems, it can cause the following warning on v1 space cache:
BTRFS error (device dm-1): csum mismatch on free space cache
BTRFS warning (device dm-1): failed to load free space cache for block group 84082688, rebuilding it now
Although not a big deal, as kernel can rebuild it without problem, such
warning will bother end users, especially if they want to switch the
same btrfs seamlessly between different page sized systems.
[CAUSE]
V1 free space cache is still using fixed PAGE_SIZE for various bitmap,
like BITS_PER_BITMAP.
Such hard-coded PAGE_SIZE usage will cause various mismatch, from v1
cache size to checksum.
Thus kernel will always reject v1 cache with a different PAGE_SIZE with
csum mismatch.
[FIX]
Although we should fix v1 cache, it's already going to be marked
deprecated soon.
And we have v2 cache based on metadata (which is already fully subpage
compatible), and it has almost everything superior than v1 cache.
So just force subpage mount to use v2 cache on mount.
Linus Torvalds [Thu, 5 May 2022 17:38:11 +0000 (10:38 -0700)]
Merge tag 's390-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Heiko Carstens:
- Disable -Warray-bounds warning for gcc12, since the only known way to
workaround false positive warnings on lowcore accesses would result
in worse code on fast paths.
- Avoid lockdep_assert_held() warning in kvm vm memop code.
- Reduce overhead within gmap_rmap code to get rid of long latencies
when e.g. shutting down 2nd level guests.
* tag 's390-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
KVM: s390: vsie/gmap: reduce gmap_rmap overhead
KVM: s390: Fix lockdep issue in vm memop
s390: disable -Warray-bounds
Linus Torvalds [Thu, 5 May 2022 16:45:12 +0000 (09:45 -0700)]
Merge tag 'net-5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from can, rxrpc and wireguard.
Previous releases - regressions:
- igmp: respect RCU rules in ip_mc_source() and ip_mc_msfilter()
- mld: respect RCU rules in ip6_mc_source() and ip6_mc_msfilter()
- rds: acquire netns refcount on TCP sockets
- rxrpc: enable IPv6 checksums on transport socket
- nic: hinic: fix bug of wq out of bound access
- nic: thunder: don't use pci_irq_vector() in atomic context
- nic: bnxt_en: fix possible bnxt_open() failure caused by wrong RFS
flag
- nic: mlx5e:
- lag, fix use-after-free in fib event handler
- fix deadlock in sync reset flow
Previous releases - always broken:
- tcp: fix insufficient TCP source port randomness
- can: grcan: grcan_close(): fix deadlock
- nfc: reorder destructive operations in to avoid bugs
Misc:
- wireguard: improve selftests reliability"
* tag 'net-5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (63 commits)
NFC: netlink: fix sleep in atomic bug when firmware download timeout
selftests: ocelot: tc_flower_chains: specify conform-exceed action for policer
tcp: drop the hash_32() part from the index calculation
tcp: increase source port perturb table to 2^16
tcp: dynamically allocate the perturb table used by source ports
tcp: add small random increments to the source port
tcp: resalt the secret every 10 seconds
tcp: use different parts of the port_offset for index and offset
secure_seq: use the 64 bits of the siphash for port offset calculation
wireguard: selftests: set panic_on_warn=1 from cmdline
wireguard: selftests: bump package deps
wireguard: selftests: restore support for ccache
wireguard: selftests: use newer toolchains to fill out architectures
wireguard: selftests: limit parallelism to $(nproc) tests at once
wireguard: selftests: make routing loop test non-fatal
net/mlx5: Fix matching on inner TTC
net/mlx5: Avoid double clear or set of sync reset requested
net/mlx5: Fix deadlock in sync reset flow
net/mlx5e: Fix trust state reset in reload
net/mlx5e: Avoid checking offload capability in post_parse action
...
The fwnode of GPIO IRQ must be set to its own fwnode, not the fwnode of the
parent IRQ. Therefore, this sets own fwnode instead of the parent IRQ fwnode to
GPIO IRQ's.
Thomas Pfaff [Mon, 2 May 2022 11:28:29 +0000 (13:28 +0200)]
genirq: Synchronize interrupt thread startup
A kernel hang can be observed when running setserial in a loop on a kernel
with force threaded interrupts. The sequence of events is:
setserial
open("/dev/ttyXXX")
request_irq()
do_stuff()
-> serial interrupt
-> wake(irq_thread)
desc->threads_active++;
close()
free_irq()
kthread_stop(irq_thread)
synchronize_irq() <- hangs because desc->threads_active != 0
The thread is created in request_irq() and woken up, but does not get on a
CPU to reach the actual thread function, which would handle the pending
wake-up. kthread_stop() sets the should stop condition which makes the
thread immediately exit, which in turn leaves the stale threads_active
count around.
This problem was introduced with commit 21cd120f39b8, which addressed a
interrupt sharing issue in the PCIe code.
Before that commit free_irq() invoked synchronize_irq(), which waits for
the hard interrupt handler and also for associated threads to complete.
To address the PCIe issue synchronize_irq() was replaced with
__synchronize_hardirq(), which only waits for the hard interrupt handler to
complete, but not for threaded handlers.
This was done under the assumption, that the interrupt thread already
reached the thread function and waits for a wake-up, which is guaranteed to
be handled before acting on the stop condition. The problematic case, that
the thread would not reach the thread function, was obviously overlooked.
Make sure that the interrupt thread is really started and reaches
thread_fn() before returning from __setup_irq().
This utilizes the existing wait queue in the interrupt descriptor. The
wait queue is unused for non-shared interrupts. For shared interrupts the
usage might cause a spurious wake-up of a waiter in synchronize_irq() or the
completion of a threaded handler might cause a spurious wake-up of the
waiter for the ready flag. Both are harmless and have no functional impact.
[ tglx: Amended changelog ]
Fixes: 21cd120f39b8 ("genirq: Synchronize only with single thread on free_irq()") Signed-off-by: Thomas Pfaff <tpfaff@pcs.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com
Duoming Zhou [Wed, 4 May 2022 05:58:47 +0000 (13:58 +0800)]
NFC: netlink: fix sleep in atomic bug when firmware download timeout
There are sleep in atomic bug that could cause kernel panic during
firmware download process. The root cause is that nlmsg_new with
GFP_KERNEL parameter is called in fw_dnld_timeout which is a timer
handler. The call trace is shown below:
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
Call Trace:
kmem_cache_alloc_node
__alloc_skb
nfc_genl_fw_download_done
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
...
The nlmsg_new with GFP_KERNEL parameter may sleep during memory
allocation process, and the timer handler is run as the result of
a "software interrupt" that should not call any other function
that could sleep.
This patch changes allocation mode of netlink message from GFP_KERNEL
to GFP_ATOMIC in order to prevent sleep in atomic bug. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.
Fixes: 38c8c679fb78 ("NFC: Add firmware upload netlink command") Fixes: 60ec4b069e14 ("NFC: netlink: Rename CMD_FW_UPLOAD to CMD_FW_DOWNLOAD") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reading 100KB chunks from a big file (eg dd bs=100K) leads to poor
readahead behaviour. Studying the traces in detail, I noticed two
problems.
The first is that we were setting the readahead flag on the folio which
contains the last byte read from the block. This is wrong because we
will trigger readahead at the end of the read without waiting to see
if a subsequent read is going to use the pages we just read. Instead,
we need to set the readahead flag on the first folio _after_ the one
which contains the last byte that we're reading.
The second is that we were looking for the index of the folio with the
readahead flag set to exactly match the start + size - async_size.
If we've rounded this, either down (as previously) or up (as now),
we'll think we hit a folio marked as readahead by a different read,
and try to read the wrong pages. So round the expected index to the
order of the folio we hit.
Reported-by: Guo Xuenan <guoxuenan@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
block: Do not call folio_next() on an unreferenced folio
It is unsafe to call folio_next() on a folio unless you hold a reference
on it that prevents it from being split or freed. After returning
from the iterator, iomap calls folio_end_writeback() which may drop
the last reference to the page, or allow the page to be split. If that
happens, the iterator will not advance far enough through the bio_vec,
leading to assertion failures like the BUG() in folio_end_writeback()
that checks we're not trying to end writeback on a page not currently
under writeback. Other assertion failures were also seen, but they're
all explained by this one bug.
Fix the bug by remembering where the next folio starts before returning
from the iterator. There are other ways of fixing this bug, but this
seems the simplest.
Reported-by: Darrick J. Wong <djwong@kernel.org> Tested-by: Darrick J. Wong <djwong@kernel.org> Reported-by: Brian Foster <bfoster@redhat.com> Tested-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Vladimir Oltean [Tue, 3 May 2022 12:14:28 +0000 (15:14 +0300)]
selftests: ocelot: tc_flower_chains: specify conform-exceed action for policer
As discussed here with Ido Schimmel:
https://patchwork.kernel.org/project/netdevbpf/patch/20220224102908.5255-2-jianbol@nvidia.com/
the default conform-exceed action is "reclassify", for a reason we don't
really understand.
The point is that hardware can't offload that police action, so not
specifying "conform-exceed" was always wrong, even though the command
used to work in hardware (but not in software) until the kernel started
adding validation for it.
Fix the command used by the selftest by making the policer drop on
exceed, and pass the packet to the next action (goto) on conform.
Fixes: 02e198d4c961 ("selftests: ocelot: add some example VCAP IS1, IS2 and ES0 tc offloads") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20220503121428.842906-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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