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* s390/mm: fix huge pte soft dirty copyingJanosch Frank2020-07-161-1/+1
| | | | | | | | | | | | | | | | commit 528a9539348a0234375dfaa1ca5dbbb2f8f8e8d2 upstream. If the pmd is soft dirty we must mark the pte as soft dirty (and not dirty). This fixes some cases for guest migration with huge page backings. Cc: <stable@vger.kernel.org> # 4.8 Fixes: bc29b7ac1d9f ("s390/mm: clean up pte/pmd encoding") Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: fix set_huge_pte_at() for empty ptesGerald Schaefer2020-06-071-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ac8372f3b4e41015549b331a4f350224661e7fc6 ] On s390, the layout of normal and large ptes (i.e. pmds/puds) differs. Therefore, set_huge_pte_at() does a conversion from a normal pte to the corresponding large pmd/pud. So, when converting an empty pte, this should result in an empty pmd/pud, which would return true for pmd/pud_none(). However, after conversion we also mark the pmd/pud as large, and therefore present. For empty ptes, this will result in an empty pmd/pud that is also marked as large, and pmd/pud_none() would not return true. There is currently no issue with this behaviour, as set_huge_pte_at() does not seem to be called for empty ptes. It would be valid though, so let's fix this by not marking empty ptes as large in set_huge_pte_at(). This was found by testing a patch from from Anshuman Khandual, which is currently discussed on LKML ("mm/debug: Add more arch page table helper tests"). Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/mm: fix page table upgrade vs 2ndary address mode accessesChristian Borntraeger2020-04-291-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 316ec154810960052d4586b634156c54d0778f74 upstream. A page table upgrade in a kernel section that uses secondary address mode will mess up the kernel instructions as follows: Consider the following scenario: two threads are sharing memory. On CPU1 thread 1 does e.g. strnlen_user(). That gets to old_fs = enable_sacf_uaccess(); len = strnlen_user_srst(src, size); and " la %2,0(%1)\n" " la %3,0(%0,%1)\n" " slgr %0,%0\n" " sacf 256\n" "0: srst %3,%2\n" in strnlen_user_srst(). At that point we are in secondary space mode, control register 1 points to kernel page table and instruction fetching happens via c1, rather than usual c13. Interrupts are not disabled, for obvious reasons. On CPU2 thread 2 does MAP_FIXED mmap(), forcing the upgrade of page table from 3-level to e.g. 4-level one. We'd allocated new top-level table, set it up and now we hit this: notify = 1; spin_unlock_bh(&mm->page_table_lock); } if (notify) on_each_cpu(__crst_table_upgrade, mm, 0); OK, we need to actually change over to use of new page table and we need that to happen in all threads that are currently running. Which happens to include the thread 1. IPI is delivered and we have static void __crst_table_upgrade(void *arg) { struct mm_struct *mm = arg; if (current->active_mm == mm) set_user_asce(mm); __tlb_flush_local(); } run on CPU1. That does static inline void set_user_asce(struct mm_struct *mm) { S390_lowcore.user_asce = mm->context.asce; OK, user page table address updated... __ctl_load(S390_lowcore.user_asce, 1, 1); ... and control register 1 set to it. clear_cpu_flag(CIF_ASCE_PRIMARY); } IPI is run in home space mode, so it's fine - insns are fetched using c13, which always points to kernel page table. But as soon as we return from the interrupt, previous PSW is restored, putting CPU1 back into secondary space mode, at which point we no longer get the kernel instructions from the kernel mapping. The fix is to only fixup the control registers that are currently in use for user processes during the page table update. We must also disable interrupts in enable_sacf_uaccess to synchronize the cr and thread.mm_segment updates against the on_each-cpu. Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode") Cc: stable@vger.kernel.org # 4.15+ Reported-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> References: CVE-2020-11884 Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: s390: vsie: Fix possible race when shadowing region 3 tablesDavid Hildenbrand2020-04-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1493e0f944f3c319d11e067c185c904d01c17ae5 ] We have to properly retry again by returning -EINVAL immediately in case somebody else instantiated the table concurrently. We missed to add the goto in this function only. The code now matches the other, similar shadowing functions. We are overwriting an existing region 2 table entry. All allocated pages are added to the crst_list to be freed later, so they are not lost forever. However, when unshadowing the region 2 table, we wouldn't trigger unshadowing of the original shadowed region 3 table that we replaced. It would get unshadowed when the original region 3 table is modified. As it's not connected to the page table hierarchy anymore, it's not going to get used anymore. However, for a limited time, this page table will stick around, so it's in some sense a temporary memory leak. Identified by manual code inspection. I don't think this classifies as stable material. Fixes: 998f637cc4b9 ("s390/mm: avoid races on region/segment/page table shadowing") Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-4-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checksDavid Hildenbrand2020-04-171-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | commit a1d032a49522cb5368e5dfb945a85899b4c74f65 upstream. In case we have a region 1 the following calculation (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11) results in 64. As shifts beyond the size are undefined the compiler is free to use instructions like sllg. sllg will only use 6 bits of the shift value (here 64) resulting in no shift at all. That means that ALL addresses will be rejected. The can result in endless loops, e.g. when prefix cannot get mapped. Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Tested-by: Janosch Frank <frankja@linux.ibm.com> Reported-by: Janosch Frank <frankja@linux.ibm.com> Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200403153050.20569-2-david@redhat.com Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: fix patch description, remove WARN_ON_ONCE] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: fix dynamic pagetable upgrade for hugetlbfsGerald Schaefer2020-02-111-1/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5f490a520bcb393389a4d44bec90afcb332eb112 upstream. Commit ee71d16d22bb ("s390/mm: make TASK_SIZE independent from the number of page table levels") changed the logic of TASK_SIZE and also removed the arch_mmap_check() implementation for s390. This combination has a subtle effect on how get_unmapped_area() for hugetlbfs pages works. It is now possible that a user process establishes a hugetlbfs mapping at an address above 4 TB, without triggering a dynamic pagetable upgrade from 3 to 4 levels. This is because hugetlbfs mappings will not use mm->get_unmapped_area, but rather file->f_op->get_unmapped_area, which currently is the generic implementation of hugetlb_get_unmapped_area() that does not know about s390 dynamic pagetable upgrades, but with the new definition of TASK_SIZE, it will now allow mappings above 4 TB. Subsequent access to such a mapped address above 4 TB will result in a page fault loop, because the CPU cannot translate such a large address with 3 pagetable levels. The fault handler will try to map in a hugepage at the address, but due to the folded pagetable logic it will end up with creating entries in the 3 level pagetable, possibly overwriting existing mappings, and then it all repeats when the access is retried. Apart from the page fault loop, this can have various nasty effects, e.g. kernel panic from one of the BUG_ON() checks in memory management code, or even data loss if an existing mapping gets overwritten. Fix this by implementing HAVE_ARCH_HUGETLB_UNMAPPED_AREA support for s390, providing an s390 version for hugetlb_get_unmapped_area() with pagetable upgrade support similar to arch_get_unmapped_area(), which will then be used instead of the generic version. Fixes: ee71d16d22bb ("s390/mm: make TASK_SIZE independent from the number of page table levels") Cc: <stable@vger.kernel.org> # 4.12+ Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/memory_hotplug: shrink zones when offlining memoryDavid Hildenbrand2020-01-291-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVEDavid Hildenbrand2020-01-291-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* s390x/mm: implement arch_remove_memory()David Hildenbrand2020-01-291-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 18c86506c80f6b6b5e67d95bf0d6f7e665de5239 upstream. Will come in handy when wanting to handle errors after arch_add_memory(). Link: http://lkml.kernel.org/r/20190527111152.16324-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arun KS <arunks@codeaurora.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.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: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Mark Brown <broonie@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> 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>
* mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never failDavid Hildenbrand2020-01-291-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm, memory_hotplug: add nid parameter to arch_remove_memoryOscar Salvador2020-01-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm, gup: add missing refcount overflow checks on s390Vlastimil Babka2019-12-051-3/+6
| | | | | | | | | | | | | | | | | | | The mainline commit 8fde12ca79af ("mm: prevent get_user_pages() from overflowing page refcount") was backported to 4.19.y stable as commit d972ebbf42ba. The backport however missed that in 4.19, there are several arch-specific gup.c versions with fast gup implementations, so these do not prevent refcount overflow. This stable-only commit fixes the s390 version, and is based on the backport in SUSE SLES/openSUSE 4.12-based kernels. The remaining architectures with own gup.c are sparc, mips, sh. It's unlikely the known overflow scenario based on FUSE, which needs 140GB of RAM, is a problem for those architectures, and I don't feel confident enough to patch them. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/cmm: fix information leak in cmm_timeout_handler()Yihui ZENG2019-11-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | commit b8e51a6a9db94bc1fb18ae831b3dab106b5a4b5f upstream. The problem is that we were putting the NUL terminator too far: buf[sizeof(buf) - 1] = '\0'; If the user input isn't NUL terminated and they haven't initialized the whole buffer then it leads to an info leak. The NUL terminator should be: buf[len - 1] = '\0'; Signed-off-by: Yihui Zeng <yzeng56@asu.edu> Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> [heiko.carstens@de.ibm.com: keep semantics of how *lenp and *ppos are handled] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: fix address space detection in exception handlingGerald Schaefer2019-06-111-1/+4
| | | | | | | | | | | | | | | | | | | | | | commit 962f0af83c239c0aef05639631e871c874b00f99 upstream. Commit 0aaba41b58bc ("s390: remove all code using the access register mode") removed access register mode from the kernel, and also from the address space detection logic. However, user space could still switch to access register mode (trans_exc_code == 1), and exceptions in that mode would not be correctly assigned. Fix this by adding a check for trans_exc_code == 1 to get_fault_type(), and remove the wrong comment line before that function. Fixes: 0aaba41b58bc ("s390: remove all code using the access register mode") Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: <stable@vger.kernel.org> # v4.15+ Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: silence compiler warning when compiling without CONFIG_PGSTEThomas Huth2019-05-311-0/+2
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 81a8f2beb32a5951ecf04385301f50879abc092b ] If CONFIG_PGSTE is not set (e.g. when compiling without KVM), GCC complains: CC arch/s390/mm/pgtable.o arch/s390/mm/pgtable.c:413:15: warning: ‘pmd_alloc_map’ defined but not used [-Wunused-function] static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr) ^~~~~~~~~~~~~ Wrap the function with "#ifdef CONFIG_PGSTE" to silence the warning. Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/mm: fix mis-accounting of pgtable_bytesMartin Schwidefsky2018-11-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e12e4044aede97974f2222eb7f0ed726a5179a32 ] In case a fork or a clone system fails in copy_process and the error handling does the mmput() at the bad_fork_cleanup_mm label, the following warning messages will appear on the console: BUG: non-zero pgtables_bytes on freeing mm: 16384 The reason for that is the tricks we play with mm_inc_nr_puds() and mm_inc_nr_pmds() in init_new_context(). A normal 64-bit process has 3 levels of page table, the p4d level and the pud level are folded. On process termination the free_pud_range() function in mm/memory.c will subtract 16KB from pgtable_bytes with a mm_dec_nr_puds() call, but there actually is not really a pud table. One issue with this is the fact that pgtable_bytes is usually off by a few kilobytes, but the more severe problem is that for a failed fork or clone the free_pgtables() function is not called. In this case there is no mm_dec_nr_puds() or mm_dec_nr_pmds() that go together with the mm_inc_nr_puds() and mm_inc_nr_pmds in init_new_context(). The pgtable_bytes will be off by 16384 or 32768 bytes and we get the BUG message. The message itself is purely cosmetic, but annoying. To fix this override the mm_pmd_folded, mm_pud_folded and mm_p4d_folded function to check for the true size of the address space. Reported-by: Li Wang <liwang@redhat.com> Tested-by: Li Wang <liwang@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/mm: Check for valid vma before zapping in gmap_discardJanosch Frank2018-09-121-1/+3
| | | | | | | | | | | | | | | Userspace could have munmapped the area before doing unmapping from the gmap. This would leave us with a valid vmaddr, but an invalid vma from which we would try to zap memory. Let's check before using the vma. Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Message-Id: <20180816082432.78828-1-frankja@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* mm: convert return type of handle_mm_fault() caller to vm_fault_tSouptick Joarder2018-08-171-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t") In this patch all the caller of handle_mm_fault() are changed to return vm_fault_t type. Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Tony Luck <tony.luck@intel.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: James Hogan <jhogan@kernel.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: David S. Miller <davem@davemloft.net> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2018-08-139-116/+611
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request from me: - Host large page support for KVM guests. As the patches have large impact on arch/s390/mm/ this series goes out via both the KVM and the s390 tree. - Add an option for no compression to the "Kernel compression mode" menu, this will come in handy with the rework of the early boot code. - A large rework of the early boot code that will make life easier for KASAN and KASLR. With the rework the bootable uncompressed image is not generated anymore, only the bzImage is available. For debuggung purposes the new "no compression" option is used. - Re-enable the gcc plugins as the issue with the latent entropy plugin is solved with the early boot code rework. - More spectre relates changes: + Detect the etoken facility and remove expolines automatically. + Add expolines to a few more indirect branches. - A rewrite of the common I/O layer trace points to make them consumable by 'perf stat'. - Add support for format-3 PCI function measurement blocks. - Changes for the zcrypt driver: + Add attributes to indicate the load of cards and queues. + Restructure some code for the upcoming AP device support in KVM. - Build flags improvements in various Makefiles. - A few fixes for the kdump support. - A couple of patches for gcc 8 compile warning cleanup. - Cleanup s390 specific proc handlers. - Add s390 support to the restartable sequence self tests. - Some PTR_RET vs PTR_ERR_OR_ZERO cleanup. - Lots of bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (107 commits) s390/dasd: fix hanging offline processing due to canceled worker s390/dasd: fix panic for failed online processing s390/mm: fix addressing exception after suspend/resume rseq/selftests: add s390 support s390: fix br_r1_trampoline for machines without exrl s390/lib: use expoline for all bcr instructions s390/numa: move initial setup of node_to_cpumask_map s390/kdump: Fix elfcorehdr size calculation s390/cpum_sf: save TOD clock base in SDBs for time conversion KVM: s390: Add huge page enablement control s390/mm: Add huge page gmap linking support s390/mm: hugetlb pages within a gmap can not be freed KVM: s390: Add skey emulation fault handling s390/mm: Add huge pmd storage key handling s390/mm: Clear skeys for newly mapped huge guest pmds s390/mm: Clear huge page storage keys on enable_skey s390/mm: Add huge page dirty sync support s390/mm: Add gmap pmd invalidation and clearing s390/mm: Add gmap pmd notification bit setting s390/mm: Add gmap pmd linking ...
| * s390/mm: fix addressing exception after suspend/resumeGerald Schaefer2018-08-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c9b5ad546e7d "s390/mm: tag normal pages vs pages used in page tables" accidentally changed the logic in arch_set_page_states(), which is used by the suspend/resume code. set_page_stable(page, order) was changed to set_page_stable_dat(page, 0). After this, only the first page of higher order pages will be set to stable, and a write to one of the unstable pages will result in an addressing exception. Fix this by using "order" again, instead of "0". Fixes: c9b5ad546e7d ("s390/mm: tag normal pages vs pages used in page tables") Cc: stable@vger.kernel.org # 4.14+ Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * Merge tag 'hlp_stage1' of ↵Martin Schwidefsky2018-07-314-71/+572
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into features Pull hlp_stage1 from Christian Borntraeger with the following changes: KVM: s390: initial host large page support - must be enabled via module parameter hpage=1 - cannot be used together with nested - does support migration - does support hugetlbfs - no THP yet
| | * s390/mm: Add huge page gmap linking supportJanosch Frank2018-07-302-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's allow huge pmd linking when enabled through the KVM_CAP_S390_HPAGE_1M capability. Also we can now restrict gmap invalidation and notification to the cases where the capability has been activated and save some cycles when that's not the case. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: hugetlb pages within a gmap can not be freedDominik Dingel2018-07-301-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Guests backed by huge pages could theoretically free unused pages via the diagnose 10 instruction. We currently don't allow that, so we don't have to refault it once it's needed again. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
| | * s390/mm: Add huge pmd storage key handlingJanosch Frank2018-07-301-10/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | Storage keys for guests with huge page mappings have to be managed in hardware. There are no PGSTEs for PMDs that we could use to retain the guests's logical view of the key. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: Clear skeys for newly mapped huge guest pmdsJanosch Frank2018-07-302-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similarly to the pte skey handling, where we set the storage key to the default key for each newly mapped pte, we have to also do that for huge pmds. With the PG_arch_1 flag we keep track if the area has already been cleared of its skeys. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| | * s390/mm: Clear huge page storage keys on enable_skeyDominik Dingel2018-07-302-7/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a guest starts using storage keys, we trap and set a default one for its whole valid address space. With this patch we are now able to do that for large pages. To speed up the storage key insertion, we use __storage_key_init_range, which in-turn will use sske_frame to set multiple storage keys with one instruction. As it has been previously used for debuging we have to get rid of the default key check and make it quiescing. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> [replaced page_set_storage_key loop with __storage_key_init_range] Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: Add huge page dirty sync supportJanosch Frank2018-07-302-36/+125
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To do dirty loging with huge pages, we protect huge pmds in the gmap. When they are written to, we unprotect them and mark them dirty. We introduce the function gmap_test_and_clear_dirty_pmd which handles dirty sync for huge pages. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: Add gmap pmd invalidation and clearingJanosch Frank2018-07-302-3/+139
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the host invalidates a pmd, we also have to invalidate the corresponding gmap pmds, as well as flush them from the TLB. This is necessary, as we don't share the pmd tables between host and guest as we do with ptes. The clearing part of these three new functions sets a guest pmd entry to _SEGMENT_ENTRY_EMPTY, so the guest will fault on it and we will re-link it. Flushing the gmap is not necessary in the host's lazy local and csp cases. Both purge the TLB completely. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: Add gmap pmd notification bit settingJanosch Frank2018-07-301-6/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like for ptes, we also need invalidation notification for pmds, to make sure the guest lowcore pages are always accessible and later addition of shadowed pmds. With PMDs we do not have PGSTEs or some other bits we could use in the host PMD. Instead we pick one of the free bits in the gmap PMD. Every time a host pmd will be invalidated, we will check if the respective gmap PMD has the bit set and in that case fire up the notifier. Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
| | * s390/mm: Add gmap pmd linkingJanosch Frank2018-07-301-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's allow pmds to be linked into gmap for the upcoming s390 KVM huge page support. Before this patch we copied the full userspace pmd entry. This is not correct, as it contains SW defined bits that might be interpreted differently in the GMAP context. Now we only copy over all hardware relevant information leaving out the software bits. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: Abstract gmap notify bit settingJanosch Frank2018-07-301-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we use the software PGSTE bits PGSTE_IN_BIT and PGSTE_VSIE_BIT to notify before an invalidation occurs on a prefix page or a VSIE page respectively. Both bits are pgste specific, but are used when protecting a memory range. Let's introduce abstract GMAP_NOTIFY_* bits that will be realized into the respective bits when gmap DAT table entries are protected. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
| | * s390/mm: Make gmap_protect_range more modularJanosch Frank2018-07-301-10/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch reworks the gmap_protect_range logic and extracts the pte handling into an own function. Also we do now walk to the pmd and make it accessible in the function for later use. This way we can add huge page handling logic more easily. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | s390/kvm: fix deadlock when killed by oomClaudio Imbrenda2018-07-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the oom killer kills a userspace process in the page fault handler while in guest context, the fault handler fails to release the mm_sem if the FAULT_FLAG_RETRY_NOWAIT option is set. This leads to a deadlock when tearing down the mm when the process terminates. This bug can only happen when pfault is enabled, so only KVM clients are affected. The problem arises in the rare cases in which handle_mm_fault does not release the mm_sem. This patch fixes the issue by manually releasing the mm_sem when needed. Fixes: 24eb3a824c4f3 ("KVM: s390: Add FAULT_FLAG_RETRY_NOWAIT for guest fault") Cc: <stable@vger.kernel.org> # 3.15+ Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | s390/cmm: avoid add_timer on concurrently used timerVasily Gorbik2018-07-161-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cmm_set_timer could be called concurrently from cmm_thread, cmm proc handler, upon cmm smsg receive and timer function itself. To avoid potential race condition and hitting BUG_ON in add_timer on already pending timer simply reuse mod_timer which is according to documentation "the only safe way to modify the timeout" with multiple unserialized concurrent users. mod_timer can handle both active and inactive timers which allows to carry out minor code simplification as well. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | s390/cmm: split and simplify cmm pages proc handlerVasily Gorbik2018-07-061-35/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split cmm_pages_handler into cmm_pages_handler and cmm_timed_pages_handler, each handling separate proc entry. And reuse proc_doulongvec_minmax to simplify proc handlers. Min/max values are optional and are omitted here. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | s390/mm: correct allocate_pgste proc_handler callbackVasily Gorbik2018-07-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since proc_dointvec does not perform value range control, proc_dointvec_minmax should be used to limit value range, which is clearly intended here, as the internal representation of the value: unsigned int alloc_pgste:1; In fact it currently works, since we have mm->context.alloc_pgste = page_table_allocate_pgste || ... ... since commit 23fefe119ceb5 ("s390/kvm: avoid global config of vm.alloc_pgste=1") Before that it was mm->context.alloc_pgste = page_table_allocate_pgste; which was broken. That was introduced with commit 0b46e0a3ec0d7 ("s390/kvm: remove delayed reallocation of page tables for KVM"). Fixes: 0b46e0a3ec0d7 ("s390/kvm: remove delayed reallocation of page tables for KVM") Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | s390/extmem: fix gcc 8 stringop-overflow warningVasily Gorbik2018-07-021-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch/s390/mm/extmem.c: In function '__segment_load': arch/s390/mm/extmem.c:436:2: warning: 'strncat' specified bound 7 equals source length [-Wstringop-overflow=] strncat(seg->res_name, " (DCSS)", 7); What gcc complains about here is the misuse of strncat function, which in this case does not limit a number of bytes taken from "src", so it is in the end the same as strcat(seg->res_name, " (DCSS)"); Keeping in mind that a res_name is 15 bytes, strncat in this case would overflow the buffer and write 0 into alignment byte between the fields in the struct. To avoid that increasing res_name size to 16, and reusing strlcat. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* / s390/mm: fix refcount usage for 4K pgsteEric Farman2018-07-021-0/+4
|/ | | | | | | | | | | | | | | | | | | | s390 no longer uses the _mapcount field in struct page to identify the page table format being used. While the code was diligent in handling the different mappings, it neglected to turn "off" the map bits when alloc_pgste was being used. This resulted in bits remaining "on" in the _refcount field, and thus an artifically huge "in use" count that prevents the pages from actually being released by __free_page. There's opportunity for improvement in the "1 vs 3" vs "1U vs 3U" vs "0x1 vs 0x11" etc. variations for all these calls, I am just keeping things simple compared to neighboring code. Fixes: 620b4e903179 ("s390: use _refcount for pgtables") Reported-by: Halil Pasic <pasic@linux.ibm.com> Bisected-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge tag 'overflow-v4.18-rc1-part2' of ↵Linus Torvalds2018-06-121-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull more overflow updates from Kees Cook: "The rest of the overflow changes for v4.18-rc1. This includes the explicit overflow fixes from Silvio, further struct_size() conversions from Matthew, and a bug fix from Dan. But the bulk of it is the treewide conversions to use either the 2-factor argument allocators (e.g. kmalloc(a * b, ...) into kmalloc_array(a, b, ...) or the array_size() macros (e.g. vmalloc(a * b) into vmalloc(array_size(a, b)). Coccinelle was fighting me on several fronts, so I've done a bunch of manual whitespace updates in the patches as well. Summary: - Error path bug fix for overflow tests (Dan) - Additional struct_size() conversions (Matthew, Kees) - Explicitly reported overflow fixes (Silvio, Kees) - Add missing kvcalloc() function (Kees) - Treewide conversions of allocators to use either 2-factor argument variant when available, or array_size() and array3_size() as needed (Kees)" * tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (26 commits) treewide: Use array_size in f2fs_kvzalloc() treewide: Use array_size() in f2fs_kzalloc() treewide: Use array_size() in f2fs_kmalloc() treewide: Use array_size() in sock_kmalloc() treewide: Use array_size() in kvzalloc_node() treewide: Use array_size() in vzalloc_node() treewide: Use array_size() in vzalloc() treewide: Use array_size() in vmalloc() treewide: devm_kzalloc() -> devm_kcalloc() treewide: devm_kmalloc() -> devm_kmalloc_array() treewide: kvzalloc() -> kvcalloc() treewide: kvmalloc() -> kvmalloc_array() treewide: kzalloc_node() -> kcalloc_node() treewide: kzalloc() -> kcalloc() treewide: kmalloc() -> kmalloc_array() mm: Introduce kvcalloc() video: uvesafb: Fix integer overflow in allocation UBIFS: Fix potential integer overflow in allocation leds: Use struct_size() in allocation Convert intel uncore to struct_size ...
| * treewide: kmalloc() -> kmalloc_array()Kees Cook2018-06-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
* | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2018-06-122-5/+5
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM updates from Paolo Bonzini: "Small update for KVM: ARM: - lazy context-switching of FPSIMD registers on arm64 - "split" regions for vGIC redistributor s390: - cleanups for nested - clock handling - crypto - storage keys - control register bits x86: - many bugfixes - implement more Hyper-V super powers - implement lapic_timer_advance_ns even when the LAPIC timer is emulated using the processor's VMX preemption timer. - two security-related bugfixes at the top of the branch" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits) kvm: fix typo in flag name kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system KVM: x86: introduce linear_{read,write}_system kvm: nVMX: Enforce cpl=0 for VMX instructions kvm: nVMX: Add support for "VMWRITE to any supported field" kvm: nVMX: Restrict VMX capability MSR changes KVM: VMX: Optimize tscdeadline timer latency KVM: docs: nVMX: Remove known limitations as they do not exist now KVM: docs: mmu: KVM support exposing SLAT to guests kvm: no need to check return value of debugfs_create functions kvm: Make VM ioctl do valloc for some archs kvm: Change return type to vm_fault_t KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008 kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation KVM: introduce kvm_make_vcpus_request_mask() API KVM: x86: hyperv: do rep check for each hypercall separately ...
| * KVM: s390: Add storage key facility interpretation controlJanosch Frank2018-05-172-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now we always expected to have the storage key facility available for our (non-VSIE) KVM guests. For huge page support, we need to be able to disable it, so let's introduce that now. We add the use_skf variable to manage KVM storage key facility usage. Also we rename use_skey in the mm context struct to uses_skeys to make it more clear that it is an indication that the vm actively uses storage keys. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* | s390: use _refcount for pgtablesMatthew Wilcox2018-06-071-9/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Rearrange struct page", v6. As presented at LSFMM, this patch-set rearranges struct page to give more contiguous usable space to users who have allocated a struct page for their own purposes. For a graphical view of before-and-after, see the first two tabs of https://docs.google.com/spreadsheets/d/1tvCszs_7FXrjei9_mtFiKV6nW1FLnYyvPvW-qNZhdog/edit?usp=sharing Highlights: - deferred_list now really exists in struct page instead of just a comment. - hmm_data also exists in struct page instead of being a nasty hack. - x86's PGD pages have a real pointer to the mm_struct. - VMalloc pages now have all sorts of extra information stored in them to help with debugging and tuning. - rcu_head is no longer tied to slab in case anyone else wants to free pages by RCU. - slub's counters no longer share space with _refcount. - slub's freelist+counters are now naturally dword aligned. - slub loses a parameter to a lot of functions and a sysfs file. This patch (of 17): s390 borrows the storage used for _mapcount in struct page in order to account whether the bottom or top half is being used for 2kB page tables. I want to use that for something else, so use the top byte of _refcount instead of the bottom byte of _mapcount. _refcount may temporarily be incremented by other CPUs that see a stale pointer to this page in the page cache, but each CPU can only increment it by one, and there are no systems with 2^24 CPUs today, so they will not change the upper byte of _refcount. We do have to be a little careful not to lose any of their writes (as they will subsequently decrement the counter). Link: http://lkml.kernel.org/r/20180518194519.3820-2-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signal/s390: Use force_sig_fault where appropriateEric W. Biederman2018-04-251-17/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Filling in struct siginfo before calling force_sig_info a tedious and error prone process, where once in a great while the wrong fields are filled out, and siginfo has been inconsistently cleared. Simplify this process by using the helper force_sig_fault. Which takes as a parameters all of the information it needs, ensures all of the fiddly bits of filling in struct siginfo are done properly and then calls force_sig_info. In short about a 5 line reduction in code for every time force_sig_info is called, which makes the calling function clearer. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Acked-by: Martin Schwidefsky >schwidefsky@de.ibm.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | signal: Ensure every siginfo we send has all bits initializedEric W. Biederman2018-04-251-0/+2
|/ | | | | | | | | | | | | | | | | | | | | | | Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* mm/gup.c: document return valueMichael S. Tsirkin2018-04-131-0/+2
| | | | | | | | | | | | | | | | | | __get_user_pages_fast handles errors differently from get_user_pages_fast: the former always returns the number of pages pinned, the later might return a negative error code. Link: http://lkml.kernel.org/r/1522962072-182137-6-git-send-email-mst@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: pass stack rlimit into mm layout functionsKees Cook2018-04-111-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "exec: Pin stack limit during exec". Attempts to solve problems with the stack limit changing during exec continue to be frustrated[1][2]. In addition to the specific issues around the Stack Clash family of flaws, Andy Lutomirski pointed out[3] other places during exec where the stack limit is used and is assumed to be unchanging. Given the many places it gets used and the fact that it can be manipulated/raced via setrlimit() and prlimit(), I think the only way to handle this is to move away from the "current" view of the stack limit and instead attach it to the bprm, and plumb this down into the functions that need to know the stack limits. This series implements the approach. [1] 04e35f4495dd ("exec: avoid RLIMIT_STACK races with prlimit()") [2] 779f4e1c6c7c ("Revert "exec: avoid RLIMIT_STACK races with prlimit()"") [3] to security@kernel.org, "Subject: existing rlimit races?" This patch (of 3): Since it is possible that the stack rlimit can change externally during exec (either via another thread calling setrlimit() or another process calling prlimit()), provide a way to pass the rlimit down into the per-architecture mm layout functions so that the rlimit can stay in the bprm structure instead of sitting in the signal structure until exec is finalized. Link: http://lkml.kernel.org/r/1518638796-20819-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Willy Tarreau <w@1wt.eu> Cc: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Rik van Riel <riel@redhat.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Greg KH <greg@kroah.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: unify linker symbols usageVasily Gorbik2018-02-271-2/+2
| | | | | | | | | | | | | Common code defines linker symbols which denote sections start/end in a form of char []. Referencing those symbols as _symbol or &_symbol yields the same result, but "_symbol" form is more widespread across newly written code. Convert s390 specific code to this style. Also removes unused _text symbol definition in boot/compressed/misc.c. Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: provide base_asce_alloc() / base_asce_free() helper functionsHeiko Carstens2018-02-221-1/+292
| | | | | | | | | | | | | | | | | Provide base_asce_alloc() and base_asce_free() helper functions which can be used to allocate an ASCE and all required region, segment and page tables required to access memory regions of the virtual kernel address space. Both, the ASCE and all tables, do not use any features that correspond to e.g. enhanced DAT features. This is required for some I/O functions that pass an ASCE, like e.g. some service call requests, but which may not use any enhanced features. Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2018-02-101-26/+18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM updates from Radim Krčmář: "ARM: - icache invalidation optimizations, improving VM startup time - support for forwarded level-triggered interrupts, improving performance for timers and passthrough platform devices - a small fix for power-management notifiers, and some cosmetic changes PPC: - add MMIO emulation for vector loads and stores - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without requiring the complex thread synchronization of older CPU versions - improve the handling of escalation interrupts with the XIVE interrupt controller - support decrement register migration - various cleanups and bugfixes. s390: - Cornelia Huck passed maintainership to Janosch Frank - exitless interrupts for emulated devices - cleanup of cpuflag handling - kvm_stat counter improvements - VSIE improvements - mm cleanup x86: - hypervisor part of SEV - UMIP, RDPID, and MSR_SMI_COUNT emulation - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512 features - show vcpu id in its anonymous inode name - many fixes and cleanups - per-VCPU MSR bitmaps (already merged through x86/pti branch) - stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)" * tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits) KVM: PPC: Book3S: Add MMIO emulation for VMX instructions KVM: PPC: Book3S HV: Branch inside feature section KVM: PPC: Book3S HV: Make HPT resizing work on POWER9 KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code KVM: PPC: Book3S PR: Fix broken select due to misspelling KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs() KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled KVM: PPC: Book3S HV: Drop locks before reading guest memory kvm: x86: remove efer_reload entry in kvm_vcpu_stat KVM: x86: AMD Processor Topology Information x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested kvm: embed vcpu id to dentry of vcpu anon inode kvm: Map PFN-type memory regions as writable (if possible) x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n KVM: arm/arm64: Fixup userspace irqchip static key optimization KVM: arm/arm64: Fix userspace_irqchip_in_use counting KVM: arm/arm64: Fix incorrect timer_is_pending logic MAINTAINERS: update KVM/s390 maintainers MAINTAINERS: add Halil as additional vfio-ccw maintainer MAINTAINERS: add David as a reviewer for KVM/s390 ...
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