kernel.git/arch/powerpc/platforms, branch linux-5.5.y

powerpc/pseries: Avoid NULL pointer dereference when drmem is unavailable

2020-04-17T14:12:14Z

commit a83836dbc53e96f13fec248ecc201d18e1e3111d upstream. In guests without hotplugagble memory drmem structure is only zero initialized. Trying to manipulate DLPAR parameters results in a crash. $ echo "memory add count 1" > /sys/kernel/dlpar Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries ... NIP: c0000000000ff294 LR: c0000000000ff248 CTR: 0000000000000000 REGS: c0000000fb9d3880 TRAP: 0300 Tainted: G E (5.5.0-rc6-2-default) MSR: 8000000000009033 CR: 28242428 XER: 20000000 CFAR: c0000000009a6c10 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0 ... NIP dlpar_memory+0x6e4/0xd00 LR dlpar_memory+0x698/0xd00 Call Trace: dlpar_memory+0x698/0xd00 (unreliable) handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 __vfs_write+0x3c/0x70 vfs_write+0xd0/0x260 ksys_write+0xdc/0x130 system_call+0x5c/0x68 Taking closer look at the code, I can see that for_each_drmem_lmb is a macro expanding into `for (lmb = &drmem_info->lmbs[0]; lmb <= &drmem_info->lmbs[drmem_info->n_lmbs - 1]; lmb++)`. When drmem_info->lmbs is NULL, the loop would iterate through the whole address range if it weren't stopped by the NULL pointer dereference on the next line. This patch aligns for_each_drmem_lmb and for_each_drmem_lmb_in_range macro behavior with the common C semantics, where the end marker does not belong to the scanned range, and alters get_lmb_range() semantics. As a side effect, the wraparound observed in the crash is prevented. Fixes: 6c6ea53725b3 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Libor Pechacek Signed-off-by: Michal Suchanek Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200131132829.10281-1-msuchanek@suse.de Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/lparcfg: Fix display of Maximum Memory

2020-02-24T07:38:42Z

[ Upstream commit f1dbc1c5c70d0d4c60b5d467ba941fba167c12f6 ] Correct overflow problem in calculation and display of Maximum Memory value to syscfg. Signed-off-by: Michael Bringmann [mpe: Only n_lmbs needs casting to unsigned long] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5577aef8-1d5a-ca95-ff0a-9c7b5977e5bf@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/iov: Move VF pdev fixup into pcibios_fixup_iov()

2020-02-24T07:38:07Z

[ Upstream commit 965c94f309be58fbcc6c8d3e4f123376c5970d79 ] An ioda_pe for each VF is allocated in pnv_pci_sriov_enable() before the pci_dev for the VF is created. We need to set the pe->pdev pointer at some point after the pci_dev is created. Currently we do that in: pcibios_bus_add_device() pnv_pci_dma_dev_setup() (via phb->ops.dma_dev_setup) /* fixup is done here */ pnv_pci_ioda_dma_dev_setup() (via pnv_phb->dma_dev_setup) The fixup needs to be done before setting up DMA for for the VF's PE, but there's no real reason to delay it until this point. Move the fixup into pnv_pci_ioda_fixup_iov() so the ordering is: pcibios_add_device() pnv_pci_ioda_fixup_iov() (via ppc_md.pcibios_fixup_sriov) pcibios_bus_add_device() ... This isn't strictly required, but it's a slightly more logical place to do the fixup and it simplifies pnv_pci_dma_dev_setup(). Signed-off-by: Oliver O'Halloran Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200110070207.439-4-oohall@gmail.com Signed-off-by: Sasha Levin

powerpc/powernv/iov: Ensure the pdn for VFs always contains a valid PE number

2020-02-24T07:38:03Z

[ Upstream commit 3b5b9997b331e77ce967eba2c4bc80dc3134a7fe ] On pseries there is a bug with adding hotplugged devices to an IOMMU group. For a number of dumb reasons fixing that bug first requires re-working how VFs are configured on PowerNV. For background, on PowerNV we use the pcibios_sriov_enable() hook to do two things: 1. Create a pci_dn structure for each of the VFs, and 2. Configure the PHB's internal BARs so the MMIO range for each VF maps to a unique PE. Roughly speaking a PE is the hardware counterpart to a Linux IOMMU group since all the devices in a PE share the same IOMMU table. A PE also defines the set of devices that should be isolated in response to a PCI error (i.e. bad DMA, UR/CA, AER events, etc). When isolated all MMIO and DMA traffic to and from devicein the PE is blocked by the root complex until the PE is recovered by the OS. The requirement to block MMIO causes a giant headache because the P8 PHB generally uses a fixed mapping between MMIO addresses and PEs. As a result we need to delay configuring the IOMMU groups for device until after MMIO resources are assigned. For physical devices (i.e. non-VFs) the PE assignment is done in pcibios_setup_bridge() which is called immediately after the MMIO resources for downstream devices (and the bridge's windows) are assigned. For VFs the setup is more complicated because: a) pcibios_setup_bridge() is not called again when VFs are activated, and b) The pci_dev for VFs are created by generic code which runs after pcibios_sriov_enable() is called. The work around for this is a two step process: 1. A fixup in pcibios_add_device() is used to initialised the cached pe_number in pci_dn, then 2. A bus notifier then adds the device to the IOMMU group for the PE specified in pci_dn->pe_number. A side effect fixing the pseries bug mentioned in the first paragraph is moving the fixup out of pcibios_add_device() and into pcibios_bus_add_device(), which is called much later. This results in step 2. failing because pci_dn->pe_number won't be initialised when the bus notifier is run. We can fix this by removing the need for the fixup. The PE for a VF is known before the VF is even scanned so we can initialise pci_dn->pe_number pcibios_sriov_enable() instead. Unfortunately, moving the initialisation causes two problems: 1. We trip the WARN_ON() in the current fixup code, and 2. The EEH core clears pdn->pe_number when recovering a VF and relies on the fixup to correctly re-set it. The only justification for either of these is a comment in eeh_rmv_device() suggesting that pdn->pe_number *must* be set to IODA_INVALID_PE in order for the VF to be scanned. However, this comment appears to have no basis in reality. Both bugs can be fixed by just deleting the code. Tested-by: Alexey Kardashevskiy Reviewed-by: Alexey Kardashevskiy Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191028085424.12006-1-oohall@gmail.com Signed-off-by: Sasha Levin

powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW

2020-02-14T21:53:02Z

commit 7559d3d295f3365ea7ac0c0274c05e633fe4f594 upstream. By default a pseries guest supports a H_PUT_TCE hypercall which maps a single IOMMU page in a DMA window. Additionally the hypervisor may support H_PUT_TCE_INDIRECT/H_STUFF_TCE which update multiple TCEs at once; this is advertised via the device tree /rtas/ibm,hypertas-functions property which Linux converts to FW_FEATURE_MULTITCE. FW_FEATURE_MULTITCE is checked when dma_iommu_ops is used; however the code managing the huge DMA window (DDW) ignores it and calls H_PUT_TCE_INDIRECT even if it is explicitly disabled via the "multitce=off" kernel command line parameter. This adds FW_FEATURE_MULTITCE checking to the DDW code path. This changes tce_build_pSeriesLP to take liobn and page size as the huge window does not have iommu_table descriptor which usually the place to store these numbers. Fixes: 4e8b0cf46b25 ("powerpc/pseries: Add support for dynamic dma windows") Signed-off-by: Alexey Kardashevskiy Reviewed-by: Thiago Jung Bauermann Tested-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191216041924.42318-3-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/vio: Fix iommu_table use-after-free refcount warning

2020-02-14T21:53:02Z

commit aff8c8242bc638ba57247ae1ec5f272ac3ed3b92 upstream. Commit e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") missed an iommu_table allocation in the pseries vio code. The iommu_table is allocated with kzalloc and as a result the associated kref gets a value of zero. This has the side effect that during a DLPAR remove of the associated virtual IOA the iommu_tce_table_put() triggers a use-after-free underflow warning. Call Trace: [c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190 (unreliable) [c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0 [c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70 [c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0 [c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240 [c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40 [c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250 [c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0 [c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60 [c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0 [c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260 [c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70 [c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250 [c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120 [c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68 Further, since the refcount was always zero the iommu_tce_table_put() fails to call the iommu_table release function resulting in a leak. Fix this issue be initilizing the iommu_table kref immediately after allocation. Fixes: e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") Signed-off-by: Tyrel Datwyler Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1579558202-26052-1-git-send-email-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/papr_scm: Fix leaking 'bus_desc.provider_name' in some paths

2020-02-14T21:53:02Z

commit 5649607a8d0b0e019a4db14aab3de1e16c3a2b4f upstream. String 'bus_desc.provider_name' allocated inside papr_scm_nvdimm_init() will leaks in case call to nvdimm_bus_register() fails or when papr_scm_remove() is called. This minor patch ensures that 'bus_desc.provider_name' is freed in error path for nvdimm_bus_register() as well as in papr_scm_remove(). Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200122155140.120429-1-vaibhav@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

Revert "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests"

2020-02-14T21:53:02Z

commit d862b44133b7a1d7de25288e09eabf4df415e971 upstream. This reverts commit edea902c1c1efb855f77e041f9daf1abe7a9768a. At the time the change allowed direct DMA ops for secure VMs; however since then we switched on using SWIOTLB backed with IOMMU (direct mapping) and to make this work, we need dma_iommu_ops which handles all cases including TCE mapping I/O pages in the presence of an IOMMU. Fixes: edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests") Signed-off-by: Ram Pai [aik: added "revert" and "fixes:"] Signed-off-by: Alexey Kardashevskiy Reviewed-by: Thiago Jung Bauermann Tested-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191216041924.42318-2-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Advance pfn if section is not present in lmb_is_removable()

2020-02-11T12:36:49Z

commit fbee6ba2dca30d302efe6bddb3a886f5e964a257 upstream. In lmb_is_removable(), if a section is not present, it should continue to test the rest of the sections in the block. But the current code fails to do so. Fixes: 51925fb3c5c9 ("powerpc/pseries: Implement memory hotplug remove in the kernel") Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Pingfan Liu Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1578632042-12415-1-git-send-email-kernelfans@gmail.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/cmm: fix managed page counts when migrating pages between zones

2019-12-16T12:15:16Z

Commit 63341ab03706 (virtio-balloon: fix managed page counts when migrating pages between zones) fixed a long existing BUG in the virtio-balloon driver when pages would get migrated between zones. I did not try to reproduce on powerpc, but looking at the code, the same should apply to powerpc/cmm ever since it started using the balloon compaction infrastructure (luckily just recently). In case we have to migrate a ballon page to a newpage of another zone, the managed page count of both zones is wrong. Paired with memory offlining (which will adjust the managed page count), we can trigger kernel crashes and all kinds of different symptoms. Fix it by properly adjusting the managed page count when migrating if the zone changed. We'll temporarily modify the totalram page count. If this ever becomes a problem, we can fine tune by providing helpers that don't touch the totalram pages (e.g., adjust_zone_managed_page_count()). Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction") Signed-off-by: David Hildenbrand Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191216103058.4958-1-david@redhat.com