Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
code
Clone this repository
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Pull crypto fixes from Herbert Xu:
- fix regression in af_alg that affects iwd
- restore polling delay in qat
- fix double free in ingenic on error path
- fix potential build failure in sa2ul due to missing Kconfig dependency
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: af_alg - Work around empty control messages without MSG_MORE
crypto: sa2ul - add Kconfig selects to fix build error
crypto: ingenic - Drop kfree for memory allocated with devm_kzalloc
crypto: qat - add delay before polling mailbox
Pull x86 fixes from Thomas Gleixner:
"Three interrupt related fixes for X86:
- Move disabling of the local APIC after invoking fixup_irqs() to
ensure that interrupts which are incoming are noted in the IRR and
not ignored.
- Unbreak affinity setting.
The rework of the entry code reused the regular exception entry
code for device interrupts. The vector number is pushed into the
errorcode slot on the stack which is then lifted into an argument
and set to -1 because that's regs->orig_ax which is used in quite
some places to check whether the entry came from a syscall.
But it was overlooked that orig_ax is used in the affinity cleanup
code to validate whether the interrupt has arrived on the new
target. It turned out that this vector check is pointless because
interrupts are never moved from one vector to another on the same
CPU. That check is a historical leftover from the time where x86
supported multi-CPU affinities, but not longer needed with the now
strict single CPU affinity. Famous last words ...
- Add a missing check for an empty cpumask into the matrix allocator.
The affinity change added a warning to catch the case where an
interrupt is moved on the same CPU to a different vector. This
triggers because a condition with an empty cpumask returns an
assignment from the allocator as the allocator uses for_each_cpu()
without checking the cpumask for being empty. The historical
inconsistent for_each_cpu() behaviour of ignoring the cpumask and
unconditionally claiming that CPU0 is in the mask struck again.
Sigh.
plus a new entry into the MAINTAINER file for the HPE/UV platform"
* tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/matrix: Deal with the sillyness of for_each_cpu() on UP
x86/irq: Unbreak interrupt affinity setting
x86/hotplug: Silence APIC only after all interrupts are migrated
MAINTAINERS: Add entry for HPE Superdome Flex (UV) maintainers
The iwd daemon uses libell which sets up the skcipher operation with
two separate control messages. As the first control message is sent
without MSG_MORE, it is interpreted as an empty request.
While libell should be fixed to use MSG_MORE where appropriate, this
patch works around the bug in the kernel so that existing binaries
continue to work.
We will print a warning however.
A separate issue is that the new kernel code no longer allows the
control message to be sent twice within the same request. This
restriction is obviously incompatible with what iwd was doing (first
setting an IV and then sending the real control message). This
patch changes the kernel so that this is explicitly allowed.
Reported-by: Caleb Jorden <caljorden@hotmail.com>
Fixes: f3c802a1f300 ("crypto: algif_aead - Only wake up when...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull irq fixes from Thomas Gleixner:
"A set of fixes for interrupt chip drivers:
- Revert the platform driver conversion of interrupt chip drivers as
it turned out to create more problems than it solves.
- Fix a trivial typo in the new module helpers which made probing
reliably fail.
- Small fixes in the STM32 and MIPS Ingenic drivers
- The TI firmware rework which had badly managed dependencies and had
to wait post rc1"
* tag 'irq-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/ingenic: Leave parent IRQ unmasked on suspend
irqchip/stm32-exti: Avoid losing interrupts due to clearing pending bits by mistake
irqchip: Revert modular support for drivers using IRQCHIP_PLATFORM_DRIVER helperse
irqchip: Fix probing deferal when using IRQCHIP_PLATFORM_DRIVER helpers
arm64: dts: k3-am65: Update the RM resource types
arm64: dts: k3-am65: ti-sci-inta/intr: Update to latest bindings
arm64: dts: k3-j721e: ti-sci-inta/intr: Update to latest bindings
irqchip/ti-sci-inta: Add support for INTA directly connecting to GIC
irqchip/ti-sci-inta: Do not store TISCI device id in platform device id field
dt-bindings: irqchip: Convert ti, sci-inta bindings to yaml
dt-bindings: irqchip: ti, sci-inta: Update docs to support different parent.
irqchip/ti-sci-intr: Add support for INTR being a parent to INTR
dt-bindings: irqchip: Convert ti, sci-intr bindings to yaml
dt-bindings: irqchip: ti, sci-intr: Update bindings to drop the usage of gic as parent
firmware: ti_sci: Add support for getting resource with subtype
firmware: ti_sci: Drop unused structure ti_sci_rm_type_map
firmware: ti_sci: Drop the device id to resource type translation
Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.
The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.
Add a check for the cpumask being empty to prevent this.
Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
sa2ul.c uses sha{1,256,512}_zero_message_hash, so select the
Kconfig symbols that provide those, like other crypto drivers do.
Fixes this build error:
ld: drivers/crypto/sa2ul.o: in function `sa_sha_digest':
sa2ul.c:(.text+0x2b25): undefined reference to `sha512_zero_message_hash'
Fixes: 7694b6ca649f ("crypto: sa2ul - Add crypto driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org> # 2020-07-29
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull scheduler fix from Thomas Gleixner:
"A single fix for the scheduler:
- Make is_idle_task() __always_inline to prevent the compiler from
putting it out of line into the wrong section because it's used
inside noinstr sections"
* tag 'sched-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Use __always_inline on is_idle_task()
Pull irqchip fixes from Marc Zyngier:
- Revert the wholesale conversion to platform drivers of the pdc, sysirq
and cirq drivers, as it breaks a number of platforms even when the
driver is built-in (probe ordering bites you).
- Prevent interrupt from being lost with the STM32 exti driver
- Fix wake-up interrupts for the MIPS Ingenic driver
- Fix an embarassing typo in the new module helpers, leading to the probe
failing most of the time
- The promised TI firmware rework that couldn't make it into the merge
window due to a very badly managed set of dependencies
Several people reported that 5.8 broke the interrupt affinity setting
mechanism.
The consolidation of the entry code reused the regular exception entry code
for device interrupts and changed the way how the vector number is conveyed
from ptregs->orig_ax to a function argument.
The low level entry uses the hardware error code slot to push the vector
number onto the stack which is retrieved from there into a function
argument and the slot on stack is set to -1.
The reason for setting it to -1 is that the error code slot is at the
position where pt_regs::orig_ax is. A positive value in pt_regs::orig_ax
indicates that the entry came via a syscall. If it's not set to a negative
value then a signal delivery on return to userspace would try to restart a
syscall. But there are other places which rely on pt_regs::orig_ax being a
valid indicator for syscall entry.
But setting pt_regs::orig_ax to -1 has a nasty side effect vs. the
interrupt affinity setting mechanism, which was overlooked when this change
was made.
Moving interrupts on x86 happens in several steps. A new vector on a
different CPU is allocated and the relevant interrupt source is
reprogrammed to that. But that's racy and there might be an interrupt
already in flight to the old vector. So the old vector is preserved until
the first interrupt arrives on the new vector and the new target CPU. Once
that happens the old vector is cleaned up, but this cleanup still depends
on the vector number being stored in pt_regs::orig_ax, which is now -1.
That -1 makes the check for cleanup: pt_regs::orig_ax == new_vector
always false. As a consequence the interrupt is moved once, but then it
cannot be moved anymore because the cleanup of the old vector never
happens.
There would be several ways to convey the vector information to that place
in the guts of the interrupt handling, but on deeper inspection it turned
out that this check is pointless and a leftover from the old affinity model
of X86 which supported multi-CPU affinities. Under this model it was
possible that an interrupt had an old and a new vector on the same CPU, so
the vector match was required.
Under the new model the effective affinity of an interrupt is always a
single CPU from the requested affinity mask. If the affinity mask changes
then either the interrupt stays on the CPU and on the same vector when that
CPU is still in the new affinity mask or it is moved to a different CPU, but
it is never moved to a different vector on the same CPU.
Ergo the cleanup check for the matching vector number is not required and
can be removed which makes the dependency on pt_regs:orig_ax go away.
The remaining check for new_cpu == smp_processsor_id() is completely
sufficient. If it matches then the interrupt was successfully migrated and
the cleanup can proceed.
For paranoia sake add a warning into the vector assignment code to
validate that the assumption of never moving to a different vector on
the same CPU holds.
Fixes: 633260fa143 ("x86/irq: Convey vector as argument and not in ptregs")
Reported-by: Alex bykov <alex.bykov@scylladb.com>
Reported-by: Avi Kivity <avi@scylladb.com>
Reported-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Graf <graf@amazon.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87wo1ltaxz.fsf@nanos.tec.linutronix.de
It's not necessary to free memory allocated with devm_kzalloc
and using kfree leads to a double free.
Fixes: 190873a0ea45 ("crypto: ingenic - Add hardware RNG for Ingenic JZ4780 and X1000")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull locking fixes from Thomas Gleixner:
"A set of fixes for lockdep, tracing and RCU:
- Prevent recursion by using raw_cpu_* operations
- Fixup the interrupt state in the cpu idle code to be consistent
- Push rcu_idle_enter/exit() invocations deeper into the idle path so
that the lock operations are inside the RCU watching sections
- Move trace_cpu_idle() into generic code so it's called before RCU
goes idle.
- Handle raw_local_irq* vs. local_irq* operations correctly
- Move the tracepoints out from under the lockdep recursion handling
which turned out to be fragile and inconsistent"
* tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lockdep,trace: Expose tracepoints
lockdep: Only trace IRQ edges
mips: Implement arch_irqs_disabled()
arm64: Implement arch_irqs_disabled()
nds32: Implement arch_irqs_disabled()
locking/lockdep: Cleanup
x86/entry: Remove unused THUNKs
cpuidle: Move trace_cpu_idle() into generic code
cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic
sched,idle,rcu: Push rcu_idle deeper into the idle path
cpuidle: Fixup IRQ state
lockdep: Use raw_cpu_*() for per-cpu variables
is_idle_task() may be used from noinstr functions such as
irqentry_enter(). Since the compiler is free to not inline regular
inline functions, switch to using __always_inline.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200820172046.GA177701@elver.google.com
In irq_set_irqchip_state(), the irq descriptor is not unlocked after an
error is encountered. While that should never happen in practice, a buggy
driver may trigger it. This would result in a lockup, so fix it.
Fixes: 1d0326f352bb ("genirq: Check irq_data_get_irq_chip() return value before use")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200811180012.80269-1-linux@roeck-us.net