kernel/arch/powerpc/platforms, branch linux-5.1.y

powerpc/pseries: Fix oops in hotplug memory notifier

2019-07-26T07:13:06Z

commit 0aa82c482ab2ece530a6f44897b63b274bb43c8e upstream. During post-migration device tree updates, we can oops in pseries_update_drconf_memory() if the source device tree has an ibm,dynamic-memory-v2 property and the destination has a ibm,dynamic_memory (v1) property. The notifier processes an "update" for the ibm,dynamic-memory property but it's really an add in this scenario. So make sure the old property object is there before dereferencing it. Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/powernv: Fix stale iommu table base after VFIO

2019-07-26T07:13:06Z

commit 5636427d087a55842c1a199dfb839e6545d30e5d upstream. The powernv platform uses @dma_iommu_ops for non-bypass DMA. These ops need an iommu_table pointer which is stored in dev->archdata.iommu_table_base. It is initialized during pcibios_setup_device() which handles boot time devices. However when a device is taken from the system in order to pass it through, the default IOMMU table is destroyed but the pointer in a device is not updated; also when a device is returned back to the system, a new table pointer is not stored in dev->archdata.iommu_table_base either. So when a just returned device tries using IOMMU, it crashes on accessing stale iommu_table or its members. This calls set_iommu_table_base() when the default window is created. Note it used to be there before but was wrongly removed (see "fixes"). It did not appear before as these days most devices simply use bypass. This adds set_iommu_table_base(NULL) when a device is taken from the system to make it clear that IOMMU DMA cannot be used past that point. Fixes: c4e9d3c1e65a ("powerpc/powernv/pseries: Rework device adding to IOMMU groups") Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/powernv/npu: Fix reference leak

2019-07-26T07:13:06Z

commit 02c5f5394918b9b47ff4357b1b18335768cd867d upstream. Since 902bdc57451c, get_pci_dev() calls pci_get_domain_bus_and_slot(). This has the effect of incrementing the reference count of the PCI device, as explained in drivers/pci/search.c: * Given a PCI domain, bus, and slot/function number, the desired PCI * device is located in the list of PCI devices. If the device is * found, its reference count is increased and this function returns a * pointer to its data structure. The caller must decrement the * reference count by calling pci_dev_put(). If no device is found, * %NULL is returned. Nothing was done to call pci_dev_put() and the reference count of GPU and NPU PCI devices rockets up. A natural way to fix this would be to teach the callers about the change, so that they call pci_dev_put() when done with the pointer. This turns out to be quite intrusive, as it affects many paths in npu-dma.c, pci-ioda.c and vfio_pci_nvlink2.c. Also, the issue appeared in 4.16 and some affected code got moved around since then: it would be problematic to backport the fix to stable releases. All that code never cared for reference counting anyway. Call pci_dev_put() from get_pci_dev() to revert to the previous behavior. Fixes: 902bdc57451c ("powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn") Cc: stable@vger.kernel.org # v4.16 Signed-off-by: Greg Kurz Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/32s: fix suspend/resume when IBATs 4-7 are used

2019-07-26T07:13:06Z

commit 6ecb78ef56e08d2119d337ae23cb951a640dc52d upstream. Previously, only IBAT1 and IBAT2 were used to map kernel linear mem. Since commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX"), we may have all 8 BATs used for mapping kernel text. But the suspend/restore functions only save/restore BATs 0 to 3, and clears BATs 4 to 7. Make suspend and restore functions respectively save and reload the 8 BATs on CPUs having MMU_FTR_USE_HIGH_BATS feature. Reported-by: Andreas Schwab Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

2019-07-14T06:09:45Z

[ Upstream commit 9739ab7eda459f0669ec9807e0d9be5020bab88c ] With the strict dma mask checking introduced with the switch to the generic DMA direct code common wifi chips on 32-bit powerbooks stopped working. Add a 30-bit ZONE_DMA to the 32-bit pmac builds to allow them to reliably allocate dma coherent memory. Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported") Reported-by: Aaro Koskinen Signed-off-by: Christoph Hellwig Tested-by: Larry Finger Acked-by: Larry Finger Tested-by: Aaro Koskinen Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/powernv: Return for invalid IMC domain

2019-06-22T06:09:09Z

[ Upstream commit b59bd3527fe3c1939340df558d7f9d568fc9f882 ] Currently init_imc_pmu() can fail either because we try to register an IMC unit with an invalid domain (i.e an IMC node not supported by the kernel) or something went wrong while registering a valid IMC unit. In both the cases kernel provides a 'Register failed' error message. For example when trace-imc node is not supported by the kernel, but skiboot advertises a trace-imc node we print: IMC Unknown Device type IMC PMU (null) Register failed To avoid confusion just print the unknown device type message, before attempting PMU registration, so the second message isn't printed. Fixes: 8f95faaac56c ("powerpc/powernv: Detect and create IMC device") Reported-by: Pavaman Subramaniyam Signed-off-by: Anju T Sudhakar Reviewed-by: Madhavan Srinivasan [mpe: Reword change log a bit] Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/pseries: Track LMB nid instead of using device tree

2019-06-15T09:52:59Z

[ Upstream commit b2d3b5ee66f2a04a918cc043cec0c9ed3de58f40 ] When removing memory we need to remove the memory from the node it was added to instead of looking up the node it should be in in the device tree. During testing we have seen scenarios where the affinity for a LMB changes due to a partition migration or PRRN event. In these cases the node the LMB exists in may not match the node the device tree indicates it belongs in. This can lead to a system crash when trying to DLPAR remove the LMB after a migration or PRRN event. The current code looks up the node in the device tree to remove the LMB from, the crash occurs when we try to offline this node and it does not have any data, i.e. node_data[nid] == NULL. 36:mon> e cpu 0x36: Vector: 300 (Data Access) at [c0000001828b7810] pc: c00000000036d08c: try_offline_node+0x2c/0x1b0 lr: c0000000003a14ec: remove_memory+0xbc/0x110 sp: c0000001828b7a90 msr: 800000000280b033 dar: 9a28 dsisr: 40000000 current = 0xc0000006329c4c80 paca = 0xc000000007a55200 softe: 0 irq_happened: 0x01 pid = 76926, comm = kworker/u320:3 36:mon> t [link register ] c0000000003a14ec remove_memory+0xbc/0x110 [c0000001828b7a90] c00000000006a1cc arch_remove_memory+0x9c/0xd0 (unreliable) [c0000001828b7ad0] c0000000003a14e0 remove_memory+0xb0/0x110 [c0000001828b7b20] c0000000000c7db4 dlpar_remove_lmb+0x94/0x160 [c0000001828b7b60] c0000000000c8ef8 dlpar_memory+0x7e8/0xd10 [c0000001828b7bf0] c0000000000bf828 handle_dlpar_errorlog+0xf8/0x160 [c0000001828b7c60] c0000000000bf8cc pseries_hp_work_fn+0x3c/0xa0 [c0000001828b7c90] c000000000128cd8 process_one_work+0x298/0x5a0 [c0000001828b7d20] c000000000129068 worker_thread+0x88/0x620 [c0000001828b7dc0] c00000000013223c kthread+0x1ac/0x1c0 [c0000001828b7e30] c00000000000b45c ret_from_kernel_thread+0x5c/0x80 To resolve this we need to track the node a LMB belongs to when it is added to the system so we can remove it from that node instead of the node that the device tree indicates it should belong to. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/perf: Fix loop exit condition in nest_imc_event_init

2019-05-31T13:43:17Z

[ Upstream commit 860b7d2286236170a36f94946d03ca9888d32571 ] The data structure (i.e struct imc_mem_info) to hold the memory address information for nest imc units is allocated based on the number of nodes in the system. nest_imc_event_init() traverse this struct array to calculate the memory base address for the event-cpu. If we fail to find a match for the event cpu's chip-id in imc_mem_info struct array, then the do-while loop will iterate until we crash. Fix this by changing the loop exit condition based on the number of non zero vbase elements in the array, since the allocation is done for nr_chips + 1. Reported-by: Dan Carpenter Fixes: 885dcd709ba91 ("powerpc/perf: Add nest IMC PMU support") Signed-off-by: Anju T Sudhakar Reviewed-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/mm/radix: Make Radix require HUGETLB_PAGE

2019-04-17T08:50:26Z

Joel reported weird crashes using skiroot_defconfig, in his case we jumped into an NX page: kernel tried to execute exec-protected page (c000000002bff4f0) - exploit attempt? (uid: 0) BUG: Unable to handle kernel instruction fetch Faulting instruction address: 0xc000000002bff4f0 Looking at the disassembly, we had simply branched to that address: c000000000c001bc 49fff335 bl c000000002bff4f0 But that didn't match the original kernel image: c000000000c001bc 4bfff335 bl c000000000bff4f0 When STRICT_KERNEL_RWX is enabled, and we're using the radix MMU, we call radix__change_memory_range() late in boot to change page protections. We do that both to mark rodata read only and also to mark init text no-execute. That involves walking the kernel page tables, and clearing _PAGE_WRITE or _PAGE_EXEC respectively. With radix we may use hugepages for the linear mapping, so the code in radix__change_memory_range() uses eg. pmd_huge() to test if it has found a huge mapping, and if so it stops the page table walk and changes the PMD permissions. However if the kernel is built without HUGETLBFS support, pmd_huge() is just a #define that always returns 0. That causes the code in radix__change_memory_range() to incorrectly interpret the PMD value as a pointer to a PTE page rather than as a PTE at the PMD level. We can see this using `dv` in xmon which also uses pmd_huge(): 0:mon> dv c000000000000000 pgd @ 0xc000000001740000 pgdp @ 0xc000000001740000 = 0x80000000ffffb009 pudp @ 0xc0000000ffffb000 = 0x80000000ffffa009 pmdp @ 0xc0000000ffffa000 = 0xc00000000000018f <- this is a PTE ptep @ 0xc000000000000100 = 0xa64bb17da64ab07d <- kernel text The end result is we treat the value at 0xc000000000000100 as a PTE and clear _PAGE_WRITE or _PAGE_EXEC, potentially corrupting the code at that address. In Joel's specific case we cleared the sign bit in the offset of the branch, causing a backward branch to turn into a forward branch which caused us to branch into a non-executable page. However the exact nature of the crash depends on kernel version, compiler version, and other factors. We need to fix radix__change_memory_range() to not use accessors that depend on HUGETLBFS, but we also have radix memory hotplug code that uses pmd_huge() etc that will also need fixing. So for now just disallow the broken combination of Radix with HUGETLBFS disabled. The only defconfig we have that is affected is skiroot_defconfig, so turn on HUGETLBFS there so that it still gets Radix. Fixes: 566ca99af026 ("powerpc/mm/radix: Add dummy radix_enabled()") Cc: stable@vger.kernel.org # v4.7+ Reported-by: Joel Stanley Signed-off-by: Michael Ellerman

powerpc/pseries/mce: Fix misleading print for TLB mutlihit

2019-03-29T05:59:19Z

On pseries, TLB multihit are reported as D-Cache Multihit. This is because the wrongly populated mc_err_types[] array. Per PAPR, TLB error type is 0x04 and mc_err_types[4] points to "D-Cache" instead of "TLB" string. Fixup the mc_err_types[] array. Machine check error type per PAPR: 0x00 = Uncorrectable Memory Error (UE) 0x01 = SLB error 0x02 = ERAT Error 0x04 = TLB error 0x05 = D-Cache error 0x07 = I-Cache error Fixes: 8f0b80561f21 ("powerpc/pseries: Display machine check error details.") Cc: stable@vger.kernel.org # v4.20+ Reported-by: Aneesh Kumar K.V Signed-off-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman