talos-op-linux/arch/powerpc, branch v4.12.5

KVM: PPC: Book3S HV: Fix host crash on changing HPT size

2017-08-06T16:21:08+00:00

commit ef42719814db06fdfa26cd7566de0b64de173320 upstream. Commit f98a8bf9ee20 ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size", 2016-12-20) changed the behaviour of the KVM_PPC_ALLOCATE_HTAB ioctl so that it now allocates a new HPT and new revmap array if there was a previously-allocated HPT of a different size from the size being requested. In this case, we need to reset the rmap arrays of the memslots, because the rmap arrays will contain references to HPTEs which are no longer valid. Worse, these references are also references to slots in the new revmap array (which parallels the HPT), and the new revmap array contains random contents, since it doesn't get zeroed on allocation. The effect of having these stale references to slots in the revmap array that contain random contents is that subsequent calls to functions such as kvmppc_add_revmap_chain will crash because they will interpret the non-zero contents of the revmap array as HPTE indexes and thus index outside of the revmap array. This leads to host crashes such as the following. [ 7072.862122] Unable to handle kernel paging request for data at address 0xd000000c250c00f8 [ 7072.862218] Faulting instruction address: 0xc0000000000e1c78 [ 7072.862233] Oops: Kernel access of bad area, sig: 11 [#1] [ 7072.862286] SMP NR_CPUS=1024 [ 7072.862286] NUMA [ 7072.862325] PowerNV [ 7072.862378] Modules linked in: kvm_hv vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm iw_cxgb3 mlx5_ib ib_core ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel i2c_opal nfsd auth_rpcgss oid_registry [ 7072.863085] nfs_acl lockd grace sunrpc kvm_pr kvm xfs libcrc32c scsi_dh_alua dm_service_time radeon lpfc nvme_fc nvme_fabrics nvme_core scsi_transport_fc i2c_algo_bit tg3 drm_kms_helper ptp pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm dm_multipath i2c_core cxgb3 mlx5_core mdio [last unloaded: kvm_hv] [ 7072.863381] CPU: 72 PID: 56929 Comm: qemu-system-ppc Not tainted 4.12.0-kvm+ #59 [ 7072.863457] task: c000000fe29e7600 task.stack: c000001e3ffec000 [ 7072.863520] NIP: c0000000000e1c78 LR: c0000000000e2e3c CTR: c0000000000e25f0 [ 7072.863596] REGS: c000001e3ffef560 TRAP: 0300 Not tainted (4.12.0-kvm+) [ 7072.863658] MSR: 9000000100009033 [ 7072.863667] CR: 44082882 XER: 20000000 [ 7072.863767] CFAR: c0000000000e2e38 DAR: d000000c250c00f8 DSISR: 42000000 SOFTE: 1 GPR00: c0000000000e2e3c c000001e3ffef7e0 c000000001407d00 d000000c250c00f0 GPR04: d00000006509fb70 d00000000b3d2048 0000000003ffdfb7 0000000000000000 GPR08: 00000001007fdfb7 00000000c000000f d0000000250c0000 000000000070f7bf GPR12: 0000000000000008 c00000000fdad000 0000000010879478 00000000105a0d78 GPR16: 00007ffaf4080000 0000000000001190 0000000000000000 0000000000010000 GPR20: 4001ffffff000415 d00000006509fb70 0000000004091190 0000000ee1881190 GPR24: 0000000003ffdfb7 0000000003ffdfb7 00000000007fdfb7 c000000f5c958000 GPR28: d00000002d09fb70 0000000003ffdfb7 d00000006509fb70 d00000000b3d2048 [ 7072.864439] NIP [c0000000000e1c78] kvmppc_add_revmap_chain+0x88/0x130 [ 7072.864503] LR [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0 [ 7072.864566] Call Trace: [ 7072.864594] [c000001e3ffef7e0] [c000001e3ffef830] 0xc000001e3ffef830 (unreliable) [ 7072.864671] [c000001e3ffef830] [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0 [ 7072.864751] [c000001e3ffef920] [d00000000b38d878] kvmppc_map_vrma+0x168/0x200 [kvm_hv] [ 7072.864831] [c000001e3ffef9e0] [d00000000b38a684] kvmppc_vcpu_run_hv+0x1284/0x1300 [kvm_hv] [ 7072.864914] [c000001e3ffefb30] [d00000000f465664] kvmppc_vcpu_run+0x44/0x60 [kvm] [ 7072.865008] [c000001e3ffefb60] [d00000000f461864] kvm_arch_vcpu_ioctl_run+0x114/0x290 [kvm] [ 7072.865152] [c000001e3ffefbe0] [d00000000f453c98] kvm_vcpu_ioctl+0x598/0x7a0 [kvm] [ 7072.865292] [c000001e3ffefd40] [c000000000389328] do_vfs_ioctl+0xd8/0x8c0 [ 7072.865410] [c000001e3ffefde0] [c000000000389be4] SyS_ioctl+0xd4/0x130 [ 7072.865526] [c000001e3ffefe30] [c00000000000b760] system_call+0x58/0x6c [ 7072.865644] Instruction dump: [ 7072.865715] e95b2110 793a0020 7b4926e4 7f8a4a14 409e0098 807c000c 786326e4 7c6a1a14 [ 7072.865857] 935e0008 7bbd0020 813c000c 913e000c <93a30008> 93bc000c 48000038 60000000 [ 7072.866001] ---[ end trace 627b6e4bf8080edc ]--- Note that to trigger this, it is necessary to use a recent upstream QEMU (or other userspace that resizes the HPT at CAS time), specify a maximum memory size substantially larger than the current memory size, and boot a guest kernel that does not support HPT resizing. This fixes the problem by resetting the rmap arrays when the old HPT is freed. Fixes: f98a8bf9ee20 ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size") Reviewed-by: David Gibson Signed-off-by: Paul Mackerras Signed-off-by: Greg Kroah-Hartman

KVM: PPC: Book3S HV: Enable TM before accessing TM registers

2017-08-06T16:21:08+00:00

commit e47057151422a67ce08747176fa21cb3b526a2c9 upstream. Commit 46a704f8409f ("KVM: PPC: Book3S HV: Preserve userspace HTM state properly", 2017-06-15) added code to read transactional memory (TM) registers but forgot to enable TM before doing so. The result is that if userspace does have live values in the TM registers, a KVM_RUN ioctl will cause a host kernel crash like this: [ 181.328511] Unrecoverable TM Unavailable Exception f60 at d00000001e7d9980 [ 181.328605] Oops: Unrecoverable TM Unavailable Exception, sig: 6 [#1] [ 181.328613] SMP NR_CPUS=2048 [ 181.328613] NUMA [ 181.328618] PowerNV [ 181.328646] Modules linked in: vhost_net vhost tap nfs_layout_nfsv41_files rpcsec_gss_krb5 nfsv4 dns_resolver nfs +fscache xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat +nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun ebtable_filter ebtables +ip6table_filter ip6_tables iptable_filter bridge stp llc kvm_hv kvm nfsd ses enclosure scsi_transport_sas ghash_generic +auth_rpcgss gf128mul xts sg ctr nfs_acl lockd vmx_crypto shpchp ipmi_powernv i2c_opal grace ipmi_devintf i2c_core +powernv_rng sunrpc ipmi_msghandler ibmpowernv uio_pdrv_genirq uio leds_powernv powernv_op_panel ip_tables xfs sd_mod +lpfc ipr bnx2x libata mdio ptp pps_core scsi_transport_fc libcrc32c dm_mirror dm_region_hash dm_log dm_mod [ 181.329278] CPU: 40 PID: 9926 Comm: CPU 0/KVM Not tainted 4.12.0+ #1 [ 181.329337] task: c000003fc6980000 task.stack: c000003fe4d80000 [ 181.329396] NIP: d00000001e7d9980 LR: d00000001e77381c CTR: d00000001e7d98f0 [ 181.329465] REGS: c000003fe4d837e0 TRAP: 0f60 Not tainted (4.12.0+) [ 181.329523] MSR: 9000000000009033 [ 181.329527] CR: 24022448 XER: 00000000 [ 181.329608] CFAR: d00000001e773818 SOFTE: 1 [ 181.329608] GPR00: d00000001e77381c c000003fe4d83a60 d00000001e7ef410 c000003fdcfe0000 [ 181.329608] GPR04: c000003fe4f00000 0000000000000000 0000000000000000 c000003fd7954800 [ 181.329608] GPR08: 0000000000000001 c000003fc6980000 0000000000000000 d00000001e7e2880 [ 181.329608] GPR12: d00000001e7d98f0 c000000007b19000 00000001295220e0 00007fffc0ce2090 [ 181.329608] GPR16: 0000010011886608 00007fff8c89f260 0000000000000001 00007fff8c080028 [ 181.329608] GPR20: 0000000000000000 00000100118500a6 0000010011850000 0000010011850000 [ 181.329608] GPR24: 00007fffc0ce1b48 0000010011850000 00000000d673b901 0000000000000000 [ 181.329608] GPR28: 0000000000000000 c000003fdcfe0000 c000003fdcfe0000 c000003fe4f00000 [ 181.330199] NIP [d00000001e7d9980] kvmppc_vcpu_run_hv+0x90/0x6b0 [kvm_hv] [ 181.330264] LR [d00000001e77381c] kvmppc_vcpu_run+0x2c/0x40 [kvm] [ 181.330322] Call Trace: [ 181.330351] [c000003fe4d83a60] [d00000001e773478] kvmppc_set_one_reg+0x48/0x340 [kvm] (unreliable) [ 181.330437] [c000003fe4d83b30] [d00000001e77381c] kvmppc_vcpu_run+0x2c/0x40 [kvm] [ 181.330513] [c000003fe4d83b50] [d00000001e7700b4] kvm_arch_vcpu_ioctl_run+0x114/0x2a0 [kvm] [ 181.330586] [c000003fe4d83bd0] [d00000001e7642f8] kvm_vcpu_ioctl+0x598/0x7a0 [kvm] [ 181.330658] [c000003fe4d83d40] [c0000000003451b8] do_vfs_ioctl+0xc8/0x8b0 [ 181.330717] [c000003fe4d83de0] [c000000000345a64] SyS_ioctl+0xc4/0x120 [ 181.330776] [c000003fe4d83e30] [c00000000000b004] system_call+0x58/0x6c [ 181.330833] Instruction dump: [ 181.330869] e92d0260 e9290b50 e9290108 792807e3 41820058 e92d0260 e9290b50 e9290108 [ 181.330941] 792ae8a4 794a1f87 408204f4 e92d0260 <7d4022a6> f9490ff0 e92d0260 7d4122a6 [ 181.331013] ---[ end trace 6f6ddeb4bfe92a92 ]--- The fix is just to turn on the TM bit in the MSR before accessing the registers. Fixes: 46a704f8409f ("KVM: PPC: Book3S HV: Preserve userspace HTM state properly") Reported-by: Jan Stancek Tested-by: Jan Stancek Signed-off-by: Paul Mackerras Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix of_node_put() underflow during reconfig remove

2017-08-06T16:21:07+00:00

commit 4fd1bd443e80b12f0a01a45fb9a793206b41cb72 upstream. As for commit 68baf692c435 ("powerpc/pseries: Fix of_node_put() underflow during DLPAR remove"), the call to of_node_put() must be removed from pSeries_reconfig_remove_node(). dlpar_detach_node() and pSeries_reconfig_remove_node() both call of_detach_node(), and thus the node should not be released in both cases. Fixes: 0829f6d1f69e ("of: device_node kobject lifecycle fixes") Signed-off-by: Laurent Vivier Reviewed-by: David Gibson Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/perf: Fix SDAR_MODE value for continous sampling on Power9

2017-07-27T22:10:09+00:00

commit 20dd4c624d25156d5ec3345bbb690b98175ef879 upstream. In case of continous sampling (non-marked), the code currently sets MMCRA[SDAR_MODE] to 0b01 (Update on TLB miss) for Power9 DD1. On DD2 and later it copies the sdar_mode value from the event code, which for most events is 0b00 (No updates). However we must set a non-zero value for SDAR_MODE when doing continuous sampling, so honor the event code, unless it's zero, in which case we use use 0b01 (Update on TLB miss). Fixes: 78b4416aa249 ("powerpc/perf: Handle sdar_mode for marked event in power9") Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/mm/radix: Properly clear process table entry

2017-07-27T22:10:09+00:00

commit c6bb0b8d426a8cf865ca9c8a532cc3a2927cfceb upstream. On radix, the process table entry we want to clear when destroying a context is entry 0, not entry 1. This has no *immediate* consequence on Power9, but it can cause other bugs to become worse. Fixes: 7e381c0ff618 ("powerpc/mm/radix: Add mmu context handling callback for radix") Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/asm: Mark cr0 as clobbered in mftb()

2017-07-27T22:10:09+00:00

commit 2400fd822f467cb4c886c879d8ad99feac9cf319 upstream. The workaround for the CELL timebase bug does not correctly mark cr0 as being clobbered. This means GCC doesn't know that the asm block changes cr0 and might leave the result of an unrelated comparison in cr0 across the block, which we then trash, leading to basically random behaviour. Fixes: 859deea949c3 ("[POWERPC] Cell timebase bug workaround") Signed-off-by: Oliver O'Halloran [mpe: Tweak change log and flag for stable] Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc: Fix emulation of mfocrf in emulate_step()

2017-07-27T22:10:08+00:00

commit 64e756c55aa46fc18fd53e8f3598b73b528d8637 upstream. From POWER4 onwards, mfocrf() only places the specified CR field into the destination GPR, and the rest of it is set to 0. The PowerPC AS from version 3.0 now requires this behaviour. The emulation code currently puts the entire CR into the destination GPR. Fix it. Fixes: 6888199f7fe5 ("[POWERPC] Emulate more instructions in software") Signed-off-by: Anton Blanchard Acked-by: Naveen N. Rao Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc: Fix emulation of mcrf in emulate_step()

2017-07-27T22:10:08+00:00

commit 87c4b83e0fe234a1f0eed131ab6fa232036860d5 upstream. The mcrf emulation code was using the CR field number directly as the shift value, without taking into account that CR fields are numbered from 0-7 starting at the high bits. That meant it was looking at the CR fields in the reverse order. Fixes: cf87c3f6b647 ("powerpc: Emulate icbi, mcrf and conditional-trap instructions") Signed-off-by: Anton Blanchard Acked-by: Naveen N. Rao Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/64: Fix atomic64_inc_not_zero() to return an int

2017-07-27T22:10:08+00:00

commit 01e6a61aceb82e13bec29502a8eb70d9574f97ad upstream. Although it's not documented anywhere, there is an expectation that atomic64_inc_not_zero() returns a result which fits in an int. This is the behaviour implemented on all arches except powerpc. This has caused at least one bug in practice, in the percpu-refcount code, where the long result from our atomic64_inc_not_zero() was truncated to an int leading to lost references and stuck systems. That was worked around in that code in commit 966d2b04e070 ("percpu-refcount: fix reference leak during percpu-atomic transition"). To the best of my grepping abilities there are no other callers in-tree which truncate the value, but we should fix it anyway. Because the breakage is subtle and potentially very harmful I'm also tagging it for stable. Code generation is largely unaffected because in most cases the callers are just using the result for a test anyway. In particular the case of fget() that was mentioned in commit a6cf7ed5119f ("powerpc/atomic: Implement atomic*_inc_not_zero") generates exactly the same code. Fixes: a6cf7ed5119f ("powerpc/atomic: Implement atomic*_inc_not_zero") Noticed-by: Linus Torvalds Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/mm/radix: Fix execute permissions for interrupt_vectors

2017-07-27T22:10:08+00:00

commit 7f6d498ed3354740cfd100e4aa99e388f1a95be7 upstream. Commit 9abcc981de97 ("powerpc/mm/radix: Only add X for pages overlapping kernel text") changed the linear mapping on Radix to only mark the kernel text executable. However if the kernel is run relocated, for example as a kdump kernel, then the exception vectors are split from the kernel text, ie. they remain at real address 0. We tend to get away with it, because the kernel itself will usually be below 1G, which means the 1G page at 0-1G is marked executable and everything works OK. However if the kernel is loaded above 1G, or the system has less than 1G in total (meaning we can't use a 1G page), then the exception vectors will not be marked executable and the kernel will fail to boot. Fix it by also checking if the address range overlaps the exception vectors when deciding if we should add PAGE_KERNEL_X. Fixes: 9abcc981de97 ("powerpc/mm/radix: Only add X for pages overlapping kernel text") Signed-off-by: Balbir Singh [mpe: Combine with the existing check, rewrite change log] Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman