Fixes for recently merged code:
- a fix for the _PAGE_DEVMAP support, which was breaking KVM on Power9 radix
- avoid a (harmless) lockdep warning in the early SMP code
- return failure for some uses of dma_set_mask() rather than falling back to 32-bits
- fix stack setup in watchdog soft_nmi_common() to use emergency stack
- fix of_irq_to_resource() error check in of_fsl_spi_probe()
Two fixes going to stable:
- fix saving of Transactional Memory SPRs in core dump
- fix __check_irq_replay missing decrementer interrupt
And two misc:
- fix 64-bit boot wrapper build with non-biarch compiler
- work around a POWER9 PMU hang after state-loss idle
Thanks to:
Alistair Popple, Aneesh Kumar K.V, Cyril Bur, Gustavo Romero, Jose Ricardo
Ziviani, Laurent Vivier, Nicholas Piggin, Oliver O'Halloran, Sergei Shtylyov,
Suraj Jitindar Singh, Thomas Gleixner.
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Merge tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Fixes for recently merged code:
- a fix for the _PAGE_DEVMAP support, which was breaking KVM on
Power9 radix
- avoid a (harmless) lockdep warning in the early SMP code
- return failure for some uses of dma_set_mask() rather than falling
back to 32-bits
- fix stack setup in watchdog soft_nmi_common() to use emergency
stack
- fix of_irq_to_resource() error check in of_fsl_spi_probe()
Two fixes going to stable:
- fix saving of Transactional Memory SPRs in core dump
- fix __check_irq_replay missing decrementer interrupt
And two misc:
- fix 64-bit boot wrapper build with non-biarch compiler
- work around a POWER9 PMU hang after state-loss idle
Thanks to: Alistair Popple, Aneesh Kumar K.V, Cyril Bur, Gustavo
Romero, Jose Ricardo Ziviani, Laurent Vivier, Nicholas Piggin, Oliver
O'Halloran, Sergei Shtylyov, Suraj Jitindar Singh, Thomas Gleixner"
* tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Fix __check_irq_replay missing decrementer interrupt
powerpc/perf: POWER9 PMU stops after idle workaround
powerpc/83xx/mpc832x_rdb: fix of_irq_to_resource() error check
powerpc/64s: Fix stack setup in watchdog soft_nmi_common()
powerpc/powernv/pci: Return failure for some uses of dma_set_mask()
powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compiler
powerpc/smp: Call smp_ops->setup_cpu() directly on the boot CPU
powerpc/tm: Fix saving of TM SPRs in core dump
powerpc/mm: Fix pmd/pte_devmap() on non-leaf entries
If the decrementer wraps again and de-asserts the decrementer
exception while hard-disabled, __check_irq_replay() has a test to
notice the wrap when interrupts are re-enabled.
The decrementer check must be done when clearing the PACA_IRQ_HARD_DIS
flag, not when the PACA_IRQ_DEC flag is tested. Previously this worked
because the decrementer interrupt was always the first one checked
after clearing the hard disable flag, but HMI check was moved ahead of
that, which introduced this bug.
This can cause a missed decrementer interrupt if we soft-disable
interrupts then take an HMI which is recorded in irq_happened, then
hard-disable interrupts for > 4s to wrap the decrementer.
Fixes: e0e0d6b739 ("powerpc/64: Replay hypervisor maintenance interrupt first")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
A solution is to set then clear MMCRA[60] after wake from state-loss
idle. MMCRA[60] is a non-architected bit, see the user manual for
details.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
of_irq_to_resource() has recently been fixed to return negative error #'s
along with 0 in case of failure, however the Freescale MPC832x RDB board
code still only regards 0 as a failure indication -- fix it up.
Fixes: 7a4228bbff ("of: irq: use of_irq_get() in of_irq_to_resource()")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The watchdog soft-NMI exception stack setup loads a stack pointer
twice, which is an obvious error. It ends up using the system reset
interrupt (true-NMI) stack, which is also a bug because the watchdog
could be preempted by a system reset interrupt that overwrites the
NMI stack.
Change the soft-NMI to use the "emergency stack". The current kernel
stack is not used, because of the longer-term goal to prevent
asynchronous stack access using soft-disable.
Fixes: 2104180a53 ("powerpc/64s: implement arch-specific hardlockup watchdog")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Merge tag 'v4.13-rc1' into fixes
The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.
However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!
PPC: host crash fixes.
x86: bugfixes, including making nested posted interrupts really work.
Generic: tweaks to kvm_stat and to uevents
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"s390:
- SRCU fix
PPC:
- host crash fixes
x86:
- bugfixes, including making nested posted interrupts really work
Generic:
- tweaks to kvm_stat and to uevents"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: LAPIC: Fix reentrancy issues with preempt notifiers
tools/kvm_stat: add '-f help' to get the available event list
tools/kvm_stat: use variables instead of hard paths in help output
KVM: nVMX: Fix loss of L2's NMI blocking state
KVM: nVMX: Fix posted intr delivery when vcpu is in guest mode
x86: irq: Define a global vector for nested posted interrupts
KVM: x86: do mask out upper bits of PAE CR3
KVM: make pid available for uevents without debugfs
KVM: s390: take srcu lock when getting/setting storage keys
KVM: VMX: remove unused field
KVM: PPC: Book3S HV: Fix host crash on changing HPT size
KVM: PPC: Book3S HV: Enable TM before accessing TM registers
The highlight is Ben's patch to work around a host killing bug when running KVM
guests with the Radix MMU on Power9. See the long change log of that commit for
more detail.
And then three fairly minor fixes:
- Fix of_node_put() underflow during reconfig remove, using old DLPAR tools.
- Fix recently introduced ld version check with 64-bit LE-only toolchain.
- Free the subpage_prot_table correctly, avoiding a memory leak.
Thanks to:
Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier.
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Merge tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"The highlight is Ben's patch to work around a host killing bug when
running KVM guests with the Radix MMU on Power9. See the long change
log of that commit for more detail.
And then three fairly minor fixes:
- fix of_node_put() underflow during reconfig remove, using old DLPAR
tools.
- fix recently introduced ld version check with 64-bit LE-only
toolchain.
- free the subpage_prot_table correctly, avoiding a memory leak.
Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier"
* tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/mm/hash: Free the subpage_prot_table correctly
powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchain
powerpc/pseries: Fix of_node_put() underflow during reconfig remove
powerpc/mm/radix: Workaround prefetch issue with KVM
Commit 8e3f1b1d82 ("powerpc/powernv/pci: Enable 64-bit devices to access
>4GB DMA space") introduced the ability for PCI device drivers to request a
DMA mask between 64 and 32 bits and actually get a mask greater than
32-bits. However currently if certain machine configuration dependent
conditions are not meet the code silently falls back to a 32-bit mask.
This makes it hard for device drivers to detect which mask they actually
got. Instead we should return an error when the request could not be
fulfilled which allows drivers to either fallback or implement other
workarounds as documented in DMA-API-HOWTO.txt.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Historically the boot wrapper was always built 32-bit big endian, even
for 64-bit kernels. That was because old firmwares didn't necessarily
support booting a 64-bit image. Because of that arch/powerpc/boot/Makefile
uses CROSS32CC for compilation.
However when we added 64-bit little endian support, we also added
support for building the boot wrapper 64-bit. However we kept using
CROSS32CC, because in most cases it is just CC and everything works.
However if the user doesn't specify CROSS32_COMPILE (which no one ever
does AFAIK), and CC is *not* biarch (32/64-bit capable), then CROSS32CC
becomes just "gcc". On native systems that is probably OK, but if we're
cross building it definitely isn't, leading to eg:
gcc ... -m64 -mlittle-endian -mabi=elfv2 ... arch/powerpc/boot/cpm-serial.c
gcc: error: unrecognized argument in option ‘-mabi=elfv2’
gcc: error: unrecognized command line option ‘-mlittle-endian’
make: *** [zImage] Error 2
To fix it, stop using CROSS32CC, because we may or may not be building
32-bit. Instead setup a BOOTCC, which defaults to CC, and only use
CROSS32_COMPILE if it's set and we're building for 32-bit.
Fixes: 147c05168f ("powerpc/boot: Add support for 64bit little endian wrapper")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
In smp_cpus_done() we need to call smp_ops->setup_cpu() for the boot
CPU, which means it has to run *on* the boot CPU.
In the past we ensured it ran on the boot CPU by changing the CPU
affinity mask of current directly. That was removed in commit
6d11b87d55 ("powerpc/smp: Replace open coded task affinity logic"),
and replaced with a work queue call.
Unfortunately using a work queue leads to a lockdep warning, now that
the CPU hotplug lock is a regular semaphore:
======================================================
WARNING: possible circular locking dependency detected
...
kworker/0:1/971 is trying to acquire lock:
(cpu_hotplug_lock.rw_sem){++++++}, at: [<c000000000100974>] apply_workqueue_attrs+0x34/0xa0
but task is already holding lock:
((&wfc.work)){+.+.+.}, at: [<c0000000000fdb2c>] process_one_work+0x25c/0x800
...
CPU0 CPU1
---- ----
lock((&wfc.work));
lock(cpu_hotplug_lock.rw_sem);
lock((&wfc.work));
lock(cpu_hotplug_lock.rw_sem);
Although the deadlock can't happen in practice, because
smp_cpus_done() only runs in early boot before CPU hotplug is allowed,
lockdep can't tell that.
Luckily in commit 8fb12156b8 ("init: Pin init task to the boot CPU,
initially") tglx changed the generic code to pin init to the boot CPU
to begin with. The unpinning of init from the boot CPU happens in
sched_init_smp(), which is called after smp_cpus_done().
So smp_cpus_done() is always called on the boot CPU, which means we
don't need the work queue call at all - and the lockdep warning goes
away.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Currently flush_tmregs_to_thread() does not save the TM SPRs (TFHAR,
TFIAR, TEXASR) to the thread struct, unless the process is currently
inside a suspended transaction.
If the process is core dumping, and the TM SPRs have changed since the
last time the process was context switched, then we will save stale
values of the TM SPRs to the core dump.
Fix it by saving the live register state to the thread struct in that
case.
Fixes: 08e1c01d6a ("powerpc/ptrace: Enable support for TM SPR state")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Radix MMU translation tree as defined in ISA v3.0 contains two
different types of entry, directories and leaves. Leaves are
identified by _PAGE_PTE being set.
The formats of the two entries are different, with the directory
entries containing no spare bits for use by software. In particular
the bit we use for _PAGE_DEVMAP is not reserved for software, and is
part of the NLB (Next Level Base) field, essentially the address of
the next level in the tree.
Note that the Linux pte_t is not == _PAGE_PTE. A huge page pmd
entry (or devmap!) is also a leaf and so has _PAGE_PTE set, even
though we use a pmd_t for it in Linux.
The fix is to ensure that the pmd/pte_devmap() confirm they are
looking at a leaf entry (_PAGE_PTE) as well as checking _PAGE_DEVMAP.
Fixes: ebd3119793 ("powerpc/mm: Add devmap support for ppc64")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Add a comment in the code and flesh out change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fixes: dad6f37c26 ("powerpc: subpage_protect: Increase the array size to take care of 64TB")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit efe0160cfd ("powerpc/64: Linker on-demand sfpr functions
for modules"), we added an ld version check early in the powerpc
top-level Makefile.
Because the Makefile runs before the kernel config is setup, the
checks for CONFIG_CPU_LITTLE_ENDIAN etc. all take the default case. So
we end up configuring ld for 32-bit big endian.
That would be OK, except that for historical (or perhaps no) reason,
we use 'override LD' to add the endian flags to the LD variable
itself, rather than the normal approach of adding them to LDFLAGS.
The end result is that when we check the ld version we run it as:
$(CROSS_COMPILE)ld -EB -m elf32ppc --version
This often works, unless you are using a 64-bit only and/or little
endian only, toolchain. In which case you see something like:
$ make defconfig
powerpc64le-linux-ld: unrecognised emulation mode: elf32ppc
Supported emulations: elf64lppc elf32lppc elf32lppclinux elf32lppcsim
/bin/sh: 1: [: -ge: unexpected operator
The proper fix is to stop using 'override LD', but that will require a
fair bit of testing. Instead we can fix it for now just by reordering
the Makefile to do the version check earlier.
Fixes: efe0160cfd ("powerpc/64: Linker on-demand sfpr functions for modules")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As for commit 68baf692c4 ("powerpc/pseries: Fix of_node_put()
underflow during DLPAR remove"), the call to of_node_put() must be
removed from pSeries_reconfig_remove_node().
dlpar_detach_node() and pSeries_reconfig_remove_node() both call
of_detach_node(), and thus the node should not be released in both
cases.
Fixes: 0829f6d1f6 ("of: device_node kobject lifecycle fixes")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There's a somewhat architectural issue with Radix MMU and KVM.
When coming out of a guest with AIL (Alternate Interrupt Location, ie,
MMU enabled), we start executing hypervisor code with the PID register
still containing whatever the guest has been using.
The problem is that the CPU can (and will) then start prefetching or
speculatively load from whatever host context has that same PID (if
any), thus bringing translations for that context into the TLB, which
Linux doesn't know about.
This can cause stale translations and subsequent crashes.
Fixing this in a way that is neither racy nor a huge performance
impact is difficult. We could just make the host invalidations always
use broadcast forms but that would hurt single threaded programs for
example.
We chose to fix it instead by partitioning the PID space between guest
and host. This is possible because today Linux only use 19 out of the
20 bits of PID space, so existing guests will work if we make the host
use the top half of the 20 bits space.
We additionally add support for a property to indicate to Linux the
size of the PID register which will be useful if we eventually have
processors with a larger PID space available.
There is still an issue with malicious guests purposefully setting the
PID register to a value in the hosts PID range. Hopefully future HW
can prevent that, but in the meantime, we handle it with a pair of
kludges:
- On the way out of a guest, before we clear the current VCPU in the
PACA, we check the PID and if it's outside of the permitted range
we flush the TLB for that PID.
- When context switching, if the mm is "new" on that CPU (the
corresponding bit was set for the first time in the mm cpumask), we
check if any sibling thread is in KVM (has a non-NULL VCPU pointer
in the PACA). If that is the case, we also flush the PID for that
CPU (core).
This second part is needed to handle the case where a process is
migrated (or starts a new pthread) on a sibling thread of the CPU
coming out of KVM, as there's a window where stale translations can
exist before we detect it and flush them out.
A future optimization could be added by keeping track of whether the
PID has ever been used and avoid doing that for completely fresh PIDs.
We could similarily mark PIDs that have been the subject of a global
invalidation as "fresh". But for now this will do.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Rework the asm to build with CONFIG_PPC_RADIX_MMU=n, drop
unneeded include of kvm_book3s_asm.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit f98a8bf9ee ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB
ioctl() to change HPT size", 2016-12-20) changed the behaviour of
the KVM_PPC_ALLOCATE_HTAB ioctl so that it now allocates a new HPT
and new revmap array if there was a previously-allocated HPT of a
different size from the size being requested. In this case, we need
to reset the rmap arrays of the memslots, because the rmap arrays
will contain references to HPTEs which are no longer valid. Worse,
these references are also references to slots in the new revmap
array (which parallels the HPT), and the new revmap array contains
random contents, since it doesn't get zeroed on allocation.
The effect of having these stale references to slots in the revmap
array that contain random contents is that subsequent calls to
functions such as kvmppc_add_revmap_chain will crash because they
will interpret the non-zero contents of the revmap array as HPTE
indexes and thus index outside of the revmap array. This leads to
host crashes such as the following.
[ 7072.862122] Unable to handle kernel paging request for data at address 0xd000000c250c00f8
[ 7072.862218] Faulting instruction address: 0xc0000000000e1c78
[ 7072.862233] Oops: Kernel access of bad area, sig: 11 [#1]
[ 7072.862286] SMP NR_CPUS=1024
[ 7072.862286] NUMA
[ 7072.862325] PowerNV
[ 7072.862378] Modules linked in: kvm_hv 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 iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm iw_cxgb3 mlx5_ib ib_core ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel i2c_opal nfsd auth_rpcgss oid_registry
[ 7072.863085] nfs_acl lockd grace sunrpc kvm_pr kvm xfs libcrc32c scsi_dh_alua dm_service_time radeon lpfc nvme_fc nvme_fabrics nvme_core scsi_transport_fc i2c_algo_bit tg3 drm_kms_helper ptp pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm dm_multipath i2c_core cxgb3 mlx5_core mdio [last unloaded: kvm_hv]
[ 7072.863381] CPU: 72 PID: 56929 Comm: qemu-system-ppc Not tainted 4.12.0-kvm+ #59
[ 7072.863457] task: c000000fe29e7600 task.stack: c000001e3ffec000
[ 7072.863520] NIP: c0000000000e1c78 LR: c0000000000e2e3c CTR: c0000000000e25f0
[ 7072.863596] REGS: c000001e3ffef560 TRAP: 0300 Not tainted (4.12.0-kvm+)
[ 7072.863658] MSR: 9000000100009033 <SF,HV,EE,ME,IR,DR,RI,LE,TM[E]>
[ 7072.863667] CR: 44082882 XER: 20000000
[ 7072.863767] CFAR: c0000000000e2e38 DAR: d000000c250c00f8 DSISR: 42000000 SOFTE: 1
GPR00: c0000000000e2e3c c000001e3ffef7e0 c000000001407d00 d000000c250c00f0
GPR04: d00000006509fb70 d00000000b3d2048 0000000003ffdfb7 0000000000000000
GPR08: 00000001007fdfb7 00000000c000000f d0000000250c0000 000000000070f7bf
GPR12: 0000000000000008 c00000000fdad000 0000000010879478 00000000105a0d78
GPR16: 00007ffaf4080000 0000000000001190 0000000000000000 0000000000010000
GPR20: 4001ffffff000415 d00000006509fb70 0000000004091190 0000000ee1881190
GPR24: 0000000003ffdfb7 0000000003ffdfb7 00000000007fdfb7 c000000f5c958000
GPR28: d00000002d09fb70 0000000003ffdfb7 d00000006509fb70 d00000000b3d2048
[ 7072.864439] NIP [c0000000000e1c78] kvmppc_add_revmap_chain+0x88/0x130
[ 7072.864503] LR [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0
[ 7072.864566] Call Trace:
[ 7072.864594] [c000001e3ffef7e0] [c000001e3ffef830] 0xc000001e3ffef830 (unreliable)
[ 7072.864671] [c000001e3ffef830] [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0
[ 7072.864751] [c000001e3ffef920] [d00000000b38d878] kvmppc_map_vrma+0x168/0x200 [kvm_hv]
[ 7072.864831] [c000001e3ffef9e0] [d00000000b38a684] kvmppc_vcpu_run_hv+0x1284/0x1300 [kvm_hv]
[ 7072.864914] [c000001e3ffefb30] [d00000000f465664] kvmppc_vcpu_run+0x44/0x60 [kvm]
[ 7072.865008] [c000001e3ffefb60] [d00000000f461864] kvm_arch_vcpu_ioctl_run+0x114/0x290 [kvm]
[ 7072.865152] [c000001e3ffefbe0] [d00000000f453c98] kvm_vcpu_ioctl+0x598/0x7a0 [kvm]
[ 7072.865292] [c000001e3ffefd40] [c000000000389328] do_vfs_ioctl+0xd8/0x8c0
[ 7072.865410] [c000001e3ffefde0] [c000000000389be4] SyS_ioctl+0xd4/0x130
[ 7072.865526] [c000001e3ffefe30] [c00000000000b760] system_call+0x58/0x6c
[ 7072.865644] Instruction dump:
[ 7072.865715] e95b2110 793a0020 7b4926e4 7f8a4a14 409e0098 807c000c 786326e4 7c6a1a14
[ 7072.865857] 935e0008 7bbd0020 813c000c 913e000c <93a30008> 93bc000c 48000038 60000000
[ 7072.866001] ---[ end trace 627b6e4bf8080edc ]---
Note that to trigger this, it is necessary to use a recent upstream
QEMU (or other userspace that resizes the HPT at CAS time), specify
a maximum memory size substantially larger than the current memory
size, and boot a guest kernel that does not support HPT resizing.
This fixes the problem by resetting the rmap arrays when the old HPT
is freed.
Fixes: f98a8bf9ee ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size")
Cc: stable@vger.kernel.org # v4.11+
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Here are some small tty and serial driver fixes for 4.13-rc2. Nothing
huge at all, a revert of a patch that turned out to break things, a fix
up for a new tty ioctl we added in 4.13-rc1 to get the uapi definition
correct, and a few minor serial driver fixes for reported issues.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are some small tty and serial driver fixes for 4.13-rc2. Nothing
huge at all, a revert of a patch that turned out to break things, a
fix up for a new tty ioctl we added in 4.13-rc1 to get the uapi
definition correct, and a few minor serial driver fixes for reported
issues.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: Fix TIOCGPTPEER ioctl definition
tty: hide unused pty_get_peer function
tty: serial: lpuart: Fix the logic for detecting the 32-bit type UART
serial: imx: Prevent TX buffer PIO write when a DMA has been started
Revert "serial: imx-serial - move DMA buffer configuration to DT"
serial: sh-sci: Uninitialized variables in sysfs files
serial: st-asc: Potential error pointer dereference
A handful of fixes, mostly for new code.
Some reworking of the new STRICT_KERNEL_RWX support to make sure we also remove
executable permission from __init memory before it's freed.
A fix to some recent optimisations to the hypercall entry where we were
clobbering r12, this was breaking nested guests (PR KVM).
A fix for the recent patch to opal_configure_cores(). This could break booting
on bare metal Power8 boxes if the kernel was built without
CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG.
And finally a workaround for spurious PMU interrupts on Power9 DD2.
Thanks to:
Nicholas Piggin, Anton Blanchard, Balbir Singh.
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Merge tag 'powerpc-4.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"A handful of fixes, mostly for new code:
- some reworking of the new STRICT_KERNEL_RWX support to make sure we
also remove executable permission from __init memory before it's
freed.
- a fix to some recent optimisations to the hypercall entry where we
were clobbering r12, this was breaking nested guests (PR KVM).
- a fix for the recent patch to opal_configure_cores(). This could
break booting on bare metal Power8 boxes if the kernel was built
without CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG.
- .. and finally a workaround for spurious PMU interrupts on Power9
DD2.
Thanks to: Nicholas Piggin, Anton Blanchard, Balbir Singh"
* tag 'powerpc-4.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y
powerpc/mm/hash: Refactor hash__mark_rodata_ro()
powerpc/mm/radix: Refactor radix__mark_rodata_ro()
powerpc/64s: Fix hypercall entry clobbering r12 input
powerpc/perf: Avoid spurious PMU interrupts after idle
powerpc/powernv: Fix boot on Power8 bare metal due to opal_configure_cores()
Pull core fixes from Ingo Molnar:
"A fix to WARN_ON_ONCE() done by modules, plus a MAINTAINERS update"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debug: Fix WARN_ON_ONCE() for modules
MAINTAINERS: Update the PTRACE entry
Mike Galbraith reported a situation where a WARN_ON_ONCE() call in DRM
code turned into an oops. As it turns out, WARN_ON_ONCE() seems to be
completely broken when called from a module.
The bug was introduced with the following commit:
19d436268d ("debug: Add _ONCE() logic to report_bug()")
That commit changed WARN_ON_ONCE() to move its 'once' logic into the bug
trap handler. It requires a writable bug table so that the BUGFLAG_DONE
bit can be written to the flags to indicate the first warning has
occurred.
The bug table was made writable for vmlinux, which relies on
vmlinux.lds.S and vmlinux.lds.h for laying out the sections. However,
it wasn't made writable for modules, which rely on the ELF section
header flags.
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-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>
Fixes: 19d436268d ("debug: Add _ONCE() logic to report_bug()")
Link: http://lkml.kernel.org/r/a53b04235a65478dd9afc51f5b329fdc65c84364.1500095401.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently even with STRICT_KERNEL_RWX we leave the __init text marked
executable after init, which is bad.
Add a hook to mark it NX (no-execute) before we free it, and implement
it for radix and hash.
Note that we use __init_end as the end address, not _einittext,
because overlaps_kernel_text() uses __init_end, because there are
additional executable sections other than .init.text between
__init_begin and __init_end.
Tested on radix and hash with:
0:mon> p $__init_begin
*** 400 exception occurred
Fixes: 1e0fc9d1eb ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the core logic into a helper, so we can use it for changing other
permissions.
We also change the logic to align start down, and end up. This means
calling the function with a range will expand that range to be at
least 1 mmu_linear_psize page in size. We need that so we can use it
on __init_begin ... __init_end which is not a full page in size.
This should always work for _stext/__init_begin, because we align
__init_begin to _stext + 16M in the linker script.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move the core logic into a helper, so we can use it for changing permissions
other than _PAGE_WRITE.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
A previous optimisation incorrectly assumed the PAPR hcall does
not use r12, and clobbers it upon entry. In fact it is used as
an input. This can result in KVM guests crashing (observed with
PR KVM).
Instead of using r12 to save r13, tihs patch saves r13 in ctr.
This is more costly, but not as slow as using the SPRG.
Fixes: acd7d8cef0 ("powerpc/64s: Optimize hypercall/syscall entry")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD2 can see spurious PMU interrupts after state-loss idle in
some conditions.
A solution is to save and reload MMCR0 over state-loss idle.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This ioctl does nothing to justify an _IOC_READ or _IOC_WRITE flag
because it doesn't copy anything from/to userspace to access the
argument.
Fixes: 54ebbfb160 ("tty: add TIOCGPTPEER ioctl")
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Acked-by: Aleksa Sarai <asarai@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 1c0eaf0f56 ("powerpc/powernv: Tell OPAL about our MMU mode
on POWER9"), we added additional flags to the OPAL call to configure
CPUs at boot.
These flags only work on Power9 firmwares, and worse can cause boot
failures on Power8 machines, so we check for CPU_FTR_ARCH_300 (aka POWER9)
before adding the extra flags.
Unfortunately we forgot that opal_configure_cores() is called before
the CPU feature checks are dynamically patched, meaning the check
always returns true.
We definitely need to do something to make the CPU feature checks less
prone to bugs like this, but for now the minimal fix is to use
early_cpu_has_feature().
Reported-and-tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Fixes: 1c0eaf0f56 ("powerpc/powernv: Tell OPAL about our MMU mode on POWER9")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull ->s_options removal from Al Viro:
"Preparations for fsmount/fsopen stuff (coming next cycle). Everything
gets moved to explicit ->show_options(), killing ->s_options off +
some cosmetic bits around fs/namespace.c and friends. Basically, the
stuff needed to work with fsmount series with minimum of conflicts
with other work.
It's not strictly required for this merge window, but it would reduce
the PITA during the coming cycle, so it would be nice to have those
bits and pieces out of the way"
* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
isofs: Fix isofs_show_options()
VFS: Kill off s_options and helpers
orangefs: Implement show_options
9p: Implement show_options
isofs: Implement show_options
afs: Implement show_options
affs: Implement show_options
befs: Implement show_options
spufs: Implement show_options
bpf: Implement show_options
ramfs: Implement show_options
pstore: Implement show_options
omfs: Implement show_options
hugetlbfs: Implement show_options
VFS: Don't use save/replace_mount_options if not using generic_show_options
VFS: Provide empty name qstr
VFS: Make get_filesystem() return the affected filesystem
VFS: Clean up whitespace in fs/namespace.c and fs/super.c
Provide a function to create a NUL-terminated string from unterminated data
Pull uacess-unaligned removal from Al Viro:
"That stuff had just one user, and an exotic one, at that - binfmt_flat
on arm and m68k"
* 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
kill {__,}{get,put}_user_unaligned()
binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail
Nothing that really stands out, just a bunch of fixes that have come in in the
last couple of weeks.
None of these are actually fixes for code that is new in 4.13. It's roughly half
older bugs, with fixes going to stable, and half fixes/updates for Power9.
Thanks to:
Aneesh Kumar K.V, Anton Blanchard, Balbir Singh, Benjamin Herrenschmidt,
Madhavan Srinivasan, Michael Neuling, Nicholas Piggin, Oliver O'Halloran.
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Merge tag 'powerpc-4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Nothing that really stands out, just a bunch of fixes that have come
in in the last couple of weeks.
None of these are actually fixes for code that is new in 4.13. It's
roughly half older bugs, with fixes going to stable, and half
fixes/updates for Power9.
Thanks to: Aneesh Kumar K.V, Anton Blanchard, Balbir Singh, Benjamin
Herrenschmidt, Madhavan Srinivasan, Michael Neuling, Nicholas Piggin,
Oliver O'Halloran"
* tag 'powerpc-4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64: Fix atomic64_inc_not_zero() to return an int
powerpc: Fix emulation of mfocrf in emulate_step()
powerpc: Fix emulation of mcrf in emulate_step()
powerpc/perf: Add POWER9 alternate PM_RUN_CYC and PM_RUN_INST_CMPL events
powerpc/perf: Fix SDAR_MODE value for continous sampling on Power9
powerpc/asm: Mark cr0 as clobbered in mftb()
powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9
powerpc/mm/radix: Synchronize updates to the process table
powerpc/mm/radix: Properly clear process table entry
powerpc/powernv: Tell OPAL about our MMU mode on POWER9
powerpc/kexec: Fix radix to hash kexec due to IAMR/AMOR
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator. This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always
ignored for smaller sizes. This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.
Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success. This will work independent of the order and overrides the
default allocator behavior. Page allocator users have several levels of
guarantee vs. cost options (take GFP_KERNEL as an example)
- GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
attempt to free memory at all. The most light weight mode which even
doesn't kick the background reclaim. Should be used carefully because
it might deplete the memory and the next user might hit the more
aggressive reclaim
- GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
allocation without any attempt to free memory from the current
context but can wake kswapd to reclaim memory if the zone is below
the low watermark. Can be used from either atomic contexts or when
the request is a performance optimization and there is another
fallback for a slow path.
- (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
non sleeping allocation with an expensive fallback so it can access
some portion of memory reserves. Usually used from interrupt/bh
context with an expensive slow path fallback.
- GFP_KERNEL - both background and direct reclaim are allowed and the
_default_ page allocator behavior is used. That means that !costly
allocation requests are basically nofail but there is no guarantee of
that behavior so failures have to be checked properly by callers
(e.g. OOM killer victim is allowed to fail currently).
- GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
and all allocation requests fail early rather than cause disruptive
reclaim (one round of reclaim in this implementation). The OOM killer
is not invoked.
- GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
behavior and all allocation requests try really hard. The request
will fail if the reclaim cannot make any progress. The OOM killer
won't be triggered.
- GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
and all allocation requests will loop endlessly until they succeed.
This might be really dangerous especially for larger orders.
Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic. No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.
This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.
[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When RLIMIT_STACK is, for example, 256MB, the current code results in a
gap between the top of the task and mmap_base of 256MB, failing to take
into account the amount by which the stack address was randomized. In
other words, the stack gets less than RLIMIT_STACK space.
Ensure that the gap between the stack and mmap_base always takes stack
randomization and the stack guard gap into account.
Inspired by Daniel Micay's linux-hardened tree.
Link: http://lkml.kernel.org/r/20170622200033.25714-4-riel@redhat.com
Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Florian Weimer <fweimer@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds support for compiling with a rough equivalent to the glibc
_FORTIFY_SOURCE=1 feature, providing compile-time and runtime buffer
overflow checks for string.h functions when the compiler determines the
size of the source or destination buffer at compile-time. Unlike glibc,
it covers buffer reads in addition to writes.
GNU C __builtin_*_chk intrinsics are avoided because they would force a
much more complex implementation. They aren't designed to detect read
overflows and offer no real benefit when using an implementation based
on inline checks. Inline checks don't add up to much code size and
allow full use of the regular string intrinsics while avoiding the need
for a bunch of _chk functions and per-arch assembly to avoid wrapper
overhead.
This detects various overflows at compile-time in various drivers and
some non-x86 core kernel code. There will likely be issues caught in
regular use at runtime too.
Future improvements left out of initial implementation for simplicity,
as it's all quite optional and can be done incrementally:
* Some of the fortified string functions (strncpy, strcat), don't yet
place a limit on reads from the source based on __builtin_object_size of
the source buffer.
* Extending coverage to more string functions like strlcat.
* It should be possible to optionally use __builtin_object_size(x, 1) for
some functions (C strings) to detect intra-object overflows (like
glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative
approach to avoid likely compatibility issues.
* The compile-time checks should be made available via a separate config
option which can be enabled by default (or always enabled) once enough
time has passed to get the issues it catches fixed.
Kees said:
"This is great to have. While it was out-of-tree code, it would have
blocked at least CVE-2016-3858 from being exploitable (improper size
argument to strlcpy()). I've sent a number of fixes for
out-of-bounds-reads that this detected upstream already"
[arnd@arndb.de: x86: fix fortified memcpy]
Link: http://lkml.kernel.org/r/20170627150047.660360-1-arnd@arndb.de
[keescook@chromium.org: avoid panic() in favor of BUG()]
Link: http://lkml.kernel.org/r/20170626235122.GA25261@beast
[keescook@chromium.org: move from -mm, add ARCH_HAS_FORTIFY_SOURCE, tweak Kconfig help]
Link: http://lkml.kernel.org/r/20170526095404.20439-1-danielmicay@gmail.com
Link: http://lkml.kernel.org/r/1497903987-21002-8-git-send-email-keescook@chromium.org
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Testing the fortified string functions[1] would cause a kernel panic on
boot in test_feature_fixups() due to a buffer overflow in memcmp.
This boils down to things like this:
extern unsigned int ftr_fixup_test1;
extern unsigned int ftr_fixup_test1_orig;
check(memcmp(&ftr_fixup_test1, &ftr_fixup_test1_orig, size) == 0);
We know that these are asm labels so it is safe to read up to 'size'
bytes at those addresses.
However, because we have passed the address of a single unsigned int to
memcmp, the compiler believes the underlying object is in fact a single
unsigned int. So if size > sizeof(unsigned int), there will be a panic
at runtime.
We can fix this by changing the types: instead of calling the asm labels
unsigned ints, call them unsigned int[]s. Therefore the size isn't
incorrectly determined at compile time and we get a regular unsafe
memcmp and no panic.
[1] http://openwall.com/lists/kernel-hardening/2017/05/09/2
Link: http://lkml.kernel.org/r/1497903987-21002-7-git-send-email-keescook@chromium.org
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
prom_init is a bit special; in theory it should be able to be linked
separately to the kernel. To keep this from getting too complex, the
symbols that prom_init.c uses are checked.
Fortification adds symbols, and it gets quite messy as it includes
things like panic(). So just don't fortify prom_init.c for now.
Link: http://lkml.kernel.org/r/1497903987-21002-6-git-send-email-keescook@chromium.org
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement an arch-speicfic watchdog rather than use the perf-based
hardlockup detector.
The new watchdog takes the soft-NMI directly, rather than going through
perf. Perf interrupts are to be made maskable in future, so that would
prevent the perf detector from working in those regions.
Additionally, implement a SMP based detector where all CPUs watch one
another by pinging a shared cpumask. This is because powerpc Book3S
does not have a true periodic local NMI, but some platforms do implement
a true NMI IPI.
If a CPU is stuck with interrupts hard disabled, the soft-NMI watchdog
does not work, but the SMP watchdog will. Even on platforms without a
true NMI IPI to get a good trace from the stuck CPU, other CPUs will
notice the lockup sufficiently to report it and panic.
[npiggin@gmail.com: honor watchdog disable at boot/hotplug]
Link: http://lkml.kernel.org/r/20170621001346.5bb337c9@roar.ozlabs.ibm.com
[npiggin@gmail.com: fix false positive warning at CPU unplug]
Link: http://lkml.kernel.org/r/20170630080740.20766-1-npiggin@gmail.com
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170616065715.18390-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Tested-by: Babu Moger <babu.moger@oracle.com> [sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split
HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR.
LOCKUP_DETECTOR implies the general boot, sysctl, and programming
interfaces for the lockup detectors.
An architecture that wants to use a hard lockup detector must define
HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH.
Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the
minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and
does not implement the LOCKUP_DETECTOR interfaces.
sparc is unusual in that it has started to implement some of the
interfaces, but not fully yet. It should probably be converted to a full
HAVE_HARDLOCKUP_DETECTOR_ARCH.
[npiggin@gmail.com: fix]
Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com
Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Tested-by: Babu Moger <babu.moger@oracle.com> [sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmcoreinfo_max_size stands for the vmcoreinfo_data, the correct one we
should use is vmcoreinfo_note whose total size is VMCOREINFO_NOTE_SIZE.
Like explained in commit 77019967f0 ("kdump: fix exported size of
vmcoreinfo note"), it should not affect the actual function, but we
better fix it, also this change should be safe and backward compatible.
After this, we can get rid of variable vmcoreinfo_max_size, let's use
the corresponding macros directly, fewer variables means more safety for
vmcoreinfo operation.
[xlpang@redhat.com: fix build warning]
Link: http://lkml.kernel.org/r/1494830606-27736-1-git-send-email-xlpang@redhat.com
Link: http://lkml.kernel.org/r/1493281021-20737-2-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although it's not documented anywhere, there is an expectation that
atomic64_inc_not_zero() returns a result which fits in an int. This is
the behaviour implemented on all arches except powerpc.
This has caused at least one bug in practice, in the percpu-refcount
code, where the long result from our atomic64_inc_not_zero() was
truncated to an int leading to lost references and stuck systems. That
was worked around in that code in commit 966d2b04e0 ("percpu-refcount:
fix reference leak during percpu-atomic transition").
To the best of my grepping abilities there are no other callers
in-tree which truncate the value, but we should fix it anyway. Because
the breakage is subtle and potentially very harmful I'm also tagging
it for stable.
Code generation is largely unaffected because in most cases the
callers are just using the result for a test anyway. In particular the
case of fget() that was mentioned in commit a6cf7ed511
("powerpc/atomic: Implement atomic*_inc_not_zero") generates exactly
the same code.
Fixes: a6cf7ed511 ("powerpc/atomic: Implement atomic*_inc_not_zero")
Cc: stable@vger.kernel.org # v3.4
Noticed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
From POWER4 onwards, mfocrf() only places the specified CR field into
the destination GPR, and the rest of it is set to 0. The PowerPC AS
from version 3.0 now requires this behaviour.
The emulation code currently puts the entire CR into the destination GPR.
Fix it.
Fixes: 6888199f7f ("[POWERPC] Emulate more instructions in software")
Cc: stable@vger.kernel.org # v2.6.22+
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The mcrf emulation code was using the CR field number directly as the shift
value, without taking into account that CR fields are numbered from 0-7 starting
at the high bits. That meant it was looking at the CR fields in the reverse
order.
Fixes: cf87c3f6b6 ("powerpc: Emulate icbi, mcrf and conditional-trap instructions")
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Similar to POWER8, POWER9 can count run cycles and run instructions
completed on more than one PMU.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In case of continous sampling (non-marked), the code currently
sets MMCRA[SDAR_MODE] to 0b01 (Update on TLB miss) for Power9 DD1.
On DD2 and later it copies the sdar_mode value from the event code,
which for most events is 0b00 (No updates).
However we must set a non-zero value for SDAR_MODE when doing
continuous sampling, so honor the event code, unless it's zero, in
which case we use use 0b01 (Update on TLB miss).
Fixes: 78b4416aa2 ("powerpc/perf: Handle sdar_mode for marked event in power9")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Implement the show_options superblock op for spufs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeremy Kerr <jk@ozlabs.org>
cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The workaround for the CELL timebase bug does not correctly mark cr0 as
being clobbered. This means GCC doesn't know that the asm block changes cr0 and
might leave the result of an unrelated comparison in cr0 across the block, which
we then trash, leading to basically random behaviour.
Fixes: 859deea949 ("[POWERPC] Cell timebase bug workaround")
Cc: stable@vger.kernel.org # v2.6.19+
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Tweak change log and flag for stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are two cases outside the normal address space management
where a CPU's local TLB is to be flushed:
1. Host boot; in case something has left stale entries in the
TLB (e.g., kexec).
2. Machine check; to clean corrupted TLB entries.
CPU state restore from deep idle states also flushes the TLB.
However this seems to be a side effect of reusing the boot code to set
CPU state, rather than a requirement itself.
The current flushing has a number of problems with ISA v3.0B:
- The current radix mode of the MMU is not taken into account. tlbiel
is undefined if the R field does not match the current radix mode.
- ISA v3.0B hash must flush the partition and process table caches.
- ISA v3.0B radix must flush partition and process scoped translations,
partition and process table caches, and also the page walk cache.
Add POWER9 cases to handle these, with radix vs hash determined by the
host MMU mode.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.
For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers. On 32-bit use 4MB, which is the
traditional x86 minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).
Link: http://lkml.kernel.org/r/1498154792-49952-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds