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2016-01-19s390: remove all usages of PSW_ADDR_INSNHeiko Carstens
Yet another leftover from the 31 bit era. The usual operation "y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for CONFIG_64BIT. Therefore remove all usages and hope the code is a bit less confusing. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
2016-01-19s390: remove all usages of PSW_ADDR_AMODEHeiko Carstens
This is a leftover from the 31 bit area. For CONFIG_64BIT the usual operation "y = x | PSW_ADDR_AMODE" is a nop. Therefore remove all usages of PSW_ADDR_AMODE and make the code a bit less confusing. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
2016-01-19s390/irqflags: optimize irq restoreChristian Borntraeger
The ssm instruction takes longer that stnsm/stosm as it is often used to modify DAT and PER. We know that irqsave/irqrestore only deals with external and I/O interrupts and we know that irqrestore can transition only from disabled->disabled or disabled->enabled, so we can use the faster stosm. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-01-19s390/mm: use TASK_MAX_SIZE where applicableDominik Dingel
To improve readability we can use TASK_MAX_SIZE when we just check for the upper limit. All places explicitly dealing with 3 vs 4 level pgtables were left unchanged. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
2016-01-16s390/mm: enable fixup_user_fault retryingDominik Dingel
By passing a non-null flag we allow fixup_user_fault to retry, which enables userfaultfd. As during these retries we might drop the mmap_sem we need to check if that happened and redo the complete chain of actions. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Jason J. Herne" <jjherne@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm: bring in additional flag for fixup_user_fault to signal unlockDominik Dingel
During Jason's work with postcopy migration support for s390 a problem regarding gmap faults was discovered. The gmap code will call fixup_user_fault which will end up always in handle_mm_fault. Till now we never cared about retries, but as the userfaultfd code kind of relies on it. this needs some fix. This patchset does not take care of the futex code. I will now look closer at this. This patch (of 2): With the introduction of userfaultfd, kvm on s390 needs fixup_user_fault to pass in FAULT_FLAG_ALLOW_RETRY and give feedback if during the faulting we ever unlocked mmap_sem. This patch brings in the logic to handle retries as well as it cleans up the current documentation. fixup_user_fault was not having the same semantics as filemap_fault. It never indicated if a retry happened and so a caller wasn't able to handle that case. So we now changed the behaviour to always retry a locked mmap_sem. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Jason J. Herne" <jjherne@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16s390, thp: remove infrastructure for handling splitting PMDsKirill A. Shutemov
With new refcounting we don't need to mark PMDs splitting. Let's drop code to handle this. pmdp_splitting_flush() is not needed too: on splitting PMD we will do pmdp_clear_flush() + set_pte_at(). pmdp_clear_flush() will do IPI as needed for fast_gup. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm: drop tail page refcountingKirill A. Shutemov
Tail page refcounting is utterly complicated and painful to support. It uses ->_mapcount on tail pages to store how many times this page is pinned. get_page() bumps ->_mapcount on tail page in addition to ->_count on head. This information is required by split_huge_page() to be able to distribute pins from head of compound page to tails during the split. We will need ->_mapcount to account PTE mappings of subpages of the compound page. We eliminate need in current meaning of ->_mapcount in tail pages by forbidding split entirely if the page is pinned. The only user of tail page refcounting is THP which is marked BROKEN for now. Let's drop all this mess. It makes get_page() and put_page() much simpler. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, shmem: add internal shmem resident memory accountingJerome Marchand
Currently looking at /proc/<pid>/status or statm, there is no way to distinguish shmem pages from pages mapped to a regular file (shmem pages are mapped to /dev/zero), even though their implication in actual memory use is quite different. The internal accounting currently counts shmem pages together with regular files. As a preparation to extend the userspace interfaces, this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for shmem pages separately from MM_FILEPAGES. The next patch will expose it to userspace - this patch doesn't change the exported values yet, by adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was used before. The only user-visible change after this patch is the OOM killer message that separates the reported "shmem-rss" from "file-rss". [vbabka@suse.cz: forward-porting, tweak changelog] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "Among the traditional bug fixes and cleanups are some improvements: - A tool to generated the facility lists, generating the bit fields by hand has been a source of bugs in the past - The spinlock loop is reordered to avoid bursts of hypervisor calls - Add support for the open-for-business interface to the service element - The get_cpu call is added to the vdso - A set of tracepoints is defined for the common I/O layer - The deprecated sclp_cpi module is removed - Update default configuration" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (56 commits) s390/sclp: fix possible control register corruption s390: fix normalization bug in exception table sorting s390/configs: update default configurations s390/vdso: optimize getcpu system call s390: drop smp_mb in vdso_init s390: rename struct _lowcore to struct lowcore s390/mem_detect: use unsigned longs s390/ptrace: get rid of long longs in psw_bits s390/sysinfo: add missing SYSIB 1.2.2 multithreading fields s390: get rid of CONFIG_SCHED_MC and CONFIG_SCHED_BOOK s390/Kconfig: remove pointless 64 bit dependencies s390/dasd: fix failfast for disconnected devices s390/con3270: testing return kzalloc retval s390/hmcdrv: constify hmcdrv_ftp_ops structs s390/cio: add NULL test s390/cio: Change I/O instructions from inline to normal functions s390/cio: Introduce common I/O layer tracepoints s390/cio: Consolidate inline assemblies and related data definitions s390/cio: Fix incorrect xsch opcode specification s390/cio: Remove unused inline assemblies ...
2016-01-11s390: fix normalization bug in exception table sortingArd Biesheuvel
The normalization pass in the sorting routine of the relative exception table serves two purposes: - it ensures that the address fields of the exception table entries are fully ordered, so that no ambiguities arise between entries with identical instruction offsets (i.e., when two instructions that are exactly 8 bytes apart each have an exception table entry associated with them) - it ensures that the offsets of both the instruction and the fixup fields of each entry are relative to their final location after sorting. Commit eb608fb366de ("s390/exceptions: switch to relative exception table entries") ported the relative exception table format from x86, but modified the sorting routine to only normalize the instruction offset field and not the fixup offset field. The result is that the fixup offset of each entry will be relative to the original location of the entry before sorting, likely leading to crashes when those entries are dereferenced. Fixes: eb608fb366de ("s390/exceptions: switch to relative exception table entries") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-11s390: rename struct _lowcore to struct lowcoreHeiko Carstens
Finally get rid of the leading underscore. I tried this already two or three years ago, however Michael Holzheu objected since this would break the crash utility (again). However Michael integrated support for the new name into the crash utility back then, so it doesn't break if the name will be changed now. So finally get rid of the ever confusing leading underscore. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-11s390/mem_detect: use unsigned longsHeiko Carstens
The memory detection code historically had to use unsigned long long since the machine reported the true memory size (>4GB) even if the virtual machine was running in ESA/390 mode. Since the old code is gone use unsigned long everywhere and also get rid of an unused ADDR2G define. (this patch converts all long longs within sclp_info to longs) There are many more possible conversions, however that can be done if somebody touches the corresponding code. Since people started to convert unrelated long types to long longs because of the types within struct sclp_info convert this now. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-12-18s390/extmem: remove unused variableChristian Borntraeger
findseg_scode is assigned, but never used. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-12-18s390/fault: remove unused variableChristian Borntraeger
address is assigned but never used. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-12-15KVM: s390: fix mismatch between user and in-kernel guest limitDominik Dingel
While the userspace interface requests the maximum size the gmap code expects to get a maximum address. This error resulted in bigger page tables than necessary for some guest sizes, e.g. a 2GB guest used 3 levels instead of 2. At the same time we introduce KVM_S390_NO_MEM_LIMIT, which allows in a bright future that a guest spans the complete 64 bit address space. We also switch to TASK_MAX_SIZE for the initial memory size, this is a cosmetic change as the previous size also resulted in a 4 level pagetable creation. Reported-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-11-27s390: get_user_pages_fast() might sleepDavid Hildenbrand
Let's annotate it correctly, so we directly get a warning if we ever were to use it in atomic/preempt_disable/spinlock environment. Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-11-16s390: avoid cache aliasing under z/VM and KVMMartin Schwidefsky
commit 1f6b83e5e4d3 ("s390: avoid z13 cache aliasing") checks for the machine type to optimize address space randomization and zero page allocation to avoid cache aliases. This check might fail under a hypervisor with migration support. z/VMs "Single System Image and Live Guest Relocation" facility will "fake" the machine type of the oldest system in the group. For example in a group of zEC12 and Z13 the guest appears to run on a zEC12 (architecture fencing within the relocation domain) Remove the machine type detection and always use cache aliasing rules that are known to work for all machines. These are the z13 aliasing rules. Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14s390/cpumf: rework program parameter setting to detect guest samplesChristian Borntraeger
The program parameter can be used to mark hardware samples with some token. Previously, it was used to mark guest samples only. Improve the program parameter doubleword by combining two parts, the leftmost LPP part and the rightmost PID part. Set the PID part for processes by using the task PID. To distinguish host and guest samples for the kernel (PID part is zero), the guest must always set the program paramater to a non-zero value. Use the leftmost bit in the LPP part of the program parameter to be able to detect guest kernel samples. [brueckner@linux.vnet.ibm.com]: Split __LC_CURRENT and introduced __LC_LPP. Corrected __LC_CURRENT users and adjusted assembler parts. And updated the commit message accordingly. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14s390/diag: add a statistic for diagnose callsMartin Schwidefsky
Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose calls have been done by each CPU in the system. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14s390/mm: implement soft-dirty bits for user memory change trackingMartin Schwidefsky
Use bit 2**1 of the pte and bit 2**14 of the pmd for the soft dirty bit. The fault mechanism to do dirty tracking is already in place. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-08Merge tag 'libnvdimm-for-4.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This update has successfully completed a 0day-kbuild run and has appeared in a linux-next release. The changes outside of the typical drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and the introduction of ZONE_DEVICE + devm_memremap_pages(). Summary: - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic mechanism for adding device-driver-discovered memory regions to the kernel's direct map. This facility is used by the pmem driver to enable pfn_to_page() operations on the page frames returned by DAX ('direct_access' in 'struct block_device_operations'). For now, the 'memmap' allocation for these "device" pages comes from "System RAM". Support for allocating the memmap from device memory will arrive in a later kernel. - Introduce memremap() to replace usages of ioremap_cache() and ioremap_wt(). memremap() drops the __iomem annotation for these mappings to memory that do not have i/o side effects. The replacement of ioremap_cache() with memremap() is limited to the pmem driver to ease merging the api change in v4.3. Completion of the conversion is targeted for v4.4. - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem driver, update the VFS DAX implementation and PMEM api to provide persistence guarantees for kernel operations on a DAX mapping. - Convert the ACPI NFIT 'BLK' driver to map the block apertures as cacheable to improve performance. - Miscellaneous updates and fixes to libnvdimm including support for issuing "address range scrub" commands, clarifying the optimal 'sector size' of pmem devices, a clarification of the usage of the ACPI '_STA' (status) property for DIMM devices, and other minor fixes" * tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits) libnvdimm, pmem: direct map legacy pmem by default libnvdimm, pmem: 'struct page' for pmem libnvdimm, pfn: 'struct page' provider infrastructure x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB add devm_memremap_pages mm: ZONE_DEVICE for "device memory" mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h dax: drop size parameter to ->direct_access() nd_blk: change aperture mapping from WC to WB nvdimm: change to use generic kvfree() pmem, dax: have direct_access use __pmem annotation dax: update I/O path to do proper PMEM flushing pmem: add copy_from_iter_pmem() and clear_pmem() pmem, x86: clean up conditional pmem includes pmem: remove layer when calling arch_has_wmb_pmem() pmem, x86: move x86 PMEM API to new pmem.h header libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option pmem: switch to devm_ allocations devres: add devm_memremap libnvdimm, btt: write and validate parent_uuid ...
2015-08-27mm: ZONE_DEVICE for "device memory"Dan Williams
While pmem is usable as a block device or via DAX mappings to userspace there are several usage scenarios that can not target pmem due to its lack of struct page coverage. In preparation for "hot plugging" pmem into the vmemmap add ZONE_DEVICE as a new zone to tag these pages separately from the ones that are subject to standard page allocations. Importantly "device memory" can be removed at will by userspace unbinding the driver of the device. Having a separate zone prevents allocation and otherwise marks these pages that are distinct from typical uniform memory. Device memory has different lifetime and performance characteristics than RAM. However, since we have run out of ZONES_SHIFT bits this functionality currently depends on sacrificing ZONE_DMA. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Jerome Glisse <j.glisse@gmail.com> [hch: various simplifications in the arch interface] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-19s390/mm: simplify page table alloc/free codeMartin Schwidefsky
With the removal of the dynamic reallocation of page tables for KVM (see git commit 0b46e0a3ec0d7a04af6a091354f1b5e1b952d70a) the page table allocation / freeing code can be simplified. The page table free code can now use the alloc_pgste bit in the mm context to decide if a page table is 2K or 4K, there is no mix of different sized page tables anymore. This eliminates the need to use "page->_mapcount == 0" to check for 4K page table. Use the lower two bits in page->_mapcount to indicate which 2K fragments of the 4K page are in use. As 31-bit support is gone, remove the two defines ALLOC_ORDER and FRAG_MASK and use the constants directly where appropriate. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-19s390: remove unneeded sizeof(void *) comparisonsHeiko Carstens
Remove two more statements which always evaluate to 'false'. These are more leftovers from the 31 bit era. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-03s390/numa: add core infrastructurePhilipp Hachtmann
Enable core NUMA support for s390 and add one simple default mode "plain" that creates one single NUMA node. This patch contains several changes from Michael Holzheu. Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-03s390/mm: make arch_add_memory() NUMA awareGerald Schaefer
With NUMA support for s390, arch_add_memory() needs to respect the nid parameter. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-03s390/mm: enable gup code for NUMAGerald Schaefer
Force get_user_page() to take the slow path for NUMA migration pages. Signed-off-by: Gerald Schaefer <geraldsc@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-07-17revert "s390/mm: make hugepages_supported a boot time decision"Dominik Dingel
Heiko noticed that the current check for hugepage support on s390 is a little bit too harsh as systems which do not support will crash. The reason is that pageblock_order can now get negative when we set HPAGE_SHIFT to 0. To avoid all this and to avoid opening another can of worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best to simply allow architectures to define their own hugepages_supported(). Revert bea41197ead3 ("s390/mm: make hugepages_supported a boot time decision") in preparation. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17revert "s390/mm: change HPAGE_SHIFT type to int"Dominik Dingel
Heiko noticed that the current check for hugepage support on s390 is a little bit too harsh as systems which do not support will crash. The reason is that pageblock_order can now get negative when we set HPAGE_SHIFT to 0. To avoid all this and to avoid opening another can of worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best to simply allow architectures to define their own hugepages_supported(). This patch (of 4): revert commit cf54e2fce51c ("s390/mm: change HPAGE_SHIFT type to int") in preparation. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26s390/mm: change HPAGE_SHIFT type to intDominik Dingel
With making HPAGE_SHIFT an unsigned integer we also accidentally changed pageblock_order. In order to avoid compiler warnings we make HPAGE_SHFIT an int again. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26s390/mm: forward check for huge pmds to pmd_large()Dominik Dingel
We already do the check in pmd_large, so we can just forward the call. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26s390/hugetlb: remove dead code for sw emulated huge pagesDominik Dingel
We now support only hugepages on hardware with EDAT1 support. So we remove the prepare/release_hugepage hooks and simplify set_huge_pte_at and huge_ptep_get. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26s390/mm: make hugepages_supported a boot time decisionDominik Dingel
There is a potential bug with KVM and hugetlbfs if the hardware does not support hugepages (EDAT1). We fix this by making EDAT1 a hard requirement for hugepages and therefore removing and simplifying code. As s390, with the sw-emulated hugepages, was the only user of arch_prepare/release_hugepage I also removed theses calls from common and other architecture code. This patch (of 5): By dropping support for hugepages on machines which do not have the hardware feature EDAT1, we fix a potential s390 KVM bug. The bug would happen if a guest is backed by hugetlbfs (not supported currently), but does not get pagetables with PGSTE. This would lead to random memory overwrites. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25mm/hugetlb: reduce arch dependent code about huge_pmd_unshareZhang Zhen
Currently we have many duplicates in definitions of huge_pmd_unshare. In all architectures this function just returns 0 when CONFIG_ARCH_WANT_HUGE_PMD_SHARE is N. This patch puts the default implementation in mm/hugetlb.c and lets these architectures use the common code. Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Rientjes <rientjes@google.com> Cc: James Yang <James.Yang@freescale.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "Pretty boring for a merge window pull. One change in behaviour is the patch for dasd driver, the module which provides the diagnose discipline is now loaded automatically. The SCLP code got a nice cleanup, a new global structure replaces a bunch of accessor functions. And a couple of random, small improvements" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pci: improve handling of hotplug event 0x301 s390/setup: fix DMA_API_DEBUG warnings s390/zcrypt: remove obsolete __constant s390/keyboard: avoid off-by-one when using strnlen_user() s390/sclp: pass timeout as HZ independent value s390/mm: s/specifiation/specification/, s/an specification/a specification/ s390/sclp: Use DECLARE_BITMAP s390/dasd: Enable automatic loading of dasd_diag_mod s390/sclp: move sclp_facilities into "struct sclp" s390/sclp: get rid of sclp_get_mtid() and sclp_get_mtid_max() s390/sclp: unify basic sclp access by exposing "struct sclp" s390/sclp: prepare smp_fill_possible_mask for global "struct sclp"
2015-05-19mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in ↵David Hildenbrand
the handler Introduce faulthandler_disabled() and use it to check for irq context and disabled pagefaults (via pagefault_disable()) in the pagefault handlers. Please note that we keep the in_atomic() checks in place - to detect whether in irq context (in which case preemption is always properly disabled). In contrast, preempt_disable() should never be used to disable pagefaults. With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt counter, and therefore the result of in_atomic() differs. We validate that condition by using might_fault() checks when calling might_sleep(). Therefore, add a comment to faulthandler_disabled(), describing why this is needed. faulthandler_disabled() and pagefault_disable() are defined in linux/uaccess.h, so let's properly add that include to all relevant files. This patch is based on a patch from Thomas Gleixner. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-13s390/sclp: unify basic sclp access by exposing "struct sclp"David Hildenbrand
Let's unify basic access to sclp fields by storing the data in an external struct in asm/sclp.h. The values can now directly be accessed by other components, so there is no need for most accessor functions and external variables anymore. The mtid, mtid_max and facility part will be cleaned up separately. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-04-23s390/mm: change swap pte encoding and pgtable cleanupMartin Schwidefsky
After the file ptes have been removed the bit combination used to encode non-linear mappings can be reused for the swap ptes. This frees up a precious pte software bit. Reflect the change in the swap encoding in the comments and do some cleanup while we are at it. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-04-23s390/mm: correct transfer of dirty & young bits in __pmd_to_pteMartin Schwidefsky
The dirty & young bit from the pmd is not copied correctly to the pseudo pte in __pmd_to_pte. In fact it is not copied at all, the bits get lost. As the old style huge page currently does not need the dirty & young information this has no effect, but may be needed in the future. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-04-23s390/kvm: remove delayed reallocation of page tables for KVMMartin Schwidefsky
Replacing a 2K page table with a 4K page table while a VMA is active for the affected memory region is fundamentally broken. Rip out the page table reallocation code and replace it with a simple system control 'vm.allocate_pgste'. If the system control is set the page tables for all processes are allocated as full 4K pages, even for processes that do not need it. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-04-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The major change in this merge is the removal of the support for 31-bit kernels. Naturally 31-bit user space will continue to work via the compat layer. And then some cleanup, some improvements and bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (23 commits) s390/smp: wait until secondaries are active & online s390/hibernate: fix save and restore of kernel text section s390/cacheinfo: add missing facility check s390/syscalls: simplify syscall_get_arch() s390/irq: enforce correct irqclass_sub_desc array size s390: remove "64" suffix from mem64.S and swsusp_asm64.S s390/ipl: cleanup macro usage s390/ipl: cleanup shutdown_action attributes s390/ipl: cleanup bin attr usage s390/uprobes: fix address space annotation s390: add missing arch_release_task_struct() declaration s390: make couple of functions and variables static s390/maccess: improve s390_kernel_write() s390/maccess: remove potentially broken probe_kernel_write() s390/watchdog: support for KVM hypervisors and delete pr_info messages s390/watchdog: enable KEEPALIVE for /dev/watchdog s390/dasd: remove setting of scheduler from driver s390/traps: panic() instead of die() on translation exception s390: remove test_facility(2) (== z/Architecture mode active) checks s390/cmpxchg: simplify cmpxchg_double ...
2015-04-14mm: split ET_DYN ASLR from mmap ASLRKees Cook
This fixes the "offset2lib" weakness in ASLR for arm, arm64, mips, powerpc, and x86. The problem is that if there is a leak of ASLR from the executable (ET_DYN), it means a leak of shared library offset as well (mmap), and vice versa. Further details and a PoC of this attack is available here: http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html With this patch, a PIE linked executable (ET_DYN) has its own ASLR region: $ ./show_mmaps_pie 54859ccd6000-54859ccd7000 r-xp ... /tmp/show_mmaps_pie 54859ced6000-54859ced7000 r--p ... /tmp/show_mmaps_pie 54859ced7000-54859ced8000 rw-p ... /tmp/show_mmaps_pie 7f75be764000-7f75be91f000 r-xp ... /lib/x86_64-linux-gnu/libc.so.6 7f75be91f000-7f75beb1f000 ---p ... /lib/x86_64-linux-gnu/libc.so.6 7f75beb1f000-7f75beb23000 r--p ... /lib/x86_64-linux-gnu/libc.so.6 7f75beb23000-7f75beb25000 rw-p ... /lib/x86_64-linux-gnu/libc.so.6 7f75beb25000-7f75beb2a000 rw-p ... 7f75beb2a000-7f75beb4d000 r-xp ... /lib64/ld-linux-x86-64.so.2 7f75bed45000-7f75bed46000 rw-p ... 7f75bed46000-7f75bed47000 r-xp ... 7f75bed47000-7f75bed4c000 rw-p ... 7f75bed4c000-7f75bed4d000 r--p ... /lib64/ld-linux-x86-64.so.2 7f75bed4d000-7f75bed4e000 rw-p ... /lib64/ld-linux-x86-64.so.2 7f75bed4e000-7f75bed4f000 rw-p ... 7fffb3741000-7fffb3762000 rw-p ... [stack] 7fffb377b000-7fffb377d000 r--p ... [vvar] 7fffb377d000-7fffb377f000 r-xp ... [vdso] The change is to add a call the newly created arch_mmap_rnd() into the ELF loader for handling ET_DYN ASLR in a separate region from mmap ASLR, as was already done on s390. Removes CONFIG_BINFMT_ELF_RANDOMIZE_PIE, which is no longer needed. Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> 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: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14s390: redefine randomize_et_dyn for ELF_ET_DYN_BASEKees Cook
In preparation for moving ET_DYN randomization into the ELF loader (which requires a static ELF_ET_DYN_BASE), this redefines s390's existing ET_DYN randomization in a call to arch_mmap_rnd(). This refactoring results in the same ET_DYN randomization on s390. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14mm: expose arch_mmap_rnd when availableKees Cook
When an architecture fully supports randomizing the ELF load location, a per-arch mmap_rnd() function is used to find a randomized mmap base. In preparation for randomizing the location of ET_DYN binaries separately from mmap, this renames and exports these functions as arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE for describing this feature on architectures that support it (which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390 already supports a separated ET_DYN ASLR from mmap ASLR without the ARCH_BINFMT_ELF_RANDOMIZE_PIE logic). Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> 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: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14s390: standardize mmap_rnd() usageKees Cook
In preparation for splitting out ET_DYN ASLR, this refactors the use of mmap_rnd() to be used similarly to arm and x86, and extracts the checking of PF_RANDOMIZE. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-25s390: make couple of functions and variables staticHeiko Carstens
As reported by sparse these can and should be static. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25s390/maccess: improve s390_kernel_write()Heiko Carstens
Use the sturg instruction instead of the stura instruction. This allows to modify up to eight bytes in a row instead of only four. For function tracer enabling and disabling this reduces the time needed to modify the text sections by 50%, since for each mcount call site six bytes need to be changed. Also remove the EXTABLE entries, since calls to this function are not supposed to fail. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25s390/maccess: remove potentially broken probe_kernel_write()Heiko Carstens
Remove the s390 architecture implementation of probe_kernel_write() and instead use a new function s390_kernel_write() to modify kernel text and data everywhere. The s390 implementation of probe_kernel_write() was potentially broken since it modified memory in a read-modify-write fashion, which read four bytes, modified the requested bytes within those four bytes and wrote the result back. If two cpus would modify the same four byte area at different locations within that area, this could lead to corruption. Right now the only places which called probe_kernel_write() did run within stop_machine_run. Therefore the scenario can't happen right now, however that might change at any time. To fix this rename probe_kernel_write() to s390_kernel_write() which can have special semantics, like only call it while running within stop_machine(). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25s390: remove 31 bit supportHeiko Carstens
Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>