commit 8667d0d64d upstream.
Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:
{standard input}: Assembler messages:
{standard input}:1190: Error: unrecognized opcode: `stbcix'
{standard input}:1433: Error: unrecognized opcode: `lwzcix'
{standard input}:1453: Error: unrecognized opcode: `stbcix'
{standard input}:1460: Error: unrecognized opcode: `stwcix'
{standard input}:1596: Error: unrecognized opcode: `stbcix'
...
Rework to add assembler directives [1] around the instruction. Going
through them one by one shows that the changes should be safe. Like
__get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(),
which according to the name is specific to power9. And __raw_rm_read*()
are only called in things that are powernv or book3s_hv specific.
[1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo
Cc: stable@vger.kernel.org
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Make commit subject more descriptive]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-2-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e89257e28e upstream.
Clang warns:
arch/powerpc/platforms/cell/pervasive.c:81:2: error: unannotated fall-through between switch labels
case SRR1_WAKEEE:
^
arch/powerpc/platforms/cell/pervasive.c:81:2: note: insert 'break;' to avoid fall-through
case SRR1_WAKEEE:
^
break;
1 error generated.
Clang is more pedantic than GCC, which does not warn when failing
through to a case that is just break or return. Clang's version is more
in line with the kernel's own stance in deprecated.rst. Add athe missing
break to silence the warning.
Fixes: 6e83985b0f ("powerpc/cbe: Do not process external or decremeter interrupts from sreset")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211207110228.698956-1-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a841fd009e ]
for_each_node_by_name performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.
A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):
// <smpl>
@@
expression e,e1;
local idexpression n;
@@
for_each_node_by_name(n, e1) {
... when != of_node_put(n)
when != e = n
(
return n;
|
+ of_node_put(n);
? return ...;
)
...
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-7-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f6e82647ff ]
for_each_compatible_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.
A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):
// <smpl>
@@
expression e;
local idexpression n;
@@
@@
local idexpression n;
expression e;
@@
for_each_compatible_node(n,...) {
...
(
of_node_put(n);
|
e = n
|
+ of_node_put(n);
? break;
)
...
}
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-2-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c45361abb9 upstream.
When CONFIG_SMP=y, timebase synchronization is required when the second
kernel is started.
arch/powerpc/kernel/smp.c:
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
...
if (smp_ops->give_timebase)
smp_ops->give_timebase();
...
}
void start_secondary(void *unused)
{
...
if (smp_ops->take_timebase)
smp_ops->take_timebase();
...
}
When CONFIG_HOTPLUG_CPU=n and CONFIG_KEXEC_CORE=n,
smp_85xx_ops.give_timebase is NULL,
smp_85xx_ops.take_timebase is NULL,
As a result, the timebase is not synchronized.
Timebase synchronization does not depend on CONFIG_HOTPLUG_CPU.
Fixes: 56f1ba2807 ("powerpc/mpc85xx: refactor the PM operations")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210929033646.39630-3-nixiaoming@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9583922563 ]
Commit a21d1becaa ("powerpc: Reintroduce is_kvm_guest() as a fast-path
check") added is_kvm_guest() and changed kvm_para_available() to use it.
is_kvm_guest() checks a static key, kvm_guest, and that static key is
set in check_kvm_guest().
The problem is check_kvm_guest() is only called on pseries, and even
then only in some configurations. That means is_kvm_guest() always
returns false on all non-pseries and some pseries depending on
configuration. That's a bug.
For PR KVM guests this is noticable because they no longer do live
patching of themselves, which can be detected by the omission of a
message in dmesg such as:
KVM: Live patching for a fast VM worked
To fix it make check_kvm_guest() an initcall, to ensure it's always
called at boot. It needs to be core so that it runs before
kvm_guest_init() which is postcore. To be an initcall it needs to return
int, where 0 means success, so update that.
We still call it manually in pSeries_smp_probe(), because that runs
before init calls are run.
Fixes: a21d1becaa ("powerpc: Reintroduce is_kvm_guest() as a fast-path check")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210623130514.2543232-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eb8257a121 ]
On pseries LPAR when an empty slot is assigned to partition OR in single
LPAR mode, kdump kernel crashes during issuing PHB reset.
In the kdump scenario, we traverse all PHBs and issue reset using the
pe_config_addr of the first child device present under each PHB. However
the code assumes that none of the PHB slots can be empty and uses
list_first_entry() to get the first child device under the PHB. Since
list_first_entry() expects the list to be non-empty, it returns an
invalid pci_dn entry and ends up accessing NULL phb pointer under
pci_dn->phb causing kdump kernel crash.
This patch fixes the below kdump kernel crash by skipping empty slots:
audit: initializing netlink subsys (disabled)
thermal_sys: Registered thermal governor 'fair_share'
thermal_sys: Registered thermal governor 'step_wise'
cpuidle: using governor menu
pstore: Registered nvram as persistent store backend
Issue PHB reset ...
audit: type=2000 audit(1631267818.000:1): state=initialized audit_enabled=0 res=1
BUG: Kernel NULL pointer dereference on read at 0x00000268
Faulting instruction address: 0xc000000008101fb0
Oops: Kernel access of bad area, sig: 7 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 7 PID: 1 Comm: swapper/7 Not tainted 5.14.0 #1
NIP: c000000008101fb0 LR: c000000009284ccc CTR: c000000008029d70
REGS: c00000001161b840 TRAP: 0300 Not tainted (5.14.0)
MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 28000224 XER: 20040002
CFAR: c000000008101f0c DAR: 0000000000000268 DSISR: 00080000 IRQMASK: 0
...
NIP pseries_eeh_get_pe_config_addr+0x100/0x1b0
LR __machine_initcall_pseries_eeh_pseries_init+0x2cc/0x350
Call Trace:
0xc00000001161bb80 (unreliable)
__machine_initcall_pseries_eeh_pseries_init+0x2cc/0x350
do_one_initcall+0x60/0x2d0
kernel_init_freeable+0x350/0x3f8
kernel_init+0x3c/0x17c
ret_from_kernel_thread+0x5c/0x64
Fixes: 5a090f7c36 ("powerpc/pseries: PCIE PHB reset")
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
[mpe: Tweak wording and trim oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/163215558252.413351.8600189949820258982.stgit@jupiter
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 333cf50746 upstream.
With commit c9f3401313 ("powerpc: Always enable queued spinlocks for
64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always
enabled on ppc64le, external modules that use spinlock APIs are
failing.
ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor'
Before the above commit, modules were able to build without any
issues. Also this problem is not seen on other architectures. This
problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in
the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by
default and only enabled in certain conditions like
CONFIG_DEBUG_SPINLOCKS is set in the kernel config.
#include <linux/module.h>
spinlock_t spLock;
static int __init spinlock_test_init(void)
{
spin_lock_init(&spLock);
spin_lock(&spLock);
spin_unlock(&spLock);
return 0;
}
static void __exit spinlock_test_exit(void)
{
printk("spinlock_test unloaded\n");
}
module_init(spinlock_test_init);
module_exit(spinlock_test_exit);
MODULE_DESCRIPTION ("spinlock_test");
MODULE_LICENSE ("non-GPL");
MODULE_AUTHOR ("Srikar Dronamraju");
Given that spin locks are one of the basic facilities for module code,
this effectively makes it impossible to build/load almost any non GPL
modules on ppc64le.
This was first reported at https://github.com/openzfs/zfs/issues/11172
Currently shared_processor is exported as GPL only symbol.
Fix this for parity with other architectures by exposing
shared_processor to non-GPL modules too.
Fixes: 14c73bd344 ("powerpc/vcpu: Assume dedicated processors as non-preempt")
Cc: stable@vger.kernel.org # v5.5+
Reported-by: marc.c.dionne@gmail.com
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210729060449.292780-1-srikar@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9733862e50 ]
Commit f959dcd6dd (dma-direct: Fix
potential NULL pointer dereference) added a null check on the
dma_mask pointer of the kernel's device structure.
Add a dma_mask variable to the ps3_dma_region structure and set
the device structure's dma_mask pointer to point to this new variable.
Fixes runtime errors like these:
# WARNING: Fixes tag on line 10 doesn't match correct format
# WARNING: Fixes tag on line 10 doesn't match correct format
ps3_system_bus_match:349: dev=8.0(sb_01), drv=8.0(ps3flash): match
WARNING: CPU: 0 PID: 1 at kernel/dma/mapping.c:151 .dma_map_page_attrs+0x34/0x1e0
ps3flash sb_01: ps3stor_setup:193: map DMA region failed
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/562d0c9ea0100a30c3b186bcc7adb34b0bbd2cd7.1622746428.git.geoff@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 91cdbb955a upstream.
The kernel handles the NX fault by updating CSB or sending
signal to process. In multithread applications, children can
open VAS windows and can exit without closing them. But the
parent can continue to send NX requests with these windows. To
prevent pid reuse, reference will be taken on pid and tgid
when the window is opened and release them during window close.
The current code is not releasing the tgid reference which can
cause pid leak and this patch fixes the issue.
Fixes: db1c08a740 ("powerpc/vas: Take reference to PID and mm for user space windows")
Cc: stable@vger.kernel.org # 5.8+
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6020fc4d444864fe20f7dcdc5edfe53e67480a1c.camel@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2c669ef697 upstream.
Powerpc currently resets a CPU's idle task preempt_count to 0 before
said task starts executing the secondary startup routine (and becomes an
idle task proper).
This conflicts with commit f1a0a376ca ("sched/core: Initialize the
idle task with preemption disabled").
which initializes all of the idle tasks' preempt_count to
PREEMPT_DISABLED during smp_init(). Note that this was superfluous
before said commit, as back then the hotplug machinery would invoke
init_idle() via idle_thread_get(), which would have already reset the
CPU's idle task's preempt_count to PREEMPT_ENABLED.
Get rid of this preempt_count write.
Fixes: f1a0a376ca ("sched/core: Initialize the idle task with preemption disabled")
Reported-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210707183831.2106509-1-valentin.schneider@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ed78f56e12 ]
In case performance stats for an nvdimm are not available, reading the
'perf_stats' sysfs file returns an -ENOENT error. A better approach is
to make the 'perf_stats' file entirely invisible to indicate that
performance stats for an nvdimm are unavailable.
So this patch updates 'papr_nd_attribute_group' to add a 'is_visible'
callback implemented as newly introduced 'papr_nd_attribute_visible()'
that returns an appropriate mode in case performance stats aren't
supported in a given nvdimm.
Also the initialization of 'papr_scm_priv.stat_buffer_len' is moved
from papr_scm_nvdimm_init() to papr_scm_probe() so that it value is
available when 'papr_nd_attribute_visible()' is called during nvdimm
initialization.
Even though 'perf_stats' attribute is available since v5.9, there are
no known user-space tools/scripts that are dependent on presence of its
sysfs file. Hence I dont expect any user-space breakage with this
patch.
Fixes: 2d02bf835e ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210513092349.285021-1-vaibhav@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c8c89b958 ]
The paravit queued spinlock slow path adds itself to the queue then
calls pv_wait to wait for the lock to become free. This is implemented
by calling H_CONFER to donate cycles.
When hcall tracing is enabled, this H_CONFER call can lead to a spin
lock being taken in the tracing code, which will result in the lock to
be taken again, which will also go to the slow path because it queues
behind itself and so won't ever make progress.
An example trace of a deadlock:
__pv_queued_spin_lock_slowpath
trace_clock_global
ring_buffer_lock_reserve
trace_event_buffer_lock_reserve
trace_event_buffer_reserve
trace_event_raw_event_hcall_exit
__trace_hcall_exit
plpar_hcall_norets_trace
__pv_queued_spin_lock_slowpath
trace_clock_global
ring_buffer_lock_reserve
trace_event_buffer_lock_reserve
trace_event_buffer_reserve
trace_event_raw_event_rcu_dyntick
rcu_irq_exit
irq_exit
__do_irq
call_do_irq
do_IRQ
hardware_interrupt_common_virt
Fix this by introducing plpar_hcall_norets_notrace(), and using that to
make SPLPAR virtual processor dispatching hcalls by the paravirt
spinlock code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210508101455.1578318-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ed8029d7b4 ]
RCU complains about us calling printk() from an offline CPU:
=============================
WARNING: suspicious RCU usage
5.12.0-rc7-02874-g7cf90e481cb8 #1 Not tainted
-----------------------------
kernel/locking/lockdep.c:3568 RCU-list traversed in non-reader section!!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 2, debug_locks = 1
no locks held by swapper/0/0.
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7-02874-g7cf90e481cb8 #1
Call Trace:
dump_stack+0xec/0x144 (unreliable)
lockdep_rcu_suspicious+0x124/0x144
__lock_acquire+0x1098/0x28b0
lock_acquire+0x128/0x600
_raw_spin_lock_irqsave+0x6c/0xc0
down_trylock+0x2c/0x70
__down_trylock_console_sem+0x60/0x140
vprintk_emit+0x1a8/0x4b0
vprintk_func+0xcc/0x200
printk+0x40/0x54
pseries_cpu_offline_self+0xc0/0x120
arch_cpu_idle_dead+0x54/0x70
do_idle+0x174/0x4a0
cpu_startup_entry+0x38/0x40
rest_init+0x268/0x388
start_kernel+0x748/0x790
start_here_common+0x1c/0x614
Which happens because by the time we get to rtas_stop_self() we are
already offline. In addition the message can be spammy, and is not that
helpful for users, so remove it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210418135413.1204031-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 38d0b1c9ce ]
The pci_bus->bridge reference may no longer be valid after
pci_bus_remove() resulting in passing a bad value to device_unregister()
for the associated bridge device.
Store the host_bridge reference in a separate variable prior to
pci_bus_remove().
Fixes: 7340056567 ("powerpc/pci: Reorder pci bus/bridge unregistration during PHB removal")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210211182435.47968-1-tyreld@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 11d92156f7 ]
The vio bus is a fake bus, which we use on pseries LPARs (guests) to
discover devices provided by the hypervisor. There's no need or sense
in creating the vio bus on bare metal systems.
Which is why commit 4336b93378 ("powerpc/pseries: Make vio and
ibmebus initcalls pseries specific") made the initialisation of the
vio bus only happen in LPARs.
However as a result of that commit we now see errors at boot on bare
metal systems:
Driver 'hvc_console' was unable to register with bus_type 'vio' because the bus was not initialized.
Driver 'tpm_ibmvtpm' was unable to register with bus_type 'vio' because the bus was not initialized.
This happens because those drivers are built-in, and are calling
vio_register_driver(). It in turn calls driver_register() with a
reference to vio_bus_type, but we haven't registered vio_bus_type with
the driver core.
Fix it by also guarding vio_register_driver() with a check to see if
we are on pseries.
Fixes: 4336b93378 ("powerpc/pseries: Make vio and ibmebus initcalls pseries specific")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20210316010938.525657-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f9619d5e51 upstream.
Depending on the number of online CPUs in the original kernel, it is
likely for CPU #0 to be offline in a kdump kernel. The associated IRQs
in the affinity mappings provided by irq_create_affinity_masks() are
thus not started by irq_startup(), as per-design with managed IRQs.
This can be a problem with multi-queue block devices driven by blk-mq :
such a non-started IRQ is very likely paired with the single queue
enforced by blk-mq during kdump (see blk_mq_alloc_tag_set()). This
causes the device to remain silent and likely hangs the guest at
some point.
This is a regression caused by commit 9ea69a55b3 ("powerpc/pseries:
Pass MSI affinity to irq_create_mapping()"). Note that this only happens
with the XIVE interrupt controller because XICS has a workaround to bypass
affinity, which is activated during kdump with the "noirqdistrib" kernel
parameter.
The issue comes from a combination of factors:
- discrepancy between the number of queues detected by the multi-queue
block driver, that was used to create the MSI vectors, and the single
queue mode enforced later on by blk-mq because of kdump (i.e. keeping
all queues fixes the issue)
- CPU#0 offline (i.e. kdump always succeed with CPU#0)
Given that I couldn't reproduce on x86, which seems to always have CPU#0
online even during kdump, I'm not sure where this should be fixed. Hence
going for another approach : fine-grained affinity is for performance
and we don't really care about that during kdump. Simply revert to the
previous working behavior of ignoring affinity masks in this case only.
Fixes: 9ea69a55b3 ("powerpc/pseries: Pass MSI affinity to irq_create_mapping()")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210215094506.1196119-1-groug@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 768d70e19b ]
dlpar_configure_connector() has two problems in its handling of
ibm,configure-connector's return status:
1. When the status is -2 (busy, call again), we call
ibm,configure-connector again immediately without checking whether
to schedule, which can result in monopolizing the CPU.
2. Extended delay status (9900..9905) goes completely unhandled,
causing the configuration to unnecessarily terminate.
Fix both of these issues by using rtas_busy_delay().
Fixes: ab519a011c ("powerpc/pseries: Kernel DLPAR Infrastructure")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210107025900.410369-1-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 59d512e437 ]
This is way to catch some cases of decrementer overflow, when the
decrementer has underflowed an odd number of times, while MSR[EE] was
disabled.
With a typical small decrementer, a timer that fires when MSR[EE] is
disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and
8.6 seconds after the timer expires. In any case, the decrementer
interrupt would be taken at 8.6 seconds and the timer would be found at
that point.
So this check is for catching extreme latency events, and it prevents
those latencies from being a further few seconds long. It's not obvious
this is a good tradeoff. This is already a watchdog magnitude event and
that situation is not improved a significantly with this check. For
large decrementers, it's useless.
Therefore remove this check, which avoids a mftb when enabling hard
disabled interrupts (e.g., when enabling after coming from hardware
interrupt handlers). Perhaps more importantly, it also removes the
clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay
which simplifies the code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201107014336.2337337-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d6718941a2 upstream.
It's very easy to crash the kernel right now by simply trying to
enable memtrace concurrently, hammering on the "enable" interface
loop.sh:
#!/bin/bash
dmesg --console-off
while true; do
echo 0x40000000 > /sys/kernel/debug/powerpc/memtrace/enable
done
[root@localhost ~]# loop.sh &
[root@localhost ~]# loop.sh &
Resulting quickly in a kernel crash. Let's properly protect using a
mutex.
Fixes: 9d5171a8f2 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Cc: stable@vger.kernel.org# v4.14+
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201111145322.15793-3-david@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b1198a8823 upstream.
We execute certain NPU2 setup code (such as mapping an LPID to a device
in NPU2) unconditionally if an Nvlink bridge is detected. However this
cannot succeed on POWER8NVL machines and errors appear in dmesg. This is
harmless as skiboot returns an error and the only place we check it is
vfio-pci but that code does not get called on P8+ either.
This adds a check if pnv_npu2_xxx helpers are called on a machine with
NPU2 which initializes pnv_phb::npu in pnv_npu2_init();
pnv_phb::npu==NULL on POWER8/NVL (Naples).
While at this, fix NULL derefencing in pnv_npu_peers_take_ownership/
pnv_npu_peers_release_ownership which occurs when GPUs on mentioned P8s
cause EEH which happens if "vfio-pci" disables devices using
the D3 power state; the vfio-pci's disable_idle_d3 module parameter
controls this and must be set on Naples. The EEH handling clears
the entire pnv_ioda_pe struct in pnv_ioda_free_pe() hence
the NULL derefencing. We cannot recover from that but at least we stop
crashing.
Tested on
- POWER9 pvr=004e1201, Ubuntu 19.04 host, Ubuntu 18.04 vm,
NVIDIA GV100 10de:1db1 driver 418.39
- POWER8 pvr=004c0100, RHEL 7.6 host, Ubuntu 16.10 vm,
NVIDIA P100 10de:15f9 driver 396.47
Fixes: 1b785611e1 ("powerpc/powernv/npu: Add release_ownership hook")
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201122073828.15446-1-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b866459489 ]
Partitions with cache nodes in the device tree can encounter the
following warning on resume:
CPU 0 already accounted in PowerPC,POWER9@0(Data)
WARNING: CPU: 0 PID: 3177 at arch/powerpc/kernel/cacheinfo.c:197 cacheinfo_cpu_online+0x640/0x820
These calls to cacheinfo_cpu_offline/online have been redundant since
commit e610a466d1 ("powerpc/pseries/mobility: rebuild cacheinfo
hierarchy post-migration").
Fixes: e610a466d1 ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-25-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 52719fce3f ]
There are three ways pseries_suspend_begin() can be reached:
1. When "mem" is written to /sys/power/state:
kobj_attr_store()
-> state_store()
-> pm_suspend()
-> suspend_devices_and_enter()
-> pseries_suspend_begin()
This never works because there is no way to supply a valid stream id
using this interface, and H_VASI_STATE is called with a stream id of
zero. So this call path is useless at best.
2. When a stream id is written to /sys/devices/system/power/hibernate.
pseries_suspend_begin() is polled directly from store_hibernate()
until the stream is in the "Suspending" state (i.e. the platform is
ready for the OS to suspend execution):
dev_attr_store()
-> store_hibernate()
-> pseries_suspend_begin()
3. When a stream id is written to /sys/devices/system/power/hibernate
(continued). After #2, pseries_suspend_begin() is called once again
from the pm core:
dev_attr_store()
-> store_hibernate()
-> pm_suspend()
-> suspend_devices_and_enter()
-> pseries_suspend_begin()
This is redundant because the VASI suspend state is already known to
be Suspending.
The begin() callback of platform_suspend_ops is optional, so we can
simply remove that assignment with no loss of function.
Fixes: 32d8ad4e62 ("powerpc/pseries: Partition hibernation support")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-18-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Pull irq fixes from Thomas Gleixner:
"A set of updates for the interrupt subsystem:
- Make multiqueue devices which use the managed interrupt affinity
infrastructure work on PowerPC/Pseries. PowerPC does not use the
generic infrastructure for setting up PCI/MSI interrupts and the
multiqueue changes failed to update the legacy PCI/MSI
infrastructure. Make this work by passing the affinity setup
information down to the mapping and allocation functions.
- Move Jason Cooper from MAINTAINERS to CREDITS as his mail is
bouncing and he's not reachable. We hope all is well with him and
say thanks for his work over the years"
* tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
powerpc/pseries: Pass MSI affinity to irq_create_mapping()
genirq/irqdomain: Add an irq_create_mapping_affinity() function
MAINTAINERS: Move Jason Cooper to CREDITS
With virtio multiqueue, normally each queue IRQ is mapped to a CPU.
Commit 0d9f0a52c8 ("virtio_scsi: use virtio IRQ affinity") exposed
an existing shortcoming of the arch code by moving virtio_scsi to
the automatic IRQ affinity assignment.
The affinity is correctly computed in msi_desc but this is not applied
to the system IRQs.
It appears the affinity is correctly passed to rtas_setup_msi_irqs() but
lost at this point and never passed to irq_domain_alloc_descs()
(see commit 06ee6d571f ("genirq: Add affinity hint to irq allocation"))
because irq_create_mapping() doesn't take an affinity parameter.
Use the new irq_create_mapping_affinity() function, which allows to forward
the affinity setting from rtas_setup_msi_irqs() to irq_domain_alloc_descs().
With this change, the virtqueues are correctly dispatched between the CPUs
on pseries.
Fixes: e75eafb9b0 ("genirq/msi: Switch to new irq spreading infrastructure")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201126082852.1178497-3-lvivier@redhat.com
When offlining a CPU, powerpc/64s does not flush TLBs, rather it just
leaves the CPU set in mm_cpumasks, so it continues to receive TLBIEs
to manage its TLBs.
However the exit_flush_lazy_tlbs() function expects that after
returning, all CPUs (except self) have flushed TLBs for that mm, in
which case TLBIEL can be used for this flush. This breaks for offline
CPUs because they don't get the IPI to flush their TLB. This can lead
to stale translations.
Fix this by clearing the CPU from mm_cpumasks, then flushing all TLBs
before going offline.
These offlined CPU bits stuck in the cpumask also prevents the cpumask
from being trimmed back to local mode, which means continual broadcast
IPIs or TLBIEs are needed for TLB flushing. This patch prevents that
situation too.
A cast of many were involved in working this out, but in particular
Milton, Aneesh, Paul made key discoveries.
Fixes: 0cef77c779 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Debugged-by: Milton Miller <miltonm@us.ibm.com>
Debugged-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Debugged-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-5-npiggin@gmail.com
pseries|pnv_setup_rfi_flush already does the count cache flush setup, and
we just added entry and uaccess flushes. So the name is not very accurate
any more. In both platforms we then also immediately setup the STF flush.
Rename them to _setup_security_mitigations and fold the STF flush in.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache after user accesses.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull powerpc fixes from Michael Ellerman:
- A fix for undetected data corruption on Power9 Nimbus <= DD2.1 in the
emulation of VSX loads. The affected CPUs were not widely available.
- Two fixes for machine check handling in guests under PowerVM.
- A fix for our recent changes to SMP setup, when
CONFIG_CPUMASK_OFFSTACK=y.
- Three fixes for races in the handling of some of our powernv sysfs
attributes.
- One change to remove TM from the set of Power10 CPU features.
- A couple of other minor fixes.
Thanks to: Aneesh Kumar K.V, Christophe Leroy, Ganesh Goudar, Jordan
Niethe, Mahesh Salgaonkar, Michael Neuling, Oliver O'Halloran, Qian Cai,
Srikar Dronamraju, Vasant Hegde.
* tag 'powerpc-5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/pseries: Avoid using addr_to_pfn in real mode
powerpc/uaccess: Don't use "m<>" constraint with GCC 4.9
powerpc/eeh: Fix eeh_dev_check_failure() for PE#0
powerpc/64s: Remove TM from Power10 features
selftests/powerpc: Make alignment handler test P9N DD2.1 vector CI load workaround
powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation
powerpc/powernv/dump: Handle multiple writes to ack attribute
powerpc/powernv/dump: Fix race while processing OPAL dump
powerpc/smp: Use GFP_ATOMIC while allocating tmp mask
powerpc/smp: Remove unnecessary variable
powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash
powerpc/opal_elog: Handle multiple writes to ack attribute
Anders Roxell
Hangyu Hua
Christophe Leroy
Julia Lawall
Nicholas Piggin
Xiaoming Ni
Alexey Kardashevskiy
Vasant Hegde
Bixuan Cui
Michael Ellerman
Srikar Dronamraju
Mahesh Salgaonkar
Geoff Levand
Haren Myneni
Valentin Schneider
Vaibhav Jain
Andy Shevchenko
Tyrel Datwyler
Greg Kurz
Nathan Lynch
David Hildenbrand
Kaixu Xia
Zhang Xiaoxu
Linus Torvalds
Laurent Vivier
Daniel Axtens