| Age | Commit message (Collapse) | Author | Files | Lines |
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Allow to select RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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This is invoked from the secondary CPU in atomic context. On x86 we use
tsc instead. On Power we XOR it against mftb() so lets use stack address
as the initial value.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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While converting the openpic emulation code to use a raw_spinlock_t enables
guests to run on RT, there's still a performance issue. For interrupts sent in
directed delivery mode with a multiple CPU mask, the emulated openpic will loop
through all of the VCPUs, and for each VCPUs, it call IRQ_check, which will loop
through all the pending interrupts for that VCPU. This is done while holding the
raw_lock, meaning that in all this time the interrupts and preemption are
disabled on the host Linux. A malicious user app can max both these number and
cause a DoS.
This temporary fix is sent for two reasons. First is so that users who want to
use the in-kernel MPIC emulation are aware of the potential latencies, thus
making sure that the hardware MPIC and their usage scenario does not involve
interrupts sent in directed delivery mode, and the number of possible pending
interrupts is kept small. Secondly, this should incentivize the development of a
proper openpic emulation that would be better suited for RT.
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The locallock protects the per-CPU variable tce_page. The function
attempts to allocate memory while tce_page is protected (by disabling
interrupts).
Use local_irq_save() instead of local_irq_disable().
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Add PREEMPT_RT to the backtrace if enabled.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Implement the powerpc pieces for lazy preempt.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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PREEMPT_RT preempts softirqs and the current implementation avoids
do_softirq_own_stack() and only uses __do_softirq().
Disable the unused softirqs stacks on PREEMPT_RT to safe some memory and
ensure that do_softirq_own_stack() is not used which is not expected.
[bigeasy: commit description.]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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The printk header file includes ratelimit_types.h for its __ratelimit()
based usage. It requires it for the static initializer used in
printk_ratelimited(). It uses a raw_spinlock_t and includes the
spinlock_types.h. It makes no difference on non PREEMPT-RT builds but
PREEMPT-RT replaces the inner part of some locks and therefore includes
rtmutex.h and atomic.h which leads to recursive includes where defines
are missing.
By including only the raw_spinlock_t defines it avoids the atomic.h
related includes at this stage.
An example on powerpc:
| CALL scripts/atomic/check-atomics.sh
|In file included from include/linux/bug.h:5,
| from include/linux/page-flags.h:10,
| from kernel/bounds.c:10:
|arch/powerpc/include/asm/page_32.h: In function ‘clear_page’:
|arch/powerpc/include/asm/bug.h:87:4: error: implicit declaration of function ‘__WARN’ [-Werror=implicit-function-declaration]
| 87 | __WARN(); \
| | ^~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ON’
| 48 | WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
| | ^~~~~~~
|arch/powerpc/include/asm/bug.h:58:17: error: invalid application of ‘sizeof’ to incomplete type ‘struct bug_entry’
| 58 | "i" (sizeof(struct bug_entry)), \
| | ^~~~~~
|arch/powerpc/include/asm/bug.h:89:3: note: in expansion of macro ‘BUG_ENTRY’
| 89 | BUG_ENTRY(PPC_TLNEI " %4, 0", \
| | ^~~~~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ON’
| 48 | WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
| | ^~~~~~~
|In file included from arch/powerpc/include/asm/ptrace.h:298,
| from arch/powerpc/include/asm/hw_irq.h:12,
| from arch/powerpc/include/asm/irqflags.h:12,
| from include/linux/irqflags.h:16,
| from include/asm-generic/cmpxchg-local.h:6,
| from arch/powerpc/include/asm/cmpxchg.h:526,
| from arch/powerpc/include/asm/atomic.h:11,
| from include/linux/atomic.h:7,
| from include/linux/rwbase_rt.h:6,
| from include/linux/rwlock_types.h:55,
| from include/linux/spinlock_types.h:74,
| from include/linux/ratelimit_types.h:7,
| from include/linux/printk.h:10,
| from include/asm-generic/bug.h:22,
| from arch/powerpc/include/asm/bug.h:109,
| from include/linux/bug.h:5,
| from include/linux/page-flags.h:10,
| from kernel/bounds.c:10:
|include/linux/thread_info.h: In function ‘copy_overflow’:
|include/linux/thread_info.h:210:2: error: implicit declaration of function ‘WARN’ [-Werror=implicit-function-declaration]
| 210 | WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
| | ^~~~
The WARN / BUG include pulls in printk.h and then ptrace.h expects WARN
(from bug.h) which is not yet complete. Even hw_irq.h has WARN_ON()
statements.
On POWERPC64 there are missing atomic64 defines while building 32bit
VDSO:
| VDSO32C arch/powerpc/kernel/vdso32/vgettimeofday.o
|In file included from include/linux/atomic.h:80,
| from include/linux/rwbase_rt.h:6,
| from include/linux/rwlock_types.h:55,
| from include/linux/spinlock_types.h:74,
| from include/linux/ratelimit_types.h:7,
| from include/linux/printk.h:10,
| from include/linux/kernel.h:19,
| from arch/powerpc/include/asm/page.h:11,
| from arch/powerpc/include/asm/vdso/gettimeofday.h:5,
| from include/vdso/datapage.h:137,
| from lib/vdso/gettimeofday.c:5,
| from <command-line>:
|include/linux/atomic-arch-fallback.h: In function ‘arch_atomic64_inc’:
|include/linux/atomic-arch-fallback.h:1447:2: error: implicit declaration of function ‘arch_atomic64_add’; did you mean ‘arch_atomic_add’? [-Werror=impl
|icit-function-declaration]
| 1447 | arch_atomic64_add(1, v);
| | ^~~~~~~~~~~~~~~~~
| | arch_atomic_add
The generic fallback is not included, atomics itself are not used. If
kernel.h does not include printk.h then it comes later from the bug.h
include.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Since printing occurs either atomically or from the printing
kthread, there is no need for any deferring or tracking possible
recursion paths. Remove all printk defer functions and context
tracking.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Add a write_atomic() callback to the console. This is an optional
function for console drivers. The function must be atomic (including
NMI safe) for writing to the console.
Console drivers must still implement the write() callback. The
write_atomic() callback will only be used in special situations,
such as when the kernel panics.
Creating an NMI safe write_atomic() that must synchronize with
write() requires a careful implementation of the console driver. To
aid with the implementation, a set of console_atomic_*() functions
are provided:
void console_atomic_lock(unsigned long flags);
void console_atomic_unlock(unsigned long flags);
These functions synchronize using the printk cpulock and disable
hardware interrupts.
kgdb makes use of its own cpulock (@dbg_master_lock, @kgdb_active)
during cpu roundup. This will conflict with the printk cpulock.
Therefore, a CPU must ensure that it is not holding the printk
cpulock when calling kgdb_cpu_enter(). If it is, it must allow its
printk context to complete first.
A new helper function kgdb_roundup_delay() is introduced for kgdb
to determine if it is holding the printk cpulock. If so, a flag is
set so that when the printk cpulock is released, kgdb will be
re-triggered for that CPU.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Three commits fixing some issues introduced with the recent IOMMU
changes we merged.
Thanks to Alexey Kardashevskiy"
* tag 'powerpc-5.15-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/pseries/iommu: Create huge DMA window if no MMIO32 is present
powerpc/pseries/iommu: Check if the default window in use before removing it
powerpc/pseries/iommu: Use correct vfree for it_map
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The iommu_init_table() helper takes an address range to reserve in
the IOMMU table being initialized to exclude MMIO addresses, this is
useful if the window stretches far beyond 4GB (although wastes some TCEs).
At the moment the code searches for such MMIO32 range and fails if none
found which is considered a problem while it really is not: it is actually
better as this says there is no MMIO32 to reserve and we can use
usually wasted TCEs. Furthermore PHYP never actually allows creating
windows starting at busaddress=0 so this MMIO32 range is never useful.
This removes error exit and initializes the table with zero range if
no MMIO32 is detected.
Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211020132315.2287178-5-aik@ozlabs.ru
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At the moment this check is performed after we remove the default window
which is late and disallows to revert whatever changes enable_ddw()
has made to DMA windows.
This moves the check and error exit before removing the window.
This raised the message severity from "debug" to "warning" as this
should not happen in practice and cannot be triggered by the userspace.
Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211020132315.2287178-4-aik@ozlabs.ru
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The it_map array is vzalloc'ed so use vfree() for it when creating
a huge DMA window failed for whatever reason.
While at this, write zero to it_map.
Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211020132315.2287178-3-aik@ozlabs.ru
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a bug exposed by a previous fix, where running guests with
certain SMT topologies could crash the host on Power8.
- Fix atomic sleep warnings when re-onlining CPUs, when PREEMPT is
enabled.
Thanks to Nathan Lynch, Srikar Dronamraju, and Valentin Schneider.
* tag 'powerpc-5.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/smp: do not decrement idle task preempt count in CPU offline
powerpc/idle: Don't corrupt back chain when going idle
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With PREEMPT_COUNT=y, when a CPU is offlined and then onlined again, we
get:
BUG: scheduling while atomic: swapper/1/0/0x00000000
no locks held by swapper/1/0.
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.0-rc2+ #100
Call Trace:
dump_stack_lvl+0xac/0x108
__schedule_bug+0xac/0xe0
__schedule+0xcf8/0x10d0
schedule_idle+0x3c/0x70
do_idle+0x2d8/0x4a0
cpu_startup_entry+0x38/0x40
start_secondary+0x2ec/0x3a0
start_secondary_prolog+0x10/0x14
This is because powerpc's arch_cpu_idle_dead() decrements the idle task's
preempt count, for reasons explained in commit a7c2bb8279d2 ("powerpc:
Re-enable preemption before cpu_die()"), specifically "start_secondary()
expects a preempt_count() of 0."
However, since commit 2c669ef6979c ("powerpc/preempt: Don't touch the idle
task's preempt_count during hotplug") and commit f1a0a376ca0c ("sched/core:
Initialize the idle task with preemption disabled"), that justification no
longer holds.
The idle task isn't supposed to re-enable preemption, so remove the
vestigial preempt_enable() from the CPU offline path.
Tested with pseries and powernv in qemu, and pseries on PowerVM.
Fixes: 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preempt_count during hotplug")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015173902.2278118-1-nathanl@linux.ibm.com
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In isa206_idle_insn_mayloss() we store various registers into the stack
red zone, which is allowed.
However inside the IDLE_STATE_ENTER_SEQ_NORET macro we save r2 again,
to 0(r1), which corrupts the stack back chain.
We used to do the same in isa206_idle_insn_mayloss() itself, but we
fixed that in 73287caa9210 ("powerpc64/idle: Fix SP offsets when saving
GPRs"), however we missed that the macro also corrupts the back chain.
Corrupting the back chain is bad for debuggability but doesn't
necessarily cause a bug.
However we recently changed the stack handling in some KVM code, and it
now relies on the stack back chain being valid when it returns. The
corruption causes that code to return with r1 pointing somewhere in
kernel data, at some point LR is restored from the stack and we branch
to NULL or somewhere else invalid.
Only affects Power8 hosts running KVM guests, with dynamic_mt_modes
enabled (which it is by default).
The fixes tag below points to the commit that changed the KVM stack
handling, exposing this bug. The actual corruption of the back chain has
always existed since 948cf67c4726 ("powerpc: Add NAP mode support on
Power7 in HV mode").
Fixes: 9b4416c5095c ("KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211020094826.3222052-1-mpe@ellerman.id.au
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a bug where guests on P9 with interrupts passed through could get
stuck in synchronize_irq().
- Fix a bug in KVM on P8 where secondary threads entering a guest would
write outside their allocated stack.
- Fix a bug in KVM on P8 where secondary threads could confuse the host
offline code and cause the guest or host to crash.
Thanks to Cédric Le Goater.
* tag 'powerpc-5.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV: Make idle_kvm_start_guest() return 0 if it went to guest
KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
powerpc/xive: Discard disabled interrupts in get_irqchip_state()
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We call idle_kvm_start_guest() from power7_offline() if the thread has
been requested to enter KVM. We pass it the SRR1 value that was returned
from power7_idle_insn() which tells us what sort of wakeup we're
processing.
Depending on the SRR1 value we pass in, the KVM code might enter the
guest, or it might return to us to do some host action if the wakeup
requires it.
If idle_kvm_start_guest() is able to handle the wakeup, and enter the
guest it is supposed to indicate that by returning a zero SRR1 value to
us.
That was the behaviour prior to commit 10d91611f426 ("powerpc/64s:
Reimplement book3s idle code in C"), however in that commit the
handling of SRR1 was reworked, and the zeroing behaviour was lost.
Returning from idle_kvm_start_guest() without zeroing the SRR1 value can
confuse the host offline code, causing the guest to crash and other
weirdness.
Fixes: 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015133929.832061-2-mpe@ellerman.id.au
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In commit 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in
C") kvm_start_guest() became idle_kvm_start_guest(). The old code
allocated a stack frame on the emergency stack, but didn't use the
frame to store anything, and also didn't store anything in its caller's
frame.
idle_kvm_start_guest() on the other hand is written more like a normal C
function, it creates a frame on entry, and also stores CR/LR into its
callers frame (per the ABI). The problem is that there is no caller
frame on the emergency stack.
The emergency stack for a given CPU is allocated with:
paca_ptrs[i]->emergency_sp = alloc_stack(limit, i) + THREAD_SIZE;
So emergency_sp actually points to the first address above the emergency
stack allocation for a given CPU, we must not store above it without
first decrementing it to create a frame. This is different to the
regular kernel stack, paca->kstack, which is initialised to point at an
initial frame that is ready to use.
idle_kvm_start_guest() stores the backchain, CR and LR all of which
write outside the allocation for the emergency stack. It then creates a
stack frame and saves the non-volatile registers. Unfortunately the
frame it creates is not large enough to fit the non-volatiles, and so
the saving of the non-volatile registers also writes outside the
emergency stack allocation.
The end result is that we corrupt whatever is at 0-24 bytes, and 112-248
bytes above the emergency stack allocation.
In practice this has gone unnoticed because the memory immediately above
the emergency stack happens to be used for other stack allocations,
either another CPUs mc_emergency_sp or an IRQ stack. See the order of
calls to irqstack_early_init() and emergency_stack_init().
The low addresses of another stack are the top of that stack, and so are
only used if that stack is under extreme pressue, which essentially
never happens in practice - and if it did there's a high likelyhood we'd
crash due to that stack overflowing.
Still, we shouldn't be corrupting someone else's stack, and it is purely
luck that we aren't corrupting something else.
To fix it we save CR/LR into the caller's frame using the existing r1 on
entry, we then create a SWITCH_FRAME_SIZE frame (which has space for
pt_regs) on the emergency stack with the backchain pointing to the
existing stack, and then finally we switch to the new frame on the
emergency stack.
Fixes: 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015133929.832061-1-mpe@ellerman.id.au
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When an interrupt is passed through, the KVM XIVE device calls the
set_vcpu_affinity() handler which raises the P bit to mask the
interrupt and to catch any in-flight interrupts while routing the
interrupt to the guest.
On the guest side, drivers (like some Intels) can request at probe
time some MSIs and call synchronize_irq() to check that there are no
in flight interrupts. This will call the XIVE get_irqchip_state()
handler which will always return true as the interrupt P bit has been
set on the host side and lock the CPU in an infinite loop.
Fix that by discarding disabled interrupts in get_irqchip_state().
Fixes: da15c03b047d ("powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race")
Cc: stable@vger.kernel.org #v5.4+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: seeteena <s1seetee@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211011070203.99726-1-clg@kaod.org
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"A bit of a big batch, partly because I didn't send any last week, and
also just because the BPF fixes happened to land this week.
Summary:
- Fix a regression hit by the IPR SCSI driver, introduced by the
recent addition of MSI domains on pseries.
- A big series including 8 BPF fixes, some with potential security
impact and the rest various code generation issues.
- Fix our program check assembler entry path, which was accidentally
jumping into a gas macro and generating strange stack frames, which
could confuse find_bug().
- A couple of fixes, and related changes, to fix corner cases in our
machine check handling.
- Fix our DMA IOMMU ops, which were not always returning the optimal
DMA mask, leading to at least one device falling back to 32-bit DMA
when it shouldn't.
- A fix for KUAP handling on 32-bit Book3S.
- Fix crashes seen when kdumping on some pseries systems.
Thanks to Naveen N. Rao, Nicholas Piggin, Alexey Kardashevskiy, Cédric
Le Goater, Christophe Leroy, Mahesh Salgaonkar, Abdul Haleem,
Christoph Hellwig, Johan Almbladh, Stan Johnson"
* tag 'powerpc-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
pseries/eeh: Fix the kdump kernel crash during eeh_pseries_init
powerpc/32s: Fix kuap_kernel_restore()
powerpc/pseries/msi: Add an empty irq_write_msi_msg() handler
powerpc/64s: Fix unrecoverable MCE calling async handler from NMI
powerpc/64/interrupt: Reconcile soft-mask state in NMI and fix false BUG
powerpc/64: warn if local irqs are enabled in NMI or hardirq context
powerpc/traps: do not enable irqs in _exception
powerpc/64s: fix program check interrupt emergency stack path
powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000
powerpc/bpf ppc32: Do not emit zero extend instruction for 64-bit BPF_END
powerpc/bpf ppc32: Fix JMP32_JSET_K
powerpc/bpf ppc32: Fix ALU32 BPF_ARSH operation
powerpc/bpf: Emit stf barrier instruction sequences for BPF_NOSPEC
powerpc/security: Add a helper to query stf_barrier type
powerpc/bpf: Fix BPF_SUB when imm == 0x80000000
powerpc/bpf: Fix BPF_MOD when imm == 1
powerpc/bpf: Validate branch ranges
powerpc/lib: Add helper to check if offset is within conditional branch range
powerpc/iommu: Report the correct most efficient DMA mask for PCI devices
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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: 5a090f7c363fd ("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
|
|
At interrupt exit, kuap_kernel_restore() calls kuap_unlock() with the
value contained in regs->kuap. However, when regs->kuap contains
0xffffffff it means that KUAP was not unlocked so calling kuap_unlock()
is unrelevant and results in jeopardising the contents of kernel space
segment registers.
So check that regs->kuap doesn't contain KUAP_NONE before calling
kuap_unlock(). In the meantime it also means that if KUAP has not
been correcly locked back at interrupt exit, it must be locked
before continuing. This is done by checking the content of
current->thread.kuap which was returned by kuap_get_and_assert_locked()
Fixes: 16132529cee5 ("powerpc/32s: Rework Kernel Userspace Access Protection")
Reported-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0d0c4d0f050a637052287c09ba521bad960a2790.1631715131.git.christophe.leroy@csgroup.eu
|
|
The IPR drivers tests for MSI support at probe time with MSI vector 0
and when done, frees the IRQ with free_irq(). This test was introduced
by 95fecd90397e ("ipr: add test for MSI interrupt support") as an
improvement of commit 5a9ef25b14d3 ("[SCSI] ipr: add MSI support")
because a boot failure was reported on a Bimini PowerPC system:
https://lore.kernel.org/r/1242926159.3007.5.camel@localhost.localdomain
It was finally decided to remove MSI support on Bimini systems in
6eb0ac03899a ("powerpc/maple: Add a quirk to disable MSI for IPR on
Bimini").
Linux 5.15-rc1 added MSI domain support to the pseries machine and
when free_irq is called() in the driver, msi_domain_deactivate() also
is. This resets the MSI table entry of the associate vector by calling
__pci_write_msi_msg() with an empty message and breaks any further
activation of the same vector. In the case of the IPR driver, it
breaks the initialization sequence of the IOA.
Introduce an empty irq_write_msi_msg() handler in the MSI domain of
the pseries machine to avoid clearing the MSI vector entry. Updating
the entry is not strictly necessary since it is initialized by the
underlying hypervisor, PowerVM or QEMU/KVM.
Fixes: a5f3d2c17b07 ("powerpc/pseries/pci: Add MSI domains")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Tested-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
[mpe: Tweak comment wording and formatting slightly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210930102535.1047230-1-clg@kaod.org
|
|
The machine check handler is not considered NMI on 64s. The early
handler is the true NMI handler, and then it schedules the
machine_check_exception handler to run when interrupts are enabled.
This works fine except the case of an unrecoverable MCE, where the true
NMI is taken when MSR[RI] is clear, it can not recover, so it calls
machine_check_exception directly so something might be done about it.
Calling an async handler from NMI context can result in irq state and
other things getting corrupted. This can also trigger the BUG at
arch/powerpc/include/asm/interrupt.h:168
BUG_ON(!arch_irq_disabled_regs(regs) && !(regs->msr & MSR_EE));
Fix this by making an _async version of the handler which is called
in the normal case, and a NMI version that is called for unrecoverable
interrupts.
Fixes: 2b43dd7653cc ("powerpc/64: enable MSR[EE] in irq replay pt_regs")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-6-npiggin@gmail.com
|
|
If a NMI hits early in an interrupt handler before the irq soft-mask
state is reconciled, that can cause a false-positive BUG with a
CONFIG_PPC_IRQ_SOFT_MASK_DEBUG assertion.
Remove that assertion and instead check the case that if regs->msr has
EE clear, then regs->softe should be marked as disabled so the irq state
looks correct to NMI handlers, the same as how it's fixed up in the
case it was implicit soft-masked.
This doesn't fix a known problem -- the change that was fixed by commit
4ec5feec1ad02 ("powerpc/64s: Make NMI record implicitly soft-masked code
as irqs disabled") was the addition of a warning in the soft-nmi
watchdog interrupt which can never actually fire when MSR[EE]=0. However
it may be important if NMI handlers grow more code, and it's less
surprising to anything using 'regs' - (I tripped over this when working
in the area).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-5-npiggin@gmail.com
|
|
This can help catch bugs such as the one fixed by the previous change
to prevent _exception() from enabling irqs.
ppc32 could have a similar warning but it has no good config option to
debug this stuff (the test may be overkill to add for production
kernels).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-4-npiggin@gmail.com
|
|
_exception can be called by machine check handlers when the MCE hits
user code (e.g., pseries and powernv). This will enable local irqs
because, which is a dicey thing to do in NMI or hard irq context.
This seemed to worked out okay because a userspace MCE can basically be
treated like a synchronous interrupt (after async / imprecise MCEs are
filtered out). Since NMI and hard irq handlers have started growing
nmi_enter / irq_enter, and more irq state sanity checks, this has
started to cause problems (or at least trigger warnings).
The Fixes tag to the commit which introduced this rather than try to
work out exactly which commit was the first that could possibly cause a
problem because that may be difficult to prove.
Fixes: 9f2f79e3a3c1 ("powerpc: Disable interrupts in 64-bit kernel FP and vector faults")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-3-npiggin@gmail.com
|
|
Emergency stack path was jumping into a 3: label inside the
__GEN_COMMON_BODY macro for the normal path after it had finished,
rather than jumping over it. By a small miracle this is the correct
place to build up a new interrupt frame with the existing stack
pointer, so things basically worked okay with an added weird looking
700 trap frame on top (which had the wrong ->nip so it didn't decode
bug messages either).
Fix this by avoiding using numeric labels when jumping over non-trivial
macros.
Before:
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 88 Comm: sh Not tainted 5.15.0-rc2-00034-ge057cdade6e5 #2637
NIP: 7265677368657265 LR: c00000000006c0c8 CTR: c0000000000097f0
REGS: c0000000fffb3a50 TRAP: 0700 Not tainted
MSR: 9000000000021031 <SF,HV,ME,IR,DR,LE> CR: 00000700 XER: 20040000
CFAR: c0000000000098b0 IRQMASK: 0
GPR00: c00000000006c964 c0000000fffb3cf0 c000000001513800 0000000000000000
GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299
GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8
GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001
GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8
GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158
GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300
GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80
NIP [7265677368657265] 0x7265677368657265
LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10
Call Trace:
[c0000000fffb3cf0] [c00000000000bdac] soft_nmi_common+0x13c/0x1d0 (unreliable)
--- interrupt: 700 at decrementer_common_virt+0xb8/0x230
NIP: c0000000000098b8 LR: c00000000006c0c8 CTR: c0000000000097f0
REGS: c0000000fffb3d60 TRAP: 0700 Not tainted
MSR: 9000000000021031 <SF,HV,ME,IR,DR,LE> CR: 22424282 XER: 20040000
CFAR: c0000000000098b0 IRQMASK: 0
GPR00: c00000000006c964 0000000000002400 c000000001513800 0000000000000000
GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299
GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8
GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001
GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8
GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158
GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300
GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80
NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230
LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10
--- interrupt: 700
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
---[ end trace 6d28218e0cc3c949 ]---
After:
------------[ cut here ]------------
kernel BUG at arch/powerpc/kernel/exceptions-64s.S:491!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 88 Comm: login Not tainted 5.15.0-rc2-00034-ge057cdade6e5-dirty #2638
NIP: c0000000000098b8 LR: c00000000006bf04 CTR: c0000000000097f0
REGS: c0000000fffb3d60 TRAP: 0700 Not tainted
MSR: 9000000000021031 <SF,HV,ME,IR,DR,LE> CR: 24482227 XER: 00040000
CFAR: c0000000000098b0 IRQMASK: 0
GPR00: c00000000006bf04 0000000000002400 c000000001513800 c000000001271868
GPR04: 00000000100f0d29 0000000042000000 0000000000000007 0000000000000009
GPR08: 00000000100f0d29 0000000024482227 0000000000002710 c000000000181b3c
GPR12: 9000000000009033 c0000000016b0000 00000000100f0d29 c000000005b22f00
GPR16: 00000000ffff0000 0000000000000001 0000000000000009 00000000100eed90
GPR20: 00000000100eed90 0000000010000000 000000001000a49c 00000000100f1430
GPR24: c000000001271868 0000000002000000 0000000000000215 0000000000000300
GPR28: c000000001271800 0000000042000000 00000000100f0d29 c000000080647860
NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230
LR [c00000000006bf04] ___do_page_fault+0x234/0xb10
Call Trace:
Instruction dump:
4182000c 39400001 48000008 894d0932 714a0001 39400008 408225fc 718a4000
7c2a0b78 3821fcf0 41c20008 e82d0910 <0981fcf0> f92101a0 f9610170 f9810178
---[ end trace a5dbd1f5ea4ccc51 ]---
Fixes: 0a882e28468f4 ("powerpc/64s/exception: remove bad stack branch")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-2-npiggin@gmail.com
|
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Special case handling of the smallest 32-bit negative number for BPF_SUB.
Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7135360a0cdf70adedbccf9863128b8daef18764.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
|
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Suppress emitting zero extend instruction for 64-bit BPF_END_FROM_[L|B]E
operation.
Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b4e3c3546121315a8e2059b19a1bda84971816e4.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
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'andi' only takes an unsigned 16-bit value. Correct the imm range used
when emitting andi.
Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b94489f52831305ec15aca4dd04a3527236be7e8.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
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Correct the destination register used for ALU32 BPF_ARSH operation.
Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6d24c1f9e79b6f61f5135eaf2ea1e8bcd4dac87b.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
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Emit similar instruction sequences to commit a048a07d7f4535
("powerpc/64s: Add support for a store forwarding barrier at kernel
entry/exit") when encountering BPF_NOSPEC.
Mitigations are enabled depending on what the firmware advertises. In
particular, we do not gate these mitigations based on current settings,
just like in x86. Due to this, we don't need to take any action if
mitigations are enabled or disabled at runtime.
Signed-off-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/956570cbc191cd41f8274bed48ee757a86dac62a.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
|
|
Add a helper to return the stf_barrier type for the current processor.
Signed-off-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/3bd5d7f96ea1547991ac2ce3137dc2b220bae285.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
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We aren't handling subtraction involving an immediate value of
0x80000000 properly. Fix the same.
Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fold in fix from Naveen to use imm <= 32768]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc4b1276eb10761fd7ce0814c8dd089da2815251.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
|
|
Only ignore the operation if dividing by 1.
Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c674ca18c3046885602caebb326213731c675d06.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
|
|
Add checks to ensure that we never emit branch instructions with
truncated branch offsets.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/71d33a6b7603ec1013c9734dd8bdd4ff5e929142.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
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Add a helper to check if a given offset is within the branch range for a
powerpc conditional branch instruction, and update some sites to use the
new helper.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/442b69a34ced32ca346a0d9a855f3f6cfdbbbd41.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
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Property phy-connection-type contains invalid value "sgmii-2500" per scheme
defined in file ethernet-controller.yaml.
Correct phy-connection-type value should be "2500base-x".
Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: 84e0f1c13806 ("powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s)")
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
According to dma-api.rst, the dma_get_required_mask() helper should return
"the mask that the platform requires to operate efficiently". Which in
the case of PPC64 means the bypass mask and not a mask from an IOMMU table
which is shorter and slower to use due to map/unmap operations (especially
expensive on "pseries").
However the existing implementation ignores the possibility of bypassing
and returns the IOMMU table mask on the pseries platform which makes some
drivers (mpt3sas is one example) choose 32bit DMA even though bypass is
supported. The powernv platform sort of handles it by having a bigger
default window with a mask >=40 but it only works as drivers choose
63/64bit if the required mask is >32 which is rather pointless.
This reintroduces the bypass capability check to let drivers make
a better choice of the DMA mask.
Fixes: f1565c24b596 ("powerpc: use the generic dma_ops_bypass mode")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210930034454.95794-1-aik@ozlabs.ru
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Invoke rseq_handle_notify_resume() from tracehook_notify_resume() now
that the two function are always called back-to-back by architectures
that have rseq. The rseq helper is stubbed out for architectures that
don't support rseq, i.e. this is a nop across the board.
Note, tracehook_notify_resume() is horribly named and arguably does not
belong in tracehook.h as literally every line of code in it has nothing
to do with tracing. But, that's been true since commit a42c6ded827d
("move key_repace_session_keyring() into tracehook_notify_resume()")
first usurped tracehook_notify_resume() back in 2012. Punt cleaning that
mess up to future patches.
No functional change intended.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210901203030.1292304-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix crashes when scv (System Call Vectored) is used to make a syscall
when a transaction is active, on Power9 or later.
- Fix bad interactions between rfscv (Return-from scv) and Power9
fake-suspend mode.
- Fix crashes when handling machine checks in LPARs using the Hash MMU.
- Partly revert a recent change to our XICS interrupt controller code,
which broke the recently added Microwatt support.
Thanks to Cédric Le Goater, Eirik Fuller, Ganesh Goudar, Gustavo Romero,
Joel Stanley, Nicholas Piggin.
* tag 'powerpc-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/xics: Set the IRQ chip data for the ICS native backend
powerpc/mce: Fix access error in mce handler
KVM: PPC: Book3S HV: Tolerate treclaim. in fake-suspend mode changing registers
powerpc/64s: system call rfscv workaround for TM bugs
selftests/powerpc: Add scv versions of the basic TM syscall tests
powerpc/64s: system call scv tabort fix for corrupt irq soft-mask state
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The ICS native driver relies on the IRQ chip data to find the struct
'ics_native' describing the ICS controller but it was removed by commit
248af248a8f4 ("powerpc/xics: Rename the map handler in a check handler").
Revert this change to fix the Microwatt SoC platform.
Fixes: 248af248a8f4 ("powerpc/xics: Rename the map handler in a check handler")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210913134056.3761960-1-clg@kaod.org
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Stephen reported that the build was broken since commit
6d2ef226f2f1 ("compiler_attributes.h: drop __has_attribute() support for
gcc4"), with errors such as:
include/linux/compiler_attributes.h:296:5: warning: "__has_attribute" is not defined, evaluates to 0 [-Wundef]
296 | #if __has_attribute(__warning__)
| ^~~~~~~~~~~~~~~
make[2]: *** [arch/powerpc/boot/Makefile:225: arch/powerpc/boot/crt0.o] Error 1
But we expect __has_attribute() to always be defined now that we've
stopped using GCC 4.
Linus debugged it to the point of reading the GCC sources, and noticing
that the problem is that __has_attribute() is not defined when
preprocessing assembly files, which is what we're doing here.
Our assembly files don't include, or need, compiler_attributes.h, but
they are getting it unconditionally from the -include in BOOT_CFLAGS,
which is then added in its entirety to BOOT_AFLAGS.
That -include was added in commit 77433830ed16 ("powerpc: boot: include
compiler_attributes.h") so that we'd have "fallthrough" and other
attributes defined for the C files in arch/powerpc/boot. But it's not
needed for assembly files.
The minimal fix is to move the addition to BOOT_CFLAGS of -include
compiler_attributes.h until after we've copied BOOT_CFLAGS into
BOOT_AFLAGS. That avoids including compiler_attributes.h for asm files,
but makes no other change to BOOT_CFLAGS or BOOT_AFLAGS.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Debugged-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge patch series from Nick Desaulniers to update the minimum gcc
version to 5.1.
This is some of the left-overs from the merge window that I didn't want
to deal with yesterday, so it comes in after -rc1 but was sent before.
Gcc-4.9 support has been an annoyance for some time, and with -Werror I
had the choice of applying a fairly big patch from Kees Cook to remove a
fair number of initializer warnings (still leaving some), or this patch
series from Nick that just removes the source of the problem.
The initializer cleanups might still be worth it regardless, but
honestly, I preferred just tackling the problem with gcc-4.9 head-on.
We've been more aggressiuve about no longer having to care about
compilers that were released a long time ago, and I think it's been a
good thing.
I added a couple of patches on top to sort out a few left-overs now that
we no longer support gcc-4.x.
As noted by Arnd, as a result of this minimum compiler version upgrade
we can probably change our use of '--std=gnu89' to '--std=gnu11', and
finally start using local loop declarations etc. But this series does
_not_ yet do that.
Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/
Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
* emailed patches from Nick Desaulniers <ndesaulniers@google.com>:
Drop some straggling mentions of gcc-4.9 as being stale
compiler_attributes.h: drop __has_attribute() support for gcc4
vmlinux.lds.h: remove old check for GCC 4.9
compiler-gcc.h: drop checks for older GCC versions
Makefile: drop GCC < 5 -fno-var-tracking-assignments workaround
arm64: remove GCC version check for ARCH_SUPPORTS_INT128
powerpc: remove GCC version check for UPD_CONSTR
riscv: remove Kconfig check for GCC version for ARCH_RV64I
Kconfig.debug: drop GCC 5+ version check for DWARF5
mm/ksm: remove old GCC 4.9+ check
compiler.h: drop fallback overflow checkers
Documentation: raise minimum supported version of GCC to 5.1
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Now that GCC 5.1 is the minimum supported version, we can drop this
workaround for older versions of GCC. This adversely affected clang,
too.
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We queue an irq work for deferred processing of mce event in realmode
mce handler, where translation is disabled. Queuing of the work may
result in accessing memory outside RMO region, such access needs the
translation to be enabled for an LPAR running with hash mmu else the
kernel crashes.
After enabling translation in mce_handle_error() we used to leave it
enabled to avoid crashing here, but now with the commit
74c3354bc1d89 ("powerpc/pseries/mce: restore msr before returning from
handler") we are restoring the MSR to disable translation.
Hence to fix this enable the translation before queuing the work.
Without this change following trace is seen on injecting SLB multihit in
an LPAR running with hash mmu.
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
CPU: 5 PID: 1883 Comm: insmod Tainted: G OE 5.14.0-mce+ #137
NIP: c000000000735d60 LR: c000000000318640 CTR: 0000000000000000
REGS: c00000001ebff9a0 TRAP: 0300 Tainted: G OE (5.14.0-mce+)
MSR: 8000000000001003 <SF,ME,RI,LE> CR: 28008228 XER: 00000001
CFAR: c00000000031863c DAR: c00000027fa8fe08 DSISR: 40000000 IRQMASK: 0
...
NIP llist_add_batch+0x0/0x40
LR __irq_work_queue_local+0x70/0xc0
Call Trace:
0xc00000001ebffc0c (unreliable)
irq_work_queue+0x40/0x70
machine_check_queue_event+0xbc/0xd0
machine_check_early_common+0x16c/0x1f4
Fixes: 74c3354bc1d89 ("powerpc/pseries/mce: restore msr before returning from handler")
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
[mpe: Fix comment formatting, trim oops in change log for readability]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210909064330.312432-1-ganeshgr@linux.ibm.com
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POWER9 DD2.2 and 2.3 hardware implements a "fake-suspend" mode where
certain TM instructions executed in HV=0 mode cause softpatch interrupts
so the hypervisor can emulate them and prevent problematic processor
conditions. In this fake-suspend mode, the treclaim. instruction does
not modify registers.
Unfortunately the rfscv instruction executed by the guest do not
generate softpatch interrupts, which can cause the hypervisor to lose
track of the fake-suspend mode, and it can execute this treclaim. while
not in fake-suspend mode. This modifies GPRs and crashes the hypervisor.
It's not trivial to disable scv in the guest with HFSCR now, because
they assume a POWER9 has scv available. So this fix saves and restores
checkpointed registers across the treclaim.
Fixes: 7854f7545bff ("KVM: PPC: Book3S: Rework TM save/restore code and make it C-callable")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210908101718.118522-2-npiggin@gmail.com
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