commit 6a942f5780 upstream.
S390's init_idle_preempt_count(p, cpu) doesn't actually let us initialize the
preempt_count of the requested CPU's idle task: it unconditionally writes
to the current CPU's. This clearly conflicts with idle_threads_init(),
which intends to initialize *all* the idle tasks, including their
preempt_count (or their CPU's, if the arch uses a per-CPU preempt_count).
Unfortunately, it seems the way s390 does things doesn't let us initialize
every possible CPU's preempt_count early on, as the pages where this
resides are only allocated when a CPU is brought up and are freed when it
is brought down.
Let the arch-specific code set a CPU's preempt_count when its lowcore is
allocated, and turn init_idle_preempt_count() into an empty stub.
Fixes: f1a0a376ca ("sched/core: Initialize the idle task with preemption disabled")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20210707163338.1623014-1-valentin.schneider@arm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5d3516b364 ]
APPLDATA_BASE should depend on PROC_SYSCTL instead of PROC_FS.
Building with PROC_FS but not PROC_SYSCTL causes a build error,
since appldata_base.c uses data and APIs from fs/proc/proc_sysctl.c.
arch/s390/appldata/appldata_base.o: in function `appldata_generic_handler':
appldata_base.c:(.text+0x192): undefined reference to `sysctl_vals'
Fixes: c185b783b0 ("[S390] Remove config options.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20210528002420.17634-1-rdunlap@infradead.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d460bb6c64 ]
In commit b02002cc4c ("s390/pci: Implement ioremap_wc/prot() with
MIO") we implemented both ioremap_wc() and ioremap_prot() however until
now we had not set HAVE_IOREMAP_PROT in Kconfig, do so now.
This also requires implementing pte_pgprot() as this is used in the
generic_access_phys() code enabled by CONFIG_HAVE_IOREMAP_PROT. As with
ioremap_wc() we need to take the MMIO Write Back bit index into account.
Moreover since the pgprot value returned from pte_pgprot() is to be used
for mappings into kernel address space we must make sure that it uses
appropriate kernel page table protection bits. In particular a pgprot
value originally coming from userspace could have the _PAGE_PROTECT
bit set to enable fault based dirty bit accounting which would then make
the mapping inaccessible when used in kernel address space.
Fixes: b02002cc4c ("s390/pci: Implement ioremap_wc/prot() with MIO")
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9ceed9988a ]
irq_exit() is always called on async stack. Therefore select
HAVE_IRQ_EXIT_ON_IRQ_STACK and get a tiny optimization in
invoke_softirq().
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4fa3b91bde ]
Using register asm statements has been proven to be very error prone,
especially when using code instrumentation where gcc may add function
calls, which clobbers register contents in an unexpected way.
Therefore get rid of register asm statements in kvm code, even though
there is currently nothing wrong with them. This way we know for sure
that this bug class won't be introduced here.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20210621140356.1210771-1-hca@linux.ibm.com
[borntraeger@de.ibm.com: checkpatch strict fix]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f1a0a376ca ]
As pointed out by commit
de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")
init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.
As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().
Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().
Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().
Secondary startups were patched via coccinelle:
@begone@
@@
-preempt_disable();
...
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 85b18d7b5e upstream.
Turns out that the bit 61 in the TEID is not always 1 and if that's
the case the address space ID and the address are
unpredictable. Without an address and its address space ID we can't
export memory and hence we can only send a SIGSEGV to the process or
panic the kernel depending on who caused the exception.
Unfortunately bit 61 is only reliable if we have the "misc" UV feature
bit.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 084ea4d611 ("s390/mm: add (non)secure page access exceptions handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67147e96a3 upstream.
The CALL_ON_STACK macro is used to call a C function from inline
assembly, and therefore must consider the C ABI, which says that only
registers 6-13, and 15 are non-volatile (restored by the called
function).
The inline assembly incorrectly marks all registers used to pass
parameters to the called function as read-only input operands, instead
of operands that are read and written to. This might result in
register corruption depending on usage, compiler, and compile options.
Fix this by marking all operands used to pass parameters as read/write
operands. To keep the code simple even register 6, if used, is marked
as read-write operand.
Fixes: ff340d2472 ("s390: add stack switch helper")
Cc: <stable@kernel.org> # 4.20
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5bcbe3285f upstream.
The size of SIE critical section is calculated wrongly
as result of a missed subtraction in commit 0b0ed657fe
("s390: remove critical section cleanup from entry.S")
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5ac14bac08 upstream.
Extend kvm_s390_shadow_fault to return the pointer to the valid leaf
DAT table entry, or to the invalid entry.
Also return some flags in the lower bits of the address:
PEI_DAT_PROT: indicates that DAT protection applies because of the
protection bit in the segment (or, if EDAT, region) tables.
PEI_NOT_PTE: indicates that the address of the DAT table entry returned
does not refer to a PTE, but to a segment or region table.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: stable@vger.kernel.org
Reviewed-by: Janosch Frank <frankja@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210302174443.514363-3-imbrenda@linux.ibm.com
[borntraeger@de.ibm.com: fold in a fix from Claudio]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c5d1f6b531 upstream.
A new function _kvm_s390_real_to_abs will apply prefixing to a real address
with a given prefix value.
The old kvm_s390_real_to_abs becomes now a wrapper around the new function.
This is needed to avoid code duplication in vSIE.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210322140559.500716-2-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c3171e94cc upstream.
Prefixing needs to be applied to the guest real address to translate it
into a guest absolute address.
The value of MSO needs to be added to a guest-absolute address in order to
obtain the host-virtual.
Fixes: bdf7509bbe ("s390/kvm: VSIE: correctly handle MVPG when in VSIE")
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210322140559.500716-3-imbrenda@linux.ibm.com
[borntraeger@de.ibm.com simplify mso]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b208108638 upstream.
The PoP documents:
134: The vector packed decimal facility is installed in the
z/Architecture architectural mode. When bit 134 is
one, bit 129 is also one.
135: The vector enhancements facility 1 is installed in
the z/Architecture architectural mode. When bit 135
is one, bit 129 is also one.
Looks like we confuse the vector enhancements facility 1 ("EXT") with the
Vector packed decimal facility ("BCD"). Let's fix the facility checks.
Detected while working on QEMU/tcg z14 support and only unlocking
the vector enhancements facility 1, but not the vector packed decimal
facility.
Fixes: 2583b848ca ("s390: report new vector facilities")
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20210503121244.25232-1-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 44bada2821 upstream.
store_regs_fmt2() has an ordering problem: first the guarded storage
facility is enabled on the local cpu, then preemption disabled, and
then the STGSC (store guarded storage controls) instruction is
executed.
If the process gets scheduled away between enabling the guarded
storage facility and before preemption is disabled, this might lead to
a special operation exception and therefore kernel crash as soon as
the process is scheduled back and the STGSC instruction is executed.
Fixes: 4e0b1ab72b ("KVM: s390: gs support for kvm guests")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: <stable@vger.kernel.org> # 4.12
Link: https://lore.kernel.org/r/20210415080127.1061275-1-hca@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f85f1baaa1 upstream.
Split kvm_s390_logical_to_effective to a generic function called
_kvm_s390_logical_to_effective. The new function takes a PSW and an address
and returns the address with the appropriate bits masked off. The old
function now calls the new function with the appropriate PSW from the vCPU.
This is needed to avoid code duplication for vSIE.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # for VSIE: correctly handle MVPG when in VSIE
Link: https://lore.kernel.org/r/20210302174443.514363-2-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2809606768 ]
A review of the code showed, that this function which is exposed
within the whole kernel should do a parameter check for the
amount of bytes requested. If this requested bytes is too high
an unsigned int overflow could happen causing this function to
try to memcpy a really big memory chunk.
This is not a security issue as there are only two invocations
of this function from arch/s390/include/asm/archrandom.h and both
are not exposed to userland.
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a994eddb94 ]
Currently psw_idle does not allocate a stack frame and does not
save its r14 and r15 into the save area. Even though this is valid from
call ABI point of view, because psw_idle does not make any calls
explicitly, in reality psw_idle is an entry point for controlled
transition into serving interrupts. So, in practice, psw_idle stack
frame is analyzed during stack unwinding. Depending on build options
that r14 slot in the save area of psw_idle might either contain a value
saved by previous sibling call or complete garbage.
[task 0000038000003c28] do_ext_irq+0xd6/0x160
[task 0000038000003c78] ext_int_handler+0xba/0xe8
[task *0000038000003dd8] psw_idle_exit+0x0/0x8 <-- pt_regs
([task 0000038000003dd8] 0x0)
[task 0000038000003e10] default_idle_call+0x42/0x148
[task 0000038000003e30] do_idle+0xce/0x160
[task 0000038000003e70] cpu_startup_entry+0x36/0x40
[task 0000038000003ea0] arch_call_rest_init+0x76/0x80
So, to make a stacktrace nicer and actually point for the real caller of
psw_idle in this frequently occurring case, make psw_idle save its r14.
[task 0000038000003c28] do_ext_irq+0xd6/0x160
[task 0000038000003c78] ext_int_handler+0xba/0xe8
[task *0000038000003dd8] psw_idle_exit+0x0/0x6 <-- pt_regs
([task 0000038000003dd8] arch_cpu_idle+0x3c/0xd0)
[task 0000038000003e10] default_idle_call+0x42/0x148
[task 0000038000003e30] do_idle+0xce/0x160
[task 0000038000003e70] cpu_startup_entry+0x36/0x40
[task 0000038000003ea0] arch_call_rest_init+0x76/0x80
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b24bacd67f upstream.
The s390 specific vdso function __arch_get_hw_counter() is supposed to
consider tod clock steering.
If a tod clock steering event happens and the tod clock is set to a
new value __arch_get_hw_counter() will not return the real tod clock
value but slowly drift it from the old delta until the returned value
finally matches the real tod clock value again.
Unfortunately the type of tod_steering_delta unsigned while it is
supposed to be signed. It depends on if tod_steering_delta is negative
or positive in which direction the vdso code drifts the clock value.
Worst case is now that instead of drifting the clock slowly it will
jump into the opposite direction by a factor of two.
Fix this by simply making tod_steering_delta signed.
Fixes: 4bff8cb545 ("s390: convert to GENERIC_VDSO")
Cc: <stable@vger.kernel.org> # 5.10
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 72bbc226ed upstream.
When converting the vdso assembler code to C it was forgotten to
actually copy the tod_steering_delta value to vdso_data page.
Which in turn means that tod clock steering will not work correctly.
Fix this by simply copying the value whenever it is updated.
Fixes: 4bff8cb545 ("s390: convert to GENERIC_VDSO")
Cc: <stable@vger.kernel.org> # 5.10
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0b13525c20 upstream.
In commit 05bc1be6db ("s390/pci: create zPCI bus") we removed the
pci_dev_put() call matching the earlier pci_get_slot() done as part of
__zpci_event_availability(). This was based on the wrong understanding
that the device_put() done as part of pci_destroy_device() would counter
the pci_get_slot() when it only counters the initial reference. This
same understanding and existing bad example also lead to not doing
a pci_dev_put() in zpci_remove_device().
Since releasing the PCI devices, unlike releasing the PCI slot, does not
print any debug message for testing I added one in pci_release_dev().
This revealed that we are indeed leaking the PCI device on PCI
hotunplug. Further testing also revealed another missing pci_dev_put() in
disable_slot().
Fix this by adding the missing pci_dev_put() in disable_slot() and fix
zpci_remove_device() with the correct pci_dev_put() calls. Also instead
of calling pci_get_slot() in __zpci_event_availability() to determine if
a PCI device is registered and then doing the same again in
zpci_remove_device() do this once in zpci_remove_device() which makes
sure that the pdev in __zpci_event_availability() is only used for the
result of pci_scan_single_device() which does not need a reference count
decremnt as its ownership goes to the PCI bus.
Also move the check if zdev->zbus->bus is set into zpci_remove_device()
since it may be that we're removing a device with devfn != 0 which never
had a PCI bus. So we can still set the pdev->error_state to indicate
that the device is not usable anymore, add a flag to set the error state.
Fixes: 05bc1be6db ("s390/pci: create zPCI bus")
Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cd s390/pci: remove superfluous zdev->zbus check
Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703 s390/pci: refactor zpci_create_device()
Cc: <stable@vger.kernel.org> # 5.8+
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e1bff843cd upstream.
Checking zdev->zbus for NULL in __zpci_event_availability() is
superfluous as it can never be NULL at this point. While harmless this
check causes smatch warnings because we later access zdev->zbus with
only having checked zdev != NULL which is sufficient.
The reason zdev->zbus can never be NULL is since with zdev != NULL given
we know the zdev came from get_zdev_by_fid() and thus the zpci_list.
Now on first glance at zpci_create_device() one may assume that there is
a window where the zdev is in the list without a zdev, however this
window can't overlap with __zpci_event_availability() as
zpci_create_device() either runs on the same kthread as part of
availability events, or during the initial CLP List PCI at which point
the __zpci_event_availability() is not yet called as zPCI is not yet
initialized.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ba764dd703 upstream.
Currently zpci_create_device() is only called in clp_add_pci_device()
which allocates the memory for the struct zpci_dev being created. There
is little separation of concerns as only both functions together can
create a zpci_dev and the only CLP specific code in
clp_add_pci_device() is a call to clp_query_pci_fn().
Improve this by removing clp_add_pci_device() and refactor
zpci_create_device() such that it alone creates and initializes the
zpci_dev given the FID and Function Handle. For this we need to make
clp_query_pci_fn() non-static. While at it remove the function handle
parameter since we can just take that from the zpci_dev. Also move
adding to the zpci_list to after the zdev has been fully created which
eliminates a window where a partially initialized zdev can be found by
get_zdev_by_fid().
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d54cb7d548 upstream.
Commit 152e9b8676 ("s390/vtime: steal time exponential moving average")
inadvertently changed the input value for account_steal_time() from
"cputime_to_nsecs(steal)" to just "steal", resulting in broken increased
steal time accounting.
Fix this by changing it back to "cputime_to_nsecs(steal)".
Fixes: 152e9b8676 ("s390/vtime: steal time exponential moving average")
Cc: <stable@vger.kernel.org> # 5.1
Reported-by: Sabine Forkel <sabine.forkel@de.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 62c8dca9e1 ]
Avoid a potentially large stack frame and overflow by making
"cpumask_t avail" a static variable. There is no concurrent
access due to the existing locking.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b29c509382 upstream.
The stck/stckf instruction used within the inline assembly within
do_account_vtime() changes the condition code. This is not reflected
with the clobber list, and therefore might result in incorrect code
generation.
It seems unlikely that the compiler could generate incorrect code
considering the surrounding C code, but it must still be fixed.
Cc: <stable@vger.kernel.org>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e82080e1f4 upstream.
The number reported by the query is N-1 and I think people reading the
sysfs file would expect N instead. For users creating VMs there's no
actual difference because KVM's limit is currently below the UV's
limit.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: a0f60f8431 ("s390/protvirt: Add sysfs firmware interface for Ultravisor information")
Cc: stable@vger.kernel.org
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 87dbc209ea ]
Make <asm-generic/local64.h> mandatory in include/asm-generic/Kbuild and
remove all arch/*/include/asm/local64.h arch-specific files since they
only #include <asm-generic/local64.h>.
This fixes build errors on arch/c6x/ and arch/nios2/ for
block/blk-iocost.c.
Build-tested on 21 of 25 arch-es. (tools problems on the others)
Yes, we could even rename <asm-generic/local64.h> to
<linux/local64.h> and change all #includes to use
<linux/local64.h> instead.
Link: https://lkml.kernel.org/r/20201227024446.17018-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9365965db0 ]
Clear the kernel stack backchain before potentially calling the
lockdep trace_hardirqs_off/on functions. Without this walking the
kernel backchain, e.g. during a panic, might stop too early.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 454efcf82e upstream.
When a machine check interrupt is triggered during idle, the code
is using the async timer/clock for idle time calculation. It should use
the machine check enter timer/clock which is passed to the macro.
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e259b3fafa upstream.
During removal of the critical section cleanup the calculation
of mt_cycles during idle was removed. This causes invalid
accounting on systems with SMT enabled.
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 613775d62e upstream.
diag308 subcode 0 performes a clear reset which inlcudes the reset of
all registers in the system. While this is the preferred behavior when
loading a normal kernel via kexec it prevents the crash kernel to store
the register values in the dump. To prevent this use subcode 1 when
loading a crash kernel instead.
Fixes: ee337f5469 ("s390/kexec_file: Add crash support to image loader")
Cc: <stable@vger.kernel.org> # 4.17
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Reported-by: Xiaoying Yan <yiyan@redhat.com>
Tested-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5e438ebd7 upstream.
Not resetting the SMT siblings might leave them in unpredictable
state. One of the observed problems was that the CPU timer wasn't
reset and therefore large system time values where accounted during
CPU bringup.
Cc: <stable@kernel.org> # 4.0
Fixes: 10ad34bc76 ("s390: add SMT support")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f22b9c219a ]
The CALL_ON_STACK tests use the no_dat stack to switch to a different
stack for unwinding tests. If an interrupt or machine check happens
while using that stack, and previously being on the async stack, the
interrupt / machine check entry code (SWITCH_ASYNC) will assume that
the previous context did not use the async stack and happily use the
async stack again.
This will lead to stack corruption of the previous context.
To solve this disable both interrupts and machine checks before
switching to the no_dat stack.
Fixes: 7868249fbb ("s390/test_unwind: add CALL_ON_STACK tests")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
With commit 58c644ba51 ("sched/idle: Fix arch_cpu_idle() vs
tracing") common code calls arch_cpu_idle() with a lockdep state that
tells irqs are on.
This doesn't work very well for s390: psw_idle() will enable interrupts
to wait for an interrupt. As soon as an interrupt occurs the interrupt
handler will verify if the old context was psw_idle(). If that is the
case the interrupt enablement bits in the old program status word will
be cleared.
A subsequent test in both the external as well as the io interrupt
handler checks if in the old context interrupts were enabled. Due to
the above patching of the old program status word it is assumed the
old context had interrupts disabled, and therefore a call to
TRACE_IRQS_OFF (aka trace_hardirqs_off_caller) is skipped. Which in
turn makes lockdep incorrectly "think" that interrupts are enabled
within the interrupt handler.
Fix this by unconditionally calling TRACE_IRQS_OFF when entering
interrupt handlers. Also call unconditionally TRACE_IRQS_ON when
leaving interrupts handlers.
This leaves the special psw_idle() case, which now returns with
interrupts disabled, but has an "irqs on" lockdep state. So callers of
psw_idle() must adjust the state on their own, if required. This is
currently only __udelay_disabled().
Fixes: 58c644ba51 ("sched/idle: Fix arch_cpu_idle() vs tracing")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The directed MSIs are delivered to CPUs whose address is
written to the MSI message address. The current code assumes
that a CPU logical number (as it is seen by the kernel)
is also the CPU address.
The above assumption is not correct, as the CPU address
is rather the value returned by STAP instruction. That
value does not necessarily match the kernel logical CPU
number.
Fixes: e979ce7bce ("s390/pci: provide support for CPU directed interrupts")
Cc: <stable@vger.kernel.org> # v5.2+
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
idle path. Similar to the entry path the low level idle functions have to
be non-instrumentable.
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Merge tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"Two more places which invoke tracing from RCU disabled regions in the
idle path.
Similar to the entry path the low level idle functions have to be
non-instrumentable"
* tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
intel_idle: Fix intel_idle() vs tracing
sched/idle: Fix arch_cpu_idle() vs tracing
- Fix alignment of the new HYP sections
- Fix GICR_TYPER access from userspace
S390:
- do not reset the global diag318 data for per-cpu reset
- do not mark memory as protected too early
- fix for destroy page ultravisor call
x86:
- fix for SEV debugging
- fix incorrect return code
- fix for "noapic" with PIC in userspace and LAPIC in kernel
- fix for 5-level paging
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"ARM:
- Fix alignment of the new HYP sections
- Fix GICR_TYPER access from userspace
S390:
- do not reset the global diag318 data for per-cpu reset
- do not mark memory as protected too early
- fix for destroy page ultravisor call
x86:
- fix for SEV debugging
- fix incorrect return code
- fix for 'noapic' with PIC in userspace and LAPIC in kernel
- fix for 5-level paging"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: x86/mmu: Fix get_mmio_spte() on CPUs supporting 5-level PT
KVM: x86: Fix split-irqchip vs interrupt injection window request
KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint
MAINTAINERS: Update email address for Sean Christopherson
MAINTAINERS: add uv.c also to KVM/s390
s390/uv: handle destroy page legacy interface
KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace
KVM: SVM: fix error return code in svm_create_vcpu()
KVM: SVM: Fix offset computation bug in __sev_dbg_decrypt().
KVM: arm64: Correctly align nVHE percpu data
KVM: s390: remove diag318 reset code
KVM: s390: pv: Mark mm as protected after the set secure parameters and improve cleanup
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.
Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.
(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
We need to disable interrupts in load_fpu_regs(). Otherwise an
interrupt might come in after the registers are loaded, but before
CIF_FPU is cleared in load_fpu_regs(). When the interrupt returns,
CIF_FPU will be cleared and the registers will never be restored.
The entry.S code usually saves the interrupt state in __SF_EMPTY on the
stack when disabling/restoring interrupts. sie64a however saves the pointer
to the sie control block in __SF_SIE_CONTROL, which references the same
location. This is non-obvious to the reader. To avoid thrashing the sie
control block pointer in load_fpu_regs(), move the __SIE_* offsets eight
bytes after __SF_EMPTY on the stack.
Cc: <stable@vger.kernel.org> # 5.8
Fixes: 0b0ed657fe ("s390: remove critical section cleanup from entry.S")
Reported-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Older firmware can return rc=0x107 rrc=0xd for destroy page if the
page is already non-secure. This should be handled like a success
as already done by newer firmware.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 1a80b54d1c ("s390/uv: add destroy page call")
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
any TIF/CIF/PIF set
- fix file permission for cpum_sfb_size parameter
- another small defconfig update
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Merge tag 's390-5.10-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Heiko Carstens:
- fix system call exit path; avoid return to user space with any
TIF/CIF/PIF set
- fix file permission for cpum_sfb_size parameter
- another small defconfig update
* tag 's390-5.10-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cpum_sf.c: fix file permission for cpum_sfb_size
s390: update defconfigs
s390: fix system call exit path
- do not reset the global diag318 data for per-cpu reset
- do not mark memory as protected too early
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Merge tag 'kvm-s390-master-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master
KVM: s390: Fixes for 5.10
- do not reset the global diag318 data for per-cpu reset
- do not mark memory as protected too early
This file is installed by the s390 CPU Measurement sampling
facility device driver to export supported minimum and
maximum sample buffer sizes.
This file is read by lscpumf tool to display the details
of the device driver capabilities. The lscpumf tool might
be invoked by a non-root user. In this case it does not
print anything because the file contents can not be read.
Fix this by allowing read access for all users. Reading
the file contents is ok, changing the file contents is
left to the root user only.
For further reference and details see:
[1] https://github.com/ibm-s390-tools/s390-tools/issues/97
Fixes: 69f239ed33 ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur")
Cc: <stable@vger.kernel.org> # 3.14
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The diag318 data must be set to 0 by VM-wide reset events
triggered by diag308. As such, KVM should not handle
resetting this data via the VCPU ioctls.
Fixes: 23a60f8344 ("s390/kvm: diagnose 0x318 sync and reset")
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20201104181032.109800-1-walling@linux.ibm.com
