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2020-01-29mm/memory_hotplug: shrink zones when offlining memoryDavid Hildenbrand
commit feee6b2989165631b17ac6d4ccdbf6759254e85a upstream. -- snip -- - Missing arm64 hot(un)plug support - Missing some vmem_altmap_offset() cleanups - Missing sub-section hotadd support - Missing unification of mm/hmm.c and kernel/memremap.c -- snip -- We currently try to shrink a single zone when removing memory. We use the zone of the first page of the memory we are removing. If that memmap was never initialized (e.g., memory was never onlined), we will read garbage and can trigger kernel BUGs (due to a stale pointer): BUG: unable to handle page fault for address: 000000000000353d #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:clear_zone_contiguous+0x5/0x10 Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840 RSP: 0018:ffffad2400043c98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000 RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40 RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000 R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680 FS: 0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_pages+0x4b/0x640 arch_remove_memory+0x63/0x8d try_remove_memory+0xdb/0x130 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x70/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x227/0x3a0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x221/0x550 worker_thread+0x50/0x3b0 kthread+0x105/0x140 ret_from_fork+0x3a/0x50 Modules linked in: CR2: 000000000000353d Instead, shrink the zones when offlining memory or when onlining failed. Introduce and use remove_pfn_range_from_zone(() for that. We now properly shrink the zones, even if we have DIMMs whereby - Some memory blocks fall into no zone (never onlined) - Some memory blocks fall into multiple zones (offlined+re-onlined) - Multiple memory blocks that fall into different zones Drop the zone parameter (with a potential dubious value) from __remove_pages() and __remove_section(). Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319] Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: <stable@vger.kernel.org> [5.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVEDavid Hildenbrand
commit 80ec922dbd87fd38d15719c86a94457204648aeb upstream. -- snip -- Missing arm64 memory hot(un)plug support. -- snip -- We want to improve error handling while adding memory by allowing to use arch_remove_memory() and __remove_pages() even if CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like: arch_add_memory() rc = do_something(); if (rc) { arch_remove_memory(); } We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require quite some dependencies for memory offlining. Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Mark Brown <broonie@kernel.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Rob Herring <robh@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Qian Cai <cai@lca.pw> Cc: Mathieu Malaterre <malat@debian.org> Cc: Baoquan He <bhe@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never failDavid Hildenbrand
commit ac5c94264580f498e484c854031d0226b3c1038f upstream. -- snip -- Minor conflict in arch/powerpc/mm/mem.c -- snip -- All callers of arch_remove_memory() ignore errors. And we should really try to remove any errors from the memory removal path. No more errors are reported from __remove_pages(). BUG() in s390x code in case arch_remove_memory() is triggered. We may implement that properly later. WARN in case powerpc code failed to remove the section mapping, which is better than ignoring the error completely right now. Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stefan Agner <stefan@agner.ch> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Rob Herring <robh@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Qian Cai <cai@lca.pw> Cc: Mathieu Malaterre <malat@debian.org> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mike Travis <mike.travis@hpe.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29powerpc/mm: Fix section mismatch warningAneesh Kumar K.V
commit 26ad26718dfaa7cf49d106d212ebf2370076c253 upstream. This patch fix the below section mismatch warnings. WARNING: vmlinux.o(.text+0x2d1f44): Section mismatch in reference from the function devm_memremap_pages_release() to the function .meminit.text:arch_remove_memory() WARNING: vmlinux.o(.text+0x2d265c): Section mismatch in reference from the function devm_memremap_pages() to the function .meminit.text:arch_add_memory() Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29mm, memory_hotplug: add nid parameter to arch_remove_memoryOscar Salvador
commit 2c2a5af6fed20cf74401c9d64319c76c5ff81309 upstream. -- snip -- Missing unification of mm/hmm.c and kernel/memremap.c -- snip -- Patch series "Do not touch pages in hot-remove path", v2. This patchset aims for two things: 1) A better definition about offline and hot-remove stage 2) Solving bugs where we can access non-initialized pages during hot-remove operations [2] [3]. This is achieved by moving all page/zone handling to the offline stage, so we do not need to access pages when hot-removing memory. [1] https://patchwork.kernel.org/cover/10691415/ [2] https://patchwork.kernel.org/patch/10547445/ [3] https://www.spinics.net/lists/linux-mm/msg161316.html This patch (of 5): This is a preparation for the following-up patches. The idea of passing the nid is that it will allow us to get rid of the zone parameter afterwards. Link: http://lkml.kernel.org/r/20181127162005.15833-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-27powerpc/64s/radix: Fix memory hot-unplug page table splitNicholas Piggin
[ Upstream commit 31f210cf42d4b308eacef89b6cb0b1459338b8de ] create_physical_mapping expects physical addresses, but splitting these mapping on hot unplug is supplying virtual (effective) addresses. Fixes: 4dd5f8a99e791 ("powerpc/mm/radix: Split linear mapping on hot-unplug") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-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/20190724084638.24982-2-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27powerpc/mm: Check secondary hash page tableRashmica Gupta
[ Upstream commit 790845e2f12709d273d08ea7a2af7c2593689519 ] We were always calling base_hpte_find() with primary = true, even when we wanted to check the secondary table. mpe: I broke this when refactoring Rashmica's original patch. Fixes: 1515ab932156 ("powerpc/mm: Dump hash table") Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12powerpc: Ensure that swiotlb buffer is allocated from low memoryMike Rapoport
[ Upstream commit 8fabc623238e68b3ac63c0dd1657bf86c1fa33af ] Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a system has more physical memory than this limit, the swiotlb buffer is not addressable because it is allocated from memblock using top-down mode. Force memblock to bottom-up mode before calling swiotlb_init() to ensure that the swiotlb buffer is DMA-able. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warningAneesh Kumar K.V
[ Upstream commit 16f6b67cf03cb43db7104acb2ca877bdc2606c92 ] With large memory (8TB and more) hotplug, we can get soft lockup warnings as below. These were caused by a long loop without any explicit cond_resched which is a problem for !PREEMPT kernels. Avoid this using cond_resched() while inserting hash page table entries. We already do similar cond_resched() in __add_pages(), see commit f64ac5e6e306 ("mm, memory_hotplug: add scheduling point to __add_pages"). rcu: 3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001 (t=24003 jiffies g=4285 q=2002) NMI backtrace for cpu 3 CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ #2 Call Trace: dump_stack+0xb0/0xf4 (unreliable) nmi_cpu_backtrace+0x124/0x130 nmi_trigger_cpumask_backtrace+0x1ac/0x1f0 arch_trigger_cpumask_backtrace+0x28/0x3c rcu_dump_cpu_stacks+0xf8/0x154 rcu_sched_clock_irq+0x878/0xb40 update_process_times+0x48/0x90 tick_sched_handle.isra.16+0x4c/0x80 tick_sched_timer+0x68/0xe0 __hrtimer_run_queues+0x180/0x430 hrtimer_interrupt+0x110/0x300 timer_interrupt+0x108/0x2f0 decrementer_common+0x114/0x120 --- interrupt: 901 at arch_add_memory+0xc0/0x130 LR = arch_add_memory+0x74/0x130 memremap_pages+0x494/0x650 devm_memremap_pages+0x3c/0xa0 pmem_attach_disk+0x188/0x750 nvdimm_bus_probe+0xac/0x2c0 really_probe+0x148/0x570 driver_probe_device+0x19c/0x1d0 device_driver_attach+0xcc/0x100 bind_store+0x134/0x1c0 drv_attr_store+0x44/0x60 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1a0/0x270 __vfs_write+0x3c/0x70 vfs_write+0xd0/0x260 ksys_write+0xdc/0x130 system_call+0x5c/0x68 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/20191001084656.31277-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04powerpc/pseries: Don't fail hash page table insert for bolted mappingAneesh Kumar K.V
[ Upstream commit 75838a3290cd4ebbd1f567f310ba04b6ef017ce4 ] If the hypervisor returned H_PTEG_FULL for H_ENTER hcall, retry a hash page table insert by removing a random entry from the group. After some runtime, it is very well possible to find all the 8 hash page table entry slot in the hpte group used for mapping. Don't fail a bolted entry insert in that case. With Storage class memory a user can find this error easily since a namespace enable/disable is equivalent to memory add/remove. This results in failures as reported below: $ ndctl create-namespace -r region1 -t pmem -m devdax -a 65536 -s 100M libndctl: ndctl_dax_enable: dax1.3: failed to enable Error: namespace1.2: failed to enable failed to create namespace: No such device or address In kernel log we find the details as below: Unable to create mapping for hot added memory 0xc000042006000000..0xc00004200d000000: -1 dax_pmem: probe of dax1.3 failed with error -14 This indicates that we failed to create a bolted hash table entry for direct-map address backing the namespace. We also observe failures such that not all namespaces will be enabled with ndctl enable-namespace all command. 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/20191024093542.29777-2-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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>
2019-12-01powerpc/64s/radix: Fix radix__flush_tlb_collapsed_pmd double flushing pmdNicholas Piggin
[ Upstream commit dd76ff5af35350fd6d5bb5b069e73b6017f66893 ] 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>
2019-12-01powerpc/mm/radix: Fix small page at boundary when splittingMichael Ellerman
[ Upstream commit 81d1b54dec95209ab5e5be2cf37182885f998753 ] When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the linear mapping at the text/data boundary so we can map the kernel text read only. Currently we always use a small page at the text/data boundary, even when that's not necessary: Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages This is because the check that the mapping crosses the __init_begin boundary is too strict, it also returns true when we map exactly up to the boundary. So fix it to check that the mapping would actually map past __init_begin, and with that we see: Mapped 0x0000000000000000-0x0000000040000000 with 2.00 MiB pages Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01powerpc/mm/radix: Fix overuse of small pages in splitting logicMichael Ellerman
[ Upstream commit 3b5657ed5b4e27ccf593a41ff3c5aa27dae8df18 ] When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the linear mapping at the text/data boundary so we can map the kernel text read only. But the current logic uses small pages for the entire text section, regardless of whether a larger page size would fit. eg. with the boundary at 16M we could use 2M pages, but instead we use 64K pages up to the 16M boundary: Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages This is because the test is checking if addr is < __init_begin and addr + mapping_size is >= _stext. But that is true for all pages between _stext and __init_begin. Instead what we want to check is if we are crossing the text/data boundary, which is at __init_begin. With that fixed we see: Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages ie. we're correctly using 2MB pages below __init_begin, but we still drop down to 64K pages unnecessarily at the boundary. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01powerpc/mm/radix: Fix off-by-one in split mapping logicMichael Ellerman
[ Upstream commit 5c6499b7041b43807dfaeda28aa87fc0e62558f7 ] When we have CONFIG_STRICT_KERNEL_RWX enabled, we try to split the kernel linear (1:1) mapping so that the kernel text is in a separate page to kernel data, so we can mark the former read-only. We could achieve that just by always using 64K pages for the linear mapping, but we try to be smarter. Instead we use huge pages when possible, and only switch to smaller pages when necessary. However we have an off-by-one bug in that logic, which causes us to calculate the wrong boundary between text and data. For example with the end of the kernel text at 16M we see: radix-mmu: Mapped 0x0000000000000000-0x0000000001200000 with 64.0 KiB pages radix-mmu: Mapped 0x0000000001200000-0x0000000040000000 with 2.00 MiB pages radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages ie. we mapped from 0 to 18M with 64K pages, even though the boundary between text and data is at 16M. With the fix we see we're correctly hitting the 16M boundary: radix-mmu: Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages radix-mmu: Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24powerpc/64s/radix: Explicitly flush ERAT with local LPID invalidationNicholas Piggin
[ Upstream commit 053c5a753e951c5dd1729af2cf4d8107f2e6e09b ] Local radix TLB flush operations that operate on congruence classes have explicit ERAT flushes for POWER9. The process scoped LPID flush did not have a flush, so add it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> 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>
2019-11-20powerpc/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 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 v4.19] Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11powerpc/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. Fixes: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9") Cc: stable@vger.kernel.org # v4.16+ 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 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>
2019-09-16powerpc/mm: Limit rma_size to 1TB when running without HV modeSuraj Jitindar Singh
[ Upstream commit da0ef93310e67ae6902efded60b6724dab27a5d1 ] The virtual real mode addressing (VRMA) mechanism is used when a partition is using HPT (Hash Page Table) translation and performs real mode accesses (MSR[IR|DR] = 0) in non-hypervisor mode. In this mode effective address bits 0:23 are treated as zero (i.e. the access is aliased to 0) and the access is performed using an implicit 1TB SLB entry. The size of the RMA (Real Memory Area) is communicated to the guest as the size of the first memory region in the device tree. And because of the mechanism described above can be expected to not exceed 1TB. In the event that the host erroneously represents the RMA as being larger than 1TB, guest accesses in real mode to memory addresses above 1TB will be aliased down to below 1TB. This means that a memory access performed in real mode may differ to one performed in virtual mode for the same memory address, which would likely have unintended consequences. To avoid this outcome have the guest explicitly limit the size of the RMA to the current maximum, which is 1TB. This means that even if the first memory block is larger than 1TB, only the first 1TB should be accessed in real mode. Fixes: c610d65c0ad0 ("powerpc/pseries: lift RTAS limit for hash") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190710052018.14628-1-sjitindarsingh@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16powerpc/pkeys: Fix handling of pkey state across fork()Ram Pai
[ Upstream commit 2cd4bd192ee94848695c1c052d87913260e10f36 ] Protection key tracking information is not copied over to the mm_struct of the child during fork(). This can cause the child to erroneously allocate keys that were already allocated. Any allocated execute-only key is lost aswell. Add code; called by dup_mmap(), to copy the pkey state from parent to child explicitly. This problem was originally found by Dave Hansen on x86, which turns out to be a problem on powerpc aswell. Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31powerpc/mm: Handle page table allocation failuresAneesh Kumar K.V
[ Upstream commit 2230ebf6e6dd0b7751e2921b40f6cfe34f09bb16 ] This fixes kernel crash that arises due to not handling page table allocation failures while allocating hugetlb page table. Fixes: e2b3d202d1db ("powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format") 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>
2019-06-25powerpc/mm/64s/hash: Reallocate context ids on forkMichael Ellerman
commit ca72d88378b2f2444d3ec145dd442d449d3fefbc upstream. When using the Hash Page Table (HPT) MMU, userspace memory mappings are managed at two levels. Firstly in the Linux page tables, much like other architectures, and secondly in the SLB (Segment Lookaside Buffer) and HPT. It's the SLB and HPT that are actually used by the hardware to do translations. As part of the series adding support for 4PB user virtual address space using the hash MMU, we added support for allocating multiple "context ids" per process, one for each 512TB chunk of address space. These are tracked in an array called extended_id in the mm_context_t of a process that has done a mapping above 512TB. If such a process forks (ie. clone(2) without CLONE_VM set) it's mm is copied, including the mm_context_t, and then init_new_context() is called to reinitialise parts of the mm_context_t as appropriate to separate the address spaces of the two processes. The key step in ensuring the two processes have separate address spaces is to allocate a new context id for the process, this is done at the beginning of hash__init_new_context(). If we didn't allocate a new context id then the two processes would share mappings as far as the SLB and HPT are concerned, even though their Linux page tables would be separate. For mappings above 512TB, which use the extended_id array, we neglected to allocate new context ids on fork, meaning the parent and child use the same ids and therefore share those mappings even though they're supposed to be separate. This can lead to the parent seeing writes done by the child, which is essentially memory corruption. There is an additional exposure which is that if the child process exits, all its context ids are freed, including the context ids that are still in use by the parent for mappings above 512TB. One or more of those ids can then be reallocated to a third process, that process can then read/write to the parent's mappings above 512TB. Additionally if the freed id is used for the third process's primary context id, then the parent is able to read/write to the third process's mappings *below* 512TB. All of these are fundamental failures to enforce separation between processes. The only mitigating factor is that the bug only occurs if a process creates mappings above 512TB, and most applications still do not create such mappings. Only machines using the hash page table MMU are affected, eg. PowerPC 970 (G5), PA6T, Power5/6/7/8/9. By default Power9 bare metal machines (powernv) use the Radix MMU and are not affected, unless the machine has been explicitly booted in HPT mode (using disable_radix on the kernel command line). KVM guests on Power9 may be affected if the host or guest is configured to use the HPT MMU. LPARs under PowerVM on Power9 are affected as they always use the HPT MMU. Kernels built with PAGE_SIZE=4K are not affected. The fix is relatively simple, we need to reallocate context ids for all extended mappings on fork. Fixes: f384796c40dc ("powerpc/mm: Add support for handling > 512TB address in SLB miss") Cc: stable@vger.kernel.org # v4.17+ 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>
2019-02-15powerpc/radix: Fix kernel crash with mremap()Aneesh Kumar K.V
commit 579b9239c1f38665b21e8d0e6ee83ecc96dbd6bb upstream. With support for split pmd lock, we use pmd page pmd_huge_pte pointer to store the deposited page table. In those config when we move page tables we need to make sure we move the deposited page table to the correct pmd page. Otherwise this can result in crash when we withdraw of deposited page table because we can find the pmd_huge_pte NULL. eg: __split_huge_pmd+0x1070/0x1940 __split_huge_pmd+0xe34/0x1940 (unreliable) vma_adjust_trans_huge+0x110/0x1c0 __vma_adjust+0x2b4/0x9b0 __split_vma+0x1b8/0x280 __do_munmap+0x13c/0x550 sys_mremap+0x220/0x7e0 system_call+0x5c/0x70 Fixes: 675d995297d4 ("powerpc/book3s64: Enable split pmd ptlock.") Cc: stable@vger.kernel.org # v4.18+ 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>
2019-02-12powerpc/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: Fallback to RAM if the altmap is unusableOliver O'Halloran
[ Upstream commit 9ef34630a4614ee1cd478f9859ebea55d55f10ec ] The "altmap" is used to provide a pool of memory that is reserved for the vmemmap backing of hot-plugged memory. This is useful when adding large amount of ZONE_DEVICE memory to a system with a limited amount of normal memory. On ppc64 we use huge pages to map the vmemmap which requires the backing storage to be contigious and aligned to the hugepage size. The altmap implementation allows for the altmap provider to reserve a few PFNs at the start of the range for it's own uses and when this occurs the first chunk of the altmap is not usable for hugepage mappings. On hash there is no sane way to fall back to a normal sized page mapping so we fail the allocation. This results in memory hotplug failing with ENOMEM when the new range doesn't fall into an existing vmemmap block. This patch handles this case by falling back to using system memory rather than failing if we cannot allocate from the altmap. This fallback should only ever be used for the first vmemmap block so it should not cause excess memory consumption. Fixes: 7b73d978a5d0 ("mm: pass the vmem_altmap to vmemmap_populate") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> 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>
2018-11-21Revert "powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP"Christophe Leroy
commit cc4ebf5c0a3440ed0a32d25c55ebdb6ce5f3c0bc upstream. This reverts commit 4f94b2c7462d9720b2afa7e8e8d4c19446bb31ce. That commit was buggy, as it used rlwinm instead of rlwimi. Instead of fixing that bug, we revert the previous commit in order to reduce the dependency between L1 entries and L2 entries Fixes: 4f94b2c7462d9 ("powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP") Cc: stable@vger.kernel.org Signed-off-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>
2018-11-21powerpc/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 always true/false warning in slice.cChristophe Leroy
[ Upstream commit 37e9c674e7e6f445e12cb1151017bd4bacdd1e2d ] This patch fixes the following warnings (obtained with make W=1). arch/powerpc/mm/slice.c: In function 'slice_range_to_mask': arch/powerpc/mm/slice.c:73:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:81:20: error: comparison is always false due to limited range of data type [-Werror=type-limits] if ((start + len) > SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'slice_mask_for_free': arch/powerpc/mm/slice.c:136:17: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (high_limit <= SLICE_LOW_TOP) ^ arch/powerpc/mm/slice.c: In function 'slice_check_range_fits': arch/powerpc/mm/slice.c:185:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:195:39: error: comparison is always false due to limited range of data type [-Werror=type-limits] if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) { ^ arch/powerpc/mm/slice.c: In function 'slice_scan_available': arch/powerpc/mm/slice.c:306:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'get_slice_psize': arch/powerpc/mm/slice.c:709:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ 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/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>
2018-11-13powerpc/64s/hash: Do not use PPC_INVALIDATE_ERAT on CPUs before POWER9Nicholas Piggin
commit bc276ecba132caccb1fda5863a652c15def2b8c6 upstream. PPC_INVALIDATE_ERAT is slbia IH=7 which is a new variant introduced with POWER9, and the result is undefined on earlier CPUs. Commits 7b9f71f974 ("powerpc/64s: POWER9 machine check handler") and d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9") caused POWER7/8 code to use this instruction. Remove it. An ERAT flush can be made by invalidatig the SLB, but before POWER9 that requires a flush and rebolt. Fixes: 7b9f71f974 ("powerpc/64s: POWER9 machine check handler") Fixes: d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-07Merge tag 'powerpc-4.19-4' of ↵Greg Kroah-Hartman
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Michael writes: "powerpc fixes for 4.19 #4 Four regression fixes. A fix for a change to lib/xz which broke our zImage loader when building with XZ compression. OK'ed by Herbert who merged the original patch. The recent fix we did to avoid patching __init text broke some 32-bit machines, fix that. Our show_user_instructions() could be tricked into printing kernel memory, add a check to avoid that. And a fix for a change to our NUMA initialisation logic, which causes crashes in some kdump configurations. Thanks to: Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis Roos, Murilo Opsfelder Araujo, Srikar Dronamraju." * tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/numa: Skip onlining a offline node in kdump path powerpc: Don't print kernel instructions in show_user_instructions() powerpc/lib: fix book3s/32 boot failure due to code patching lib/xz: Put CRC32_POLY_LE in xz_private.h
2018-10-05powerpc/numa: Skip onlining a offline node in kdump pathSrikar Dronamraju
With commit 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot"), kdump kernel on shared LPAR may crash. The necessary conditions are - Shared LPAR with at least 2 nodes having memory and CPUs. - Memory requirement for kdump kernel must be met by the first N-1 nodes where there are at least N nodes with memory and CPUs. Example numactl of such a machine. $ numactl -H available: 5 nodes (0,2,5-7) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 2 cpus: node 2 size: 255 MB node 2 free: 189 MB node 5 cpus: 24 25 26 27 28 29 30 31 node 5 size: 4095 MB node 5 free: 4024 MB node 6 cpus: 0 1 2 3 4 5 6 7 16 17 18 19 20 21 22 23 node 6 size: 6353 MB node 6 free: 5998 MB node 7 cpus: 8 9 10 11 12 13 14 15 32 33 34 35 36 37 38 39 node 7 size: 7640 MB node 7 free: 7164 MB node distances: node 0 2 5 6 7 0: 10 40 40 40 40 2: 40 10 40 40 40 5: 40 40 10 40 40 6: 40 40 40 10 20 7: 40 40 40 20 10 Steps to reproduce. 1. Load / start kdump service. 2. Trigger a kdump (for example : echo c > /proc/sysrq-trigger) When booting a kdump kernel with 2048M: kexec: Starting switchover sequence. I'm in purgatory Using 1TB segments hash-mmu: Initializing hash mmu with SLB Linux version 4.19.0-rc5-master+ (srikar@linux-xxu6) (gcc version 4.8.5 (SUSE Linux)) #1 SMP Thu Sep 27 19:45:00 IST 2018 Found initrd at 0xc000000009e70000:0xc00000000ae554b4 Using pSeries machine description ----------------------------------------------------- ppc64_pft_size = 0x1e phys_mem_size = 0x88000000 dcache_bsize = 0x80 icache_bsize = 0x80 cpu_features = 0x000000ff8f5d91a7 possible = 0x0000fbffcf5fb1a7 always = 0x0000006f8b5c91a1 cpu_user_features = 0xdc0065c2 0xef000000 mmu_features = 0x7c006001 firmware_features = 0x00000007c45bfc57 htab_hash_mask = 0x7fffff physical_start = 0x8000000 ----------------------------------------------------- numa: NODE_DATA [mem 0x87d5e300-0x87d67fff] numa: NODE_DATA(0) on node 6 numa: NODE_DATA [mem 0x87d54600-0x87d5e2ff] Top of RAM: 0x88000000, Total RAM: 0x88000000 Memory hole size: 0MB Zone ranges: DMA [mem 0x0000000000000000-0x0000000087ffffff] DMA32 empty Normal empty Movable zone start for each node Early memory node ranges node 6: [mem 0x0000000000000000-0x0000000087ffffff] Could not find start_pfn for node 0 Initmem setup node 0 [mem 0x0000000000000000-0x0000000000000000] On node 0 totalpages: 0 Initmem setup node 6 [mem 0x0000000000000000-0x0000000087ffffff] On node 6 totalpages: 34816 Unable to handle kernel paging request for data at address 0x00000060 Faulting instruction address: 0xc000000008703a54 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 11 PID: 1 Comm: swapper/11 Not tainted 4.19.0-rc5-master+ #1 NIP: c000000008703a54 LR: c000000008703a38 CTR: 0000000000000000 REGS: c00000000b673440 TRAP: 0380 Not tainted (4.19.0-rc5-master+) MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 24022022 XER: 20000002 CFAR: c0000000086fc238 IRQMASK: 0 GPR00: c000000008703a38 c00000000b6736c0 c000000009281900 0000000000000000 GPR04: 0000000000000000 0000000000000000 fffffffffffff001 c00000000b660080 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000220 GPR12: 0000000000002200 c000000009e51400 0000000000000000 0000000000000008 GPR16: 0000000000000000 c000000008c152e8 c000000008c152a8 0000000000000000 GPR20: c000000009422fd8 c000000009412fd8 c000000009426040 0000000000000008 GPR24: 0000000000000000 0000000000000000 c000000009168bc8 c000000009168c78 GPR28: c00000000b126410 0000000000000000 c00000000916a0b8 c00000000b126400 NIP [c000000008703a54] bus_add_device+0x84/0x1e0 LR [c000000008703a38] bus_add_device+0x68/0x1e0 Call Trace: [c00000000b6736c0] [c000000008703a38] bus_add_device+0x68/0x1e0 (unreliable) [c00000000b673740] [c000000008700194] device_add+0x454/0x7c0 [c00000000b673800] [c00000000872e660] __register_one_node+0xb0/0x240 [c00000000b673860] [c00000000839a6bc] __try_online_node+0x12c/0x180 [c00000000b673900] [c00000000839b978] try_online_node+0x58/0x90 [c00000000b673930] [c0000000080846d8] find_and_online_cpu_nid+0x158/0x190 [c00000000b673a10] [c0000000080848a0] numa_update_cpu_topology+0x190/0x580 [c00000000b673c00] [c000000008d3f2e4] smp_cpus_done+0x94/0x108 [c00000000b673c70] [c000000008d5c00c] smp_init+0x174/0x19c [c00000000b673d00] [c000000008d346b8] kernel_init_freeable+0x1e0/0x450 [c00000000b673dc0] [c0000000080102e8] kernel_init+0x28/0x160 [c00000000b673e30] [c00000000800b65c] ret_from_kernel_thread+0x5c/0x80 Instruction dump: 60000000 60000000 e89e0020 7fe3fb78 4bff87d5 60000000 7c7d1b79 4082008c e8bf0050 e93e0098 3b9f0010 2fa50000 <e8690060> 38630018 419e0114 7f84e378 ---[ end trace 593577668c2daa65 ]--- However a regular kernel with 4096M (2048 gets reserved for crash kernel) boots properly. Unlike regular kernels, which mark all available nodes as online, kdump kernel only marks just enough nodes as online and marks the rest as offline at boot. However kdump kernel boots with all available CPUs. With Commit 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot"), all CPUs are onlined on their respective nodes at boot time. try_online_node() tries to online the offline nodes but fails as all needed subsystems are not yet initialized. As part of fix, detect and skip early onlining of a offline node. Fixes: 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot") Reported-by: Pavithra Prakash <pavrampu@in.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-28Merge tag 'powerpc-4.19-3' of ↵Greg Kroah-Hartman
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Michael writes: "powerpc fixes for 4.19 #3 A reasonably big batch of fixes due to me being away for a few weeks. A fix for the TM emulation support on Power9, which could result in corrupting the guest r11 when running under KVM. Two fixes to the TM code which could lead to userspace GPR corruption if we take an SLB miss at exactly the wrong time. Our dynamic patching code had a bug that meant we could patch freed __init text, which could lead to corrupting userspace memory. csum_ipv6_magic() didn't work on little endian platforms since we optimised it recently. A fix for an endian bug when reading a device tree property telling us how many storage keys the machine has available. Fix a crash seen on some configurations of PowerVM when migrating the partition from one machine to another. A fix for a regression in the setup of our CPU to NUMA node mapping in KVM guests. A fix to our selftest Makefiles to make them work since a recent change to the shared Makefile logic." * tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: selftests/powerpc: Fix Makefiles for headers_install change powerpc/numa: Use associativity if VPHN hcall is successful powerpc/tm: Avoid possible userspace r1 corruption on reclaim powerpc/tm: Fix userspace r13 corruption powerpc/pseries: Fix unitialized timer reset on migration powerpc/pkeys: Fix reading of ibm, processor-storage-keys property powerpc: fix csum_ipv6_magic() on little endian platforms powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again) powerpc: Avoid code patching freed init sections KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workarounds
2018-09-25powerpc/numa: Use associativity if VPHN hcall is successfulSrikar Dronamraju
Currently associativity is used to lookup node-id even if the preceding VPHN hcall failed. However this can cause CPU to be made part of the wrong node, (most likely to be node 0). This is because VPHN is not enabled on KVM guests. With 2ea6263 ("powerpc/topology: Get topology for shared processors at boot"), associativity is used to set to the wrong node. Hence KVM guest topology is broken. For example : A 4 node KVM guest before would have reported. [root@localhost ~]# numactl -H available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 node 0 size: 1746 MB node 0 free: 1604 MB node 1 cpus: 4 5 6 7 node 1 size: 2044 MB node 1 free: 1765 MB node 2 cpus: 8 9 10 11 node 2 size: 2044 MB node 2 free: 1837 MB node 3 cpus: 12 13 14 15 node 3 size: 2044 MB node 3 free: 1903 MB node distances: node 0 1 2 3 0: 10 40 40 40 1: 40 10 40 40 2: 40 40 10 40 3: 40 40 40 10 Would now report: [root@localhost ~]# numactl -H available: 4 nodes (0-3) node 0 cpus: 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 node 0 size: 1746 MB node 0 free: 1244 MB node 1 cpus: node 1 size: 2044 MB node 1 free: 2032 MB node 2 cpus: 1 node 2 size: 2044 MB node 2 free: 2028 MB node 3 cpus: node 3 size: 2044 MB node 3 free: 2032 MB node distances: node 0 1 2 3 0: 10 40 40 40 1: 40 10 40 40 2: 40 40 10 40 3: 40 40 40 10 Fix this by skipping associativity lookup if the VPHN hcall failed. Fixes: 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot") Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-24powerpc/pseries: Fix unitialized timer reset on migrationMichael Bringmann
After migration of a powerpc LPAR, the kernel executes code to update the system state to reflect new platform characteristics. Such changes include modifications to device tree properties provided to the system by PHYP. Property notifications received by the post_mobility_fixup() code are passed along to the kernel in general through a call to of_update_property() which in turn passes such events back to all modules through entries like the '.notifier_call' function within the NUMA module. When the NUMA module updates its state, it resets its event timer. If this occurs after a previous call to stop_topology_update() or on a system without VPHN enabled, the code runs into an unitialized timer structure and crashes. This patch adds a safety check along this path toward the problem code. An example crash log is as follows. ibmvscsi 30000081: Re-enabling adapter! ------------[ cut here ]------------ kernel BUG at kernel/time/timer.c:958! Oops: Exception in kernel mode, sig: 5 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: nfsv3 nfs_acl nfs tcp_diag udp_diag inet_diag lockd unix_diag af_packet_diag netlink_diag grace fscache sunrpc xts vmx_crypto pseries_rng sg binfmt_misc ip_tables xfs libcrc32c sd_mod ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod CPU: 11 PID: 3067 Comm: drmgr Not tainted 4.17.0+ #179 ... NIP mod_timer+0x4c/0x400 LR reset_topology_timer+0x40/0x60 Call Trace: 0xc0000003f9407830 (unreliable) reset_topology_timer+0x40/0x60 dt_update_callback+0x100/0x120 notifier_call_chain+0x90/0x100 __blocking_notifier_call_chain+0x60/0x90 of_property_notify+0x90/0xd0 of_update_property+0x104/0x150 update_dt_property+0xdc/0x1f0 pseries_devicetree_update+0x2d0/0x510 post_mobility_fixup+0x7c/0xf0 migration_store+0xa4/0xc0 kobj_attr_store+0x30/0x60 sysfs_kf_write+0x64/0xa0 kernfs_fop_write+0x16c/0x240 __vfs_write+0x40/0x200 vfs_write+0xc8/0x240 ksys_write+0x5c/0x100 system_call+0x58/0x6c Fixes: 5d88aa85c00b ("powerpc/pseries: Update CPU maps when device tree is updated") Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-20powerpc/pkeys: Fix reading of ibm, processor-storage-keys propertyThiago Jung Bauermann
scan_pkey_feature() uses of_property_read_u32_array() to read the ibm,processor-storage-keys property and calls be32_to_cpu() on the value it gets. The problem is that of_property_read_u32_array() already returns the value converted to the CPU byte order. The value of pkeys_total ends up more or less sane because there's a min() call in pkey_initialize() which reduces pkeys_total to 32. So in practice the kernel ignores the fact that the hypervisor reserved one key for itself (the device tree advertises 31 keys in my test VM). This is wrong, but the effect in practice is that when a process tries to allocate the 32nd key, it gets an -EINVAL error instead of -ENOSPC which would indicate that there aren't any keys available Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-18powerpc: Avoid code patching freed init sectionsMichael Neuling
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>
2018-09-12KVM: PPC: Avoid marking DMA-mapped pages dirty in real modeAlexey Kardashevskiy
At the moment the real mode handler of H_PUT_TCE calls iommu_tce_xchg_rm() which in turn reads the old TCE and if it was a valid entry, marks the physical page dirty if it was mapped for writing. Since it is in real mode, realmode_pfn_to_page() is used instead of pfn_to_page() to get the page struct. However SetPageDirty() itself reads the compound page head and returns a virtual address for the head page struct and setting dirty bit for that kills the system. This adds additional dirty bit tracking into the MM/IOMMU API for use in the real mode. Note that this does not change how VFIO and KVM (in virtual mode) set this bit. The KVM (real mode) changes include: - use the lowest bit of the cached host phys address to carry the dirty bit; - mark pages dirty when they are unpinned which happens when the preregistered memory is released which always happens in virtual mode; - add mm_iommu_ua_mark_dirty_rm() helper to set delayed dirty bit; - change iommu_tce_xchg_rm() to take the kvm struct for the mm to use in the new mm_iommu_ua_mark_dirty_rm() helper; - move iommu_tce_xchg_rm() to book3s_64_vio_hv.c (which is the only caller anyway) to reduce the real mode KVM and IOMMU knowledge across different subsystems. This removes realmode_pfn_to_page() as it is not used anymore. While we at it, remove some EXPORT_SYMBOL_GPL() as that code is for the real mode only and modules cannot call it anyway. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-06-19 22:24:56 +0000