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2019-12-05powerpc/mm: Make NULL pointer deferences explicit on bad page faults.Christophe Leroy
[ Upstream commit 49a502ea23bf9dec47f8f3c3960909ff409cd1bb ] As several other arches including x86, this patch makes it explicit that a bad page fault is a NULL pointer dereference when the fault address is lower than PAGE_SIZE In the mean time, this page makes all bad_page_fault() messages shorter so that they remain on one single line. And it prefixes them by "BUG: " so that they get easily grepped. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Avoid pr_cont()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05powerpc/book3s/32: fix number of bats in p/v_block_mapped()Christophe Leroy
[ Upstream commit e93ba1b7eb5b188c749052df7af1c90821c5f320 ] This patch fixes the loop in p_block_mapped() and v_block_mapped() to scan the entire bat_addrs[] array. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20powerpc/64s/hash: Fix stab_rr off by one initializationNicholas Piggin
[ Upstream commit 09b4438db13fa83b6219aee5993711a2aa2a0c64 ] This causes SLB alloation to start 1 beyond the start of the SLB. There is no real problem because after it wraps it stats behaving properly, it's just surprisig to see when looking at SLB traces. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-10powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9Aneesh Kumar K.V
commit 047e6575aec71d75b765c22111820c4776cd1c43 upstream. On POWER9, under some circumstances, a broadcast TLB invalidation will fail to invalidate the ERAT cache on some threads when there are parallel mtpidr/mtlpidr happening on other threads of the same core. This can cause stores to continue to go to a page after it's unmapped. The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie flush. This additional TLB flush will cause the ERAT cache invalidation. Since we are using PID=0 or LPID=0, we don't get filtered out by the TLB snoop filtering logic. We need to still follow this up with another tlbie to take care of store vs tlbie ordering issue explained in commit: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9"). The presence of ERAT cache implies we can still get new stores and they may miss store queue marking flush. Cc: stable@vger.kernel.org # v4.14 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com [sandipan: Backported to v4.14] Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flagAneesh Kumar K.V
commit 09ce98cacd51fcd0fa0af2f79d1e1d3192f4cbb0 upstream. Rename the #define to indicate this is related to store vs tlbie ordering issue. In the next patch, we will be adding another feature flag that is used to handles ERAT flush vs tlbie ordering issue. Cc: stable@vger.kernel.org # v4.14 Fixes: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.com [sandipan: Backported to v4.14] Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10powerpc/mm: Fixup tlbie vs store ordering issue on POWER9Aneesh Kumar K.V
commit a5d4b5891c2f1f865a2def1eb0030f534e77ff86 upstream. On POWER9, under some circumstances, a broadcast TLB invalidation might complete before all previous stores have drained, potentially allowing stale stores from becoming visible after the invalidation. This works around it by doubling up those TLB invalidations which was verified by HW to be sufficient to close the risk window. This will be documented in a yet-to-be-published errata. Cc: stable@vger.kernel.org # v4.14 Fixes: 1a472c9dba6b ("powerpc/mm/radix: Add tlbflush routines") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Enable the feature in the DT CPU features code for all Power9, rename the feature to CPU_FTR_P9_TLBIE_BUG per benh.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20180323045627.16800-3-aneesh.kumar@linux.vnet.ibm.com/ [sandipan: Backported to v4.14] Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11powerpc/pseries: Fix cpu_hotplug_lock acquisition in resize_hpt()Gautham R. Shenoy
[ Upstream commit c784be435d5dae28d3b03db31753dd7a18733f0c ] The calls to arch_add_memory()/arch_remove_memory() are always made with the read-side cpu_hotplug_lock acquired via memory_hotplug_begin(). On pSeries, arch_add_memory()/arch_remove_memory() eventually call resize_hpt() which in turn calls stop_machine() which acquires the read-side cpu_hotplug_lock again, thereby resulting in the recursive acquisition of this lock. In the absence of CONFIG_PROVE_LOCKING, we hadn't observed a system lockup during a memory hotplug operation because cpus_read_lock() is a per-cpu rwsem read, which, in the fast-path (in the absence of the writer, which in our case is a CPU-hotplug operation) simply increments the read_count on the semaphore. Thus a recursive read in the fast-path doesn't cause any problems. However, we can hit this problem in practice if there is a concurrent CPU-Hotplug operation in progress which is waiting to acquire the write-side of the lock. This will cause the second recursive read to block until the writer finishes. While the writer is blocked since the first read holds the lock. Thus both the reader as well as the writers fail to make any progress thereby blocking both CPU-Hotplug as well as Memory Hotplug operations. Memory-Hotplug CPU-Hotplug CPU 0 CPU 1 ------ ------ 1. down_read(cpu_hotplug_lock.rw_sem) [memory_hotplug_begin] 2. down_write(cpu_hotplug_lock.rw_sem) [cpu_up/cpu_down] 3. down_read(cpu_hotplug_lock.rw_sem) [stop_machine()] Lockdep complains as follows in these code-paths. swapper/0/1 is trying to acquire lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: stop_machine+0x2c/0x60 but task is already holding lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(cpu_hotplug_lock.rw_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by swapper/0/1: #0: (____ptrval____) (&dev->mutex){....}, at: __driver_attach+0x12c/0x1b0 #1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 #2: (____ptrval____) (mem_hotplug_lock.rw_sem){++++}, at: percpu_down_write+0x54/0x1a0 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc5-58373-gbc99402235f3-dirty #166 Call Trace: dump_stack+0xe8/0x164 (unreliable) __lock_acquire+0x1110/0x1c70 lock_acquire+0x240/0x290 cpus_read_lock+0x64/0xf0 stop_machine+0x2c/0x60 pseries_lpar_resize_hpt+0x19c/0x2c0 resize_hpt_for_hotplug+0x70/0xd0 arch_add_memory+0x58/0xfc devm_memremap_pages+0x5e8/0x8f0 pmem_attach_disk+0x764/0x830 nvdimm_bus_probe+0x118/0x240 really_probe+0x230/0x4b0 driver_probe_device+0x16c/0x1e0 __driver_attach+0x148/0x1b0 bus_for_each_dev+0x90/0x130 driver_attach+0x34/0x50 bus_add_driver+0x1a8/0x360 driver_register+0x108/0x170 __nd_driver_register+0xd0/0xf0 nd_pmem_driver_init+0x34/0x48 do_one_initcall+0x1e0/0x45c kernel_init_freeable+0x540/0x64c kernel_init+0x2c/0x160 ret_from_kernel_thread+0x5c/0x68 Fix this issue by 1) Requiring all the calls to pseries_lpar_resize_hpt() be made with cpu_hotplug_lock held. 2) In pseries_lpar_resize_hpt() invoke stop_machine_cpuslocked() as a consequence of 1) 3) To satisfy 1), in hpt_order_set(), call mmu_hash_ops.resize_hpt() with cpu_hotplug_lock held. Fixes: dbcf929c0062 ("powerpc/pseries: Add support for hash table resizing") Cc: stable@vger.kernel.org # v4.11+ Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1557906352-29048-1-git-send-email-ego@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-21powerpc/mm/radix: Use the right page size for vmemmap mappingAneesh Kumar K.V
commit 89a3496e0664577043666791ec07fb731d57c950 upstream. We use mmu_vmemmap_psize to find the page size for mapping the vmmemap area. With radix translation, we are suboptimally setting this value to PAGE_SIZE. We do check for 2M page size support and update mmu_vmemap_psize to use hugepage size but we suboptimally reset the value to PAGE_SIZE in radix__early_init_mmu(). This resulted in always mapping vmemmap area with 64K page size. Fixes: 2bfd65e45e87 ("powerpc/mm/radix: Add radix callbacks for early init routines") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31powerpc/numa: improve control of topology updatesNathan Lynch
[ Upstream commit 2d4d9b308f8f8dec68f6dbbff18c68ec7c6bd26f ] When booted with "topology_updates=no", or when "off" is written to /proc/powerpc/topology_updates, NUMA reassignments are inhibited for PRRN and VPHN events. However, migration and suspend unconditionally re-enable reassignments via start_topology_update(). This is incoherent. Check the topology_updates_enabled flag in start/stop_topology_update() so that callers of those APIs need not be aware of whether reassignments are enabled. This allows the administrative decision on reassignments to remain in force across migrations and suspensions. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-08powerpc/mm/hash: Handle mmap_min_addr correctly in get_unmapped_area topdown ↵Aneesh Kumar K.V
search commit 3b4d07d2674f6b4a9281031f99d1f7efd325b16d upstream. When doing top-down search the low_limit is not PAGE_SIZE but rather max(PAGE_SIZE, mmap_min_addr). This handle cases in which mmap_min_addr > PAGE_SIZE. Fixes: fba2369e6ceb ("mm: use vm_unmapped_area() on powerpc architecture") Reviewed-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-05powerpc/pseries: Perform full re-add of CPU for topology update post-migrationNathan Fontenot
[ Upstream commit 81b61324922c67f73813d8a9c175f3c153f6a1c6 ] On pseries systems, performing a partition migration can result in altering the nodes a CPU is assigned to on the destination system. For exampl, pre-migration on the source system CPUs are in node 1 and 3, post-migration on the destination system CPUs are in nodes 2 and 3. Handling the node change for a CPU can cause corruption in the slab cache if we hit a timing where a CPUs node is changed while cache_reap() is invoked. The corruption occurs because the slab cache code appears to rely on the CPU and slab cache pages being on the same node. The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c does not prevent us from hitting this scenario. Changing the device tree property update notification handler that recognizes an affinity change for a CPU to do a full DLPAR remove and add of the CPU instead of dynamically changing its node resolves this issue. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Tested-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05powerpc/hugetlb: Handle mmap_min_addr correctly in get_unmapped_area callbackAneesh Kumar K.V
[ Upstream commit 5330367fa300742a97e20e953b1f77f48392faae ] After we ALIGN up the address we need to make sure we didn't overflow and resulted in zero address. In that case, we need to make sure that the returned address is greater than mmap_min_addr. This fixes selftest va_128TBswitch --run-hugetlb reporting failures when run as non root user for mmap(-1, MAP_HUGETLB) The bug is that a non-root user requesting address -1 will be given address 0 which will then fail, whereas they should have been given something else that would have succeeded. We also avoid the first mmap(-1, MAP_HUGETLB) returning NULL address as mmap address with this change. So we think this is not a security issue, because it only affects whether we choose an address below mmap_min_addr, not whether we actually allow that address to be mapped. ie. there are existing capability checks to prevent a user mapping below mmap_min_addr and those will still be honoured even without this fix. Fixes: 484837601d4d ("powerpc/mm: Add radix support for hugetlb") Reviewed-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-03powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)Diana Craciun
commit 10c5e83afd4a3f01712d97d3bb1ae34d5b74a185 upstream. In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e. the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12powerpc/mm: Fix reporting of kernel execute faults on the 8xxChristophe Leroy
[ Upstream commit ffca395b11c4a5a6df6d6345f794b0e3d578e2d0 ] On the 8xx, no-execute is set via PPP bits in the PTE. Therefore a no-exec fault generates DSISR_PROTFAULT error bits, not DSISR_NOEXEC_OR_G. This patch adds DSISR_PROTFAULT in the test mask. Fixes: d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-13powerpc/mm: Fix linux page tables build with some configsMichael Ellerman
[ Upstream commit 462951cd32e1496dc64b00051dfb777efc8ae5d8 ] For some configs the build fails with: arch/powerpc/mm/dump_linuxpagetables.c: In function 'populate_markers': arch/powerpc/mm/dump_linuxpagetables.c:306:39: error: 'PKMAP_BASE' undeclared (first use in this function) arch/powerpc/mm/dump_linuxpagetables.c:314:50: error: 'LAST_PKMAP' undeclared (first use in this function) These come from highmem.h, including that fixes the build. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-01powerpc/numa: Suppress "VPHN is not supported" messagesSatheesh Rajendran
[ Upstream commit 437ccdc8ce629470babdda1a7086e2f477048cbd ] When VPHN function is not supported and during cpu hotplug event, kernel prints message 'VPHN function not supported. Disabling polling...'. Currently it prints on every hotplug event, it floods dmesg when a KVM guest tries to hotplug huge number of vcpus, let's just print once and suppress further kernel prints. Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-21powerpc/mm: Don't report hugepage tables as memory leaks when using kmemleakChristophe Leroy
[ Upstream commit 803d690e68f0c5230183f1a42c7d50a41d16e380 ] When a process allocates a hugepage, the following leak is reported by kmemleak. This is a false positive which is due to the pointer to the table being stored in the PGD as physical memory address and not virtual memory pointer. unreferenced object 0xc30f8200 (size 512): comm "mmap", pid 374, jiffies 4872494 (age 627.630s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<e32b68da>] huge_pte_alloc+0xdc/0x1f8 [<9e0df1e1>] hugetlb_fault+0x560/0x8f8 [<7938ec6c>] follow_hugetlb_page+0x14c/0x44c [<afbdb405>] __get_user_pages+0x1c4/0x3dc [<b8fd7cd9>] __mm_populate+0xac/0x140 [<3215421e>] vm_mmap_pgoff+0xb4/0xb8 [<c148db69>] ksys_mmap_pgoff+0xcc/0x1fc [<4fcd760f>] ret_from_syscall+0x0/0x38 See commit a984506c542e2 ("powerpc/mm: Don't report PUDs as memory leaks when using kmemleak") for detailed explanation. To fix that, this patch tells kmemleak to ignore the allocated hugepage table. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/nohash: fix undefined behaviour when testing page size supportDaniel Axtens
[ Upstream commit f5e284803a7206d43e26f9ffcae5de9626d95e37 ] When enumerating page size definitions to check hardware support, we construct a constant which is (1U << (def->shift - 10)). However, the array of page size definitions is only initalised for various MMU_PAGE_* constants, so it contains a number of 0-initialised elements with def->shift == 0. This means we end up shifting by a very large number, which gives the following UBSan splat: ================================================================================ UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21 shift exponent 4294967286 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6 Call Trace: [c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable) [c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64 [c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4 [c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0 [c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130 [c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80 ================================================================================ Fix this by first checking if the element exists (shift != 0) before constructing the constant. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/mm: Fix page table dump to work on RadixMichael Ellerman
[ Upstream commit 0d923962ab69c27cca664a2d535e90ef655110ca ] When we're running on Book3S with the Radix MMU enabled the page table dump currently prints the wrong addresses because it uses the wrong start address. Fix it to use PAGE_OFFSET rather than KERN_VIRT_START. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13powerpc: Avoid code patching freed init sectionsMichael Neuling
commit 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 upstream. This stops us from doing code patching in init sections after they've been freed. In this chain: kvm_guest_init() -> kvm_use_magic_page() -> fault_in_pages_readable() -> __get_user() -> __get_user_nocheck() -> barrier_nospec(); We have a code patching location at barrier_nospec() and kvm_guest_init() is an init function. This whole chain gets inlined, so when we free the init section (hence kvm_guest_init()), this code goes away and hence should no longer be patched. We seen this as userspace memory corruption when using a memory checker while doing partition migration testing on powervm (this starts the code patching post migration via /sys/kernel/mobility/migration). In theory, it could also happen when using /sys/kernel/debug/powerpc/barrier_nospec. Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-09KVM: PPC: Book3S: Fix guest DMA when guest partially backed by THP pagesPaul Mackerras
commit 8cfbdbdc24815417a3ab35101ccf706b9a23ff17 upstream. Commit 76fa4975f3ed ("KVM: PPC: Check if IOMMU page is contained in the pinned physical page", 2018-07-17) added some checks to ensure that guest DMA mappings don't attempt to map more than the guest is entitled to access. However, errors in the logic mean that legitimate guest requests to map pages for DMA are being denied in some situations. Specifically, if the first page of the range passed to mm_iommu_get() is mapped with a normal page, and subsequent pages are mapped with transparent huge pages, we end up with mem->pageshift == 0. That means that the page size checks in mm_iommu_ua_to_hpa() and mm_iommu_up_to_hpa_rm() will always fail for every page in that region, and thus the guest can never map any memory in that region for DMA, typically leading to a flood of error messages like this: qemu-system-ppc64: VFIO_MAP_DMA: -22 qemu-system-ppc64: vfio_dma_map(0x10005f47780, 0x800000000000000, 0x10000, 0x7fff63ff0000) = -22 (Invalid argument) The logic errors in mm_iommu_get() are: (a) use of 'ua' not 'ua + (i << PAGE_SHIFT)' in the find_linux_pte() call (meaning that find_linux_pte() returns the pte for the first address in the range, not the address we are currently up to); (b) use of 'pageshift' as the variable to receive the hugepage shift returned by find_linux_pte() - for a normal page this gets set to 0, leading to us setting mem->pageshift to 0 when we conclude that the pte returned by find_linux_pte() didn't match the page we were looking at; (c) comparing 'compshift', which is a page order, i.e. log base 2 of the number of pages, with 'pageshift', which is a log base 2 of the number of bytes. To fix these problems, this patch introduces 'cur_ua' to hold the current user address and uses that in the find_linux_pte() call; introduces 'pteshift' to hold the hugepage shift found by find_linux_pte(); and compares 'pteshift' with 'compshift + PAGE_SHIFT' rather than 'compshift'. The patch also moves the local_irq_restore to the point after the PTE pointer returned by find_linux_pte() has been dereferenced because otherwise the PTE could change underneath us, and adds a check to avoid doing the find_linux_pte() call once mem->pageshift has been reduced to PAGE_SHIFT, as an optimization. Fixes: 76fa4975f3ed ("KVM: PPC: Check if IOMMU page is contained in the pinned physical page") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03powerpc/64s: Fix compiler store ordering to SLB shadow areaNicholas Piggin
[ Upstream commit 926bc2f100c24d4842b3064b5af44ae964c1d81c ] The stores to update the SLB shadow area must be made as they appear in the C code, so that the hypervisor does not see an entry with mismatched vsid and esid. Use WRITE_ONCE for this. GCC has been observed to elide the first store to esid in the update, which means that if the hypervisor interrupts the guest after storing to vsid, it could see an entry with old esid and new vsid, which may possibly result in memory corruption. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-28KVM: PPC: Check if IOMMU page is contained in the pinned physical pageAlexey Kardashevskiy
commit 76fa4975f3ed12d15762bc979ca44078598ed8ee upstream. A VM which has: - a DMA capable device passed through to it (eg. network card); - running a malicious kernel that ignores H_PUT_TCE failure; - capability of using IOMMU pages bigger that physical pages can create an IOMMU mapping that exposes (for example) 16MB of the host physical memory to the device when only 64K was allocated to the VM. The remaining 16MB - 64K will be some other content of host memory, possibly including pages of the VM, but also pages of host kernel memory, host programs or other VMs. The attacking VM does not control the location of the page it can map, and is only allowed to map as many pages as it has pages of RAM. We already have a check in drivers/vfio/vfio_iommu_spapr_tce.c that an IOMMU page is contained in the physical page so the PCI hardware won't get access to unassigned host memory; however this check is missing in the KVM fastpath (H_PUT_TCE accelerated code). We were lucky so far and did not hit this yet as the very first time when the mapping happens we do not have tbl::it_userspace allocated yet and fall back to the userspace which in turn calls VFIO IOMMU driver, this fails and the guest does not retry, This stores the smallest preregistered page size in the preregistered region descriptor and changes the mm_iommu_xxx API to check this against the IOMMU page size. This calculates maximum page size as a minimum of the natural region alignment and compound page size. For the page shift this uses the shift returned by find_linux_pte() which indicates how the page is mapped to the current userspace - if the page is huge and this is not a zero, then it is a leaf pte and the page is mapped within the range. Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05powerpc/mm/slice: Fix hugepage allocation at hint address on 8xxChristophe Leroy
commit aa0ab02ba992eb956934b21373e0138211486ddd upstream. On the 8xx, the page size is set in the PMD entry and applies to all pages of the page table pointed by the said PMD entry. When an app has some regular pages allocated (e.g. see below) and tries to mmap() a huge page at a hint address covered by the same PMD entry, the kernel accepts the hint allthough the 8xx cannot handle different page sizes in the same PMD entry. 10000000-10001000 r-xp 00000000 00:0f 2597 /root/malloc 10010000-10011000 rwxp 00000000 00:0f 2597 /root/malloc mmap(0x10080000, 524288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0) = 0x10080000 This results the app remaining forever in do_page_fault()/hugetlb_fault() and when interrupting that app, we get the following warning: [162980.035629] WARNING: CPU: 0 PID: 2777 at arch/powerpc/mm/hugetlbpage.c:354 hugetlb_free_pgd_range+0xc8/0x1e4 [162980.035699] CPU: 0 PID: 2777 Comm: malloc Tainted: G W 4.14.6 #85 [162980.035744] task: c67e2c00 task.stack: c668e000 [162980.035783] NIP: c000fe18 LR: c00e1eec CTR: c00f90c0 [162980.035830] REGS: c668fc20 TRAP: 0700 Tainted: G W (4.14.6) [162980.035854] MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24044224 XER: 20000000 [162980.036003] [162980.036003] GPR00: c00e1eec c668fcd0 c67e2c00 00000010 c6869410 10080000 00000000 77fb4000 [162980.036003] GPR08: ffff0001 0683c001 00000000 ffffff80 44028228 10018a34 00004008 418004fc [162980.036003] GPR16: c668e000 00040100 c668e000 c06c0000 c668fe78 c668e000 c6835ba0 c668fd48 [162980.036003] GPR24: 00000000 73ffffff 74000000 00000001 77fb4000 100fffff 10100000 10100000 [162980.036743] NIP [c000fe18] hugetlb_free_pgd_range+0xc8/0x1e4 [162980.036839] LR [c00e1eec] free_pgtables+0x12c/0x150 [162980.036861] Call Trace: [162980.036939] [c668fcd0] [c00f0774] unlink_anon_vmas+0x1c4/0x214 (unreliable) [162980.037040] [c668fd10] [c00e1eec] free_pgtables+0x12c/0x150 [162980.037118] [c668fd40] [c00eabac] exit_mmap+0xe8/0x1b4 [162980.037210] [c668fda0] [c0019710] mmput.part.9+0x20/0xd8 [162980.037301] [c668fdb0] [c001ecb0] do_exit+0x1f0/0x93c [162980.037386] [c668fe00] [c001f478] do_group_exit+0x40/0xcc [162980.037479] [c668fe10] [c002a76c] get_signal+0x47c/0x614 [162980.037570] [c668fe70] [c0007840] do_signal+0x54/0x244 [162980.037654] [c668ff30] [c0007ae8] do_notify_resume+0x34/0x88 [162980.037744] [c668ff40] [c000dae8] do_user_signal+0x74/0xc4 [162980.037781] Instruction dump: [162980.037821] 7fdff378 81370000 54a3463a 80890020 7d24182e 7c841a14 712a0004 4082ff94 [162980.038014] 2f890000 419e0010 712a0ff0 408200e0 <0fe00000> 54a9000a 7f984840 419d0094 [162980.038216] ---[ end trace c0ceeca8e7a5800a ]--- [162980.038754] BUG: non-zero nr_ptes on freeing mm: 1 [162985.363322] BUG: non-zero nr_ptes on freeing mm: -1 In order to fix this, this patch uses the address space "slices" implemented for BOOK3S/64 and enhanced to support PPC32 by the preceding patch. This patch modifies the context.id on the 8xx to be in the range [1:16] instead of [0:15] in order to identify context.id == 0 as not initialised contexts as done on BOOK3S This patch activates CONFIG_PPC_MM_SLICES when CONFIG_HUGETLB_PAGE is selected for the 8xx Alltough we could in theory have as many slices as PMD entries, the current slices implementation limits the number of low slices to 16. This limitation is not preventing us to fix the initial issue allthough it is suboptimal. It will be cured in a subsequent patch. Fixes: 4b91428699477 ("powerpc/8xx: Implement support of hugepages") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05powerpc/mm/slice: Enhance for supporting PPC32Christophe Leroy
commit db3a528db41caaa6dfd4c64e9f5efb1c81a80467 upstream. In preparation for the following patch which will fix an issue on the 8xx by re-using the 'slices', this patch enhances the 'slices' implementation to support 32 bits CPUs. On PPC32, the address space is limited to 4Gbytes, hence only the low slices will be used. The high slices use bitmaps. As bitmap functions are not prepared to handle bitmaps of size 0, this patch ensures that bitmap functions are called only when SLICE_NUM_HIGH is not nul. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05powerpc/mm/slice: Remove intermediate bitmap copyChristophe Leroy
commit 326691ad4f179e6edc7eb1271e618dd673e4736d upstream. bitmap_or() and bitmap_andnot() can work properly with dst identical to src1 or src2. There is no need of an intermediate result bitmap that is copied back to dst in a second step. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-01powerpc/mm: Flush cache on memory hot(un)plugBalbir Singh
commit fb5924fddf9ee31db04da7ad4e8c3434a387101b upstream. This patch adds support for flushing potentially dirty cache lines when memory is hot-plugged/hot-un-plugged. The support is currently limited to 64 bit systems. The bug was exposed when mappings for a device were actually hot-unplugged and plugged in back later. A similar issue was observed during the development of memtrace, but memtrace does it's own flushing of region via a custom routine. These patches do a flush both on hotplug/unplug to clear any stale data in the cache w.r.t mappings, there is a small race window where a clean cache line may be created again just prior to tearing down the mapping. The patches were tested by disabling the flush routines in memtrace and doing I/O on the trace file. The system immediately checkstops (quite reliablly if prior to the hot-unplug of the memtrace region, we memset the regions we are about to hot unplug). After these patches no custom flushing is needed in the memtrace code. Fixes: 9d5171a8f248 ("powerpc/powernv: Enable removal of memory for in memory tracing") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Reza Arbab <arbab@linux.ibm.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-26powerpc/numa: Ensure nodes initialized for hotplugMichael Bringmann
[ Upstream commit ea05ba7c559c8e5a5946c3a94a2a266e9a6680a6 ] This patch fixes some problems encountered at runtime with configurations that support memory-less nodes, or that hot-add CPUs into nodes that are memoryless during system execution after boot. The problems of interest include: * Nodes known to powerpc to be memoryless at boot, but to have CPUs in them are allowed to be 'possible' and 'online'. Memory allocations for those nodes are taken from another node that does have memory until and if memory is hot-added to the node. * Nodes which have no resources assigned at boot, but which may still be referenced subsequently by affinity or associativity attributes, are kept in the list of 'possible' nodes for powerpc. Hot-add of memory or CPUs to the system can reference these nodes and bring them online instead of redirecting the references to one of the set of nodes known to have memory at boot. Note that this software operates under the context of CPU hotplug. We are not doing memory hotplug in this code, but rather updating the kernel's CPU topology (i.e. arch_update_cpu_topology / numa_update_cpu_topology). We are initializing a node that may be used by CPUs or memory before it can be referenced as invalid by a CPU hotplug operation. CPU hotplug operations are protected by a range of APIs including cpu_maps_update_begin/cpu_maps_update_done, cpus_read/write_lock / cpus_read/write_unlock, device locks, and more. Memory hotplug operations, including try_online_node, are protected by mem_hotplug_begin/mem_hotplug_done, device locks, and more. In the case of CPUs being hot-added to a previously memoryless node, the try_online_node operation occurs wholly within the CPU locks with no overlap. Using HMC hot-add/hot-remove operations, we have been able to add and remove CPUs to any possible node without failures. HMC operations involve a degree self-serialization, though. Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-26powerpc/numa: Use ibm,max-associativity-domains to discover possible nodesMichael Bringmann
[ Upstream commit a346137e9142b039fd13af2e59696e3d40c487ef ] On powerpc systems which allow 'hot-add' of CPU or memory resources, it may occur that the new resources are to be inserted into nodes that were not used for these resources at bootup. In the kernel, any node that is used must be defined and initialized. These empty nodes may occur when, * Dedicated vs. shared resources. Shared resources require information such as the VPHN hcall for CPU assignment to nodes. Associativity decisions made based on dedicated resource rules, such as associativity properties in the device tree, may vary from decisions made using the values returned by the VPHN hcall. * memoryless nodes at boot. Nodes need to be defined as 'possible' at boot for operation with other code modules. Previously, the powerpc code would limit the set of possible nodes to those which have memory assigned at boot, and were thus online. Subsequent add/remove of CPUs or memory would only work with this subset of possible nodes. * memoryless nodes with CPUs at boot. Due to the previous restriction on nodes, nodes that had CPUs but no memory were being collapsed into other nodes that did have memory at boot. In practice this meant that the node assignment presented by the runtime kernel differed from the affinity and associativity attributes presented by the device tree or VPHN hcalls. Nodes that might be known to the pHyp were not 'possible' in the runtime kernel because they did not have memory at boot. This patch ensures that sufficient nodes are defined to support configuration requirements after boot, as well as at boot. This patch set fixes a couple of problems. * Nodes known to powerpc to be memoryless at boot, but to have CPUs in them are allowed to be 'possible' and 'online'. Memory allocations for those nodes are taken from another node that does have memory until and if memory is hot-added to the node. * Nodes which have no resources assigned at boot, but which may still be referenced subsequently by affinity or associativity attributes, are kept in the list of 'possible' nodes for powerpc. Hot-add of memory or CPUs to the system can reference these nodes and bring them online instead of redirecting to one of the set of nodes that were known to have memory at boot. This patch extracts the value of the lowest domain level (number of allocable resources) from the device tree property "ibm,max-associativity-domains" to use as the maximum number of nodes to setup as possibly available in the system. This new setting will override the instruction: nodes_and(node_possible_map, node_possible_map, node_online_map); presently seen in the function arch/powerpc/mm/numa.c:initmem_init(). If the "ibm,max-associativity-domains" property is not present at boot, no operation will be performed to define or enable additional nodes, or enable the above 'nodes_and()'. Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-24powerpc/64: Call H_REGISTER_PROC_TBL when running as a HPT guest on POWER9Paul Mackerras
commit dbfcf3cb9c681aa0c5d0bb46068f98d5b1823dd3 upstream. On POWER9, since commit cc3d2940133d ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9", 2017-01-30), we set both the radix and HPT bits in the client-architecture-support (CAS) vector, which tells the hypervisor that we can do either radix or HPT. According to PAPR, if we use this combination we are promising to do a H_REGISTER_PROC_TBL hcall later on to let the hypervisor know whether we are doing radix or HPT. We currently do this call if we are doing radix but not if we are doing HPT. If the hypervisor is able to support both radix and HPT guests, it would be entitled to defer allocation of the HPT until the H_REGISTER_PROC_TBL call, and to fail any attempts to create HPTEs until the H_REGISTER_PROC_TBL call. Thus we need to do a H_REGISTER_PROC_TBL call when we are doing HPT; otherwise we may crash at boot time. This adds the code to call H_REGISTER_PROC_TBL in this case, before we attempt to create any HPT entries using H_ENTER. Fixes: cc3d2940133d ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22powerpc/mm/radix: Split linear mapping on hot-unplugBalbir Singh
commit 4dd5f8a99e791a8c6500e3592f3ce81ae7edcde1 upstream. This patch splits the linear mapping if the hot-unplug range is smaller than the mapping size. The code detects if the mapping needs to be split into a smaller size and if so, uses the stop machine infrastructure to clear the existing mapping and then remap the remaining range using a smaller page size. The code will skip any region of the mapping that overlaps with kernel text and warn about it once. We don't want to remove a mapping where the kernel text and the LMB we intend to remove overlap in the same TLB mapping as it may affect the currently executing code. I've tested these changes under a kvm guest with 2 vcpus, from a split mapping point of view, some of the caveats mentioned above applied to the testing I did. Fixes: 4b5d62ca17a1 ("powerpc/mm: add radix__remove_section_mapping()") Signed-off-by: Balbir Singh <bsingharora@gmail.com> [mpe: Tweak change log to match updated behaviour] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22powerpc/mm: Flush radix process translations when setting MMU typeAlexey Kardashevskiy
commit 62e984ddfd6b056d399e24113f5e6a7145e579d8 upstream. Radix guests do normally invalidate process-scoped translations when a new pid is allocated but migrated guests do not invalidate these so migrated guests crash sometime, especially easy to reproduce with migration happening within first 10 seconds after the guest boot start on the same machine. This adds the "Invalidate process-scoped translations" flush to fix radix guests migration. Fixes: 2ee13be34b13 ("KVM: PPC: Book3S HV: Update kvmppc_set_arch_compat() for ISA v3.00") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Tested-by: Laurent Vivier <lvivier@redhat.com> Tested-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22powerpc/numa: Invalidate numa_cpu_lookup_table on cpu removeNathan Fontenot
commit 1d9a090783bef19fe8cdec878620d22f05191316 upstream. When DLPAR removing a CPU, the unmapping of the cpu from a node in unmap_cpu_from_node() should also invalidate the CPUs entry in the numa_cpu_lookup_table. There is not a guarantee that on a subsequent DLPAR add of the CPU the associativity will be the same and thus could be in a different node. Invalidating the entry in the numa_cpu_lookup_table causes the associativity to be read from the device tree at the time of the add. The current behavior of not invalidating the CPUs entry in the numa_cpu_lookup_table can result in scenarios where the the topology layout of CPUs in the partition does not match the device tree or the topology reported by the HMC. This bug looks like it was introduced in 2004 in the commit titled "ppc64: cpu hotplug notifier for numa", which is 6b15e4e87e32 in the linux-fullhist tree. Hence tag it for all stable releases. Cc: stable@vger.kernel.org Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22powerpc/radix: Remove trace_tlbie call from radix__flush_tlb_allMahesh Salgaonkar
commit 8d81296cfcce89013a714feb8d25004a156f8181 upstream. radix__flush_tlb_all() is called only in kexec path in real mode and any tracepoints at this stage will make kexec to fail if enabled. To verify enable tlbie trace before kexec. $ echo 1 > /sys/kernel/debug/tracing/events/powerpc/tlbie/enable == kexec into new kernel and kexec fails. Fix this by not calling trace_tlbie from radix__flush_tlb_all(). Fixes: 0428491cba92 ("powerpc/mm: Trace tlbie(l) instructions") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-10powerpc/mm: Fix SEGV on mapped region to return SEGV_ACCERRJohn Sperbeck
commit ecb101aed86156ec7cd71e5dca668e09146e6994 upstream. The recent refactoring of the powerpc page fault handler in commit c3350602e876 ("powerpc/mm: Make bad_area* helper functions") caused access to protected memory regions to indicate SEGV_MAPERR instead of the traditional SEGV_ACCERR in the si_code field of a user-space signal handler. This can confuse debug libraries that temporarily change the protection of memory regions, and expect to use SEGV_ACCERR as an indication to restore access to a region. This commit restores the previous behavior. The following program exhibits the issue: $ ./repro read || echo "FAILED" $ ./repro write || echo "FAILED" $ ./repro exec || echo "FAILED" #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <signal.h> #include <sys/mman.h> #include <assert.h> static void segv_handler(int n, siginfo_t *info, void *arg) { _exit(info->si_code == SEGV_ACCERR ? 0 : 1); } int main(int argc, char **argv) { void *p = NULL; struct sigaction act = { .sa_sigaction = segv_handler, .sa_flags = SA_SIGINFO, }; assert(argc == 2); p = mmap(NULL, getpagesize(), (strcmp(argv[1], "write") == 0) ? PROT_READ : 0, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); assert(p != MAP_FAILED); assert(sigaction(SIGSEGV, &act, NULL) == 0); if (strcmp(argv[1], "read") == 0) printf("%c", *(unsigned char *)p); else if (strcmp(argv[1], "write") == 0) *(unsigned char *)p = 0; else if (strcmp(argv[1], "exec") == 0) ((void (*)(void))p)(); return 1; /* failed to generate SEGV */ } Fixes: c3350602e876 ("powerpc/mm: Make bad_area* helper functions") Signed-off-by: John Sperbeck <jsperbeck@google.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Add commit references in change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-05powerpc/powernv: Fix kexec crashes caused by tlbie tracingMahesh Salgaonkar
commit a3961f824cdbe7eb431254dc7d8f6f6767f474aa upstream. Rebooting into a new kernel with kexec fails in trace_tlbie() which is called from native_hpte_clear(). This happens if the running kernel has CONFIG_LOCKDEP enabled. With lockdep enabled, the tracepoints always execute few RCU checks regardless of whether tracing is on or off. We are already in the last phase of kexec sequence in real mode with HILE_BE set. At this point the RCU check ends up in RCU_LOCKDEP_WARN and causes kexec to fail. Fix this by not calling trace_tlbie() from native_hpte_clear(). mpe: It's not safe to call trace points at this point in the kexec path, even if we could avoid the RCU checks/warnings. The only solution is to not call them. Fixes: 0428491cba92 ("powerpc/mm: Trace tlbie(l) instructions") Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundaryNicholas Piggin
commit 35602f82d0c765f991420e319c8d3a596c921eb8 upstream. While mapping hints with a length that cross 128TB are disallowed, MAP_FIXED allocations that cross 128TB are allowed. These are failing on hash (on radix they succeed). Add an additional case for fixed mappings to expand the addr_limit when crossing 128TB. Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30powerpc/64s/hash: Fix fork() with 512TB process address spaceNicholas Piggin
commit effc1b25088502fbd30305c79773de2d1f7470a6 upstream. Hash unconditionally resets the addr_limit to default (128TB) when the mm context is initialised. If a process has > 128TB mappings when it forks, the child will not get the 512TB addr_limit, so accesses to valid > 128TB mappings will fail in the child. Fix this by only resetting the addr_limit to default if it was 0. Non zero indicates it was duplicated from the parent (0 means exec()). Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30powerpc/64s/hash: Fix 128TB-512TB virtual address boundary case allocationNicholas Piggin
commit 6a72dc038b615229a1b285829d6c8378d15c2347 upstream. When allocating VA space with a hint that crosses 128TB, the SLB addr_limit variable is not expanded if addr is not > 128TB, but the slice allocation looks at task_size, which is 512TB. This results in slice_check_fit() incorrectly succeeding because the slice_count truncates off bit 128 of the requested mask, so the comparison to the available mask succeeds. Fix this by using mm->context.addr_limit instead of mm->task_size for testing allocation limits. This causes such allocations to fail. Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Reported-by: Florian Weimer <fweimer@redhat.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30powerpc/64s/hash: Fix 512T hint detection to use >= 128TMichael Ellerman
commit 7ece370996b694ae263025e056ad785afc1be5ab upstream. Currently userspace is able to request mmap() search between 128T-512T by specifying a hint address that is greater than 128T. But that means a hint of 128T exactly will return an address below 128T, which is confusing and wrong. So fix the logic to check the hint is greater than *or equal* to 128T. Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Suggested-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Split out of Nick's bigger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocationNicholas Piggin
commit 85e3f1adcb9d49300b0a943bb93f9604be375bfb upstream. Radix VA space allocations test addresses against mm->task_size which is 512TB, even in cases where the intention is to limit allocation to below 128TB. This results in mmap with a hint address below 128TB but address + length above 128TB succeeding when it should fail (as hash does after the previous patch). Set the high address limit to be considered up front, and base subsequent allocation checks on that consistently. Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30powerpc/mm/radix: Fix crashes on Power9 DD1 with radix MMU and STRICT_RWXBalbir Singh
commit f79ad50ea3c73fb1ea5b09e95c864e5bb263adfb upstream. When using the radix MMU on Power9 DD1, to work around a hardware problem, radix__pte_update() is required to do a two stage update of the PTE. First we write a zero value into the PTE, then we flush the TLB, and then we write the new PTE value. In the normal case that works OK, but it does not work if we're updating the PTE that maps the code we're executing, because the mapping is removed by the TLB flush and we can no longer execute from it. Unfortunately the STRICT_RWX code needs to do exactly that. The exact symptoms when we hit this case vary, sometimes we print an oops and then get stuck after that, but I've also seen a machine just get stuck continually page faulting with no oops printed. The variance is presumably due to the exact layout of the text and the page size used for the mappings. In all cases we are unable to boot to a shell. There are possible solutions such as creating a second mapping of the TLB flush code, executing from that, and then jumping back to the original. However we don't want to add that level of complexity for a DD1 work around. So just detect that we're running on Power9 DD1 and refrain from changing the permissions, effectively disabling STRICT_RWX on Power9 DD1. Fixes: 7614ff3272a1 ("powerpc/mm/radix: Implement STRICT_RWX/mark_rodata_ro() for Radix") Reported-by: Andrew Jeffery <andrew@aj.id.au> [Changelog as suggested by Michael Ellerman <mpe@ellerman.id.au>] Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-03Merge tag 'powerpc-4.14-6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Some more powerpc fixes for 4.14. This is bigger than I like to send at rc7, but that's at least partly because I didn't send any fixes last week. If it wasn't for the IMC driver, which is new and getting heavy testing, the diffstat would look a bit better. I've also added ftrace on big endian to my test suite, so we shouldn't break that again in future. - A fix to the handling of misaligned paste instructions (P9 only), where a change to a #define has caused the check for the instruction to always fail. - The preempt handling was unbalanced in the radix THP flush (P9 only). Though we don't generally use preempt we want to keep it working as much as possible. - Two fixes for IMC (P9 only), one when booting with restricted number of CPUs and one in the error handling when initialisation fails due to firmware etc. - A revert to fix function_graph on big endian machines, and then a rework of the reverted patch to fix kprobes blacklist handling on big endian machines. Thanks to: Anju T Sudhakar, Guilherme G. Piccoli, Madhavan Srinivasan, Naveen N. Rao, Nicholas Piggin, Paul Mackerras" * tag 'powerpc-4.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/perf: Fix core-imc hotplug callback failure during imc initialization powerpc/kprobes: Dereference function pointers only if the address does not belong to kernel text Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols" powerpc/64s/radix: Fix preempt imbalance in TLB flush powerpc: Fix check for copy/paste instructions in alignment handler powerpc/perf: Fix IMC allocation routine
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-25powerpc/64s/radix: Fix preempt imbalance in TLB flushNicholas Piggin
Fixes: 424de9c6e3f8 ("powerpc/mm/radix: Avoid flushing the PWC on every flush_tlb_range") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-10powerpc: Don't call lockdep_assert_cpus_held() from arch_update_cpu_topology()Thiago Jung Bauermann
It turns out that not all paths calling arch_update_cpu_topology() hold cpu_hotplug_lock, but that's OK because those paths can't race with any concurrent hotplug events. Warnings were reported with the following trace: lockdep_assert_cpus_held arch_update_cpu_topology sched_init_domains sched_init_smp kernel_init_freeable kernel_init ret_from_kernel_thread Which is safe because it's called early in boot when hotplug is not live yet. And also this trace: lockdep_assert_cpus_held arch_update_cpu_topology partition_sched_domains cpuset_update_active_cpus sched_cpu_deactivate cpuhp_invoke_callback cpuhp_down_callbacks cpuhp_thread_fun smpboot_thread_fn kthread ret_from_kernel_thread Which is safe because it's called as part of CPU hotplug, so although we don't hold the CPU hotplug lock, there is another thread driving the CPU hotplug operation which does hold the lock, and there is no race. Thanks to tglx for deciphering it for us. Fixes: 3e401f7a2e51 ("powerpc: Only obtain cpu_hotplug_lock if called by rtasd") Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04powerpc/mm: Call flush_tlb_kernel_range with interrupts enabledGuenter Roeck
flush_tlb_kernel_range() may call smp_call_function_many() which expects interrupts to be enabled. This results in a traceback. WARNING: CPU: 0 PID: 1 at kernel/smp.c:416 smp_call_function_many+0xcc/0x2fc CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc1-00009-g0666f56 #1 task: cf830000 task.stack: cf82e000 NIP: c00a93c8 LR: c00a9634 CTR: 00000001 REGS: cf82fde0 TRAP: 0700 Not tainted (4.14.0-rc1-00009-g0666f56) MSR: 00021000 <CE,ME> CR: 24000082 XER: 00000000 GPR00: c00a9634 cf82fe90 cf830000 c050ad3c c0015a54 00000000 00000001 00000001 GPR08: 00000001 00000000 00000000 cf82e000 24000084 00000000 c0003150 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000001 00000000 c0510000 GPR24: 00000000 c0015a54 00000000 c050ad3c c051823c c050ad3c 00000025 00000000 NIP [c00a93c8] smp_call_function_many+0xcc/0x2fc LR [c00a9634] smp_call_function+0x3c/0x50 Call Trace: [cf82fe90] [00000010] 0x10 (unreliable) [cf82fed0] [c00a9634] smp_call_function+0x3c/0x50 [cf82fee0] [c0015d2c] flush_tlb_kernel_range+0x20/0x38 [cf82fef0] [c001524c] mark_initmem_nx+0x154/0x16c [cf82ff20] [c001484c] free_initmem+0x20/0x4c [cf82ff30] [c000316c] kernel_init+0x1c/0x108 [cf82ff40] [c000f3a8] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7c0803a6 7d808120 38210040 4e800020 3d20c052 812981a0 2f890000 40beffac 3d20c051 8929ac64 2f890000 40beff9c <0fe00000> 4bffff94 7fc3f378 7f64db78 Fixes: 3184cc4b6f6a ("powerpc/mm: Fix kernel RAM protection after freeing ...") Fixes: e611939fc8ec ("powerpc/mm: Ensure change_page_attr() doesn't ...") Cc: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-01powerpc/mm: Use seq_putc() in two functionsMarkus Elfring
Two single characters (line breaks) should be put into a sequence. Thus use the corresponding function "seq_putc". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-01powerpc: fix location of two EXPORT_SYMBOLChristophe Leroy
Commit 9445aa1a3062a ("ppc: move exports to definitions") added EXPORT_SYMBOL() for memset() and flush_hash_pages() in the middle of the functions. This patch moves them at the end of the two functions. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-31powerpc/mm/radix: Prettify mapped memory range print outMichael Ellerman
When we map memory at boot we print out the ranges of real addresses that we mapped and the page size that was used. Currently it's a bit ugly: Mapped range 0x0 - 0x2000000000 with 0x40000000 Mapped range 0x200000000000 - 0x202000000000 with 0x40000000 Pad the addresses so they line up, and print the page size using actual units, eg: Mapped 0x0000000000000000-0x0000000001200000 with 64.0 KiB pages Mapped 0x0000000001200000-0x0000000040000000 with 2.00 MiB pages Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-13 10:25:00 +0000