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2017-10-14KVM: PPC: Book3S HV: Handle unexpected interrupts betterPaul Mackerras2-1/+137
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>
2017-10-14KVM: PPC: Book3S: Protect kvmppc_gpa_to_ua() with SRCUAlexey Kardashevskiy1-9/+14
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: 121f80ba68f1 ("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>
2017-10-14KVM: PPC: Book3S HV: POWER9 more doorbell fixesNicholas Piggin1-0/+5
- 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: 1704a81ccebc ("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>
2017-10-14KVM: PPC: Fix oops when checking KVM_CAP_PPC_HTMGreg Kurz1-2/+1
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: 23528bb21ee2 ("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>
2017-10-13Merge tag 'powerpc-4.14-5' of ↵Linus Torvalds4-38/+53
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
2017-10-13powerpc/perf: Fix IMC initialization crashAnju T Sudhakar1-1/+2
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>
2017-10-13powerpc/modules: Use WARN_ON() in stub_for_addr()Kamalesh Babulal1-1/+2
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>
2017-10-12treewide: Fix typos in KconfigMasanari Iida1-1/+1
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>
2017-10-12powerpc/perf: Add ___GFP_NOWARN flag to alloc_pages_node()Anju T Sudhakar1-4/+4
Stack trace output during a stress test: [ 4.310049] Freeing initrd memory: 22592K [ 4.310646] rtas_flash: no firmware flash support [ 4.313341] cpuhp/64: page allocation failure: order:0, mode:0x14480c0(GFP_KERNEL|__GFP_ZERO|__GFP_THISNODE), nodemask=(null) [ 4.313465] cpuhp/64 cpuset=/ mems_allowed=0 [ 4.313521] CPU: 64 PID: 392 Comm: cpuhp/64 Not tainted 4.11.0-39.el7a.ppc64le #1 [ 4.313588] Call Trace: [ 4.313622] [c000000f1fb1b8e0] [c000000000c09388] dump_stack+0xb0/0xf0 (unreliable) [ 4.313694] [c000000f1fb1b920] [c00000000030ef6c] warn_alloc+0x12c/0x1c0 [ 4.313753] [c000000f1fb1b9c0] [c00000000030ff68] __alloc_pages_nodemask+0xea8/0x1000 [ 4.313823] [c000000f1fb1bbb0] [c000000000113a8c] core_imc_mem_init+0xbc/0x1c0 [ 4.313892] [c000000f1fb1bc00] [c000000000113cdc] ppc_core_imc_cpu_online+0x14c/0x170 [ 4.313962] [c000000f1fb1bc90] [c000000000125758] cpuhp_invoke_callback+0x198/0x5d0 [ 4.314031] [c000000f1fb1bd00] [c00000000012782c] cpuhp_thread_fun+0x8c/0x3d0 [ 4.314101] [c000000f1fb1bd60] [c0000000001678d0] smpboot_thread_fn+0x290/0x2a0 [ 4.314169] [c000000f1fb1bdc0] [c00000000015ee78] kthread+0x168/0x1b0 [ 4.314229] [c000000f1fb1be30] [c00000000000b368] ret_from_kernel_thread+0x5c/0x74 [ 4.314313] Mem-Info: [ 4.314356] active_anon:0 inactive_anon:0 isolated_anon:0 core_imc_mem_init() at system boot use alloc_pages_node() to get memory and alloc_pages_node() throws this stack dump when tried to allocate memory from a node which has no memory behind it. Add a ___GFP_NOWARN flag in allocation request as a fix. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Venkat R.B <venkatb3@in.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-12powerpc/perf: Fix for core/nest imc call trace on cpuhotplugAnju T Sudhakar1-0/+28
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>
2017-10-10powerpc: Don't call lockdep_assert_cpus_held() from arch_update_cpu_topology()Thiago Jung Bauermann1-1/+0
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: 3e401f7a2e51 ("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>
2017-10-10locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementationsWill Deacon1-3/+1
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>
2017-10-10locking/core: Remove {read,spin,write}_can_lock()Will Deacon1-3/+0
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>
2017-10-10powerpc/lib/sstep: Fix count leading zeros instructionsSandipan Das1-2/+4
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: 3cdfcbfd32b9d ("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>
2017-10-10powerpc/livepatch: Fix livepatch stack accessKamalesh Babulal1-30/+15
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>
2017-10-10Merge branch 'ppc-bundle' (bundle from Michael Ellerman)Linus Torvalds2-2/+35
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
2017-10-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-4/+2
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()
2017-10-06Merge tag 'powerpc-4.14-4' of ↵Linus Torvalds7-7/+37
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
2017-10-06Merge branch 'core-watchdog-for-linus' of ↵Linus Torvalds1-15/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2017-10-06powerpc/tm: Fix illegal TM state in signal handlerGustavo Romero1-1/+12
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: 5d176f751ee3 ("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>
2017-10-06powerpc/64s: Use emergency stack for kernel TM Bad Thing program checksCyril Bur1-1/+23
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: 5d176f751ee3 ("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>
2017-10-06powerpc: get_wchan(): solve possible race scenario due to parallel wakeupKautuk Consul1-1/+2
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>
2017-10-06powerpc: Always initialize input array when calling epapr_hypercall()Seth Forshee1-6/+6
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>
2017-10-06powerpc: Add PPC_EMULATED_STATS to powernv_defconfigMichael Neuling1-0/+1
This is useful, especially for developers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-06powerpc/xmon: Add option to show uptime informationGuilherme G. Piccoli1-0/+24
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>
2017-10-06powerpc/powernv: Make opal_event_shutdown() callable from IRQ contextMichael Ellerman1-1/+7
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: 9f0fd0499d30 ("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>
2017-10-06powerpc/powernv: Increase memory block size to 1GB on radixAnton Blanchard1-1/+9
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: 4b5d62ca17a1 ("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>
2017-10-05PCI: Remove reset argument from pci_iov_{add,remove}_virtfn()Jan H. Schönherr1-2/+2
The "reset" argument passed to pci_iov_add_virtfn() and pci_iov_remove_virtfn() is always zero since 46cb7b1bd86f ("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>
2017-10-05timer: Remove init_timer_deferrable() in favor of timer_setup()Kees Cook1-7/+5
This refactors the only users of init_timer_deferrable() to use the new timer_setup() and from_timer(). Removes definition of init_timer_deferrable(). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David S. Miller <davem@davemloft.net> # for networking parts Acked-by: Sebastian Reichel <sre@kernel.org> # for drivers/hsi parts Cc: linux-mips@linux-mips.org Cc: Petr Mladek <pmladek@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: linux1394-devel@lists.sourceforge.net Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: linux-s390@vger.kernel.org Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ursula Braun <ubraun@linux.vnet.ibm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Harish Patil <harish.patil@cavium.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Manish Chopra <manish.chopra@cavium.com> Cc: Len Brown <len.brown@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-pm@vger.kernel.org Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Julian Wiedmann <jwi@linux.vnet.ibm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mark Gross <mark.gross@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: linux-watchdog@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-wireless@vger.kernel.org Cc: Sebastian Reichel <sre@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Michael Reed <mdr@sgi.com> Cc: netdev@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linuxppc-dev@lists.ozlabs.org Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lkml.kernel.org/r/1507159627-127660-6-git-send-email-keescook@chromium.org
2017-10-05powerpc/jprobes: Validate break handler invocation as being due to a ↵Naveen N. Rao1-11/+9
jprobe_return() 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>
2017-10-05powerpc/jprobes: Disable preemption when triggered through ftraceNaveen N. Rao1-4/+11
KPROBES_SANITY_TEST throws the below splat when CONFIG_PREEMPT is enabled: Kprobe smoke test: started DEBUG_LOCKS_WARN_ON(val > preempt_count()) ------------[ cut here ]------------ WARNING: CPU: 19 PID: 1 at kernel/sched/core.c:3094 preempt_count_sub+0xcc/0x140 Modules linked in: CPU: 19 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc7-nnr+ #97 task: c0000000fea80000 task.stack: c0000000feb00000 NIP: c00000000011d3dc LR: c00000000011d3d8 CTR: c000000000a090d0 REGS: c0000000feb03400 TRAP: 0700 Not tainted (4.13.0-rc7-nnr+) MSR: 8000000000021033 <SF,ME,IR,DR,RI,LE> CR: 28000282 XER: 00000000 CFAR: c00000000015aa18 SOFTE: 0 <snip> NIP preempt_count_sub+0xcc/0x140 LR preempt_count_sub+0xc8/0x140 Call Trace: preempt_count_sub+0xc8/0x140 (unreliable) kprobe_handler+0x228/0x4b0 program_check_exception+0x58/0x3b0 program_check_common+0x16c/0x170 --- interrupt: 0 at kprobe_target+0x8/0x20 LR = init_test_probes+0x248/0x7d0 kp+0x0/0x80 (unreliable) livepatch_handler+0x38/0x74 init_kprobes+0x1d8/0x208 do_one_initcall+0x68/0x1d0 kernel_init_freeable+0x298/0x374 kernel_init+0x24/0x160 ret_from_kernel_thread+0x5c/0x70 Instruction dump: 419effdc 3d22001b 39299240 81290000 2f890000 409effc8 3c82ffcb 3c62ffcb 3884bc68 3863bc18 4803d5fd 60000000 <0fe00000> 4bffffa8 60000000 60000000 ---[ end trace 432dd46b4ce3d29f ]--- Kprobe smoke test: passed successfully The issue is that we aren't disabling preemption in kprobe_ftrace_handler(). Disable it. Fixes: ead514d5fb30a0 ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> [mpe: Trim oops a little for formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/kprobes: Fix warnings from __this_cpu_read() on preempt kernelsNaveen N. Rao1-2/+6
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 c05b8c4474c030 ("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: c05b8c4474c030 ("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>
2017-10-04powerpc/kprobes: Clean up jprobe detection in livepatch handlerNaveen N. Rao4-9/+14
In commit c05b8c4474c03 ("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>
2017-10-04powerpc/kprobes: Do not suppress instruction emulation if a single run failedNaveen N. Rao1-3/+14
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>
2017-10-04powerpc/kprobes: Some cosmetic updates to try_to_emulate()Naveen N. Rao1-2/+2
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>
2017-10-04powerpc/configs: Add Skiroot defconfigJoel Stanley1-0/+232
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>
2017-10-04powerpc/mm: Call flush_tlb_kernel_range with interrupts enabledGuenter Roeck1-1/+1
flush_tlb_kernel_range() may call smp_call_function_many() which expects interrupts to be enabled. This results in a traceback. WARNING: CPU: 0 PID: 1 at kernel/smp.c:416 smp_call_function_many+0xcc/0x2fc CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc1-00009-g0666f56 #1 task: cf830000 task.stack: cf82e000 NIP: c00a93c8 LR: c00a9634 CTR: 00000001 REGS: cf82fde0 TRAP: 0700 Not tainted (4.14.0-rc1-00009-g0666f56) MSR: 00021000 <CE,ME> CR: 24000082 XER: 00000000 GPR00: c00a9634 cf82fe90 cf830000 c050ad3c c0015a54 00000000 00000001 00000001 GPR08: 00000001 00000000 00000000 cf82e000 24000084 00000000 c0003150 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000001 00000000 c0510000 GPR24: 00000000 c0015a54 00000000 c050ad3c c051823c c050ad3c 00000025 00000000 NIP [c00a93c8] smp_call_function_many+0xcc/0x2fc LR [c00a9634] smp_call_function+0x3c/0x50 Call Trace: [cf82fe90] [00000010] 0x10 (unreliable) [cf82fed0] [c00a9634] smp_call_function+0x3c/0x50 [cf82fee0] [c0015d2c] flush_tlb_kernel_range+0x20/0x38 [cf82fef0] [c001524c] mark_initmem_nx+0x154/0x16c [cf82ff20] [c001484c] free_initmem+0x20/0x4c [cf82ff30] [c000316c] kernel_init+0x1c/0x108 [cf82ff40] [c000f3a8] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7c0803a6 7d808120 38210040 4e800020 3d20c052 812981a0 2f890000 40beffac 3d20c051 8929ac64 2f890000 40beff9c <0fe00000> 4bffff94 7fc3f378 7f64db78 Fixes: 3184cc4b6f6a ("powerpc/mm: Fix kernel RAM protection after freeing ...") Fixes: e611939fc8ec ("powerpc/mm: Ensure change_page_attr() doesn't ...") Cc: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/xive: Clear XIVE internal structures when a CPU is removedCédric Le Goater1-0/+8
Commit eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") introduced support for the XIVE exploitation mode of the P9 interrupt controller on the pseries platform. At that time, support for CPU removal was not complete on PowerVM and CPU hot unplug remained untested. It appears that some cleanups of the XIVE internal structures are required before releasing the CPU, without which the kernel crashes in a RTAS call doing the CPU isolation. These changes fix the crash by deconfiguring the IPI interrupt source and clearing the event queues of the CPU when it is removed. Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/xive: Fix IPI resetCédric Le Goater1-0/+4
When resetting an IPI, hw_ipi should also be set to zero. Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/watchdog: Make use of watchdog_nmi_probe()Thomas Gleixner1-9/+8
The rework of the core hotplug code triggers the WARN_ON in start_wd_cpu() on powerpc because it is called multiple times for the boot CPU. The first call is via: start_wd_on_cpu+0x80/0x2f0 watchdog_nmi_reconfigure+0x124/0x170 softlockup_reconfigure_threads+0x110/0x130 lockup_detector_init+0xbc/0xe0 kernel_init_freeable+0x18c/0x37c kernel_init+0x2c/0x160 ret_from_kernel_thread+0x5c/0xbc And then again via the CPU hotplug registration: start_wd_on_cpu+0x80/0x2f0 cpuhp_invoke_callback+0x194/0x620 cpuhp_thread_fun+0x7c/0x1b0 smpboot_thread_fn+0x290/0x2a0 kthread+0x168/0x1b0 ret_from_kernel_thread+0x5c/0xbc This can be avoided by setting up the cpu hotplug state with nocalls and move the initialization to the watchdog_nmi_probe() function. That initializes the hotplug callbacks without invoking the callback and the following core initialization function then configures the watchdog for the online CPUs (in this case CPU0) via softlockup_reconfigure_threads(). Reported-and-tested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org
2017-10-04watchdog/core, powerpc: Lock cpus across reconfigurationThomas Gleixner1-4/+0
Instead of dropping the cpu hotplug lock after stopping NMI watchdog and threads and reaquiring for restart, the code and the protection rules become more obvious when holding cpu hotplug lock across the full reconfiguration. Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Don Zickus <dzickus@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710022105570.2114@nanos
2017-10-04watchdog/core, powerpc: Replace watchdog_nmi_reconfigure()Thomas Gleixner1-9/+14
The recent cleanup of the watchdog code split watchdog_nmi_reconfigure() into two stages. One to stop the NMI and one to restart it after reconfiguration. That was done by adding a boolean 'run' argument to the code, which is functionally correct but not necessarily a piece of art. Replace it by two explicit functions: watchdog_nmi_stop() and watchdog_nmi_start(). Fixes: 6592ad2fcc8f ("watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage") Requested-by: Linus 'Nursing his pet-peeve' Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Thomas 'Mopping up garbage' Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Don Zickus <dzickus@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710021957480.2114@nanos
2017-10-04rapidio: remove global irq spinlocks from the subsystemIoan Nicu2-2/+23
Locking of config and doorbell operations should be done only if the underlying hardware requires it. This patch removes the global spinlocks from the rapidio subsystem and moves them to the mport drivers (fsl_rio and tsi721), only to the necessary places. For example, local config space read and write operations (lcread/lcwrite) are atomic in all existing drivers, so there should be no need for locking, while the cread/cwrite operations which generate maintenance transactions need to be synchronized with a lock. Later, each driver could chose to use a per-port lock instead of a global one, or even more granular locking. Link: http://lkml.kernel.org/r/20170824113023.GD50104@nokia.com Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com> Signed-off-by: Frank Kunz <frank.kunz@nokia.com> Acked-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> 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: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-04powerpc/lib/sstep: Fix fixed-point shift instructions that set CA32Sandipan Das1-0/+4
This fixes the emulated behaviour of existing fixed-point shift right algebraic instructions that are supposed to set both the CA and CA32 bits of XER when running on a system that is compliant with POWER ISA v3.0 independent of whether the system is executing in 32-bit mode or 64-bit mode. The following instructions are affected: * Shift Right Algebraic Word Immediate (srawi[.]) * Shift Right Algebraic Word (sraw[.]) * Shift Right Algebraic Doubleword Immediate (sradi[.]) * Shift Right Algebraic Doubleword (srad[.]) Fixes: 0016a4cf5582 ("powerpc: Emulate most Book I instructions in emulate_step()") Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/lib/sstep: Fix fixed-point arithmetic instructions that set CA32Sandipan Das1-0/+13
There are existing fixed-point arithmetic instructions that always set the CA bit of XER to reflect the carry out of bit 0 in 64-bit mode and out of bit 32 in 32-bit mode. In ISA v3.0, these instructions also always set the CA32 bit of XER to reflect the carry out of bit 32. This fixes the emulated behaviour of such instructions when running on a system that is compliant with POWER ISA v3.0. The following instructions are affected: * Add Immediate Carrying (addic) * Add Immediate Carrying and Record (addic.) * Subtract From Immediate Carrying (subfic) * Add Carrying (addc[.]) * Subtract From Carrying (subfc[.]) * Add Extended (adde[.]) * Subtract From Extended (subfe[.]) * Add to Minus One Extended (addme[.]) * Subtract From Minus One Extended (subfme[.]) * Add to Zero Extended (addze[.]) * Subtract From Zero Extended (subfze[.]) Fixes: 0016a4cf5582 ("powerpc: Emulate most Book I instructions in emulate_step()") Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/lib/sstep: Add XER bits introduced in POWER ISA v3.0Sandipan Das1-0/+2
This adds definitions for the OV32 and CA32 bits of XER that were introduced in POWER ISA v3.0. There are some existing instructions that currently set the OV and CA bits based on certain conditions. The emulation behaviour of all these instructions needs to be updated to set these new bits accordingly. Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/powermac: Use setup_timer() helperAllen Pais1-3/+1
Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by: Allen Pais <allen.lkml@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/6xx: Use setup_timer() helperAllen Pais1-2/+1
Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by: Allen Pais <allen.lkml@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/oprofile: Use setup_timer() helperAllen Pais1-6/+2
Use setup_timer function instead of initializing timer with the function and data fields. Signed-off-by: Allen Pais <allen.lkml@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/powernv: Use early_radix_enabled in POWER9 tlb flushNicholas Piggin1-1/+1
This code is used at boot and machine checks, so it should be using early_radix_enabled() (which is usable any time). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>