Currently for radix, flush_tlb_range flushes the entire PID, because
the Linux mm code does not tell us about page size here for THP vs
regular pages. This is quite sub-optimal for small mremap / mprotect
/ change_protection.
So implement va range flushes with two flush passes, one for each
page size (regular and THP). The second flush has an order of matnitude
fewer tlbie instructions than the first, so it is a relatively small
additional cost.
There is still room for improvement here with some changes to generic
APIs, particularly if there are mostly THP pages to be invalidated,
the small page flushes could be reduced.
Time to mprotect 1 page of memory (after mmap, touch):
vanilla 2.9us 1.8us
patched 1.2us 1.6us
Time to mprotect 30 pages of memory (after mmap, touch):
vanilla 8.2us 7.2us
patched 6.9us 17.9us
Time to mprotect 34 pages of memory (after mmap, touch):
vanilla 9.1us 8.0us
patched 9.0us 8.0us
34 pages is the point at which the invalidation switches from va
to entire PID, which tlbie can do in a single instruction. This is
why in the case of 30 pages, the new code runs slower for this test.
This is a deliberate tradeoff already present in the unmap and THP
promotion code, the idea is that the benefit from avoiding flushing
entire TLB for this PID on all threads in the system.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the barriers and range iteration down into the _tlbie* level,
which improves readability.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Short range flushes issue a sequences of tlbie(l) instructions for
individual effective addresses. These do not all require individual
barrier sequences, only one covering all tlbie(l) instructions.
Commit f7327e0ba3 ("powerpc/mm/radix: Remove unnecessary ptesync")
made a similar optimization for tlbiel for PID flushing.
For tlbie, the ISA says:
The tlbsync instruction provides an ordering function for the
effects of all tlbie instructions executed by the thread executing
the tlbsync instruction, with respect to the memory barrier
created by a subsequent ptesync instruction executed by the same
thread.
Time to munmap 30 pages of memory (after mmap, touch):
local global
vanilla 10.9us 22.3us
patched 3.4us 14.4us
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We have some dependencies & conflicts between patches in fixes and
things to go in next, both in the radix TLB flush code and the IMC PMU
driver. So merge fixes into next.
This rearranges the code in kvmppc_run_vcpu() and kvmppc_run_vcpu_hv()
to be neater and clearer. Deeply indented code in kvmppc_run_vcpu()
is moved out to a helper function, kvmhv_setup_mmu(). In
kvmppc_vcpu_run_hv(), make use of the existing variable 'kvm' in
place of 'vcpu->kvm'.
No functional change.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This merges in a couple of fixes from the kvm-ppc-fixes branch that
modify the same areas of code as some commits from the kvm-ppc-next
branch, in order to resolve the conflicts.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
We need to add "clean-files" in Makfiles to clean up DT blobs, but we
often miss to do so.
Since there are no source files that end with .dtb or .dtb.S, so we
can clean-up those files from the top-level Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Most of DT files are compiled under arch/*/boot/dts/, but we have some
other directories, like drivers/of/unittest-data/. We often miss to
add gitignore patterns per directory. Since there are no source files
that end with .dtb or .dtb.S, we can ignore the patterns globally.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Just one fix here for a host crash that can occur with HV KVM
as a result of resizing the guest hashed page table (HPT).
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Merge tag 'kvm-ppc-fixes-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
PPC KVM fixes for 4.14
Just one fix here for a host crash that can occur with HV KVM
as a result of resizing the guest hashed page table (HPT).
It would be nice to be able to dump page tables in a particular
context.
eg: dumping vmalloc space:
0:mon> dv 0xd00037fffff00000
pgd @ 0xc0000000017c0000
pgdp @ 0xc0000000017c00d8 = 0x00000000f10b1000
pudp @ 0xc0000000f10b13f8 = 0x00000000f10d0000
pmdp @ 0xc0000000f10d1ff8 = 0x00000000f1102000
ptep @ 0xc0000000f1102780 = 0xc0000000f1ba018e
Maps physical address = 0x00000000f1ba0000
Flags = Accessed Dirty Read Write
This patch does not replicate the complex code of dump_pagetable and
has no support for bolted linear mapping, thats why I've it's called
dump virtual page table support. The format of the PTE can be expanded
even further to add more useful information about the flags in the PTE
if required.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Bike shed the output format, show the pgdir, fix build failures]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 5e9859699a ("KVM: PPC: Book3S HV: Outline of KVM-HV HPT resizing
implementation", 2016-12-20) added code that tries to exclude any use
or update of the hashed page table (HPT) while the HPT resizing code
is iterating through all the entries in the HPT. It does this by
taking the kvm->lock mutex, clearing the kvm->arch.hpte_setup_done
flag and then sending an IPI to all CPUs in the host. The idea is
that any VCPU task that tries to enter the guest will see that the
hpte_setup_done flag is clear and therefore call kvmppc_hv_setup_htab_rma,
which also takes the kvm->lock mutex and will therefore block until
we release kvm->lock.
However, any VCPU that is already in the guest, or is handling a
hypervisor page fault or hypercall, can re-enter the guest without
rechecking the hpte_setup_done flag. The IPI will cause a guest exit
of any VCPUs that are currently in the guest, but does not prevent
those VCPU tasks from immediately re-entering the guest.
The result is that after resize_hpt_rehash_hpte() has made a HPTE
absent, a hypervisor page fault can occur and make that HPTE present
again. This includes updating the rmap array for the guest real page,
meaning that we now have a pointer in the rmap array which connects
with pointers in the old rev array but not the new rev array. In
fact, if the HPT is being reduced in size, the pointer in the rmap
array could point outside the bounds of the new rev array. If that
happens, we can get a host crash later on such as this one:
[91652.628516] Unable to handle kernel paging request for data at address 0xd0000000157fb10c
[91652.628668] Faulting instruction address: 0xc0000000000e2640
[91652.628736] Oops: Kernel access of bad area, sig: 11 [#1]
[91652.628789] LE SMP NR_CPUS=1024 NUMA PowerNV
[91652.628847] Modules linked in: binfmt_misc vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables ses enclosure scsi_transport_sas i2c_opal ipmi_powernv ipmi_devintf i2c_core ipmi_msghandler powernv_op_panel nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc kvm_hv kvm_pr kvm scsi_dh_alua dm_service_time dm_multipath tg3 ptp pps_core [last unloaded: stap_552b612747aec2da355051e464fa72a1_14259]
[91652.629566] CPU: 136 PID: 41315 Comm: CPU 21/KVM Tainted: G O 4.14.0-1.rc4.dev.gitb27fc5c.el7.centos.ppc64le #1
[91652.629684] task: c0000007a419e400 task.stack: c0000000028d8000
[91652.629750] NIP: c0000000000e2640 LR: d00000000c36e498 CTR: c0000000000e25f0
[91652.629829] REGS: c0000000028db5d0 TRAP: 0300 Tainted: G O (4.14.0-1.rc4.dev.gitb27fc5c.el7.centos.ppc64le)
[91652.629932] MSR: 900000010280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 44022422 XER: 00000000
[91652.630034] CFAR: d00000000c373f84 DAR: d0000000157fb10c DSISR: 40000000 SOFTE: 1
[91652.630034] GPR00: d00000000c36e498 c0000000028db850 c000000001403900 c0000007b7960000
[91652.630034] GPR04: d0000000117fb100 d000000007ab00d8 000000000033bb10 0000000000000000
[91652.630034] GPR08: fffffffffffffe7f 801001810073bb10 d00000000e440000 d00000000c373f70
[91652.630034] GPR12: c0000000000e25f0 c00000000fdb9400 f000000003b24680 0000000000000000
[91652.630034] GPR16: 00000000000004fb 00007ff7081a0000 00000000000ec91a 000000000033bb10
[91652.630034] GPR20: 0000000000010000 00000000001b1190 0000000000000001 0000000000010000
[91652.630034] GPR24: c0000007b7ab8038 d0000000117fb100 0000000ec91a1190 c000001e6a000000
[91652.630034] GPR28: 00000000033bb100 000000000073bb10 c0000007b7960000 d0000000157fb100
[91652.630735] NIP [c0000000000e2640] kvmppc_add_revmap_chain+0x50/0x120
[91652.630806] LR [d00000000c36e498] kvmppc_book3s_hv_page_fault+0xbb8/0xc40 [kvm_hv]
[91652.630884] Call Trace:
[91652.630913] [c0000000028db850] [c0000000028db8b0] 0xc0000000028db8b0 (unreliable)
[91652.630996] [c0000000028db8b0] [d00000000c36e498] kvmppc_book3s_hv_page_fault+0xbb8/0xc40 [kvm_hv]
[91652.631091] [c0000000028db9e0] [d00000000c36a078] kvmppc_vcpu_run_hv+0xdf8/0x1300 [kvm_hv]
[91652.631179] [c0000000028dbb30] [d00000000c2248c4] kvmppc_vcpu_run+0x34/0x50 [kvm]
[91652.631266] [c0000000028dbb50] [d00000000c220d54] kvm_arch_vcpu_ioctl_run+0x114/0x2a0 [kvm]
[91652.631351] [c0000000028dbbd0] [d00000000c2139d8] kvm_vcpu_ioctl+0x598/0x7a0 [kvm]
[91652.631433] [c0000000028dbd40] [c0000000003832e0] do_vfs_ioctl+0xd0/0x8c0
[91652.631501] [c0000000028dbde0] [c000000000383ba4] SyS_ioctl+0xd4/0x130
[91652.631569] [c0000000028dbe30] [c00000000000b8e0] system_call+0x58/0x6c
[91652.631635] Instruction dump:
[91652.631676] fba1ffe8 fbc1fff0 fbe1fff8 f8010010 f821ffa1 2fa70000 793d0020 e9432110
[91652.631814] 7bbf26e4 7c7e1b78 7feafa14 409e0094 <807f000c> 786326e4 7c6a1a14 93a40008
[91652.631959] ---[ end trace ac85ba6db72e5b2e ]---
To fix this, we tighten up the way that the hpte_setup_done flag is
checked to ensure that it does provide the guarantee that the resizing
code needs. In kvmppc_run_core(), we check the hpte_setup_done flag
after disabling interrupts and refuse to enter the guest if it is
clear (for a HPT guest). The code that checks hpte_setup_done and
calls kvmppc_hv_setup_htab_rma() is moved from kvmppc_vcpu_run_hv()
to a point inside the main loop in kvmppc_run_vcpu(), ensuring that
we don't just spin endlessly calling kvmppc_run_core() while
hpte_setup_done is clear, but instead have a chance to block on the
kvm->lock mutex.
Finally we also check hpte_setup_done inside the region in
kvmppc_book3s_hv_page_fault() where the HPTE is locked and we are about
to update the HPTE, and bail out if it is clear. If another CPU is
inside kvm_vm_ioctl_resize_hpt_commit) and has cleared hpte_setup_done,
then we know that either we are looking at a HPTE
that resize_hpt_rehash_hpte() has not yet processed, which is OK,
or else we will see hpte_setup_done clear and refuse to update it,
because of the full barrier formed by the unlock of the HPTE in
resize_hpt_rehash_hpte() combined with the locking of the HPTE
in kvmppc_book3s_hv_page_fault().
Fixes: 5e9859699a ("KVM: PPC: Book3S HV: Outline of KVM-HV HPT resizing implementation")
Cc: stable@vger.kernel.org # v4.10+
Reported-by: Satheesh Rajendran <satheera@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
<linux/pci.h> defines struct pci_bus and struct pci_dev and includes the
struct resource definition before including <asm/pci.h>. Nobody includes
<asm/pci.h> directly, so they don't need their own declarations.
Remove the redundant struct pci_dev, pci_bus, resource declarations.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> # CRIS
Acked-by: Ralf Baechle <ralf@linux-mips.org> # MIPS
In preperation for a new function that will need additional resource
information during the resource walk, update the resource walk callback to
pass the resource structure. Since the current callback start and end
arguments are pulled from the resource structure, the callback functions
can obtain them from the resource structure directly.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lkml.kernel.org/r/20171020143059.3291-10-brijesh.singh@amd.com
In commit e6f81a9201 ("powerpc/mm/hash: Support 68 bit VA") the
masking is folded into ASM_VSID_SCRAMBLE but the comment about masking
is removed only from the firt use of ASM_VSID_SCRAMBLE.
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
DMA windows can only have a size of power of two on IODA2 hardware and
using memory_hotplug_max() to determine the upper limit won't work
correcly if it returns not power of two value.
This removes the check as the platform code does this check in
pnv_pci_ioda2_setup_default_config() anyway; the other client is VFIO
and that thing checks against locked_vm limit which prevents the userspace
from locking too much memory.
It is expected to impact DPDK on machines with non-power-of-two RAM size,
mostly. KVM guests are less likely to be affected as usually guests get
less than half of hosts RAM.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The call to /proc/cpuinfo in turn calls cpufreq_quick_get() which
returns the last frequency requested by the kernel, but may not
reflect the actual frequency the processor is running at. This patch
makes a call to cpufreq_get() instead which returns the current
frequency reported by the hardware.
Fixes: fb5153d05a ("powerpc: powernv: Implement ppc_md.get_proc_freq()")
Signed-off-by: Shriya <shriyak@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
DD2.1 does not have to save MMCR0 for all state-loss idle states,
only after deep idle states (like other PMU registers).
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
DD2.1 does not have to flush the ERAT after a state-loss idle.
Performance testing was done on a DD2.1 using only the stop0 idle state
(the shallowest state which supports state loss), using context_switch
selftest configured to ping-poing between two threads on the same core
and two different cores.
Performance improvement for same core is 7.0%, different cores is 14.8%.
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
After handling a transactional FP, Altivec or VSX unavailable exception.
The return to userspace code will detect that the TIF_RESTORE_TM bit is
set and call restore_tm_state(). restore_tm_state() will call
restore_math() to ensure that the correct facilities are loaded.
This means that all the loadup code in {fp,altivec,vsx}_unavailable_tm()
is doing pointless work and can simply be removed.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Lazy save and restore of FP/Altivec means that a userspace process can
be sent to userspace with FP or Altivec disabled and loaded only as
required (by way of an FP/Altivec unavailable exception). Transactional
Memory complicates this situation as a transaction could be started
without FP/Altivec being loaded up. This causes the hardware to
checkpoint incorrect registers. Handling FP/Altivec unavailable
exceptions while a thread is transactional requires a reclaim and
recheckpoint to ensure the CPU has correct state for both sets of
registers.
tm_reclaim() has optimisations to not always save the FP/Altivec
registers to the checkpointed save area. This was originally done
because the caller might have information that the checkpointed
registers aren't valid due to lazy save and restore. We've also been a
little vague as to how tm_reclaim() leaves the FP/Altivec state since it
doesn't necessarily always save it to the thread struct. This has lead
to an (incorrect) assumption that it leaves the checkpointed state on
the CPU.
tm_recheckpoint() has similar optimisations in reverse. It may not
always reload the checkpointed FP/Altivec registers from the thread
struct before the trecheckpoint. It is therefore quite unclear where it
expects to get the state from. This didn't help with the assumption
made about tm_reclaim().
These optimisations sit in what is by definition a slow path. If a
process has to go through a reclaim/recheckpoint then its transaction
will be doomed on returning to userspace. This mean that the process
will be unable to complete its transaction and be forced to its failure
handler. This is already an out if line case for userspace. Furthermore,
the cost of copying 64 times 128 bits from registers isn't very long[0]
(at all) on modern processors. As such it appears these optimisations
have only served to increase code complexity and are unlikely to have
had a measurable performance impact.
Our transactional memory handling has been riddled with bugs. A cause
of this has been difficulty in following the code flow, code complexity
has not been our friend here. It makes sense to remove these
optimisations in favour of a (hopefully) more stable implementation.
This patch does mean that some times the assembly will needlessly save
'junk' registers which will subsequently get overwritten with the
correct value by the C code which calls the assembly function. This
small inefficiency is far outweighed by the reduction in complexity for
general TM code, context switching paths, and transactional facility
unavailable exception handler.
0: I tried to measure it once for other work and found that it was
hiding in the noise of everything else I was working with. I find it
exceedingly likely this will be the case here.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Lazy save and restore of FP/Altivec means that a userspace process can
be sent to userspace with FP or Altivec disabled and loaded only as
required (by way of an FP/Altivec unavailable exception). Transactional
Memory complicates this situation as a transaction could be started
without FP/Altivec being loaded up. This causes the hardware to
checkpoint incorrect registers. Handling FP/Altivec unavailable
exceptions while a thread is transactional requires a reclaim and
recheckpoint to ensure the CPU has correct state for both sets of
registers.
tm_reclaim() has optimisations to not always save the FP/Altivec
registers to the checkpointed save area. This was originally done
because the caller might have information that the checkpointed
registers aren't valid due to lazy save and restore. We've also been a
little vague as to how tm_reclaim() leaves the FP/Altivec state since it
doesn't necessarily always save it to the thread struct. This has lead
to an (incorrect) assumption that it leaves the checkpointed state on
the CPU.
tm_recheckpoint() has similar optimisations in reverse. It may not
always reload the checkpointed FP/Altivec registers from the thread
struct before the trecheckpoint. It is therefore quite unclear where it
expects to get the state from. This didn't help with the assumption
made about tm_reclaim().
This patch is a minimal fix for ease of backporting. A more correct fix
which removes the msr parameter to tm_reclaim() and tm_recheckpoint()
altogether has been upstreamed to apply on top of this patch.
Fixes: dc3106690b ("powerpc: tm: Always use fp_state and vr_state to
store live registers")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Lazy save and restore of FP/Altivec means that a userspace process can
be sent to userspace with FP or Altivec disabled and loaded only as
required (by way of an FP/Altivec unavailable exception). Transactional
Memory complicates this situation as a transaction could be started
without FP/Altivec being loaded up. This causes the hardware to
checkpoint incorrect registers. Handling FP/Altivec unavailable
exceptions while a thread is transactional requires a reclaim and
recheckpoint to ensure the CPU has correct state for both sets of
registers.
Lazy save and restore of FP/Altivec cannot be done if a process is
transactional. If a facility was enabled it must remain enabled whenever
a thread is transactional.
Commit dc16b553c9 ("powerpc: Always restore FPU/VEC/VSX if hardware
transactional memory in use") ensures that the facilities are always
enabled if a thread is transactional. A bug in the introduced code may
cause it to inadvertently enable a facility that was (and should remain)
disabled. The problem with this extraneous enablement is that the
registers for the erroneously enabled facility have not been correctly
recheckpointed - the recheckpointing code assumed the facility would
remain disabled.
Further compounding the issue, the transactional {fp,altivec,vsx}
unavailable code has been incorrectly using the MSR to enable
facilities. The presence of the {FP,VEC,VSX} bit in the regs->msr simply
means if the registers are live on the CPU, not if the kernel should
load them before returning to userspace. This has worked due to the bug
mentioned above.
This causes transactional threads which return to their failure handler
to observe incorrect checkpointed registers. Perhaps an example will
help illustrate the problem:
A userspace process is running and uses both FP and Altivec registers.
This process then continues to run for some time without touching
either sets of registers. The kernel subsequently disables the
facilities as part of lazy save and restore. The userspace process then
performs a tbegin and the CPU checkpoints 'junk' FP and Altivec
registers. The process then performs a floating point instruction
triggering a fp unavailable exception in the kernel.
The kernel then loads the FP registers - and only the FP registers.
Since the thread is transactional it must perform a reclaim and
recheckpoint to ensure both the checkpointed registers and the
transactional registers are correct. It then (correctly) enables
MSR[FP] for the process. Later (on exception exist) the kernel also
(inadvertently) enables MSR[VEC]. The process is then returned to
userspace.
Since the act of loading the FP registers doomed the transaction we know
CPU will fail the transaction, restore its checkpointed registers, and
return the process to its failure handler. The problem is that we're
now running with Altivec enabled and the 'junk' checkpointed registers
are restored. The kernel had only recheckpointed FP.
This patch solves this by only activating FP/Altivec if userspace was
using them when it entered the kernel and not simply if the process is
transactional.
Fixes: dc16b553c9 ("powerpc: Always restore FPU/VEC/VSX if hardware
transactional memory in use")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Also export opal_error_code() so that it can be used in modules
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds an _interruptible version of opal_async_wait_response().
This is useful when a long running OPAL call is performed on behalf of
a userspace thread, for example, the opal_flash_{read,write,erase}
functions performed by the powernv-flash MTD driver.
It is foreseeable that these functions would take upwards of two
minutes causing the wait_event() to block long enough to cause hung
task warnings. Furthermore, wait_event_interruptible() is preferable
as otherwise there is no way for signals to stop the process which is
going to be confusing in userspace.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Parallel sensor reads could run out of async tokens due to
opal_get_sensor_data grabbing tokens but then doing the sensor
read behind a mutex, essentially serializing the (possibly
asynchronous and relatively slow) sensor read.
It turns out that the mutex isn't needed at all, not only
should the OPAL interface allow concurrent reads, the implementation
is certainly safe for that, and if any sensor we were reading
from somewhere isn't, doing the mutual exclusion in the kernel
is the wrong place to do it, OPAL should be doing it for the kernel.
So, remove the mutex.
Additionally, we shouldn't be printing out an error when we don't
get a token as the only way this should happen is if we've been
interrupted in down_interruptible() on the semaphore.
Reported-by: Robert Lippert <rlippert@google.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Future work will add an opal_async_wait_response_interruptible()
which will call wait_event_interruptible(). This work requires extra
token state to be tracked as wait_event_interruptible() can return and
the caller could release the token before OPAL responds.
Currently token state is tracked with two bitfields which are 64 bits
big but may not need to be as OPAL informs Linux how many async tokens
there are. It also uses an array indexed by token to store response
messages for each token.
The bitfields make it difficult to add more state and also provide a
hard maximum as to how many tokens there can be - it is possible that
OPAL will inform Linux that there are more than 64 tokens.
Rather than add a bitfield to track the extra state, rework the
internals slightly.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Fix __opal_async_get_token() when no tokens are free]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are no callers of both __opal_async_get_token() and
__opal_async_release_token().
This patch also removes the possibility of "emergency through
synchronous call to __opal_async_get_token()" as such it makes more
sense to initialise opal_sync_sem for the maximum number of async
tokens.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The current code checks the completion map to look for the first token
that is complete. In some cases, a completion can come in but the
token can still be on lease to the caller processing the completion.
If this completed but unreleased token is the first token found in the
bitmap by another tasks trying to acquire a token, then the
__test_and_set_bit call will fail since the token will still be on
lease. The acquisition will then fail with an EBUSY.
This patch reorganizes the acquisition code to look at the
opal_async_token_map for an unleased token. If the token has no lease
it must have no outstanding completions so we should never see an
EBUSY, unless we have leased out too many tokens. Since
opal_async_get_token_inrerruptible is protected by a semaphore, we
will practically never see EBUSY anymore.
Fixes: 8d72482322 ("powerpc/powernv: Infrastructure to support OPAL async completion")
Signed-off-by: William A. Kennington III <wak@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This interface is inefficient and deprecated because of the y2038
overflow.
ktime_get_seconds() is an appropriate replacement here, since it
has sufficient granularity but is more efficient and uses monotonic
time.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Take advantage of stack_depth tracking, originally introduced for
x64, in powerpc JIT as well. Round up allocated stack by 16 bytes
to make sure it stays aligned for functions called from JITed bpf
program.
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently when we take a TM Bad Thing program check exception, we
search the bug table to see if the program check was generated by a
WARN/WARN_ON etc.
That makes no sense, the WARN macros use trap instructions, which
should never generate a TM Bad Thing exception. If they ever did that
would be a bug and we should oops.
We do have some hand-coded bugs in tm.S, using EMIT_BUG_ENTRY, but
those are all BUGs not WARNs, and they all use trap instructions
anyway. Almost certainly this check was incorrectly copied from the
REASON_TRAP handling in the same function.
Remove it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-By: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently if the hardware supports the radix MMU we will use
it, *unless* "disable_radix" is passed on the kernel command line.
However some users would like the reverse semantics. ie. The kernel
uses the hash MMU by default, unless radix is explicitly requested on
the command line.
So add a CONFIG option to choose whether we use radix by default or
not, and expand the disable_radix command line option to allow
"disable_radix=no" which *enables* radix.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
CONFIG_PPC_STD_MMU_64 indicates support for the "standard" powerpc MMU
on 64-bit CPUs. The "standard" MMU refers to the hash page table MMU
found in "server" processors, from IBM mainly.
Currently CONFIG_PPC_STD_MMU_64 is == CONFIG_PPC_BOOK3S_64. While it's
annoying to have two symbols that always have the same value, it's not
quite annoying enough to bother removing one.
However with the arrival of Power9, we now have the situation where
CONFIG_PPC_STD_MMU_64 is enabled, but the kernel is running using the
Radix MMU - *not* the "standard" MMU. So it is now actively confusing
to use it, because it implies that code is disabled or inactive when
the Radix MMU is in use, however that is not necessarily true.
So s/CONFIG_PPC_STD_MMU_64/CONFIG_PPC_BOOK3S_64/, and do some minor
formatting updates of some of the affected lines.
This will be a pain for backports, but c'est la vie.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The last user of CPU_FTR_ICSWX was removed in commit
6ff4d3e966 ("powerpc: Remove old unused icswx based coprocessor
support"), so free the bit up for future use.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
IPIC Status is provided by register IPIC_SERSR and not by IPIC_SERMR
which is the mask register.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In order to make generic IOV code work, the physical function IOV BAR
should start from offset of the first VF. Since M64 segments share
PE number space across PHB, and some PEs may be in use at the time
when IOV is enabled, the existing code shifts the IOV BAR to the index
of the first PE/VF. This creates a hole in IOMEM space which can be
potentially taken by some other device.
This reserves a temporary hole on a parent and releases it when IOV is
disabled; the temporary resources are stored in pci_dn to avoid
kmalloc/free.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When a vdevice is DLPAR removed from the system the vio subsystem
doesn't bother unmapping the virq from the irq_domain. As a result we
have a virq mapped to a hardware irq that is no longer valid for the
irq_domain. A side effect is that we are left with /proc/irq/<irq#>
affinity entries, and attempts to modify the smp_affinity of the irq
will fail.
In the following observed example the kernel log is spammed by
ics_rtas_set_affinity errors after the removal of a VSCSI adapter.
This is a result of irqbalance trying to adjust the affinity every 10
seconds.
rpadlpar_io: slot U8408.E8E.10A7ACV-V5-C25 removed
ics_rtas_set_affinity: ibm,set-xive irq=655385 returns -3
ics_rtas_set_affinity: ibm,set-xive irq=655385 returns -3
This patch fixes the issue by calling irq_dispose_mapping() on the
virq of the viodev on unregister.
Fixes: f2ab621996 ("powerpc/pseries: Add PFO support to the VIO bus")
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
According to the architecture, the process table entry cache must be
flushed with tlbie RIC=2.
Currently the process table entry is set to invalid right before the
PID is returned to the allocator, with no invalidation. This works on
existing implementations that are known to not cache the process table
entry for any except the current PIDR.
It is architecturally correct and cleaner to invalidate with RIC=2
after clearing the process table entry and before the PID is returned
to the allocator. This can be done in arch_exit_mmap that runs before
the final flush, and to ensure the final flush (fullmm) is always a
RIC=2 variant.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Preempt should be consistently disabled for mm_is_thread_local tests,
so bring the rest of these under preempt_disable().
Preempt does not need to be disabled for the mm->context.id tests,
which allows simplification and removal of gotos.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Close the recoverability gap for OPAL calls by using FIXUP_ENDIAN_HV
in the return path.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add an HV variant of FIXUP_ENDIAN which uses HSRR[01] and does not
clear MSR[RI], which improves recoverability.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When returning from an exception to a soft-enabled context, pending
IRQs are replayed but IRQ tracing is not reset, so a number of them
can get chained together into the same IRQ-disabled trace.
Fix this by having __check_irq_replay re-set IRQ trace. This is
conceptually where we respond to the next interrupt, so it fits the
semantics of the IRQ tracer.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If the host takes a system reset interrupt while a guest is running,
the CPU must exit the guest before processing the host exception
handler.
After this patch, taking a sysrq+x with a CPU running in a guest
gives a trace like this:
cpu 0x27: Vector: 100 (System Reset) at [c000000fdf5776f0]
pc: c008000010158b80: kvmppc_run_core+0x16b8/0x1ad0 [kvm_hv]
lr: c008000010158b80: kvmppc_run_core+0x16b8/0x1ad0 [kvm_hv]
sp: c000000fdf577850
msr: 9000000002803033
current = 0xc000000fdf4b1e00
paca = 0xc00000000fd4d680 softe: 3 irq_happened: 0x01
pid = 6608, comm = qemu-system-ppc
Linux version 4.14.0-rc7-01489-g47e1893a404a-dirty #26 SMP
[c000000fdf577a00] c008000010159dd4 kvmppc_vcpu_run_hv+0x3dc/0x12d0 [kvm_hv]
[c000000fdf577b30] c0080000100a537c kvmppc_vcpu_run+0x44/0x60 [kvm]
[c000000fdf577b60] c0080000100a1ae0 kvm_arch_vcpu_ioctl_run+0x118/0x310 [kvm]
[c000000fdf577c00] c008000010093e98 kvm_vcpu_ioctl+0x530/0x7c0 [kvm]
[c000000fdf577d50] c000000000357bf8 do_vfs_ioctl+0xd8/0x8c0
[c000000fdf577df0] c000000000358448 SyS_ioctl+0x68/0x100
[c000000fdf577e30] c00000000000b220 system_call+0x58/0x6c
--- Exception: c01 (System Call) at 00007fff76868df0
SP (7fff7069baf0) is in userspace
Fixes: e36d0a2ed5 ("powerpc/powernv: Implement NMI IPI with OPAL_SIGNAL_SYSTEM_RESET")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
A fix to the handling of misaligned paste instructions (P9 only), where a change
to a #define has caused the check for the instruction to always fail.
The preempt handling was unbalanced in the radix THP flush (P9 only). Though we
don't generally use preempt we want to keep it working as much as possible.
Two fixes for IMC (P9 only), one when booting with restricted number of CPUs and
one in the error handling when initialisation fails due to firmware etc.
A revert to fix function_graph on big endian machines, and then a rework of the
reverted patch to fix kprobes blacklist handling on big endian machines.
Thanks to:
Anju T Sudhakar, Guilherme G. Piccoli, Madhavan Srinivasan, Naveen N. Rao,
Nicholas Piggin, Paul Mackerras.
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Merge tag 'powerpc-4.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Some more powerpc fixes for 4.14.
This is bigger than I like to send at rc7, but that's at least partly
because I didn't send any fixes last week. If it wasn't for the IMC
driver, which is new and getting heavy testing, the diffstat would
look a bit better. I've also added ftrace on big endian to my test
suite, so we shouldn't break that again in future.
- A fix to the handling of misaligned paste instructions (P9 only),
where a change to a #define has caused the check for the
instruction to always fail.
- The preempt handling was unbalanced in the radix THP flush (P9
only). Though we don't generally use preempt we want to keep it
working as much as possible.
- Two fixes for IMC (P9 only), one when booting with restricted
number of CPUs and one in the error handling when initialisation
fails due to firmware etc.
- A revert to fix function_graph on big endian machines, and then a
rework of the reverted patch to fix kprobes blacklist handling on
big endian machines.
Thanks to: Anju T Sudhakar, Guilherme G. Piccoli, Madhavan Srinivasan,
Naveen N. Rao, Nicholas Piggin, Paul Mackerras"
* tag 'powerpc-4.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/perf: Fix core-imc hotplug callback failure during imc initialization
powerpc/kprobes: Dereference function pointers only if the address does not belong to kernel text
Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols"
powerpc/64s/radix: Fix preempt imbalance in TLB flush
powerpc: Fix check for copy/paste instructions in alignment handler
powerpc/perf: Fix IMC allocation routine
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Call trace observed during boot:
nest_capp0_imc performance monitor hardware support registered
nest_capp1_imc performance monitor hardware support registered
core_imc memory allocation for cpu 56 failed
Unable to handle kernel paging request for data at address 0xffa400010
Faulting instruction address: 0xc000000000bf3294
0:mon> e
cpu 0x0: Vector: 300 (Data Access) at [c000000ff38ff8d0]
pc: c000000000bf3294: mutex_lock+0x34/0x90
lr: c000000000bf3288: mutex_lock+0x28/0x90
sp: c000000ff38ffb50
msr: 9000000002009033
dar: ffa400010
dsisr: 80000
current = 0xc000000ff383de00
paca = 0xc000000007ae0000 softe: 0 irq_happened: 0x01
pid = 13, comm = cpuhp/0
Linux version 4.11.0-39.el7a.ppc64le (mockbuild@ppc-058.build.eng.bos.redhat.com) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) ) #1 SMP Tue Oct 3 07:42:44 EDT 2017
0:mon> t
[c000000ff38ffb80] c0000000002ddfac perf_pmu_migrate_context+0xac/0x470
[c000000ff38ffc40] c00000000011385c ppc_core_imc_cpu_offline+0x1ac/0x1e0
[c000000ff38ffc90] c000000000125758 cpuhp_invoke_callback+0x198/0x5d0
[c000000ff38ffd00] c00000000012782c cpuhp_thread_fun+0x8c/0x3d0
[c000000ff38ffd60] c0000000001678d0 smpboot_thread_fn+0x290/0x2a0
[c000000ff38ffdc0] c00000000015ee78 kthread+0x168/0x1b0
[c000000ff38ffe30] c00000000000b368 ret_from_kernel_thread+0x5c/0x74
While registering the cpuhoplug callbacks for core-imc, if we fails
in the cpuhotplug online path for any random core (either because opal call to
initialize the core-imc counters fails or because memory allocation fails for
that core), ppc_core_imc_cpu_offline() will get invoked for other cpus who
successfully returned from cpuhotplug online path.
But in the ppc_core_imc_cpu_offline() path we are trying to migrate the event
context, when core-imc counters are not even initialized. Thus creating the
above stack dump.
Add a check to see if core-imc counters are enabled or not in the cpuhotplug
offline path before migrating the context to handle this failing scenario.
Fixes: 885dcd709b ("powerpc/perf: Add nest IMC PMU support")
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull initial SPDX identifiers from Greg KH:
"License cleanup: add SPDX license identifiers to some files
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the
'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally
binding shorthand, which can be used instead of the full boiler plate
text.
This patch is based on work done by Thomas Gleixner and Kate Stewart
and Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset
of the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to
license had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied
to a file was done in a spreadsheet of side by side results from of
the output of two independent scanners (ScanCode & Windriver)
producing SPDX tag:value files created by Philippe Ombredanne.
Philippe prepared the base worksheet, and did an initial spot review
of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537
files assessed. Kate Stewart did a file by file comparison of the
scanner results in the spreadsheet to determine which SPDX license
identifier(s) to be applied to the file. She confirmed any
determination that was not immediately clear with lawyers working with
the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained
>5 lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that
was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that
became the concluded license(s).
- when there was disagreement between the two scanners (one detected
a license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply
(and which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases,
confirmation by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.
The Windriver scanner is based on an older version of FOSSology in
part, so they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot
checks in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect
the correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial
patch version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch
license was not GPL-2.0 WITH Linux-syscall-note to ensure that the
applied SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
License cleanup: add SPDX license identifier to uapi header files with a license
License cleanup: add SPDX license identifier to uapi header files with no license
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.
Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.
GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.
Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.
By default are files without license information under the default
license of the kernel, which is GPLV2. Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
otherwise syscall usage would not be possible.
Update the files which contain no license information with an SPDX
license identifier. The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception. SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Backmerge tag 'v4.14-rc7' into drm-next
Linux 4.14-rc7
Requested by Ben Skeggs for nouveau to avoid major conflicts,
and things were getting a bit conflicty already, esp around amdgpu
reverts.
This makes the changes introduced in commit 83e840c770
("powerpc64/elfv1: Only dereference function descriptor for non-text
symbols") to be specific to the kprobe subsystem.
We previously changed ppc_function_entry() to always check the provided
address to confirm if it needed to be dereferenced. This is actually
only an issue for kprobe blacklisted asm labels (through use of
_ASM_NOKPROBE_SYMBOL) and can cause other issues with ftrace. Also, the
additional checks are not really necessary for our other uses.
As such, move this check to the kprobes subsystem.
Fixes: 83e840c770 ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This reverts commit 83e840c770 ("powerpc64/elfv1: Only dereference
function descriptor for non-text symbols").
Chandan reported that on newer kernels, trying to enable function_graph
tracer on ppc64 (BE) locks up the system with the following trace:
Unable to handle kernel paging request for data at address 0x600000002fa30010
Faulting instruction address: 0xc0000000001f1300
Thread overran stack, or stack corrupted
Oops: Kernel access of bad area, sig: 11 [#1]
BE SMP NR_CPUS=2048 DEBUG_PAGEALLOC NUMA pSeries
Modules linked in:
CPU: 1 PID: 6586 Comm: bash Not tainted 4.14.0-rc3-00162-g6e51f1f-dirty #20
task: c000000625c07200 task.stack: c000000625c07310
NIP: c0000000001f1300 LR: c000000000121cac CTR: c000000000061af8
REGS: c000000625c088c0 TRAP: 0380 Not tainted (4.14.0-rc3-00162-g6e51f1f-dirty)
MSR: 8000000000001032 <SF,ME,IR,DR,RI> CR: 28002848 XER: 00000000
CFAR: c0000000001f1320 SOFTE: 0
...
NIP [c0000000001f1300] .__is_insn_slot_addr+0x30/0x90
LR [c000000000121cac] .kernel_text_address+0x18c/0x1c0
Call Trace:
[c000000625c08b40] [c0000000001bd040] .is_module_text_address+0x20/0x40 (unreliable)
[c000000625c08bc0] [c000000000121cac] .kernel_text_address+0x18c/0x1c0
[c000000625c08c50] [c000000000061960] .prepare_ftrace_return+0x50/0x130
[c000000625c08cf0] [c000000000061b10] .ftrace_graph_caller+0x14/0x34
[c000000625c08d60] [c000000000121b40] .kernel_text_address+0x20/0x1c0
[c000000625c08df0] [c000000000061960] .prepare_ftrace_return+0x50/0x130
...
[c000000625c0ab30] [c000000000061960] .prepare_ftrace_return+0x50/0x130
[c000000625c0abd0] [c000000000061b10] .ftrace_graph_caller+0x14/0x34
[c000000625c0ac40] [c000000000121b40] .kernel_text_address+0x20/0x1c0
[c000000625c0acd0] [c000000000061960] .prepare_ftrace_return+0x50/0x130
[c000000625c0ad70] [c000000000061b10] .ftrace_graph_caller+0x14/0x34
[c000000625c0ade0] [c000000000121b40] .kernel_text_address+0x20/0x1c0
This is because ftrace is using ppc_function_entry() for obtaining the
address of return_to_handler() in prepare_ftrace_return(). The call to
kernel_text_address() itself gets traced and we end up in a recursive
loop.
Fixes: 83e840c770 ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols")
Cc: stable@vger.kernel.org # v4.13+
Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch removes the restriction that a radix host can only run
radix guests, allowing us to run HPT (hashed page table) guests as
well. This is useful because it provides a way to run old guest
kernels that know about POWER8 but not POWER9.
Unfortunately, POWER9 currently has a restriction that all threads
in a given code must either all be in HPT mode, or all in radix mode.
This means that when entering a HPT guest, we have to obtain control
of all 4 threads in the core and get them to switch their LPIDR and
LPCR registers, even if they are not going to run a guest. On guest
exit we also have to get all threads to switch LPIDR and LPCR back
to host values.
To make this feasible, we require that KVM not be in the "independent
threads" mode, and that the CPU cores be in single-threaded mode from
the host kernel's perspective (only thread 0 online; threads 1, 2 and
3 offline). That allows us to use the same code as on POWER8 for
obtaining control of the secondary threads.
To manage the LPCR/LPIDR changes required, we extend the kvm_split_info
struct to contain the information needed by the secondary threads.
All threads perform a barrier synchronization (where all threads wait
for every other thread to reach the synchronization point) on guest
entry, both before and after loading LPCR and LPIDR. On guest exit,
they all once again perform a barrier synchronization both before
and after loading host values into LPCR and LPIDR.
Finally, it is also currently necessary to flush the entire TLB every
time we enter a HPT guest on a radix host. We do this on thread 0
with a loop of tlbiel instructions.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch allows for a mode on POWER9 hosts where we control all the
threads of a core, much as we do on POWER8. The mode is controlled by
a module parameter on the kvm_hv module, called "indep_threads_mode".
The normal mode on POWER9 is the "independent threads" mode, with
indep_threads_mode=Y, where the host is in SMT4 mode (or in fact any
desired SMT mode) and each thread independently enters and exits from
KVM guests without reference to what other threads in the core are
doing.
If indep_threads_mode is set to N at the point when a VM is started,
KVM will expect every core that the guest runs on to be in single
threaded mode (that is, threads 1, 2 and 3 offline), and will set the
flag that prevents secondary threads from coming online. We can still
use all four threads; the code that implements dynamic micro-threading
on POWER8 will become active in over-commit situations and will allow
up to three other VCPUs to be run on the secondary threads of the core
whenever a VCPU is run.
The reason for wanting this mode is that this will allow us to run HPT
guests on a radix host on a POWER9 machine that does not support
"mixed mode", that is, having some threads in a core be in HPT mode
while other threads are in radix mode. It will also make it possible
to implement a "strict threads" mode in future, if desired.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This sets up the machinery for switching a guest between HPT (hashed
page table) and radix MMU modes, so that in future we can run a HPT
guest on a radix host on POWER9 machines.
* The KVM_PPC_CONFIGURE_V3_MMU ioctl can now specify either HPT or
radix mode, on a radix host.
* The KVM_CAP_PPC_MMU_HASH_V3 capability now returns 1 on POWER9
with HV KVM on a radix host.
* The KVM_PPC_GET_SMMU_INFO returns information about the HPT MMU on a
radix host.
* The KVM_PPC_ALLOCATE_HTAB ioctl on a radix host will switch the
guest to HPT mode and allocate a HPT.
* For simplicity, we now allocate the rmap array for each memslot,
even on a radix host, since it will be needed if the guest switches
to HPT mode.
* Since we cannot yet run a HPT guest on a radix host, the KVM_RUN
ioctl will return an EINVAL error in that case.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently, the HPT code in HV KVM maintains a dirty bit per guest page
in the rmap array, whether or not dirty page tracking has been enabled
for the memory slot. In contrast, the radix code maintains a dirty
bit per guest page in memslot->dirty_bitmap, and only does so when
dirty page tracking has been enabled.
This changes the HPT code to maintain the dirty bits in the memslot
dirty_bitmap like radix does. This results in slightly less code
overall, and will mean that we do not lose the dirty bits when
transitioning between HPT and radix mode in future.
There is one minor change to behaviour as a result. With HPT, when
dirty tracking was enabled for a memslot, we would previously clear
all the dirty bits at that point (both in the HPT entries and in the
rmap arrays), meaning that a KVM_GET_DIRTY_LOG ioctl immediately
following would show no pages as dirty (assuming no vcpus have run
in the meantime). With this change, the dirty bits on HPT entries
are not cleared at the point where dirty tracking is enabled, so
KVM_GET_DIRTY_LOG would show as dirty any guest pages that are
resident in the HPT and dirty. This is consistent with what happens
on radix.
This also fixes a bug in the mark_pages_dirty() function for radix
(in the sense that the function no longer exists). In the case where
a large page of 64 normal pages or more is marked dirty, the
addressing of the dirty bitmap was incorrect and could write past
the end of the bitmap. Fortunately this case was never hit in
practice because a 2MB large page is only 32 x 64kB pages, and we
don't support backing the guest with 1GB huge pages at this point.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This renames the kvm->arch.hpte_setup_done field to mmu_ready because
we will want to use it for radix guests too -- both for setting things
up before vcpu execution, and for excluding vcpus from executing while
MMU-related things get changed, such as in future switching the MMU
from radix to HPT mode or vice-versa.
This also moves the call to kvmppc_setup_partition_table() that was
done in kvmppc_hv_setup_htab_rma() for HPT guests, and the setting
of mmu_ready, into the caller in kvmppc_vcpu_run_hv().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This removes the dependence of KVM on the mmu_psize_defs array (which
stores information about hardware support for various page sizes) and
the things derived from it, chiefly hpte_page_sizes[], hpte_page_size(),
hpte_actual_page_size() and get_sllp_encoding(). We also no longer
rely on the mmu_slb_size variable or the MMU_FTR_1T_SEGMENTS feature
bit.
The reason for doing this is so we can support a HPT guest on a radix
host. In a radix host, the mmu_psize_defs array contains information
about page sizes supported by the MMU in radix mode rather than the
page sizes supported by the MMU in HPT mode. Similarly, mmu_slb_size
and the MMU_FTR_1T_SEGMENTS bit are not set.
Instead we hard-code knowledge of the behaviour of the HPT MMU in the
POWER7, POWER8 and POWER9 processors (which are the only processors
supported by HV KVM) - specifically the encoding of the LP fields in
the HPT and SLB entries, and the fact that they have 32 SLB entries
and support 1TB segments.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This merges in the ppc-kvm topic branch of the powerpc tree to get the
commit that reverts the patch "KVM: PPC: Book3S HV: POWER9 does not
require secondary thread management". This is needed for subsequent
patches which will be applied on this branch.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This fixes the message:
arch/powerpc/kvm/book3s_segment.S: Assembler messages:
arch/powerpc/kvm/book3s_segment.S:330: Warning: invalid register expression
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Userland passes an array of 64 SLB descriptors to KVM_SET_SREGS,
some of which are valid (ie, SLB_ESID_V is set) and the rest are
likely all-zeroes (with QEMU at least).
Each of them is then passed to kvmppc_mmu_book3s_64_slbmte(), which
assumes to find the SLB index in the 3 lower bits of its rb argument.
When passed zeroed arguments, it happily overwrites the 0th SLB entry
with zeroes. This is exactly what happens while doing live migration
with QEMU when the destination pushes the incoming SLB descriptors to
KVM PR. When reloading the SLBs at the next synchronization, QEMU first
clears its SLB array and only restore valid ones, but the 0th one is
now gone and we cannot access the corresponding memory anymore:
(qemu) x/x $pc
c0000000000b742c: Cannot access memory
To avoid this, let's filter out non-valid SLB entries. While here, we
also force a full SLB flush before installing new entries. Since SLB
is for 64-bit only, we now build this path conditionally to avoid a
build break on 32-bit, which doesn't define SLB_ESID_V.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When running a guest on a POWER9 system with the in-kernel XICS
emulation disabled (for example by running QEMU with the parameter
"-machine pseries,kernel_irqchip=off"), the kernel does not pass
the XICS-related hypercalls such as H_CPPR up to userspace for
emulation there as it should.
The reason for this is that the real-mode handlers for these
hypercalls don't check whether a XICS device has been instantiated
before calling the xics-on-xive code. That code doesn't check
either, leading to potential NULL pointer dereferences because
vcpu->arch.xive_vcpu is NULL. Those dereferences won't cause an
exception in real mode but will lead to kernel memory corruption.
This fixes it by adding kvmppc_xics_enabled() checks before calling
the XICS functions.
Cc: stable@vger.kernel.org # v4.11+
Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Several function prototypes for the set/get functions defined by
module_param_call() have a slightly wrong argument types. This fixes
those in an effort to clean up the calls when running under type-enforced
compiler instrumentation for CFI. This is the result of running the
following semantic patch:
@match_module_param_call_function@
declarer name module_param_call;
identifier _name, _set_func, _get_func;
expression _arg, _mode;
@@
module_param_call(_name, _set_func, _get_func, _arg, _mode);
@fix_set_prototype
depends on match_module_param_call_function@
identifier match_module_param_call_function._set_func;
identifier _val, _param;
type _val_type, _param_type;
@@
int _set_func(
-_val_type _val
+const char * _val
,
-_param_type _param
+const struct kernel_param * _param
) { ... }
@fix_get_prototype
depends on match_module_param_call_function@
identifier match_module_param_call_function._get_func;
identifier _val, _param;
type _val_type, _param_type;
@@
int _get_func(
-_val_type _val
+char * _val
,
-_param_type _param
+const struct kernel_param * _param
) { ... }
Two additional by-hand changes are included for places where the above
Coccinelle script didn't notice them:
drivers/platform/x86/thinkpad_acpi.c
fs/lockd/svc.c
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Fixes: 424de9c6e3 ("powerpc/mm/radix: Avoid flushing the PWC on every flush_tlb_range")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 07d2a628bc ("powerpc/64s: Avoid cpabort in context switch
when possible", 2017-06-09) changed the definition of PPC_INST_COPY
and in so doing inadvertently broke the check for copy/paste
instructions in the alignment fault handler. The check currently
matches no instructions.
This fixes it by ANDing both sides of the comparison with the mask.
Fixes: 07d2a628bc ("powerpc/64s: Avoid cpabort in context switch when possible")
Cc: stable@vger.kernel.org # v4.13+
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When setting nr_cpus=1, we observed a crash in IMC code during boot
due to a missing allocation: basically, IMC code is taking the number
of threads into account in imc_mem_init() and if we manually set
nr_cpus for a value that is not multiple of the number of threads per
core, an integer division in that function will discard the decimal
portion, leading IMC to not allocate one mem_info struct. This causes
a NULL pointer dereference later, on is_core_imc_mem_inited().
This patch just rounds that division up, fixing the bug.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Acked-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.
However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:
----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()
// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch
virtual patch
@ depends on patch @
expression E1, E2;
@@
- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)
@ depends on patch @
expression E;
@@
- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Although kfree(NULL) is legal, it's a bit lazy to rely on that to
implement the error handling. So do it the normal Linux way using
labels for each failure path.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[mpe: Squash a few patches and rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The local variable "rc" will eventually be set only to an error code.
Thus omit the explicit initialisation at the beginning.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the hv-24x7 code there is a function memord() which tries to
implement a sort function return -1, 0, 1. However one of the
conditions is incorrect, such that it can never be true, because we
will have already returned.
I don't believe there is a bug in practice though, because the
comparisons are an optimisation prior to calling memcmp().
Fix it by swapping the second comparision, so it can be true.
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Back in 2008 we added support for "fast little-endian switch" in the
syscall path. This added a special case syscall number 0x1ebe, which
is caught very early in the system call exception and switches endian
with as little overhead as possible. See commit 745a14cc26
("[POWERPC] Add fast little-endian switch system call") for full
details.
Although it is fast, it's also completely non standard. The "syscall
number" is out of the range of normal syscalls, it can't be traced or
audited, and it's a bit of a wart. To the best of our knowledge it was
only used by one program, now long since discontinued.
So in an effort to shake out any current users, put it behind a config
option, and make it default n. If anyone *is* using it they can
quickly reinstate it with a rebuild, and we can flip it to default y.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When dumping the paca in xmon we currently show kstack. Although it's
not hard it's a bit fiddly to work out what the bounds of the kernel
stack should be based on the kstack value.
To make life easier and "kstack_base" which is the base (lowest
address) of the kernel stack, eg:
kstack = 0xc0000000f1a7be30 (0x258)
kstack_base = 0xc0000000f1a78000
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
i2c-dev provides an interface for userspace programs to interact with I2C
devices, and is very helpful for I2C-related debugging.
Enable it in pseries_defconfig and powernv_defconfig. It's already enabled
in many other powerpc defconfigs.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We call these functions with non-NULL mm or vma. Hence we can skip the
NULL check in these functions. We also remove now unused function
__local_flush_hugetlb_page().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Drop the checks with is_vm_hugetlb_page() as noticed by Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently xmon could call XIVE functions from OPAL even if the XIVE is
disabled or does not exist in the system, as in POWER8 machines. This
causes the following exception:
1:mon> dx
cpu 0x1: Vector: 700 (Program Check) at [c000000423c93450]
pc: c00000000009cfa4: opal_xive_dump+0x50/0x68
lr: c0000000000997b8: opal_return+0x0/0x50
This patch simply checks if XIVE is enabled before calling XIVE
functions.
Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Suggested-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Unfortunately userspace can construct a sigcontext which enables
suspend. Thus userspace can force Linux into a path where trechkpt is
executed.
This patch blocks this from happening on POWER9 by sanity checking
sigcontexts passed in.
ptrace doesn't have this problem as only MSR SE and BE can be changed
via ptrace.
This patch also adds a number of WARN_ON()s in case we ever enter
suspend when we shouldn't. This should not happen, but if it does the
symptoms are soft lockup warnings which are not obviously TM related,
so the WARN_ON()s should make it obvious what's happening.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some Power9 revisions can run in a mode where TM operates without
suspended state. If we find ourself on a CPU that might be in this
mode, we query OPAL to check, and if so we reenable TM in CPU
features, and enable a new user feature to signal to userspace that we
are in this mode.
We do not enable the "normal" user feature, PPC_FEATURE2_HTM, but we
do enable PPC_FEATURE2_HTM_NOSC because that indicates to userspace
that the kernel will abort transactions on syscall entry, which is
true regardless of the suspend mode.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some CPUs can operate in a mode where TM (Transactional Memory) is
enabled but the suspended state of TM is disabled. In this mode
tsuspend does not enter suspended state, instead the transaction is
aborted. Similarly any other event that would lead to suspended state
instead aborts the transaction.
There is also an ABI change, in that in this mode processes are not
allowed to sigreturn with an MSR that would lead to suspended state,
Linux will instead return an error to the sigreturn syscall.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the kernel relies on firmware to inform it whether or not the
CPU supports HTM and as long as the kernel was built with
CONFIG_PPC_TRANSACTIONAL_MEM=y then it will allow userspace to make
use of the facility.
There may be situations where it would be advantageous for the kernel
to not allow userspace to use HTM, currently the only way to achieve
this is to recompile the kernel with CONFIG_PPC_TRANSACTIONAL_MEM=n.
This patch adds a simple commandline option so that HTM can be
disabled at boot time.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Simplify to a bool, move to prom.c, put doco in the right place.
Always disable, regardless of initial state, to avoid user confusion.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we use CPU_FTR_TM to decide if the CPU/kernel can support
TM (Transactional Memory), and if it's true we advertise that to
Qemu (or similar) via KVM_CAP_PPC_HTM.
PPC_FEATURE2_HTM is the user-visible feature bit, which indicates that
the CPU and kernel can support TM. Currently CPU_FTR_TM and
PPC_FEATURE2_HTM always have the same value, either true or false, so
using the former for KVM_CAP_PPC_HTM is correct.
However some Power9 CPUs can operate in a mode where TM is enabled but
TM suspended state is disabled. In this mode CPU_FTR_TM is true, but
PPC_FEATURE2_HTM is false. Instead a different PPC_FEATURE2 bit is
set, to indicate that this different mode of TM is available.
It is not safe to let guests use TM as-is, when the CPU is in this
mode. So to prevent that from happening, use PPC_FEATURE2_HTM to
determine the value of KVM_CAP_PPC_HTM.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
After we removed all the dead wood it turns out only two architectures
actually implement dma_cache_sync as a real op: mips and parisc. Add
a cache_sync method to struct dma_map_ops and implement it for the
mips defualt DMA ops, and the parisc pa11 ops.
Note that arm, arc and openrisc support DMA_ATTR_NON_CONSISTENT, but
never provided a functional dma_cache_sync implementations, which
seems somewhat odd.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
powerpc does not implement DMA_ATTR_NON_CONSISTENT allocations, so it
doesn't make any sense to do any work in dma_cache_sync given that it
must be a no-op when dma_alloc_attrs returns coherent memory.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Only mips defines this helper, so remove all the other arch definitions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
This reverts commit 94a04bc25a.
In order to run HPT guests on a radix POWER9 host, we will have to run
the host in single-threaded mode, because POWER9 processors do not
currently support running some threads of a core in HPT mode while
others are in radix mode ("mixed mode").
That means that we will need the same mechanisms that are used on
POWER8 to make the secondary threads available to KVM, which were
disabled on POWER9 by commit 94a04bc25a.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch_spin_lock_flags() is an internal part of the spinlock implementation
and is no longer available when SMP=n and DEBUG_SPINLOCK=y, so the PPC
RTAS code fails to compile in this configuration:
arch/powerpc/kernel/rtas.c: In function 'lock_rtas':
>> arch/powerpc/kernel/rtas.c:81:2: error: implicit declaration of function 'arch_spin_lock_flags' [-Werror=implicit-function-declaration]
arch_spin_lock_flags(&rtas.lock, flags);
^~~~~~~~~~~~~~~~~~~~
Since there's no good reason to use arch_spin_lock_flags() here (the code
in question already calls local_irq_save(flags)), switch it over to
arch_spin_lock and get things building again.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508327469-20231-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Axtens reported that on the HiSilicon D05 board, the VGA device is
behind a bridge that doesn't support PCI_BRIDGE_CTL_VGA, so the VGA arbiter
never selects it as the default, which means Xorg auto-detection doesn't
work.
VGA is a legacy PCI feature: a VGA device can respond to addresses, e.g.,
[mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], [io 0x3c0-0x3df], etc., that are
not configurable by BARs. Consequently, multiple VGA devices can conflict
with each other. The VGA arbiter avoids conflicts by ensuring that those
legacy resources are only routed to one VGA device at a time.
The arbiter identifies the "default VGA" device, i.e., a legacy VGA device
that was used by boot firmware. It selects the first device that:
- is of PCI_CLASS_DISPLAY_VGA,
- has both PCI_COMMAND_IO and PCI_COMMAND_MEMORY enabled, and
- has PCI_BRIDGE_CTL_VGA set in all upstream bridges.
Some systems don't have such a device. For example, if a host bridge
doesn't support I/O space, PCI_COMMAND_IO probably won't be enabled for any
devices below it. Or, as on the HiSilicon D05, the VGA device may be
behind a bridge that doesn't support PCI_BRIDGE_CTL_VGA, so accesses to the
legacy VGA resources will never reach the device.
This patch extends the arbiter so that if it doesn't find a device that
meets all the above criteria, it selects the first device that:
- is of PCI_CLASS_DISPLAY_VGA and
- has PCI_COMMAND_IO or PCI_COMMAND_MEMORY enabled
If it doesn't find even that, it selects the first device that:
- is of class PCI_CLASS_DISPLAY_VGA.
Such a device may not be able to use the legacy VGA resources, but most
drivers can operate the device without those. Setting it as the default
device means its "boot_vga" sysfs file will contain "1", which Xorg (via
libpciaccess) uses to help select its default output device.
This fixes Xorg auto-detection on some arm64 systems (HiSilicon D05 in
particular; see the link below).
It also replaces the powerpc fixup_vga() quirk, albeit with slightly
different semantics: the quirk selected the first VGA device we found, and
overrode that selection with any enabled VGA device we found. If there
were several enabled VGA devices, the *last* one we found would become the
default.
The code here instead selects the *first* enabled VGA device we find, and
if none are enabled, the first VGA device we find.
Link: http://lkml.kernel.org/r/20170901072744.2409-1-dja@axtens.net
Tested-by: Daniel Axtens <dja@axtens.net> # arm64, ppc64-qemu-tcg
Tested-by: Zhou Wang <wangzhou1@hisilicon.com> # D05 Hisi Hip07, Hip08
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171013034721.14630.65913.stgit@bhelgaas-glaptop.roam.corp.google.com
powerpc/vphn: On Power systems with shared configurations of CPUs
and memory, there are some issues with the association of additional
CPUs and memory to nodes when hot-adding resources. This patch
fixes an end-of-updates processing problem observed occasionally
in numa_update_cpu_topology().
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/hotplug: On Power systems with shared configurations of CPUs
and memory, there are some issues with the association of additional
CPUs and memory to nodes when hot-adding resources. During hotplug
CPU operations, this patch resets the timer on topology update work
function to a small value to better ensure that the CPU topology is
detected and configured sooner.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/vphn: On Power systems with shared configurations of CPUs
and memory, there are some issues with the association of additional
CPUs and memory to nodes when hot-adding resources. This patch
updates the initialization checks to independently recognize PRRN
or VPHN support.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/vphn: On Power systems with shared configurations of CPUs
and memory, there are some issues with the association of additional
CPUs and memory to nodes when hot-adding resources. This patch
corrects the currently broken capability to set the topology for
shared CPUs in LPARs. At boot time for shared CPU lpars, the
topology for each CPU was being set to node zero. Now when
numa_update_cpu_topology() is called appropriately, the Virtual
Processor Home Node (VPHN) capabilities information provided by the
pHyp allows the appropriate node in the shared configuration to be
selected for the CPU.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If we are in user space and hit a UE error, we now have the
basic infrastructure to walk the page tables and find out
the effective address that was accessed, since the DAR
is not valid.
We use a work_queue content to hookup the bad pfn, any
other context causes problems, since memory_failure itself
can call into schedule() via lru_drain_ bits.
We could probably poison the struct page to avoid a race
between detection and taking corrective action.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Hookup instruction errors (UE) for memory offling via memory_failure()
in a manner similar to load/store errors (derror). Since we have access
to the NIP, the conversion is a one step process in this case.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Extract physical_address for UE errors by walking the page
tables for the mm and address at the NIP, to extract the
instruction. Then use the instruction to find the effective
address via analyse_instr().
We might have page table walking races, but we expect them to
be rare, the physical address extraction is best effort. The idea
is to then hook up this infrastructure to memory failure eventually.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use the same alignment as Effective address.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are no users of get_mce_fault_addr() since commit
1363875bdb ("powerpc/64s: fix handling of non-synchronous machine
checks") removed the last usage.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On POWER9 systems, we push the VCPU context onto the XIVE (eXternal
Interrupt Virtualization Engine) hardware when entering a guest,
and pull the context off the XIVE when exiting the guest. The push
is done with cache-inhibited stores, and the pull with cache-inhibited
loads.
Testing has revealed that it is possible (though very rare) for
the stores to get reordered with the loads so that we end up with the
guest VCPU context still loaded on the XIVE after we have exited the
guest. When that happens, it is possible for the same VCPU context
to then get loaded on another CPU, which causes the machine to
checkstop.
To fix this, we add I/O barrier instructions (eieio) before and
after the push and pull operations. As partial compensation for the
potential slowdown caused by the extra barriers, we remove the eieio
instructions between the two stores in the push operation, and between
the two loads in the pull operation. (The architecture requires
loads to cache-inhibited, guarded storage to be kept in order, and
requires stores to cache-inhibited, guarded storage likewise to be
kept in order, but allows such loads and stores to be reordered with
respect to each other.)
Reported-by: Carol L Soto <clsoto@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds code to make sure that we don't try to access the
non-existent HPT for a radix guest using the htab file for the VM
in debugfs, a file descriptor obtained using the KVM_PPC_GET_HTAB_FD
ioctl, or via the KVM_PPC_RESIZE_HPT_{PREPARE,COMMIT} ioctls.
At present nothing bad happens if userspace does access these
interfaces on a radix guest, mostly because kvmppc_hpt_npte()
gives 0 for a radix guest, which in turn is because 1 << -4
comes out as 0 on POWER processors. However, that relies on
undefined behaviour, so it is better to be explicit about not
accessing the HPT for a radix guest.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The handlers support PR KVM from the day one; however the PR KVM's
enable/disable hcalls handler missed these ones.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Omit an extra message for a memory allocation failure in this function.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Use vma_pages function on vma object instead of explicit computation.
Found by coccinelle spatch "api/vma_pages.cocci"
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Use ARRAY_SIZE macro, rather than explicitly coding some variant of it
yourself.
Found with: find -type f -name "*.c" -o -name "*.h" | xargs perl -p -i -e
's/\bsizeof\s*\(\s*(\w+)\s*\)\s*\ /\s*sizeof\s*\(\s*\1\s*\[\s*0\s*\]\s*\)
/ARRAY_SIZE(\1)/g' and manual check/verification.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
At present, if an interrupt (i.e. an exception or trap) occurs in the
code where KVM is switching the MMU to or from guest context, we jump
to kvmppc_bad_host_intr, where we simply spin with interrupts disabled.
In this situation, it is hard to debug what happened because we get no
indication as to which interrupt occurred or where. Typically we get
a cascade of stall and soft lockup warnings from other CPUs.
In order to get more information for debugging, this adds code to
create a stack frame on the emergency stack and save register values
to it. We start half-way down the emergency stack in order to give
ourselves some chance of being able to do a stack trace on secondary
threads that are already on the emergency stack.
On POWER7 or POWER8, we then just spin, as before, because we don't
know what state the MMU context is in or what other threads are doing,
and we can't switch back to host context without coordinating with
other threads. On POWER9 we can do better; there we load up the host
MMU context and jump to C code, which prints an oops message to the
console and panics.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
kvmppc_gpa_to_ua() accesses KVM memory slot array via
srcu_dereference_check() and this produces warnings from RCU like below.
This extends the existing srcu_read_lock/unlock to cover that
kvmppc_gpa_to_ua() as well.
We did not hit this before as this lock is not needed for the realmode
handlers and hash guests would use the realmode path all the time;
however the radix guests are always redirected to the virtual mode
handlers and hence the warning.
[ 68.253798] ./include/linux/kvm_host.h:575 suspicious rcu_dereference_check() usage!
[ 68.253799]
other info that might help us debug this:
[ 68.253802]
rcu_scheduler_active = 2, debug_locks = 1
[ 68.253804] 1 lock held by qemu-system-ppc/6413:
[ 68.253806] #0: (&vcpu->mutex){+.+.}, at: [<c00800000e3c22f4>] vcpu_load+0x3c/0xc0 [kvm]
[ 68.253826]
stack backtrace:
[ 68.253830] CPU: 92 PID: 6413 Comm: qemu-system-ppc Tainted: G W 4.14.0-rc3-00553-g432dcba58e9c-dirty #72
[ 68.253833] Call Trace:
[ 68.253839] [c000000fd3d9f790] [c000000000b7fcc8] dump_stack+0xe8/0x160 (unreliable)
[ 68.253845] [c000000fd3d9f7d0] [c0000000001924c0] lockdep_rcu_suspicious+0x110/0x180
[ 68.253851] [c000000fd3d9f850] [c0000000000e825c] kvmppc_gpa_to_ua+0x26c/0x2b0
[ 68.253858] [c000000fd3d9f8b0] [c00800000e3e1984] kvmppc_h_put_tce+0x12c/0x2a0 [kvm]
Fixes: 121f80ba68 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
- Add another case where msgsync is required.
- Required barrier sequence for global doorbells is msgsync ; lwsync
When msgsnd is used for IPIs to other cores, msgsync must be executed by
the target to order stores performed on the source before its msgsnd
(provided the source executes the appropriate sync).
Fixes: 1704a81cce ("KVM: PPC: Book3S HV: Use msgsnd for IPIs to other cores on POWER9")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The following program causes a kernel oops:
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/kvm.h>
main()
{
int fd = open("/dev/kvm", O_RDWR);
ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_PPC_HTM);
}
This happens because when using the global KVM fd with
KVM_CHECK_EXTENSION, kvm_vm_ioctl_check_extension() gets
called with a NULL kvm argument, which gets dereferenced
in is_kvmppc_hv_enabled(). Spotted while reading the code.
Let's use the hv_enabled fallback variable, like everywhere
else in this function.
Fixes: 23528bb21e ("KVM: PPC: Introduce KVM_CAP_PPC_HTM")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
A fix for a bad bug (written by me) in our livepatch handler. Removal of an
over-zealous lockdep_assert_cpus_held() in our topology code. A fix to the
recently added emulation of cntlz[wd]. And three small fixes to the recently
added IMC PMU driver.
Thanks to:
Anju T Sudhakar, Balbir Singh, Kamalesh Babulal, Naveen N. Rao, Sandipan Das,
Santosh Sivaraj, Thiago Jung Bauermann.
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Merge tag 'powerpc-4.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"A fix for a bad bug (written by me) in our livepatch handler. Removal
of an over-zealous lockdep_assert_cpus_held() in our topology code. A
fix to the recently added emulation of cntlz[wd]. And three small
fixes to the recently added IMC PMU driver.
Thanks to: Anju T Sudhakar, Balbir Singh, Kamalesh Babulal, Naveen N.
Rao, Sandipan Das, Santosh Sivaraj, Thiago Jung Bauermann"
* tag 'powerpc-4.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/perf: Fix IMC initialization crash
powerpc/perf: Add ___GFP_NOWARN flag to alloc_pages_node()
powerpc/perf: Fix for core/nest imc call trace on cpuhotplug
powerpc: Don't call lockdep_assert_cpus_held() from arch_update_cpu_topology()
powerpc/lib/sstep: Fix count leading zeros instructions
powerpc/livepatch: Fix livepatch stack access
Panic observed with latest firmware, and upstream kernel:
NIP init_imc_pmu+0x8c/0xcf0
LR init_imc_pmu+0x2f8/0xcf0
Call Trace:
init_imc_pmu+0x2c8/0xcf0 (unreliable)
opal_imc_counters_probe+0x300/0x400
platform_drv_probe+0x64/0x110
driver_probe_device+0x3d8/0x580
__driver_attach+0x14c/0x1a0
bus_for_each_dev+0x8c/0xf0
driver_attach+0x34/0x50
bus_add_driver+0x298/0x350
driver_register+0x9c/0x180
__platform_driver_register+0x5c/0x70
opal_imc_driver_init+0x2c/0x40
do_one_initcall+0x64/0x1d0
kernel_init_freeable+0x280/0x374
kernel_init+0x24/0x160
ret_from_kernel_thread+0x5c/0x74
While registering nest imc at init, cpu-hotplug callback
nest_pmu_cpumask_init() makes an OPAL call to stop the engine. And if
the OPAL call fails, imc_common_cpuhp_mem_free() is invoked to cleanup
memory and cpuhotplug setup.
But when cleaning up the attribute group, we are dereferencing the
attribute element array without checking whether the backing element
is not NULL. This causes the kernel panic.
Add a check for the backing element prior to dereferencing the
attribute element, to handle the failing case gracefully.
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reported-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
[mpe: Trim change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use WARN_ON(), while running out of stubs in stub_for_addr()
and abort loading of the module instead of BUG_ON().
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch fixes some spelling typos found in Kconfig files.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Nest/core pmu units are enabled only when it is used. A reference count is
maintained for the events which uses the nest/core pmu units. Currently in
*_imc_counters_release function a WARN() is used for notification of any
underflow of ref count.
The case where event ref count hit a negative value is, when perf session is
started, followed by offlining of all cpus in a given core.
i.e. in cpuhotplug offline path ppc_core_imc_cpu_offline() function set the
ref->count to zero, if the current cpu which is about to offline is the last
cpu in a given core and make an OPAL call to disable the engine in that core.
And on perf session termination, perf->destroy (core_imc_counters_release) will
first decrement the ref->count for this core and based on the ref->count value
an opal call is made to disable the core-imc engine.
Now, since cpuhotplug path already clears the ref->count for core and disabled
the engine, perf->destroy() decrementing again at event termination make it
negative which in turn fires the WARN_ON. The same happens for nest units.
Add a check to see if the reference count is alreday zero, before decrementing
the count, so that the ref count will not hit a negative value.
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It turns out that not all paths calling arch_update_cpu_topology() hold
cpu_hotplug_lock, but that's OK because those paths can't race with
any concurrent hotplug events.
Warnings were reported with the following trace:
lockdep_assert_cpus_held
arch_update_cpu_topology
sched_init_domains
sched_init_smp
kernel_init_freeable
kernel_init
ret_from_kernel_thread
Which is safe because it's called early in boot when hotplug is not
live yet.
And also this trace:
lockdep_assert_cpus_held
arch_update_cpu_topology
partition_sched_domains
cpuset_update_active_cpus
sched_cpu_deactivate
cpuhp_invoke_callback
cpuhp_down_callbacks
cpuhp_thread_fun
smpboot_thread_fn
kthread
ret_from_kernel_thread
Which is safe because it's called as part of CPU hotplug, so although
we don't hold the CPU hotplug lock, there is another thread driving
the CPU hotplug operation which does hold the lock, and there is no
race.
Thanks to tglx for deciphering it for us.
Fixes: 3e401f7a2e ("powerpc: Only obtain cpu_hotplug_lock if called by rtasd")
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The arch_{read,spin,write}_lock_flags() macros are simply mapped to the
non-flags versions by the majority of architectures, so do this in core
code and remove the dummy implementations. Also remove the implementation
in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call
local_irq_save(flags) anyway.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Outside of the locking code itself, {read,spin,write}_can_lock() have no
users in tree. Apparmor (the last remaining user of write_can_lock()) got
moved over to lockdep by the previous patch.
This patch removes the use of {read,spin,write}_can_lock() from the
BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the
lock status, and subsequently removes the unused macros altogether. They
aren't guaranteed to work in a concurrent environment and can give
incorrect results in the case of qrwlock.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
According to the GCC documentation, the behaviour of __builtin_clz()
and __builtin_clzl() is undefined if the value of the input argument
is zero. Without handling this special case, these builtins have been
used for emulating the following instructions:
* Count Leading Zeros Word (cntlzw[.])
* Count Leading Zeros Doubleword (cntlzd[.])
This fixes the emulated behaviour of these instructions by adding an
additional check for this special case.
Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge powerpc transactional memory fixes from Michael Ellerman:
"I figured I'd still send you the commits using a bundle to make sure
it works in case I need to do it again in future"
This fixes transactional memory state restore for powerpc.
* bundle'd patches from Michael Ellerman:
powerpc/tm: Fix illegal TM state in signal handler
powerpc/64s: Use emergency stack for kernel TM Bad Thing program checks
- fix PPC XIVE interrupt delivery
- fix x86 RCU breakage from asynchronous page faults when built without
PREEMPT_COUNT
- fix x86 build with -frecord-gcc-switches
- fix x86 build without X86_LOCAL_APIC
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
- fix PPC XIVE interrupt delivery
- fix x86 RCU breakage from asynchronous page faults when built without
PREEMPT_COUNT
- fix x86 build with -frecord-gcc-switches
- fix x86 build without X86_LOCAL_APIC
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: add X86_LOCAL_APIC dependency
x86/kvm: Move kvm_fastop_exception to .fixup section
kvm/x86: Avoid async PF preempting the kernel incorrectly
KVM: PPC: Book3S: Fix server always zero from kvmppc_xive_get_xive()
Nine small fixes, really nothing that stands out.
A work around for a spurious MCE on Power9. A CXL fault handling fix, some fixes
to the new XIVE code, and a fix to the new 32-bit STRICT_KERNEL_RWX code.
Fixes for old code/stable: an fix to an incorrect TLB flush on boot but not on
any current machines, a compile error on 4xx and a fix to memory hotplug when
using radix (Power9).
Thanks to:
Anton Blanchard, Cédric Le Goater, Christian Lamparter, Christophe Leroy,
Christophe Lombard, Guenter Roeck, Jeremy Kerr, Michael Neuling, Nicholas
Piggin.
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Merge tag 'powerpc-4.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Nine small fixes, really nothing that stands out.
A work-around for a spurious MCE on Power9. A CXL fault handling fix,
some fixes to the new XIVE code, and a fix to the new 32-bit
STRICT_KERNEL_RWX code.
Fixes for old code/stable: an fix to an incorrect TLB flush on boot
but not on any current machines, a compile error on 4xx and a fix to
memory hotplug when using radix (Power9).
Thanks to: Anton Blanchard, Cédric Le Goater, Christian Lamparter,
Christophe Leroy, Christophe Lombard, Guenter Roeck, Jeremy Kerr,
Michael Neuling, Nicholas Piggin"
* tag 'powerpc-4.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/powernv: Increase memory block size to 1GB on radix
powerpc/mm: Call flush_tlb_kernel_range with interrupts enabled
powerpc/xive: Clear XIVE internal structures when a CPU is removed
powerpc/xive: Fix IPI reset
powerpc/4xx: Fix compile error with 64K pages on 40x, 44x
powerpc: Fix action argument for cpufeatures-based TLB flush
cxl: Fix memory page not handled
powerpc: Fix workaround for spurious MCE on POWER9
powerpc: Handle MCE on POWER9 with only DSISR bit 30 set
Pull watchddog clean-up and fixes from Thomas Gleixner:
"The watchdog (hard/softlockup detector) code is pretty much broken in
its current state. The patch series addresses this by removing all
duct tape and refactoring it into a workable state.
The reasons why I ask for inclusion that late in the cycle are:
1) The code causes lockdep splats vs. hotplug locking which get
reported over and over. Unfortunately there is no easy fix.
2) The risk of breakage is minimal because it's already broken
3) As 4.14 is a long term stable kernel, I prefer to have working
watchdog code in that and the lockdep issues resolved. I wouldn't
ask you to pull if 4.14 wouldn't be a LTS kernel or if the
solution would be easy to backport.
4) The series was around before the merge window opened, but then got
delayed due to the UP failure caused by the for_each_cpu()
surprise which we discussed recently.
Changes vs. V1:
- Addressed your review points
- Addressed the warning in the powerpc code which was discovered late
- Changed two function names which made sense up to a certain point
in the series. Now they match what they do in the end.
- Fixed a 'unused variable' warning, which got not detected by the
intel robot. I triggered it when trying all possible related config
combinations manually. Randconfig testing seems not random enough.
The changes have been tested by and reviewed by Don Zickus and tested
and acked by Micheal Ellerman for powerpc"
* 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
watchdog/core: Put softlockup_threads_initialized under ifdef guard
watchdog/core: Rename some softlockup_* functions
powerpc/watchdog: Make use of watchdog_nmi_probe()
watchdog/core, powerpc: Lock cpus across reconfiguration
watchdog/core, powerpc: Replace watchdog_nmi_reconfigure()
watchdog/hardlockup/perf: Fix spelling mistake: "permanetely" -> "permanently"
watchdog/hardlockup/perf: Cure UP damage
watchdog/hardlockup: Clean up hotplug locking mess
watchdog/hardlockup/perf: Simplify deferred event destroy
watchdog/hardlockup/perf: Use new perf CPU enable mechanism
watchdog/hardlockup/perf: Implement CPU enable replacement
watchdog/hardlockup/perf: Implement init time detection of perf
watchdog/hardlockup/perf: Implement init time perf validation
watchdog/core: Get rid of the racy update loop
watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage
watchdog/sysctl: Clean up sysctl variable name space
watchdog/sysctl: Get rid of the #ifdeffery
watchdog/core: Clean up header mess
watchdog/core: Further simplify sysctl handling
watchdog/core: Get rid of the thread teardown/setup dance
...
Currently it's possible that on returning from the signal handler
through the restore_tm_sigcontexts() code path (e.g. from a signal
caught due to a `trap` instruction executed in the middle of an HTM
block, or a deliberately constructed sigframe) an illegal TM state
(like TS=10 TM=0, i.e. "T0") is set in SRR1 and when `rfid` sets
implicitly the MSR register from SRR1 register on return to userspace
it causes a TM Bad Thing exception.
That illegal state can be set (a) by a malicious user that disables
the TM bit by tweaking the bits in uc_mcontext before returning from
the signal handler or (b) by a sufficient number of context switches
occurring such that the load_tm counter overflows and TM is disabled
whilst in the signal handler.
This commit fixes the illegal TM state by ensuring that TM bit is
always enabled before we return from restore_tm_sigcontexts(). A small
comment correction is made as well.
Fixes: 5d176f751e ("powerpc: tm: Enable transactional memory (TM) lazily for userspace")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When using transactional memory (TM), the CPU can be in one of six
states as far as TM is concerned, encoded in the Machine State
Register (MSR). Certain state transitions are illegal and if attempted
trigger a "TM Bad Thing" type program check exception.
If we ever hit one of these exceptions it's treated as a bug, ie. we
oops, and kill the process and/or panic, depending on configuration.
One case where we can trigger a TM Bad Thing, is when returning to
userspace after a system call or interrupt, using RFID. When this
happens the CPU first restores the user register state, in particular
r1 (the stack pointer) and then attempts to update the MSR. However
the MSR update is not allowed and so we take the program check with
the user register state, but the kernel MSR.
This tricks the exception entry code into thinking we have a bad
kernel stack pointer, because the MSR says we're coming from the
kernel, but r1 is pointing to userspace.
To avoid this we instead always switch to the emergency stack if we
take a TM Bad Thing from the kernel. That way none of the user
register values are used, other than for printing in the oops message.
This is the fix for CVE-2017-1000255.
Fixes: 5d176f751e ("powerpc: tm: Enable transactional memory (TM) lazily for userspace")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Rewrite change log & comments, tweak asm slightly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add a check for p->state == TASK_RUNNING so that any wake-ups on
task_struct p in the interim lead to 0 being returned by get_wchan().
Signed-off-by: Kautuk Consul <kautuk.consul.1980@gmail.com>
[mpe: Confirmed other architectures do similar]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Several callers to epapr_hypercall() pass an uninitialized stack
allocated array for the input arguments, presumably because they
have no input arguments. However this can produce errors like
this one
arch/powerpc/include/asm/epapr_hcalls.h:470:42: error: 'in' may be used uninitialized in this function [-Werror=maybe-uninitialized]
unsigned long register r3 asm("r3") = in[0];
~~^~~
Fix callers to this function to always zero-initialize the input
arguments array to prevent this.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It might be useful to quickly get the uptime of a running system on
xmon, without needing to grab data from memory and doing math on
struct addresses.
For example, it'd be useful to check for how long after a crash a
system is on xmon shell or if some test was started after the first
test crashed (and this 2nd test crashed too into xmon).
This small patch adds the 'U' command, to accomplish this.
Suggested-by: Murilo Fossa Vicentini <muvic@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
[mpe: Display units (seconds), add sync()/__delay() sequence]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In opal_event_shutdown() we free all the IRQs hanging off the
opal_event_irqchip. However it's not safe to do so if we're called
from IRQ context, because free_irq() wants to synchronise versus IRQ
context. This can lead to warnings and a stuck system.
For example from sysrq-b:
Trying to free IRQ 17 from IRQ context!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/irq/manage.c:1461 __free_irq+0x398/0x8d0
...
NIP __free_irq+0x398/0x8d0
LR __free_irq+0x394/0x8d0
Call Trace:
__free_irq+0x394/0x8d0 (unreliable)
free_irq+0xa4/0x140
opal_event_shutdown+0x128/0x180
opal_shutdown+0x1c/0xb0
pnv_shutdown+0x20/0x40
machine_restart+0x38/0x90
emergency_restart+0x28/0x40
sysrq_handle_reboot+0x24/0x40
__handle_sysrq+0x198/0x590
hvc_poll+0x48c/0x8c0
hvc_handle_interrupt+0x1c/0x50
__handle_irq_event_percpu+0xe8/0x6e0
handle_irq_event_percpu+0x34/0xe0
handle_irq_event+0xc4/0x210
handle_level_irq+0x250/0x770
generic_handle_irq+0x5c/0xa0
opal_handle_events+0x11c/0x240
opal_interrupt+0x38/0x50
__handle_irq_event_percpu+0xe8/0x6e0
handle_irq_event_percpu+0x34/0xe0
handle_irq_event+0xc4/0x210
handle_fasteoi_irq+0x174/0xa10
generic_handle_irq+0x5c/0xa0
__do_irq+0xbc/0x4e0
call_do_irq+0x14/0x24
do_IRQ+0x18c/0x540
hardware_interrupt_common+0x158/0x180
We can avoid that by using disable_irq_nosync() rather than
free_irq(). Although it doesn't fully free the IRQ, it should be
sufficient when we're shutting down, particularly in an emergency.
Add an in_interrupt() check and use free_irq() when we're shutting
down normally. It's probably OK to use disable_irq_nosync() in that
case too, but for now it's safer to leave that behaviour as-is.
Fixes: 9f0fd0499d ("powerpc/powernv: Add a virtual irqchip for opal events")
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Memory hot unplug on PowerNV radix hosts is broken. Our memory block
size is 256MB but since we map the linear region with very large
pages, each pte we tear down maps 1GB.
A hot unplug of one 256MB memory block results in 768MB of memory
getting unintentionally unmapped. At this point we are likely to oops.
Fix this by increasing our memory block size to 1GB on PowerNV radix
hosts.
Fixes: 4b5d62ca17 ("powerpc/mm: add radix__remove_section_mapping()")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The "reset" argument passed to pci_iov_add_virtfn() and
pci_iov_remove_virtfn() is always zero since 46cb7b1bd8 ("PCI: Remove
unused SR-IOV VF Migration support")
Remove the argument together with the associated code.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Russell Currey <ruscur@russell.cc>
Fix a circa 2005 FIXME by implementing a check to ensure that we
actually got into the jprobe break handler() due to the trap in
jprobe_return().
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Kamalesh pointed out that we are getting the below call traces with
livepatched functions when we enable CONFIG_PREEMPT:
[ 495.470721] BUG: using __this_cpu_read() in preemptible [00000000] code: cat/8394
[ 495.471167] caller is is_current_kprobe_addr+0x30/0x90
[ 495.471171] CPU: 4 PID: 8394 Comm: cat Tainted: G K 4.13.0-rc7-nnr+ #95
[ 495.471173] Call Trace:
[ 495.471178] [c00000008fd9b960] [c0000000009f039c] dump_stack+0xec/0x160 (unreliable)
[ 495.471184] [c00000008fd9b9a0] [c00000000059169c] check_preemption_disabled+0x15c/0x170
[ 495.471187] [c00000008fd9ba30] [c000000000046460] is_current_kprobe_addr+0x30/0x90
[ 495.471191] [c00000008fd9ba60] [c00000000004e9a0] ftrace_call+0x1c/0xb8
[ 495.471195] [c00000008fd9bc30] [c000000000376fd8] seq_read+0x238/0x5c0
[ 495.471199] [c00000008fd9bcd0] [c0000000003cfd78] proc_reg_read+0x88/0xd0
[ 495.471203] [c00000008fd9bd00] [c00000000033e5d4] __vfs_read+0x44/0x1b0
[ 495.471206] [c00000008fd9bd90] [c0000000003402ec] vfs_read+0xbc/0x1b0
[ 495.471210] [c00000008fd9bde0] [c000000000342138] SyS_read+0x68/0x110
[ 495.471214] [c00000008fd9be30] [c00000000000bc6c] system_call+0x58/0x6c
Commit c05b8c4474 ("powerpc/kprobes: Skip livepatch_handler() for
jprobes") introduced a helper is_current_kprobe_addr() to help determine
if the current function has been livepatched or if it has a jprobe
installed, both of which modify the NIP. This was subsequently renamed
to __is_active_jprobe().
In the case of a jprobe, kprobe_ftrace_handler() disables pre-emption
before calling into setjmp_pre_handler() which returns without disabling
pre-emption. This is done to ensure that the jprobe handler won't
disappear beneath us if the jprobe is unregistered between the
setjmp_pre_handler() and the subsequent longjmp_break_handler() called
from the jprobe handler. Due to this, we can use __this_cpu_read() in
__is_active_jprobe() with the pre-emption check as we know that
pre-emption will be disabled.
However, if this function has been livepatched, we are still doing this
check and when we do so, pre-emption won't necessarily be disabled. This
results in the call trace shown above.
Fix this by only invoking __is_active_jprobe() when pre-emption is
disabled. And since we now guard this within a pre-emption check, we can
instead use raw_cpu_read() to get the current_kprobe value skipping the
check done by __this_cpu_read().
Fixes: c05b8c4474 ("powerpc/kprobes: Skip livepatch_handler() for jprobes")
Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit c05b8c4474 ("powerpc/kprobes: Skip livepatch_handler() for
jprobes"), we added a helper is_current_kprobe_addr() to help detect if
the modified regs->nip was due to a jprobe or livepatch. Masami felt
that the function name was not quite clear. To that end, this patch
renames is_current_kprobe_addr() to __is_active_jprobe() and adds a
comment to (hopefully) better clarify the purpose of this helper. The
helper has also now been moved to kprobes-ftrace.c so that it is only
available for KPROBES_ON_FTRACE.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, we disable instruction emulation if emulate_step() fails for
any reason. However, such failures could be transient and specific to a
particular run. Instead, only disable instruction emulation if we have
never been able to emulate this. If we had emulated this instruction
successfully at least once, then we single step only this probe hit and
continue to try emulating the instruction in subsequent probe hits.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1. This is only used in kprobes.c, so make it static.
2. Remove the un-necessary (ret == 0) comparison in the else clause.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This configuration is used by the OpenPower firmware for it's
Linux-as-bootloader implementation. Also known as the Petitboot
kernel, this configuration broke in 4.12 (CPU_HOTPLUG=n), so add it to
the upstream tree in order to get better coverage.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin