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2016-01-31arm64: bpf: fix div-by-zero caseZi Shen Lim2-13/+27
commit 251599e1d6906621f49218d7b474ddd159e58f3b upstream. In the case of division by zero in a BPF program: A = A / X; (X == 0) the expected behavior is to terminate with return value 0. This is confirmed by the test case introduced in commit 86bf1721b226 ("test_bpf: add tests checking that JIT/interpreter sets A and X to 0."). Reported-by: Yang Shi <yang.shi@linaro.org> Tested-by: Yang Shi <yang.shi@linaro.org> CC: Xi Wang <xi.wang@gmail.com> CC: Alexei Starovoitov <ast@plumgrid.com> CC: linux-arm-kernel@lists.infradead.org CC: linux-kernel@vger.kernel.org Fixes: e54bcde3d69d ("arm64: eBPF JIT compiler") Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc/module: Handle R_PPC64_ENTRY relocationsUlrich Weigand2-0/+29
commit a61674bdfc7c2bf909c4010699607b62b69b7bec upstream. GCC 6 will include changes to generated code with -mcmodel=large, which is used to build kernel modules on powerpc64le. This was necessary because the large model is supposed to allow arbitrary sizes and locations of the code and data sections, but the ELFv2 global entry point prolog still made the unconditional assumption that the TOC associated with any particular function can be found within 2 GB of the function entry point: func: addis r2,r12,(.TOC.-func)@ha addi r2,r2,(.TOC.-func)@l .localentry func, .-func To remove this assumption, GCC will now generate instead this global entry point prolog sequence when using -mcmodel=large: .quad .TOC.-func func: .reloc ., R_PPC64_ENTRY ld r2, -8(r12) add r2, r2, r12 .localentry func, .-func The new .reloc triggers an optimization in the linker that will replace this new prolog with the original code (see above) if the linker determines that the distance between .TOC. and func is in range after all. Since this new relocation is now present in module object files, the kernel module loader is required to handle them too. This patch adds support for the new relocation and implements the same optimization done by the GNU linker. Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc: Make {cmp}xchg* and their atomic_ versions fully orderedBoqun Feng1-8/+8
commit 81d7a3294de7e9828310bbf986a67246b13fa01e upstream. According to memory-barriers.txt, xchg*, cmpxchg* and their atomic_ versions all need to be fully ordered, however they are now just RELEASE+ACQUIRE, which are not fully ordered. So also replace PPC_RELEASE_BARRIER and PPC_ACQUIRE_BARRIER with PPC_ATOMIC_ENTRY_BARRIER and PPC_ATOMIC_EXIT_BARRIER in __{cmp,}xchg_{u32,u64} respectively to guarantee fully ordered semantics of atomic{,64}_{cmp,}xchg() and {cmp,}xchg(), as a complement of commit b97021f85517 ("powerpc: Fix atomic_xxx_return barrier semantics") This patch depends on patch "powerpc: Make value-returning atomics fully ordered" for PPC_ATOMIC_ENTRY_BARRIER definition. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc: Make value-returning atomics fully orderedBoqun Feng1-1/+1
commit 49e9cf3f0c04bf76ffa59242254110309554861d upstream. According to memory-barriers.txt: > Any atomic operation that modifies some state in memory and returns > information about the state (old or new) implies an SMP-conditional > general memory barrier (smp_mb()) on each side of the actual > operation ... Which mean these operations should be fully ordered. However on PPC, PPC_ATOMIC_ENTRY_BARRIER is the barrier before the actual operation, which is currently "lwsync" if SMP=y. The leading "lwsync" can not guarantee fully ordered atomics, according to Paul Mckenney: https://lkml.org/lkml/2015/10/14/970 To fix this, we define PPC_ATOMIC_ENTRY_BARRIER as "sync" to guarantee the fully-ordered semantics. This also makes futex atomics fully ordered, which can avoid possible memory ordering problems if userspace code relies on futex system call for fully ordered semantics. Fixes: b97021f85517 ("powerpc: Fix atomic_xxx_return barrier semantics") Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc/powernv: pr_warn_once on unsupported OPAL_MSG typeStewart Smith1-1/+1
commit 98da62b716a3b24ab8e77453c9a8a954124c18cd upstream. When running on newer OPAL firmware that supports sending extra OPAL_MSG types, we would print a warning on *every* message received. This could be a problem for kernels that don't support OPAL_MSG_OCC on machines that are running real close to thermal limits and the OCC is throttling the chip. For a kernel that is paying attention to the message queue, we could get these notifications quite often. Conceivably, future message types could also come fairly often, and printing that we didn't understand them 10,000 times provides no further information than printing them once. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc/opal-irqchip: Fix deadlock introduced by "Fix double endian conversion"Alistair Popple1-1/+13
commit 036592fbbe753d236402a0ae68148e7c143a0f0e upstream. Commit 25642e1459ac ("powerpc/opal-irqchip: Fix double endian conversion") fixed an endian bug by calling opal_handle_events() in opal_event_unmask(). However this introduced a deadlock if we find an event is active during unmasking and call opal_handle_events() again. The bad call sequence is: opal_interrupt() -> opal_handle_events() -> generic_handle_irq() -> handle_level_irq() -> raw_spin_lock(&desc->lock) handle_irq_event(desc) unmask_irq(desc) -> opal_event_unmask() -> opal_handle_events() -> generic_handle_irq() -> handle_level_irq() -> raw_spin_lock(&desc->lock) (BOOM) When generating multiple opal events in quick succession this would lead to the following stall warnings: EEH: Fenced PHB#0 detected, location: U78C9.001.WZS09XA-P1-C32 INFO: rcu_sched detected stalls on CPUs/tasks: 12-...: (1 GPs behind) idle=68f/140000000000001/0 softirq=860/861 fqs=2065 15-...: (1 GPs behind) idle=be5/140000000000001/0 softirq=1142/1143 fqs=2065 (detected by 13, t=2102 jiffies, g=1325, c=1324, q=602) NMI watchdog: BUG: soft lockup - CPU#18 stuck for 22s! [irqbalance:2696] INFO: rcu_sched detected stalls on CPUs/tasks: 12-...: (1 GPs behind) idle=68f/140000000000001/0 softirq=860/861 fqs=8371 15-...: (1 GPs behind) idle=be5/140000000000001/0 softirq=1142/1143 fqs=8371 (detected by 20, t=8407 jiffies, g=1325, c=1324, q=1290) This patch corrects the problem by queuing the work if an event is active during unmasking, which is similar to the pre-endian fix behaviour. Fixes: 25642e1459ac ("powerpc/opal-irqchip: Fix double endian conversion") Signed-off-by: Alistair Popple <alistair@popple.id.au> Reported-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc/opal-irqchip: Fix double endian conversionAlistair Popple1-29/+29
commit 25642e1459ace29f6ce5a171efc8b7b59a52a2d4 upstream. The OPAL event calls return a mask of events that are active in big endian format. This is checked when unmasking the events in the irqchip by comparison with a cached value. The cached value was stored in big endian format but should've been converted to CPU endian first. This bug leads to OPAL event delivery being delayed or dropped on some systems. Symptoms may include a non-functional console. The bug is fixed by calling opal_handle_events(...) instead of duplicating code in opal_event_unmask(...). Fixes: 9f0fd0499d30 ("powerpc/powernv: Add a virtual irqchip for opal events") Reported-by: Douglas L Lehr <dllehr@us.ibm.com> Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc/tm: Check for already reclaimed tasksMichael Neuling1-0/+18
commit 7f821fc9c77a9b01fe7b1d6e72717b33d8d64142 upstream. Currently we can hit a scenario where we'll tm_reclaim() twice. This results in a TM bad thing exception because the second reclaim occurs when not in suspend mode. The scenario in which this can happen is the following. We attempt to deliver a signal to userspace. To do this we need obtain the stack pointer to write the signal context. To get this stack pointer we must tm_reclaim() in case we need to use the checkpointed stack pointer (see get_tm_stackpointer()). Normally we'd then return directly to userspace to deliver the signal without going through __switch_to(). Unfortunatley, if at this point we get an error (such as a bad userspace stack pointer), we need to exit the process. The exit will result in a __switch_to(). __switch_to() will attempt to save the process state which results in another tm_reclaim(). This tm_reclaim() now causes a TM Bad Thing exception as this state has already been saved and the processor is no longer in TM suspend mode. Whee! This patch checks the state of the MSR to ensure we are TM suspended before we attempt the tm_reclaim(). If we've already saved the state away, we should no longer be in TM suspend mode. This has the additional advantage of checking for a potential TM Bad Thing exception. Found using syscall fuzzer. Fixes: fb09692e71f1 ("powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes") Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31powerpc/tm: Block signal return setting invalid MSR stateMichael Neuling3-5/+14
commit d2b9d2a5ad5ef04ff978c9923d19730cb05efd55 upstream. Currently we allow both the MSR T and S bits to be set by userspace on a signal return. Unfortunately this is a reserved configuration and will cause a TM Bad Thing exception if attempted (via rfid). This patch checks for this case in both the 32 and 64 bit signals code. If both T and S are set, we mark the context as invalid. Found using a syscall fuzzer. Fixes: 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31net: filter: make JITs zero A for SKF_AD_ALU_XOR_XRabin Vincent4-56/+6
[ Upstream commit 55795ef5469290f89f04e12e662ded604909e462 ] The SKF_AD_ALU_XOR_X ancillary is not like the other ancillary data instructions since it XORs A with X while all the others replace A with some loaded value. All the BPF JITs fail to clear A if this is used as the first instruction in a filter. This was found using american fuzzy lop. Add a helper to determine if A needs to be cleared given the first instruction in a filter, and use this in the JITs. Except for ARM, the rest have only been compile-tested. Fixes: 3480593131e0 ("net: filter: get rid of BPF_S_* enum") Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/mm: Improve switch_mm() barrier commentsAndy Lutomirski1-7/+8
commit 4eaffdd5a5fe6ff9f95e1ab4de1ac904d5e0fa8b upstream. My previous comments were still a bit confusing and there was a typo. Fix it up. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 71b3c126e611 ("x86/mm: Add barriers and document switch_mm()-vs-flush synchronization") Link: http://lkml.kernel.org/r/0a0b43cdcdd241c5faaaecfbcc91a155ddedc9a1.1452631609.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/mm: Add barriers and document switch_mm()-vs-flush synchronizationAndy Lutomirski2-4/+58
commit 71b3c126e61177eb693423f2e18a1914205b165e upstream. When switch_mm() activates a new PGD, it also sets a bit that tells other CPUs that the PGD is in use so that TLB flush IPIs will be sent. In order for that to work correctly, the bit needs to be visible prior to loading the PGD and therefore starting to fill the local TLB. Document all the barriers that make this work correctly and add a couple that were missing. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/boot: Double BOOT_HEAP_SIZE to 64KBH.J. Lu1-1/+1
commit 8c31902cffc4d716450be549c66a67a8a3dd479c upstream. When decompressing kernel image during x86 bootup, malloc memory for ELF program headers may run out of heap space, which leads to system halt. This patch doubles BOOT_HEAP_SIZE to 64KB. Tested with 32-bit kernel which failed to boot without this patch. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/reboot/quirks: Add iMac10,1 to pci_reboot_dmi_table[]Mario Kleiner1-0/+8
commit 2f0c0b2d96b1205efb14347009748d786c2d9ba5 upstream. Without the reboot=pci method, the iMac 10,1 simply hangs after printing "Restarting system" at the point when it should reboot. This fixes it. Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1450466646-26663-1-git-send-email-mario.kleiner.de@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31KVM: x86: correctly print #AC in tracesPaolo Bonzini1-1/+1
commit aba2f06c070f604e388cf77b1dcc7f4cf4577eb0 upstream. Poor #AC was so unimportant until a few days ago that we were not even tracing its name correctly. But now it's all over the place. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31KVM: x86: expose MSR_TSC_AUX to userspacePaolo Bonzini1-5/+6
commit 9dbe6cf941a6fe82933aef565e4095fb10f65023 upstream. If we do not do this, it is not properly saved and restored across migration. Windows notices due to its self-protection mechanisms, and is very upset about it (blue screen of death). Cc: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31KVM: PPC: Book3S HV: Prohibit setting illegal transaction state in MSRPaul Mackerras1-0/+6
commit c20875a3e638e4a03e099b343ec798edd1af5cc6 upstream. Currently it is possible for userspace (e.g. QEMU) to set a value for the MSR for a guest VCPU which has both of the TS bits set, which is an illegal combination. The result of this is that when we execute a hrfid (hypervisor return from interrupt doubleword) instruction to enter the guest, the CPU will take a TM Bad Thing type of program interrupt (vector 0x700). Now, if PR KVM is configured in the kernel along with HV KVM, we actually handle this without crashing the host or giving hypervisor privilege to the guest; instead what happens is that we deliver a program interrupt to the guest, with SRR0 reflecting the address of the hrfid instruction and SRR1 containing the MSR value at that point. If PR KVM is not configured in the kernel, then we try to run the host's program interrupt handler with the MMU set to the guest context, which almost certainly causes a host crash. This closes the hole by making kvmppc_set_msr_hv() check for the illegal combination and force the TS field to a safe value (00, meaning non-transactional). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31KVM: svm: unconditionally intercept #DBPaolo Bonzini1-11/+3
commit cbdb967af3d54993f5814f1cee0ed311a055377d upstream. This is needed to avoid the possibility that the guest triggers an infinite stream of #DB exceptions (CVE-2015-8104). VMX is not affected: because it does not save DR6 in the VMCS, it already intercepts #DB unconditionally. Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31KVM: PPC: Book3S HV: Don't dynamically split core when already splitPaul Mackerras1-1/+1
commit f74f2e2e26199f695ca3df94f29e9ab7cb707ea4 upstream. In static micro-threading modes, the dynamic micro-threading code is supposed to be disabled, because subcores can't make independent decisions about what micro-threading mode to put the core in - there is only one micro-threading mode for the whole core. The code that implements dynamic micro-threading checks for this, except that the check was missed in one case. This means that it is possible for a subcore in static 2-way micro-threading mode to try to put the core into 4-way micro-threading mode, which usually leads to stuck CPUs, spinlock lockups, and other stalls in the host. The problem was in the can_split_piggybacked_subcores() function, which should always return false if the system is in a static micro-threading mode. This fixes the problem by making can_split_piggybacked_subcores() use subcore_config_ok() for its checks, as subcore_config_ok() includes the necessary check for the static micro-threading modes. Credit to Gautham Shenoy for working out that the reason for the hangs and stalls we were seeing was that we were trying to do dynamic 4-way micro-threading while we were in static 2-way mode. Fixes: b4deba5c41e9 Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31KVM: VMX: fix SMEP and SMAP without EPTRadim Krčmář1-9/+10
commit 656ec4a4928a3db7d16e5cb9bce351a478cfd3d5 upstream. The comment in code had it mostly right, but we enable paging for emulated real mode regardless of EPT. Without EPT (which implies emulated real mode), secondary VCPUs won't start unless we disable SM[AE]P when the guest doesn't use paging. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/xen: don't reset vcpu_info on a cancelled suspendOuyang Zhaowei (Charles)1-1/+2
commit 6a1f513776b78c994045287073e55bae44ed9f8c upstream. On a cancelled suspend the vcpu_info location does not change (it's still in the per-cpu area registered by xen_vcpu_setup()). So do not call xen_hvm_init_shared_info() which would make the kernel think its back in the shared info. With the wrong vcpu_info, events cannot be received and the domain will hang after a cancelled suspend. Signed-off-by: Charles Ouyang <ouyangzhaowei@huawei.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/mce: Ensure offline CPUs don't participate in rendezvous processAshok Raj1-0/+11
commit d90167a941f62860f35eb960e1012aa2d30e7e94 upstream. Intel's MCA implementation broadcasts MCEs to all CPUs on the node. This poses a problem for offlined CPUs which cannot participate in the rendezvous process: Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler Kernel Offset: disabled Rebooting in 100 seconds.. More specifically, Linux does a soft offline of a CPU when writing a 0 to /sys/devices/system/cpu/cpuX/online, which doesn't prevent the #MC exception from being broadcasted to that CPU. Ensure that offline CPUs don't participate in the MCE rendezvous and clear the RIP valid status bit so that a second MCE won't cause a shutdown. Without the patch, mce_start() will increment mce_callin and wait for all CPUs. Offlined CPUs should avoid participating in the rendezvous process altogether. Signed-off-by: Ashok Raj <ashok.raj@intel.com> [ Massage commit message. ] Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1449742346-21470-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/paravirt: Prevent rtc_cmos platform device init on PV guestsDavid Vrabel6-1/+19
commit d8c98a1d1488747625ad6044d423406e17e99b7a upstream. Adding the rtc platform device in non-privileged Xen PV guests causes an IRQ conflict because these guests do not have legacy PIC and may allocate irqs in the legacy range. In a single VCPU Xen PV guest we should have: /proc/interrupts: CPU0 0: 4934 xen-percpu-virq timer0 1: 0 xen-percpu-ipi spinlock0 2: 0 xen-percpu-ipi resched0 3: 0 xen-percpu-ipi callfunc0 4: 0 xen-percpu-virq debug0 5: 0 xen-percpu-ipi callfuncsingle0 6: 0 xen-percpu-ipi irqwork0 7: 321 xen-dyn-event xenbus 8: 90 xen-dyn-event hvc_console ... But hvc_console cannot get its interrupt because it is already in use by rtc0 and the console does not work. genirq: Flags mismatch irq 8. 00000000 (hvc_console) vs. 00000000 (rtc0) We can avoid this problem by realizing that unprivileged PV guests (both Xen and lguests) are not supposed to have rtc_cmos device and so adding it is not necessary. Privileged guests (i.e. Xen's dom0) do use it but they should not have irq conflicts since they allocate irqs above legacy range (above gsi_top, in fact). Instead of explicitly testing whether the guest is privileged we can extend pv_info structure to include information about guest's RTC support. Reported-and-tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: vkuznets@redhat.com Cc: xen-devel@lists.xenproject.org Cc: konrad.wilk@oracle.com Link: http://lkml.kernel.org/r/1449842873-2613-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/signal: Fix restart_syscall number for x32 tasksDmitry V. Levin1-7/+10
commit 22eab1108781eff09961ae7001704f7bd8fb1dce upstream. When restarting a syscall with regs->ax == -ERESTART_RESTARTBLOCK, regs->ax is assigned to a restart_syscall number. For x32 tasks, this syscall number must have __X32_SYSCALL_BIT set, otherwise it will be an x86_64 syscall number instead of a valid x32 syscall number. This issue has been there since the introduction of x32. Reported-by: strace/tests/restart_syscall.test Reported-and-tested-by: Elvira Khabirova <lineprinter0@gmail.com> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Cc: Elvira Khabirova <lineprinter0@gmail.com> Link: http://lkml.kernel.org/r/20151130215436.GA25996@altlinux.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86/mpx: Fix instruction decoder conditionDave Hansen1-3/+3
commit 8e8efe0379bd93e8219ca0fc6fa80b5dd85b09cb upstream. MPX decodes instructions in order to tell which bounds register was violated. Part of this decoding involves looking at the "REX prefix" which is a special instrucion prefix used to retrofit support for new registers in to old instructions. The X86_REX_*() macros are defined to return actual bit values: #define X86_REX_R(rex) ((rex) & 4) *not* boolean values. However, the MPX code was checking for them like they were booleans. This might have led to us mis-decoding the "REX prefix" and giving false information out to userspace about bounds violations. X86_REX_B() actually is bit 1, so this is really only broken for the X86_REX_X() case. Fix the conditionals up to tolerate the non-boolean values. Fixes: fcc7ffd67991 "x86, mpx: Decode MPX instruction to get bound violation information" Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: x86@kernel.org Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20151201003113.D800C1E0@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31x86 smpboot: Re-enable init_udelay=0 by default on modern CPUsLen Brown1-4/+5
commit 656279a1f3b210cf48ccc572fd7c6b8e2250be77 upstream. commit f1ccd249319e allowed the cmdline "cpu_init_udelay=" to work with all values, including the default of 10000. But in setting the default of 10000, it over-rode the code that sets the delay 0 on modern processors. Also, tidy up use of INT/UINT. Fixes: f1ccd249319e "x86/smpboot: Fix cpu_init_udelay=10000 corner case boot parameter misbehavior" Reported-by: Shane <shrybman@teksavvy.com> Signed-off-by: Len Brown <len.brown@intel.com> Cc: dparsons@brightdsl.net Link: http://lkml.kernel.org/r/9082eb809ef40dad02db714759c7aaf618c518d4.1448232494.git.len.brown@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09xen/events: Always allocate legacy interrupts on PV guestsBoris Ostrovsky2-0/+10
commit b4ff8389ed14b849354b59ce9b360bdefcdbf99c upstream. After commit 8c058b0b9c34 ("x86/irq: Probe for PIC presence before allocating descs for legacy IRQs") early_irq_init() will no longer preallocate descriptors for legacy interrupts if PIC does not exist, which is the case for Xen PV guests. Therefore we may need to allocate those descriptors ourselves. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: s390: enable SIMD only when no VCPUs were createdDavid Hildenbrand1-1/+5
commit 5967c17b118a2bd1dd1d554cc4eee16233e52bec upstream. We should never allow to enable/disable any facilities for the guest when other VCPUs were already created. kvm_arch_vcpu_(load|put) relies on SIMD not changing during runtime. If somebody would create and run VCPUs and then decides to enable SIMD, undefined behaviour could be possible (e.g. vector save area not being set up). Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: s390: avoid memory overwrites on emergency signal injectionDavid Hildenbrand1-0/+4
commit b85de33a1a3433487b6a721cfdce25ec8673e622 upstream. Commit 383d0b050106 ("KVM: s390: handle pending local interrupts via bitmap") introduced a possible memory overwrite from user space. User space could pass an invalid emergency signal code (sending VCPU) and therefore exceed the bitmap. Let's take care of this case and check that the id is in the valid range. Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: s390: fix wrong lookup of VCPUs by array indexDavid Hildenbrand2-8/+3
commit 152e9f65d66f0a3891efc3869440becc0e7ff53f upstream. For now, VCPUs were always created sequentially with incrementing VCPU ids. Therefore, the index in the VCPUs array matched the id. As sequential creation might change with cpu hotplug, let's use the correct lookup function to find a VCPU by id, not array index. Let's also use kvm_lookup_vcpu() for validation of the sending VCPU on external call injection. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: s390: SCA must not cross page boundariesDavid Hildenbrand1-1/+3
commit c5c2c393468576bad6d10b2b5fefff8cd25df3f4 upstream. We seemed to have missed a few corner cases in commit f6c137ff00a4 ("KVM: s390: randomize sca address"). The SCA has a maximum size of 2112 bytes. By setting the sca_offset to some unlucky numbers, we exceed the page. 0x7c0 (1984) -> Fits exactly 0x7d0 (2000) -> 16 bytes out 0x7e0 (2016) -> 32 bytes out 0x7f0 (2032) -> 48 bytes out One VCPU entry is 32 bytes long. For the last two cases, we actually write data to the other page. 1. The address of the VCPU. 2. Injection/delivery/clearing of SIGP externall calls via SIGP IF. Especially the 2. happens regularly. So this could produce two problems: 1. The guest losing/getting external calls. 2. Random memory overwrites in the host. So this problem happens on every 127 + 128 created VM with 64 VCPUs. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09s390/pci: reshuffle struct used to write debug dataSebastian Ott1-3/+3
commit 7cc8944e13c73374b6f33b39ca24c0891c87b077 upstream. zpci_err_insn writes stale stack content to the debugfs. Ensure that the struct in zpci_err_insn is ordered in a way that we don't have uninitialized holes in it. In addition to that add the packed attribute. Fixes: 3d8258e (s390/pci: move debug messages to debugfs) Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09s390/kernel: fix ptrace peek/poke for floating point registersMartin Schwidefsky1-4/+4
commit 55a423b6f105fa323168f15f4bb67f23b21da44e upstream. git commit 155e839a814834a3b4b31e729f4716e59d3d2dd4 "s390/kernel: dynamically allocate FP register save area" introduced a regression in regard to ptrace. If the vector register extension is not present or unused the ptrace peek of a floating pointer register return incorrect data and the ptrace poke to a floating pointer register overwrites the task structure starting at task->thread.fpu.fprs. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09arm64: page-align sections for DEBUG_RODATAMark Rutland1-1/+4
commit cb083816ab5ac3d10a9417527f07fc5962cc3808 upstream. A kernel built with DEBUG_RO_DATA && !CONFIG_DEBUG_ALIGN_RODATA doesn't have .text aligned to a page boundary, though fixup_executable works at page-granularity thanks to its use of create_mapping. If .text is not page-aligned, the first page it exists in may be marked non-executable, leading to failures when an attempt is made to execute code in said page. This patch upgrades ALIGN_DEBUG_RO and ALIGN_DEBUG_RO_MIN to force page alignment for DEBUG_RO_DATA && !CONFIG_DEBUG_ALIGN_RODATA kernels, ensuring that all sections with specific RWX permission requirements are mapped with the correct permissions. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Laura Abbott <laura@labbott.name> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Fixes: da141706aea52c1a ("arm64: add better page protections to arm64") Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09arm64: Fix compat register mappingsRobin Murphy1-8/+8
commit 5accd17d0eb523350c9ef754d655e379c9bb93b3 upstream. For reasons not entirely apparent, but now enshrined in history, the architectural mapping of AArch32 banked registers to AArch64 registers actually orders SP_<mode> and LR_<mode> backwards compared to the intuitive r13/r14 order, for all modes except FIQ. Fix the compat_<reg>_<mode> macros accordingly, in the hope of avoiding subtle bugs with KVM and AArch32 guests. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/mpx: Fix 32-bit address space calculationDave Hansen1-5/+17
commit f3119b830264d89d216bfb378ab65065dffa02d9 upstream. I received a bug report that running 32-bit MPX binaries on 64-bit kernels was broken. I traced it down to this little code snippet. We were switching our "number of bounds directory entries" calculation correctly. But, we didn't switch the other side of the calculation: the virtual space size. This meant that we were calculating an absurd size for bd_entry_virt_space() on 32-bit because we used the 64-bit virt_space. This was _also_ broken for 32-bit kernels running on 64-bit hardware since boot_cpu_data.x86_virt_bits=48 even when running in 32-bit mode. Correct that and properly handle all 3 possible cases: 1. 32-bit binary on 64-bit kernel 2. 64-bit binary on 64-bit kernel 3. 32-bit binary on 32-bit kernel This manifested in having bounds tables not properly unmapped. It "leaked" memory but had no functional impact otherwise. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20151111181934.FA7FAC34@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/mpx: Do proper get_user() when running 32-bit binaries on 64-bit kernelsDave Hansen1-1/+24
commit 46561c3959d6307d22139c24cd0bf196162e5681 upstream. When you call get_user(foo, bar), you effectively do a copy_from_user(&foo, bar, sizeof(*bar)); Note that the sizeof() is implicit. When we reach out to userspace to try to zap an entire "bounds table" we need to go read a "bounds directory entry" in order to locate the table's address. The size of a "directory entry" depends on the binary being run and is always the size of a pointer. But, when we have a 64-bit kernel and a 32-bit application, the directory entry is still only 32-bits long, but we fetch it with a 64-bit pointer which makes get_user() does a 64-bit fetch. Reading 4 extra bytes isn't harmful, unless we are at the end of and run off the table. It might also cause the zero page to get faulted in unnecessarily even if you are not at the end. Fix it up by doing a special 32-bit get_user() via a cast when we have 32-bit userspace. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20151111181931.3ACF6822@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/fpu: Fix 32-bit signal frame handlingDave Hansen1-6/+5
commit ab6b52947545a5355154f64f449f97af9d05845f upstream. (This should have gone to LKML originally. Sorry for the extra noise, folks on the cc.) Background: Signal frames on x86 have two formats: 1. For 32-bit executables (whether on a real 32-bit kernel or under 32-bit emulation on a 64-bit kernel) we have a 'fpregset_t' that includes the "FSAVE" registers. 2. For 64-bit executables (on 64-bit kernels obviously), the 'fpregset_t' is smaller and does not contain the "FSAVE" state. When creating the signal frame, we have to be aware of whether we are running a 32 or 64-bit executable so we create the correct format signal frame. Problem: save_xstate_epilog() uses 'fx_sw_reserved_ia32' whenever it is called for a 32-bit executable. This is for real 32-bit and ia32 emulation. But, fpu__init_prepare_fx_sw_frame() only initializes 'fx_sw_reserved_ia32' when emulation is enabled, *NOT* for real 32-bit kernels. This leads to really wierd situations where 32-bit programs lose their extended state when returning from a signal handler. The kernel copies the uninitialized (zero) 'fx_sw_reserved_ia32' out to userspace in save_xstate_epilog(). But when returning from the signal, the kernel errors out in check_for_xstate() when it does not see FP_XSTATE_MAGIC1 present (because it was zeroed). This leads to the FPU/XSAVE state being initialized. For MPX, this leads to the most permissive state and means we silently lose bounds violations. I think this would also mean that we could lose *ANY* FPU/SSE/AVX state. I'm not sure why no one has spotted this bug. I believe this was broken by: 72a671ced66d ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels") way back in 2012. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@sr71.net Cc: fenghua.yu@intel.com Cc: yu-cheng.yu@intel.com Link: http://lkml.kernel.org/r/20151111002354.A0799571@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/fpu: Fix get_xsave_addr() behavior under virtualizationHuaitong Han1-1/+0
commit a05917b6ba9dc9a95fc42bdcbe3a875e8ad83935 upstream. KVM uses the get_xsave_addr() function in a different fashion from the native kernel, in that the 'xsave' parameter belongs to guest vcpu, not the currently running task. But 'xsave' is replaced with current task's (host) xsave structure, so get_xsave_addr() will incorrectly return the bad xsave address to KVM. Fix it so that the passed in 'xsave' address is used - as intended originally. Signed-off-by: Huaitong Han <huaitong.han@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave.hansen@intel.com Link: http://lkml.kernel.org/r/1446800423-21622-1-git-send-email-huaitong.han@intel.com [ Tidied up the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/cpu: Fix SMAP check in PVOPS environmentsAndrew Cooper1-2/+1
commit 581b7f158fe0383b492acd1ce3fb4e99d4e57808 upstream. There appears to be no formal statement of what pv_irq_ops.save_fl() is supposed to return precisely. Native returns the full flags, while lguest and Xen only return the Interrupt Flag, and both have comments by the implementations stating that only the Interrupt Flag is looked at. This may have been true when initially implemented, but no longer is. To make matters worse, the Xen PVOP leaves the upper bits undefined, making the BUG_ON() undefined behaviour. Experimentally, this now trips for 32bit PV guests on Broadwell hardware. The BUG_ON() is consistent for an individual build, but not consistent for all builds. It has also been a sitting timebomb since SMAP support was introduced. Use native_save_fl() instead, which will obtain an accurate view of the AC flag. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Tested-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <lguest@lists.ozlabs.org> Cc: Xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1433323874-6927-1-git-send-email-andrew.cooper3@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/cpu: Call verify_cpu() after having entered long mode tooBorislav Petkov2-5/+15
commit 04633df0c43d710e5f696b06539c100898678235 upstream. When we get loaded by a 64-bit bootloader, kernel entry point is startup_64 in head_64.S. We don't trust any and all bootloaders because some will fiddle with CPU configuration so we go ahead and massage each CPU into sanity again. For example, some dell BIOSes have this XD disable feature which set IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround for other OSes but Linux sure doesn't need it. A similar thing is present in the Surface 3 firmware - see https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit only on the BSP: # rdmsr -a 0x1a0 400850089 850089 850089 850089 I know, right?! There's not even an off switch in there. So fix all those cases by sanitizing the 64-bit entry point too. For that, make verify_cpu() callable in 64-bit mode also. Requested-and-debugged-by: "H. Peter Anvin" <hpa@zytor.com> Reported-and-tested-by: Bastien Nocera <bugzilla@hadess.net> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/irq: Probe for PIC presence before allocating descs for legacy IRQsVitaly Kuznetsov3-9/+27
commit 8c058b0b9c34d8c8d7912880956543769323e2d8 upstream. Commit d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") brought a regression for Hyper-V Gen2 instances. These instances don't have i8259 legacy PIC but they use legacy IRQs for serial port, rtc, and acpi. With this commit included we end up with these IRQs not initialized. Earlier, there was a special workaround for legacy IRQs in mp_map_pin_to_irq() doing mp_irqdomain_map() without looking at nr_legacy_irqs() and now we fail in __irq_domain_alloc_irqs() when irq_domain_alloc_descs() returns -EEXIST. The essence of the issue seems to be that early_irq_init() calls arch_probe_nr_irqs() to figure out the number of legacy IRQs before we probe for i8259 and gets 16. Later when init_8259A() is called we switch to NULL legacy PIC and nr_legacy_irqs() starts to return 0 but we already have 16 descs allocated. Solve the issue by separating i8259 probe from init and calling it in arch_probe_nr_irqs() before we actually use nr_legacy_irqs() information. Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Link: http://lkml.kernel.org/r/1446543614-3621-1-git-send-email-vkuznets@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09x86/setup: Fix low identity map for >= 2GB kernel rangeKrzysztof Mazur1-1/+1
commit 68accac392d859d24adcf1be3a90e41f978bd54c upstream. The commit f5f3497cad8c extended the low identity mapping. However, if the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory split), the normal memory mapping is overwritten by the low identity mapping causing a crash. To avoid overwritting, limit the low identity map to cover only memory before kernel range (PAGE_OFFSET). Fixes: f5f3497cad8c "x86/setup: Extend low identity map to cover whole kernel range Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: x86: work around infinite loop in microcode when #AC is deliveredEric Northup3-1/+13
commit 54a20552e1eae07aa240fa370a0293e006b5faed upstream. It was found that a guest can DoS a host by triggering an infinite stream of "alignment check" (#AC) exceptions. This causes the microcode to enter an infinite loop where the core never receives another interrupt. The host kernel panics pretty quickly due to the effects (CVE-2015-5307). Signed-off-by: Eric Northup <digitaleric@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()Laszlo Ersek1-1/+3
commit 879ae1880449c88db11c1ebdaedc2da79b2fe73f upstream. Commit b18d5431acc7 ("KVM: x86: fix CR0.CD virtualization") was technically correct, but it broke OVMF guests by slowing down various parts of the firmware. Commit fb279950ba02 ("KVM: vmx: obey KVM_QUIRK_CD_NW_CLEARED") quirked the first function modified by b18d5431acc7, vmx_get_mt_mask(), for OVMF's sake. This restored the speed of the OVMF code that runs before PlatformPei (including the memory intensive LZMA decompression in SEC). This patch extends the quirk to the second function modified by b18d5431acc7, kvm_set_cr0(). It eliminates the intrusive slowdown that hits the EFI_MP_SERVICES_PROTOCOL implementation of edk2's UefiCpuPkg/CpuDxe -- which is built into OVMF --, when CpuDxe starts up all APs at once for initialization, in order to count them. We also carry over the kvm_arch_has_noncoherent_dma() sub-condition from the other half of the original commit b18d5431acc7. Fixes: b18d5431acc7a2fd22767925f3a6f597aa4bd29e Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Tested-by: Janusz Mocek <januszmk6@gmail.com> Signed-off-by: Laszlo Ersek <lersek@redhat.com># Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: x86: allow RSM from 64-bit modePaolo Bonzini1-5/+25
commit 89651a3decbe03754f304a0b248f27eeb9a37937 upstream. The SDM says that exiting system management mode from 64-bit mode is invalid, but that would be too good to be true. But actually, most of the code is already there to support exiting from compat mode (EFER.LME=1, EFER.LMA=0). Getting all the way from 64-bit mode to real mode only requires clearing CS.L and CR4.PCIDE. Fixes: 660a5d517aaab9187f93854425c4c63f4a09195c Tested-by: Laszlo Ersek <lersek@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: x86: handle SMBASE as physical address in RSMRadim Krčmář1-4/+3
commit f40606b147dd5b4678cedc877a71deb520ca507e upstream. GET_SMSTATE depends on real mode to ensure that smbase+offset is treated as a physical address, which has already caused a bug after shuffling the code. Enforce physical addressing. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reported-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09KVM: x86: add read_phys to x86_emulate_opsRadim Krčmář2-0/+20
commit 7a036a6f670f63b32c5ee126425f9109271ca13f upstream. We want to read the physical memory when emulating RSM. X86EMUL_IO_NEEDED is returned on all errors for consistency with other helpers. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Tested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09kvm: x86: zero EFER on INITPaolo Bonzini2-8/+6
commit 5690891bcec5fcfda38da974ffa5488e36a59811 upstream. Not zeroing EFER means that a 32-bit firmware cannot enter paging mode without clearing EFER.LME first (which it should not know about). Yang Zhang from Intel confirmed that the manual is wrong and EFER is cleared to zero on INIT. Fixes: d28bc9dd25ce023270d2e039e7c98d38ecbf7758 Cc: Yang Z Zhang <yang.z.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09kvm: x86: set KVM_REQ_EVENT when updating IRRRadim Krčmář1-0/+2
commit c77f3fab441c3e466b4c3601a475fc31ce156b06 upstream. After moving PIR to IRR, the interrupt needs to be delivered manually. Reported-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>