linux/arch, branch v3.4.43

sparc64: Fix race in TLB batch processing.

2013-05-01T16:41:03Z

[ Commits f36391d2790d04993f48da6a45810033a2cdf847 and f0af97070acbad5d6a361f485828223a4faaa0ee upstream. ] As reported by Dave Kleikamp, when we emit cross calls to do batched TLB flush processing we have a race because we do not synchronize on the sibling cpus completing the cross call. So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.) and either flushes are missed or flushes will flush the wrong addresses. Fix this by using generic infrastructure to synchonize on the completion of the cross call. This first required getting the flush_tlb_pending() call out from switch_to() which operates with locks held and interrupts disabled. The problem is that smp_call_function_many() cannot be invoked with IRQs disabled and this is explicitly checked for with WARN_ON_ONCE(). We get the batch processing outside of locked IRQ disabled sections by using some ideas from the powerpc port. Namely, we only batch inside of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a region, we flush TLBs synchronously. 1) Get rid of xcall_flush_tlb_pending and per-cpu type implementations. 2) Do TLB batch cross calls instead via: smp_call_function_many() tlb_pending_func() __flush_tlb_pending() 3) Batch only in lazy mmu sequences: a) Add 'active' member to struct tlb_batch b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE c) Set 'active' in arch_enter_lazy_mmu_mode() d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode() e) Check 'active' in tlb_batch_add_one() and do a synchronous flush if it's clear. 4) Add infrastructure for synchronous TLB page flushes. a) Implement __flush_tlb_page and per-cpu variants, patch as needed. b) Likewise for xcall_flush_tlb_page. c) Implement smp_flush_tlb_page() to invoke the cross-call. d) Wire up global_flush_tlb_page() to the right routine based upon CONFIG_SMP 5) It turns out that singleton batches are very common, 2 out of every 3 batch flushes have only a single entry in them. The batch flush waiting is very expensive, both because of the poll on sibling cpu completeion, as well as because passing the tlb batch pointer to the sibling cpus invokes a shared memory dereference. Therefore, in flush_tlb_pending(), if there is only one entry in the batch perform a completely asynchronous global_flush_tlb_page() instead. Reported-by: Dave Kleikamp Signed-off-by: David S. Miller Acked-by: Dave Kleikamp Signed-off-by: Greg Kroah-Hartman

perf/x86: Fix offcore_rsp valid mask for SNB/IVB

2013-04-26T04:19:55Z

commit f1923820c447e986a9da0fc6bf60c1dccdf0408e upstream. The valid mask for both offcore_response_0 and offcore_response_1 was wrong for SNB/SNB-EP, IVB/IVB-EP. It was possible to write to reserved bit and cause a GP fault crashing the kernel. This patch fixes the problem by correctly marking the reserved bits in the valid mask for all the processors mentioned above. A distinction between desktop and server parts is introduced because bits 24-30 are only available on the server parts. This version of the patch is just a rebase to perf/urgent tree and should apply to older kernels as well. Signed-off-by: Stephane Eranian Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: ak@linux.intel.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

ARM: 7698/1: perf: fix group validation when using enable_on_exec

2013-04-26T04:19:55Z

commit cb2d8b342aa084d1f3ac29966245dec9163677fb upstream. Events may be created with attr->disabled == 1 and attr->enable_on_exec == 1, which confuses the group validation code because events with the PERF_EVENT_STATE_OFF are not considered candidates for scheduling, which may lead to failure at group scheduling time. This patch fixes the validation check for ARM, so that events in the OFF state are still considered when enable_on_exec is true. Reported-by: Sudeep KarkadaNagesha Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ARM: 7696/1: Fix kexec by setting outer_cache.inv_all for Feroceon

2013-04-26T04:19:55Z

commit cd272d1ea71583170e95dde02c76166c7f9017e6 upstream. On Feroceon the L2 cache becomes non-coherent with the CPU when the L1 caches are disabled. Thus the L2 needs to be invalidated after both L1 caches are disabled. On kexec before the starting the code for relocation the kernel, the L1 caches are disabled in cpu_froc_fin (cpu_v7_proc_fin for Feroceon), but after L2 cache is never invalidated, because inv_all is not set in cache-feroceon-l2.c. So kernel relocation and decompression may has (and usually has) errors. Setting the function enables L2 invalidation and fixes the issue. Signed-off-by: Illia Ragozin Acked-by: Jason Cooper Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

KVM: Allow cross page reads and writes from cached translations.

2013-04-26T04:19:55Z

commit 8f964525a121f2ff2df948dac908dcc65be21b5b upstream. This patch adds support for kvm_gfn_to_hva_cache_init functions for reads and writes that will cross a page. If the range falls within the same memslot, then this will be a fast operation. If the range is split between two memslots, then the slower kvm_read_guest and kvm_write_guest are used. Tested: Test against kvm_clock unit tests. Signed-off-by: Andrew Honig Signed-off-by: Gleb Natapov Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions (CVE-2013-1797)

2013-04-26T04:19:54Z

commit 0b79459b482e85cb7426aa7da683a9f2c97aeae1 upstream. There is a potential use after free issue with the handling of MSR_KVM_SYSTEM_TIME. If the guest specifies a GPA in a movable or removable memory such as frame buffers then KVM might continue to write to that address even after it's removed via KVM_SET_USER_MEMORY_REGION. KVM pins the page in memory so it's unlikely to cause an issue, but if the user space component re-purposes the memory previously used for the guest, then the guest will be able to corrupt that memory. Tested: Tested against kvmclock unit test Signed-off-by: Andrew Honig Signed-off-by: Marcelo Tosatti Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME (CVE-2013-1796)

2013-04-26T04:19:54Z

commit c300aa64ddf57d9c5d9c898a64b36877345dd4a9 upstream. If the guest sets the GPA of the time_page so that the request to update the time straddles a page then KVM will write onto an incorrect page. The write is done byusing kmap atomic to get a pointer to the page for the time structure and then performing a memcpy to that page starting at an offset that the guest controls. Well behaved guests always provide a 32-byte aligned address, however a malicious guest could use this to corrupt host kernel memory. Tested: Tested against kvmclock unit test. Signed-off-by: Andrew Honig Signed-off-by: Marcelo Tosatti Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

ARM: Do 15e0d9e37c (ARM: pm: let platforms select cpu_suspend support) properly

2013-04-26T04:19:54Z

commit b6c7aabd923a17af993c5a5d5d7995f0b27c000a upstream. Let's do the changes properly and fix the same problem everywhere, not just for one case. Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal

2013-04-17T04:27:27Z

commit 511ba86e1d386f671084b5d0e6f110bb30b8eeb2 upstream. Invoking arch_flush_lazy_mmu_mode() results in calls to preempt_enable()/disable() which may have performance impact. Since lazy MMU is not used on bare metal we can patch away arch_flush_lazy_mmu_mode() so that it is never called in such environment. [ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU updates" may cause a minor performance regression on bare metal. This patch resolves that performance regression. It is somewhat unclear to me if this is a good -stable candidate. ] Signed-off-by: Boris Ostrovsky Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.com Tested-by: Josh Boyer Tested-by: Konrad Rzeszutek Wilk Acked-by: Borislav Petkov Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman

x86, mm, paravirt: Fix vmalloc_fault oops during lazy MMU updates

2013-04-17T04:27:27Z

commit 1160c2779b826c6f5c08e5cc542de58fd1f667d5 upstream. In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops when lazy MMU updates are enabled, because set_pgd effects are being deferred. One instance of this problem is during process mm cleanup with memory cgroups enabled. The chain of events is as follows: - zap_pte_range enables lazy MMU updates - zap_pte_range eventually calls mem_cgroup_charge_statistics, which accesses the vmalloc'd mem_cgroup per-cpu stat area - vmalloc_fault is triggered which tries to sync the corresponding PGD entry with set_pgd, but the update is deferred - vmalloc_fault oopses due to a mismatch in the PUD entries The OOPs usually looks as so: ------------[ cut here ]------------ kernel BUG at arch/x86/mm/fault.c:396! invalid opcode: 0000 [#1] SMP .. snip .. CPU 1 Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1 RIP: e030:[] [] vmalloc_fault+0x11f/0x208 .. snip .. Call Trace: [] do_page_fault+0x399/0x4b0 [] ? xen_mc_extend_args+0xec/0x110 [] page_fault+0x25/0x30 [] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50 [] __mem_cgroup_uncharge_common+0xd8/0x350 [] mem_cgroup_uncharge_page+0x57/0x60 [] page_remove_rmap+0xe0/0x150 [] ? vm_normal_page+0x1a/0x80 [] unmap_single_vma+0x531/0x870 [] unmap_vmas+0x52/0xa0 [] ? pte_mfn_to_pfn+0x72/0x100 [] exit_mmap+0x98/0x170 [] ? __raw_callee_save_xen_pmd_val+0x11/0x1e [] mmput+0x83/0xf0 [] exit_mm+0x104/0x130 [] do_exit+0x15a/0x8c0 [] do_group_exit+0x3f/0xa0 [] sys_exit_group+0x17/0x20 [] system_call_fastpath+0x16/0x1b Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the changes visible to the consistency checks. RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737 Tested-by: Josh Boyer Reported-and-Tested-by: Krishna Raman Signed-off-by: Samu Kallio Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.com Tested-by: Konrad Rzeszutek Wilk Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman