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* kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()David Hildenbrand2020-10-161-3/+2
| | | | | | | | | | | | | | | | | | | | | "mem" in the name already indicates the root, similar to release_mem_region() and devm_request_mem_region(). Make it implicit. The only single caller always passes iomem_resource, other parents are not applicable. Suggested-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Baoquan He <bhe@redhat.com> Link: https://lkml.kernel.org/r/20200916073041.10355-1-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM ↵David Hildenbrand2020-10-161-0/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | resources Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where possible. Let's provide a flag (MEMHP_MERGE_RESOURCE) to specify that a resource either created within add_memory*() or passed via add_memory_resource() shall be marked mergeable and merged with applicable siblings. To implement that, we need a kernel/resource interface to mark selected System RAM resources mergeable (IORESOURCE_SYSRAM_MERGEABLE) and trigger merging. Note: We really want to merge after the whole operation succeeded, not directly when adding a resource to the resource tree (it would break add_memory_resource() and require splitting resources again when the operation failed - e.g., due to -ENOMEM). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: Julien Grall <julien@xen.org> Cc: Baoquan He <bhe@redhat.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: Leonardo Bras <leobras.c@gmail.com> Cc: Libor Pechacek <lpechacek@suse.cz> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Link: https://lkml.kernel.org/r/20200911103459.10306-6-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/resource: make release_mem_region_adjustable() never failDavid Hildenbrand2020-10-161-21/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "selective merging of system ram resources", v4. Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where possible. Resources are effectively stored in a list-based tree. Having a lot of resources not only wastes memory, it also makes traversing that tree more expensive, and makes /proc/iomem explode in size (e.g., requiring kexec-tools to manually merge resources when creating a kdump header. The current kexec-tools resource count limit does not allow for more than ~100GB of memory with a memory block size of 128MB on x86-64). Let's allow to selectively merge system ram resources by specifying a new flag for add_memory*(). Patch #5 contains a /proc/iomem example. Only tested with virtio-mem. This patch (of 8): Let's make sure splitting a resource on memory hotunplug will never fail. This will become more relevant once we merge selected System RAM resources - then, we'll trigger that case more often on memory hotunplug. In general, this function is already unlikely to fail. When we remove memory, we free up quite a lot of metadata (memmap, page tables, memory block device, etc.). The only reason it could really fail would be when injecting allocation errors. All other error cases inside release_mem_region_adjustable() seem to be sanity checks if the function would be abused in different context - let's add WARN_ON_ONCE() in these cases so we can catch them. [natechancellor@gmail.com: fix use of ternary condition in release_mem_region_adjustable] Link: https://lkml.kernel.org/r/20200922060748.2452056-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/1159 Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Julien Grall <julien@xen.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Len Brown <lenb@kernel.org> Cc: Leonardo Bras <leobras.c@gmail.com> Cc: Libor Pechacek <lpechacek@suse.cz> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Roger Pau Monn <roger.pau@citrix.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20200911103459.10306-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* resource: report parent to walk_iomem_res_desc() callbackDan Williams2020-10-141-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In support of detecting whether a resource might have been been claimed, report the parent to the walk_iomem_res_desc() callback. For example, the ACPI HMAT parser publishes "hmem" platform devices per target range. However, if the HMAT is disabled / missing a fallback driver can attach devices to the raw memory ranges as a fallback if it sees unclaimed / orphan "Soft Reserved" resources in the resource tree. Otherwise, find_next_iomem_res() returns a resource with garbage data from the stack allocation in __walk_iomem_res_desc() for the res->parent field. There are currently no users that expect ->child and ->sibling to be valid, and the resource_lock would be needed to traverse them. Use a compound literal to implicitly zero initialize the fields that are not being returned in addition to setting ->parent. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kernel test robot <lkp@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Link: https://lkml.kernel.org/r/159643097166.4062302.11875688887228572793.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* /dev/mem: Revoke mappings when a driver claims the regionDan Williams2020-05-271-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Close the hole of holding a mapping over kernel driver takeover event of a given address range. Commit 90a545e98126 ("restrict /dev/mem to idle io memory ranges") introduced CONFIG_IO_STRICT_DEVMEM with the goal of protecting the kernel against scenarios where a /dev/mem user tramples memory that a kernel driver owns. However, this protection only prevents *new* read(), write() and mmap() requests. Established mappings prior to the driver calling request_mem_region() are left alone. Especially with persistent memory, and the core kernel metadata that is stored there, there are plentiful scenarios for a /dev/mem user to violate the expectations of the driver and cause amplified damage. Teach request_mem_region() to find and shoot down active /dev/mem mappings that it believes it has successfully claimed for the exclusive use of the driver. Effectively a driver call to request_mem_region() becomes a hole-punch on the /dev/mem device. The typical usage of unmap_mapping_range() is part of truncate_pagecache() to punch a hole in a file, but in this case the implementation is only doing the "first half" of a hole punch. Namely it is just evacuating current established mappings of the "hole", and it relies on the fact that /dev/mem establishes mappings in terms of absolute physical address offsets. Once existing mmap users are invalidated they can attempt to re-establish the mapping, or attempt to continue issuing read(2) / write(2) to the invalidated extent, but they will then be subject to the CONFIG_IO_STRICT_DEVMEM checking that can block those subsequent accesses. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 90a545e98126 ("restrict /dev/mem to idle io memory ranges") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/159009507306.847224.8502634072429766747.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/memory_hotplug.c: use PFN_UP / PFN_DOWN in walk_system_ram_range()David Hildenbrand2019-09-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm/memory_hotplug: online_pages() cleanups", v2. Some cleanups (+ one fix for a special case) in the context of online_pages(). This patch (of 5): This makes it clearer that we will never call func() with duplicate PFNs in case we have multiple sub-page memory resources. All unaligned parts of PFNs are completely discarded. Link: http://lkml.kernel.org/r/20190814154109.3448-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Wei Yang <richardw.yang@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Nadav Amit <namit@vmware.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Arun KS <arunks@codeaurora.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* resource: add a not device managed request_free_mem_region variantChristoph Hellwig2019-08-201-14/+31
| | | | | | | | | | | | | | Factor out the guts of devm_request_free_mem_region so that we can implement both a device managed and a manually release version as tiny wrappers around it. Link: https://lore.kernel.org/r/20190818090557.17853-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Bharata B Rao <bharata@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
* resource: avoid unnecessary lookups in find_next_iomem_res()Nadav Amit2019-07-191-7/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_next_iomem_res() shows up to be a source for overhead in dax benchmarks. Improve performance by not considering children of the tree if the top level does not match. Since the range of the parents should include the range of the children such check is redundant. Running sysbench on dax (pmem emulation, with write_cache disabled): sysbench fileio --file-total-size=3G --file-test-mode=rndwr \ --file-io-mode=mmap --threads=4 --file-fsync-mode=fdatasync run Provides the following results: events (avg/stddev) ------------------- 5.2-rc3: 1247669.0000/16075.39 w/patch: 1286320.5000/16402.72 (+3%) Link: http://lkml.kernel.org/r/20190613045903.4922-3-namit@vmware.com Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Borislav Petkov <bp@suse.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* resource: fix locking in find_next_iomem_res()Nadav Amit2019-07-191-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | Since resources can be removed, locking should ensure that the resource is not removed while accessing it. However, find_next_iomem_res() does not hold the lock while copying the data of the resource. Keep holding the lock while the data is copied. While at it, change the return value to a more informative value. It is disregarded by the callers. [akpm@linux-foundation.org: fix find_next_iomem_res() documentation] Link: http://lkml.kernel.org/r/20190613045903.4922-2-namit@vmware.com Fixes: ff3cc952d3f00 ("resource: Add remove_resource interface") Signed-off-by: Nadav Amit <namit@vmware.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: factor out a devm_request_free_mem_region helperChristoph Hellwig2019-07-021-0/+39
| | | | | | | | | | | | Keep the physical address allocation that hmm_add_device does with the rest of the resource code, and allow future reuse of it without the hmm wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
* treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/resource: Use resource_overlaps() to simplify region_intersects()Wei Yang2019-04-191-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | The three checks in region_intersects() are basically an open-coded version of resource_overlaps() - so use the real thing. Also fix typos in comments while at it. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Reviewed-by: Like Xu <like.xu@linux.intel.com> Reviewed-by: Yuan Yao <yuan.yao@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: bhelgaas@google.com Cc: bp@suse.de Cc: dan.j.williams@intel.com Cc: jack@suse.cz Cc: rdunlap@infradead.org Cc: tiwai@suse.de Link: http://lkml.kernel.org/r/20190305083432.23675-1-richardw.yang@linux.intel.com [ Rewrote the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge tag 'devdax-for-5.1' of ↵Linus Torvalds2019-03-161-3/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull device-dax updates from Dan Williams: "New device-dax infrastructure to allow persistent memory and other "reserved" / performance differentiated memories, to be assigned to the core-mm as "System RAM". Some users want to use persistent memory as additional volatile memory. They are willing to cope with potential performance differences, for example between DRAM and 3D Xpoint, and want to use typical Linux memory management apis rather than a userspace memory allocator layered over an mmap() of a dax file. The administration model is to decide how much Persistent Memory (pmem) to use as System RAM, create a device-dax-mode namespace of that size, and then assign it to the core-mm. The rationale for device-dax is that it is a generic memory-mapping driver that can be layered over any "special purpose" memory, not just pmem. On subsequent boots udev rules can be used to restore the memory assignment. One implication of using pmem as RAM is that mlock() no longer keeps data off persistent media. For this reason it is recommended to enable NVDIMM Security (previously merged for 5.0) to encrypt pmem contents at rest. We considered making this recommendation an actively enforced requirement, but in the end decided to leave it as a distribution / administrator policy to allow for emulation and test environments that lack security capable NVDIMMs. Summary: - Replace the /sys/class/dax device model with /sys/bus/dax, and include a compat driver so distributions can opt-in to the new ABI. - Allow for an alternative driver for the device-dax address-range - Introduce the 'kmem' driver to hotplug / assign a device-dax address-range to the core-mm. - Arrange for the device-dax target-node to be onlined so that the newly added memory range can be uniquely referenced by numa apis" NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because we currently have special - and very annoying rules in the kernel about accessing PMEM only with the "MC safe" accessors, because machine checks inside the regular repeat string copy functions can be fatal in some (not described) circumstances. And apparently the PMEM modules can cause that a lot more than regular RAM. The argument is that this happens because PMEM doesn't necessarily get scrubbed at boot like RAM does, but that is planned to be added for the user space tooling. Quoting Dan from another email: "The exposure can be reduced in the volatile-RAM case by scanning for and clearing errors before it is onlined as RAM. The userspace tooling for that can be in place before v5.1-final. There's also runtime notifications of errors via acpi_nfit_uc_error_notify() from background scrubbers on the DIMM devices. With that mechanism the kernel could proactively clear newly discovered poison in the volatile case, but that would be additional development more suitable for v5.2. I understand the concern, and the need to highlight this issue by tapping the brakes on feature development, but I don't see PMEM as RAM making the situation worse when the exposure is also there via DAX in the PMEM case. Volatile-RAM is arguably a safer use case since it's possible to repair pages where the persistent case needs active application coordination" * tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: "Hotplug" persistent memory for use like normal RAM mm/resource: Let walk_system_ram_range() search child resources mm/memory-hotplug: Allow memory resources to be children mm/resource: Move HMM pr_debug() deeper into resource code mm/resource: Return real error codes from walk failures device-dax: Add a 'modalias' attribute to DAX 'bus' devices device-dax: Add a 'target_node' attribute device-dax: Auto-bind device after successful new_id acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node device-dax: Add /sys/class/dax backwards compatibility device-dax: Add support for a dax override driver device-dax: Move resource pinning+mapping into the common driver device-dax: Introduce bus + driver model device-dax: Start defining a dax bus model device-dax: Remove multi-resource infrastructure device-dax: Kill dax_region base device-dax: Kill dax_region ida
| * mm/resource: Let walk_system_ram_range() search child resourcesDave Hansen2019-02-281-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the process of onlining memory, we use walk_system_ram_range() to find the actual RAM areas inside of the area being onlined. However, it currently only finds memory resources which are "top-level" iomem_resources. Children are not currently searched which causes it to skip System RAM in areas like this (in the format of /proc/iomem): a0000000-bfffffff : Persistent Memory (legacy) a0000000-afffffff : System RAM Changing the true->false here allows children to be searched as well. We need this because we add a new "System RAM" resource underneath the "persistent memory" resource when we use persistent memory in a volatile mode. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * mm/resource: Move HMM pr_debug() deeper into resource codeDave Hansen2019-02-281-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | HMM consumes physical address space for its own use, even though nothing is mapped or accessible there. It uses a special resource description (IORES_DESC_DEVICE_PRIVATE_MEMORY) to uniquely identify these areas. When HMM consumes address space, it makes a best guess about what to consume. However, it is possible that a future memory or device hotplug can collide with the reserved area. In the case of these conflicts, there is an error message in register_memory_resource(). Later patches in this series move register_memory_resource() from using request_resource_conflict() to __request_region(). Unfortunately, __request_region() does not return the conflict like the previous function did, which makes it impossible to check for IORES_DESC_DEVICE_PRIVATE_MEMORY in a conflicting resource. Instead of warning in register_memory_resource(), move the check into the core resource code itself (__request_region()) where the conflicting resource _is_ available. This has the added bonus of producing a warning in case of HMM conflicts with devices *or* RAM address space, as opposed to the RAM- only warnings that were there previously. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Keith Busch <keith.busch@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * mm/resource: Return real error codes from walk failuresDave Hansen2019-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | walk_system_ram_range() can return an error code either becuase *it* failed, or because the 'func' that it calls returned an error. The memory hotplug does the following: ret = walk_system_ram_range(..., func); if (ret) return ret; and 'ret' makes it out to userspace, eventually. The problem s, walk_system_ram_range() failues that result from *it* failing (as opposed to 'func') return -1. That leads to a very odd -EPERM (-1) return code out to userspace. Make walk_system_ram_range() return -EINVAL for internal failures to keep userspace less confused. This return code is compatible with all the callers that I audited. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Cc: Keith Busch <keith.busch@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | powerpc: Drop page_is_ram() and walk_system_ram_range()Christophe Leroy2019-02-041-4/+0
|/ | | | | | | | | | | | | | | | | | Since commit c40dd2f76644 ("powerpc: Add System RAM to /proc/iomem") it is possible to use the generic walk_system_ram_range() and the generic page_is_ram(). To enable the use of walk_system_ram_range() by the IBM EHEA ethernet driver, we still need an export of the generic function. As powerpc was the only user of CONFIG_ARCH_HAS_WALK_MEMORY, the ifdef around the generic walk_system_ram_range() has become useless and can be dropped. Fixes: c40dd2f76644 ("powerpc: Add System RAM to /proc/iomem") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Keep the EXPORT_SYMBOL_GPL in powerpc code] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustableOscar Salvador2018-12-281-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparation for the next patch. Currently, we only call release_mem_region_adjustable() in __remove_pages if the zone is not ZONE_DEVICE, because resources that belong to HMM/devm are being released by themselves with devm_release_mem_region. Since we do not want to touch any zone/page stuff during the removing of the memory (but during the offlining), we do not want to check for the zone here. So we need another way to tell release_mem_region_adjustable() to not realease the resource in case it belongs to HMM/devm. HMM/devm acquires/releases a resource through devm_request_mem_region/devm_release_mem_region. These resources have the flag IORESOURCE_MEM, while resources acquired by hot-add memory path (register_memory_resource()) contain IORESOURCE_SYSTEM_RAM. So, we can check for this flag in release_mem_region_adjustable, and if the resource does not contain such flag, we know that we are dealing with a HMM/devm resource, so we can back off. Link: http://lkml.kernel.org/r/20181127162005.15833-3-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: Dan Williams <dan.j.williams@intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.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>
* resource/docs: Complete kernel-doc style function documentationBorislav Petkov2018-11-071-9/+14
| | | | | | | | | | | | | | | Add the missing kernel-doc style function parameters documentation. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: linux-tip-commits@vger.kernel.org Cc: rdunlap@infradead.org Fixes: b69c2e20f6e4 ("resource: Clean it up a bit") Link: http://lkml.kernel.org/r/20181105093307.GA12445@zn.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
* resource/docs: Fix new kernel-doc warningsRandy Dunlap2018-11-051-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The first group of warnings is caused by a "/**" kernel-doc notation marker but the function comments are not in kernel-doc format. Also add another error return value here. ../kernel/resource.c:337: warning: Function parameter or member 'start' not described in 'find_next_iomem_res' ../kernel/resource.c:337: warning: Function parameter or member 'end' not described in 'find_next_iomem_res' ../kernel/resource.c:337: warning: Function parameter or member 'flags' not described in 'find_next_iomem_res' ../kernel/resource.c:337: warning: Function parameter or member 'desc' not described in 'find_next_iomem_res' ../kernel/resource.c:337: warning: Function parameter or member 'first_lvl' not described in 'find_next_iomem_res' ../kernel/resource.c:337: warning: Function parameter or member 'res' not described in 'find_next_iomem_res' Add the missing function parameter documentation for the other warnings: ../kernel/resource.c:409: warning: Function parameter or member 'arg' not described in 'walk_iomem_res_desc' ../kernel/resource.c:409: warning: Function parameter or member 'func' not described in 'walk_iomem_res_desc' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: b69c2e20f6e4 ("resource: Clean it up a bit") Link: http://lkml.kernel.org/r/dda2e4d8-bedd-3167-20fe-8c7d2d35b354@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* resource: Clean it up a bitBorislav Petkov2018-10-091-29/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Drop BUG_ON()s and do normal error handling instead, in find_next_iomem_res(). - Align function arguments on opening braces. - Get rid of local var sibling_only in find_next_iomem_res(). - Shorten unnecessarily long first_level_children_only arg name. Signed-off-by: Borislav Petkov <bp@suse.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Bjorn Helgaas <bhelgaas@google.com> CC: Brijesh Singh <brijesh.singh@amd.com> CC: Dan Williams <dan.j.williams@intel.com> CC: H. Peter Anvin <hpa@zytor.com> CC: Lianbo Jiang <lijiang@redhat.com> CC: Takashi Iwai <tiwai@suse.de> CC: Thomas Gleixner <tglx@linutronix.de> CC: Tom Lendacky <thomas.lendacky@amd.com> CC: Vivek Goyal <vgoyal@redhat.com> CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com> CC: bhe@redhat.com CC: dan.j.williams@intel.com CC: dyoung@redhat.com CC: kexec@lists.infradead.org CC: mingo@redhat.com Link: <new submission>
* resource: Fix find_next_iomem_res() iteration issueBjorn Helgaas2018-10-091-54/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously find_next_iomem_res() used "*res" as both an input parameter for the range to search and the type of resource to search for, and an output parameter for the resource we found, which makes the interface confusing. The current callers use find_next_iomem_res() incorrectly because they allocate a single struct resource and use it for repeated calls to find_next_iomem_res(). When find_next_iomem_res() returns a resource, it overwrites the start, end, flags, and desc members of the struct. If we call find_next_iomem_res() again, we must update or restore these fields. The previous code restored res.start and res.end, but not res.flags or res.desc. Since the callers did not restore res.flags, if they searched for flags IORESOURCE_MEM | IORESOURCE_BUSY and found a resource with flags IORESOURCE_MEM | IORESOURCE_BUSY | IORESOURCE_SYSRAM, the next search would incorrectly skip resources unless they were also marked as IORESOURCE_SYSRAM. Fix this by restructuring the interface so it takes explicit "start, end, flags" parameters and uses "*res" only as an output parameter. Based on a patch by Lianbo Jiang <lijiang@redhat.com>. [ bp: While at it: - make comments kernel-doc style. - Originally-by: http://lore.kernel.org/lkml/20180921073211.20097-2-lijiang@redhat.com Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Brijesh Singh <brijesh.singh@amd.com> CC: Dan Williams <dan.j.williams@intel.com> CC: H. Peter Anvin <hpa@zytor.com> CC: Lianbo Jiang <lijiang@redhat.com> CC: Takashi Iwai <tiwai@suse.de> CC: Thomas Gleixner <tglx@linutronix.de> CC: Tom Lendacky <thomas.lendacky@amd.com> CC: Vivek Goyal <vgoyal@redhat.com> CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com> CC: bhe@redhat.com CC: dan.j.williams@intel.com CC: dyoung@redhat.com CC: kexec@lists.infradead.org CC: mingo@redhat.com CC: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/153805812916.1157.177580438135143788.stgit@bhelgaas-glaptop.roam.corp.google.com
* resource: Include resource end in walk_*() interfacesBjorn Helgaas2018-10-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_next_iomem_res() finds an iomem resource that covers part of a range described by "start, end". All callers expect that range to be inclusive, i.e., both start and end are included, but find_next_iomem_res() doesn't handle the end address correctly. If it finds an iomem resource that contains exactly the end address, it skips it, e.g., if "start, end" is [0x0-0x10000] and there happens to be an iomem resource [mem 0x10000-0x10000] (the single byte at 0x10000), we skip it: find_next_iomem_res(...) { start = 0x0; end = 0x10000; for (p = next_resource(...)) { # p->start = 0x10000; # p->end = 0x10000; # we *should* return this resource, but this condition is false: if ((p->end >= start) && (p->start < end)) break; Adjust find_next_iomem_res() so it allows a resource that includes the single byte at the end of the range. This is a corner case that we probably don't see in practice. Fixes: 58c1b5b07907 ("[PATCH] memory hotadd fixes: find_next_system_ram catch range fix") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Brijesh Singh <brijesh.singh@amd.com> CC: Dan Williams <dan.j.williams@intel.com> CC: H. Peter Anvin <hpa@zytor.com> CC: Lianbo Jiang <lijiang@redhat.com> CC: Takashi Iwai <tiwai@suse.de> CC: Thomas Gleixner <tglx@linutronix.de> CC: Tom Lendacky <thomas.lendacky@amd.com> CC: Vivek Goyal <vgoyal@redhat.com> CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com> CC: bhe@redhat.com CC: dan.j.williams@intel.com CC: dyoung@redhat.com CC: kexec@lists.infradead.org CC: mingo@redhat.com CC: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/153805812254.1157.16736368485811773752.stgit@bhelgaas-glaptop.roam.corp.google.com
* Merge tag 'libnvdimm-for-4.18' of ↵Linus Torvalds2018-06-091-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This adds a user for the new 'bytes-remaining' updates to memcpy_mcsafe() that you already received through Ingo via the x86-dax- for-linus pull. Not included here, but still targeting this cycle, is support for handling memory media errors (poison) consumed via userspace dax mappings. Summary: - DAX broke a fundamental assumption of truncate of file mapped pages. The truncate path assumed that it is safe to disconnect a pinned page from a file and let the filesystem reclaim the physical block. With DAX the page is equivalent to the filesystem block. Introduce dax_layout_busy_page() to enable filesystems to wait for pinned DAX pages to be released. Without this wait a filesystem could allocate blocks under active device-DMA to a new file. - DAX arranges for the block layer to be bypassed and uses dax_direct_access() + copy_to_iter() to satisfy read(2) calls. However, the memcpy_mcsafe() facility is available through the pmem block driver. In order to safely handle media errors, via the DAX block-layer bypass, introduce copy_to_iter_mcsafe(). - Fix cache management policy relative to the ACPI NFIT Platform Capabilities Structure to properly elide cache flushes when they are not necessary. The table indicates whether CPU caches are power-fail protected. Clarify that a deep flush is always performed on REQ_{FUA,PREFLUSH} requests" * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) dax: Use dax_write_cache* helpers libnvdimm, pmem: Do not flush power-fail protected CPU caches libnvdimm, pmem: Unconditionally deep flush on *sync libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH acpi, nfit: Remove ecc_unit_size dax: dax_insert_mapping_entry always succeeds libnvdimm, e820: Register all pmem resources libnvdimm: Debug probe times linvdimm, pmem: Preserve read-only setting for pmem devices x86, nfit_test: Add unit test for memcpy_mcsafe() pmem: Switch to copy_to_iter_mcsafe() dax: Report bytes remaining in dax_iomap_actor() dax: Introduce a ->copy_to_iter dax operation uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation xfs, dax: introduce xfs_break_dax_layouts() xfs: prepare xfs_break_layouts() for another layout type xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL mm, fs, dax: handle layout changes to pinned dax mappings mm: fix __gup_device_huge vs unmap mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS ...
| * libnvdimm, e820: Register all pmem resourcesDan Williams2018-06-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is currently a mismatch between the resources that will trigger the e820_pmem driver to register/load and the resources that will actually be surfaced as pmem ranges. register_e820_pmem() uses walk_iomem_res_desc() which includes children and siblings. In contrast, e820_pmem_probe() only considers top level resources. For example the following resource tree results in the driver being loaded, but no resources being registered: 398000000000-39bfffffffff : PCI Bus 0000:ae 39be00000000-39bf07ffffff : PCI Bus 0000:af 39be00000000-39beffffffff : 0000:af:00.0 39be10000000-39beffffffff : Persistent Memory (legacy) Fix this up to allow definitions of "legacy" pmem ranges anywhere in system-physical address space. Not that it is a recommended or safe to define a pmem range in PCI space, but it is useful for debug / experimentation, and the restriction on being a top-level resource was arbitrary. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | resource: switch to proc_create_seq_dataChristoph Hellwig2018-05-161-38/+5
|/ | | | | | And use the root resource directly from the proc private data. Signed-off-by: Christoph Hellwig <hch@lst.de>
* resource: fix integer overflow at reallocationTakashi Iwai2018-04-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've got a bug report indicating a kernel panic at booting on an x86-32 system, and it turned out to be the invalid PCI resource assigned after reallocation. __find_resource() first aligns the resource start address and resets the end address with start+size-1 accordingly, then checks whether it's contained. Here the end address may overflow the integer, although resource_contains() still returns true because the function validates only start and end address. So this ends up with returning an invalid resource (start > end). There was already an attempt to cover such a problem in the commit 47ea91b4052d ("Resource: fix wrong resource window calculation"), but this case is an overseen one. This patch adds the validity check of the newly calculated resource for avoiding the integer overflow problem. Bugzilla: http://bugzilla.opensuse.org/show_bug.cgi?id=1086739 Link: http://lkml.kernel.org/r/s5hpo37d5l8.wl-tiwai@suse.de Fixes: 23c570a67448 ("resource: ability to resize an allocated resource") Signed-off-by: Takashi Iwai <tiwai@suse.de> Reported-by: Michael Henders <hendersm@shaw.ca> Tested-by: Michael Henders <hendersm@shaw.ca> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ram Pai <linuxram@us.ibm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-02-071-5/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: - kasan updates - procfs - lib/bitmap updates - other lib/ updates - checkpatch tweaks - rapidio - ubsan - pipe fixes and cleanups - lots of other misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits) Documentation/sysctl/user.txt: fix typo MAINTAINERS: update ARM/QUALCOMM SUPPORT patterns MAINTAINERS: update various PALM patterns MAINTAINERS: update "ARM/OXNAS platform support" patterns MAINTAINERS: update Cortina/Gemini patterns MAINTAINERS: remove ARM/CLKDEV SUPPORT file pattern MAINTAINERS: remove ANDROID ION pattern mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors mm: docs: fix parameter names mismatch mm: docs: fixup punctuation pipe: read buffer limits atomically pipe: simplify round_pipe_size() pipe: reject F_SETPIPE_SZ with size over UINT_MAX pipe: fix off-by-one error when checking buffer limits pipe: actually allow root to exceed the pipe buffer limits pipe, sysctl: remove pipe_proc_fn() pipe, sysctl: drop 'min' parameter from pipe-max-size converter kasan: rework Kconfig settings crash_dump: is_kdump_kernel can be boolean kernel/mutex: mutex_is_locked can be boolean ...
| * kernel/resource: iomem_is_exclusive can be booleanYaowei Bai2018-02-071-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | Make iomem_is_exclusive return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-5-git-send-email-baiyaowei@cmss.chinamobile.com Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | resource: Set type when reserving new regionsBjorn Helgaas2017-12-191-2/+3
| | | | | | | | | | | | | | Set resource structs inserted by __reserve_region_with_split() to have the correct type. Setting the type doesn't fix any functional problem but makes %pR on the resource work better. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* | resource: Set type of "reserve=" user-specified resourcesBjorn Helgaas2017-12-191-6/+18
|/ | | | | | | | | | When we reserve regions because the user specified a "reserve=" parameter, set the resource type to either IORESOURCE_IO (for regions below 0x10000) or IORESOURCE_MEM. The test for 0x10000 is just a heuristic; obviously there can be memory below 0x10000 as well. Improve documentation of the "reserve=" parameter. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* x86/mm, resource: Use PAGE_KERNEL protection for ioremap of memory pagesTom Lendacky2017-11-071-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | In order for memory pages to be properly mapped when SEV is active, it's necessary to use the PAGE_KERNEL protection attribute as the base protection. This ensures that memory mapping of, e.g. ACPI tables, receives the proper mapping attributes. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Tested-by: Borislav Petkov <bp@suse.de> Cc: Laura Abbott <labbott@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: kvm@vger.kernel.org Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Link: https://lkml.kernel.org/r/20171020143059.3291-11-brijesh.singh@amd.com
* resource: Provide resource struct in resource walk callbackTom Lendacky2017-11-071-4/+5
| | | | | | | | | | | | | | | | | | | | | In preperation for a new function that will need additional resource information during the resource walk, update the resource walk callback to pass the resource structure. Since the current callback start and end arguments are pulled from the resource structure, the callback functions can obtain them from the resource structure directly. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Borislav Petkov <bp@suse.de> Tested-by: Borislav Petkov <bp@suse.de> Cc: kvm@vger.kernel.org Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: linuxppc-dev@lists.ozlabs.org Link: https://lkml.kernel.org/r/20171020143059.3291-10-brijesh.singh@amd.com
* resource: Consolidate resource walking codeTom Lendacky2017-11-071-27/+25
| | | | | | | | | | | | | | | | | | The walk_iomem_res_desc(), walk_system_ram_res() and walk_system_ram_range() functions each have much of the same code. Create a new function that consolidates the common code from these functions in one place to reduce the amount of duplicated code. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Tested-by: Borislav Petkov <bp@suse.de> Cc: kvm@vger.kernel.org Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20171020143059.3291-9-brijesh.singh@amd.com
* /proc/iomem: only expose physical resource addresses to privileged usersLinus Torvalds2016-04-141-2/+11
| | | | | | | | | | | | In commit c4004b02f8e5b ("x86: remove the kernel code/data/bss resources from /proc/iomem") I was hoping to remove the phyiscal kernel address data from /proc/iomem entirely, but that had to be reverted because some system programs actually use it. This limits all the detailed resource information to properly credentialed users instead. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* resource: Export insert_resource and remove_resourceToshi Kani2016-03-091-0/+2
| | | | | | | | | | | | | | | | | | insert_resource() and remove_resouce() are called by producers of resources, such as FW modules and bus drivers. These modules may be implemented as loadable modules. Export insert_resource() and remove_resouce() so that they can be called from such modules. link: https://lkml.org/lkml/2016/3/8/872 Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* resource: Add remove_resource interfaceToshi Kani2016-03-091-5/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | insert_resource() and insert_resource_conflict() are called by resource producers to insert a new resource. When there is any conflict, they move conflicting resources down to the children of the new resource. There is no destructor of these interfaces, however. Add remove_resource(), which removes a resource previously inserted by insert_resource() or insert_resource_conflict(), and moves the children up to where they were before. __release_resource() is changed to have @release_child, so that this function can be used for remove_resource() as well. Also add comments to clarify that these functions are intended for producers of resources to avoid any confusion with request/release_resource() for consumers. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* resource: Change __request_region to inherit from immediate parentToshi Kani2016-03-091-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __request_region() sets 'flags' of a new resource from @parent as it inherits the parent's attribute. When a target resource has a conflict, this function inserts the new resource entry under the conflicted entry by updating @parent. In this case, the new resource entry needs to inherit attribute from the updated parent. This conflict is a typical case since __request_region() is used to allocate a new resource from a specific resource range. For instance, request_mem_region() calls __request_region() with @parent set to &iomem_resource, which is the root entry of the whole iomem range. When this request results in inserting a new entry "DEV-A" under "BUS-1", "DEV-A" needs to inherit from the immediate parent "BUS-1" as it holds specific attribute for the range. root (&iomem_resource) : + "BUS-1" + "DEV-A" Change __request_region() to set 'flags' and 'desc' of a new entry from the immediate parent. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge tag 'v4.5-rc6' into core/resources, to resolve conflictIngo Molnar2016-03-041-2/+3
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * kernel/resource.c: fix muxed resource handling in __request_region()Simon Guinot2016-02-201-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In __request_region, if a conflict with a BUSY and MUXED resource is detected, then the caller goes to sleep and waits for the resource to be released. A pointer on the conflicting resource is kept. At wake-up this pointer is used as a parent to retry to request the region. A first problem is that this pointer might well be invalid (if for example the conflicting resource have already been freed). Another problem is that the next call to __request_region() fails to detect a remaining conflict. The previously conflicting resource is passed as a parameter and __request_region() will look for a conflict among the children of this resource and not at the resource itself. It is likely to succeed anyway, even if there is still a conflict. Instead, the parent of the conflicting resource should be passed to __request_region(). As a fix, this patch doesn't update the parent resource pointer in the case we have to wait for a muxed region right after. Reported-and-tested-by: Vincent Pelletier <plr.vincent@gmail.com> Signed-off-by: Simon Guinot <simon.guinot@sequanux.org> Tested-by: Vincent Donnefort <vdonnefort@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | resource: Kill walk_iomem_res()Toshi Kani2016-01-301-44/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | walk_iomem_res_desc() replaced walk_iomem_res() and there is no caller to walk_iomem_res() any more. Kill it. Also remove @name from find_next_iomem_res() as it is no longer used. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-17-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | resource: Add walk_iomem_res_desc()Toshi Kani2016-01-301-10/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new interface, walk_iomem_res_desc(), which walks through the iomem table by identifying a target with @flags and @desc. This interface provides the same functionality as walk_iomem_res(), but does not use strcmp() to @name for better efficiency. walk_iomem_res() is deprecated and will be removed in a later patch. Requested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> [ Fixup comments. ] Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-14-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | memremap: Change region_intersects() to take @flags and @descToshi Kani2016-01-301-11/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change region_intersects() to identify a target with @flags and @desc, instead of @name with strcmp(). Change the callers of region_intersects(), memremap() and devm_memremap(), to set IORESOURCE_SYSTEM_RAM in @flags and IORES_DESC_NONE in @desc when searching System RAM. Also, export region_intersects() so that the ACPI EINJ error injection driver can call this function in a later patch. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-13-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | resource: Change walk_system_ram() to use System RAM typeToshi Kani2016-01-301-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all System RAM resource entries have been initialized to IORESOURCE_SYSTEM_RAM type, change walk_system_ram_res() and walk_system_ram_range() to call find_next_iomem_res() by setting @res.flags to IORESOURCE_SYSTEM_RAM and @name to NULL. With this change, they walk through the iomem table to find System RAM ranges without the need to do strcmp() on the resource names. No functional change is made to the interfaces. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> [ Boris: fixup comments. ] Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-11-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | resource: Add I/O resource descriptorToshi Kani2016-01-301-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | walk_iomem_res() and region_intersects() still need to use strcmp() for searching a resource entry by @name in the iomem table. This patch introduces I/O resource descriptor 'desc' in struct resource for the iomem search interfaces. Drivers can assign their unique descriptor to a range when they support the search interfaces. Otherwise, 'desc' is set to IORES_DESC_NONE (0). This avoids changing most of the drivers as they typically allocate resource entries statically, or by calling alloc_resource(), kzalloc(), or alloc_bootmem_low(), which set the field to zero by default. A later patch will address some drivers that use kmalloc() without zero'ing the field. Also change release_mem_region_adjustable() to set 'desc' when its resource entry gets separated. Other resource interfaces are also changed to initialize 'desc' explicitly although alloc_resource() sets it to 0. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | resource: Handle resource flags properlyToshi Kani2016-01-301-3/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I/O resource flags consist of I/O resource types and modifier bits. Therefore, checking an I/O resource type in 'flags' must be performed with a bitwise operation. Fix find_next_iomem_res() and region_intersects() that simply compare 'flags' against a given value. Also change __request_region() to set 'res->flags' from resource_type() and resource_ext_type() of the parent, so that children nodes will inherit the extended I/O resource type. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/1453841853-11383-3-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* restrict /dev/mem to idle io memory rangesDan Williams2016-01-091-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This effectively promotes IORESOURCE_BUSY to IORESOURCE_EXCLUSIVE semantics by default. If userspace really believes it is safe to access the memory region it can also perform the extra step of disabling an active driver. This protects device address ranges with read side effects and otherwise directs userspace to use the driver. Persistent memory presents a large "mistake surface" to /dev/mem as now accidental writes can corrupt a filesystem. In general if a device driver is busily using a memory region it already informs other parts of the kernel to not touch it via request_mem_region(). /dev/mem should honor the same safety restriction by default. Debugging a device driver from userspace becomes more difficult with this enabled. Any application using /dev/mem or mmap of sysfs pci resources will now need to perform the extra step of either: 1/ Disabling the driver, for example: echo <device id> > /dev/bus/<parent bus>/drivers/<driver name>/unbind 2/ Rebooting with "iomem=relaxed" on the command line 3/ Recompiling with CONFIG_IO_STRICT_DEVMEM=n Traditional users of /dev/mem like dosemu are unaffected because the first 1MB of memory is not subject to the IO_STRICT_DEVMEM restriction. Legacy X configurations use /dev/mem to talk to graphics hardware, but that functionality has since moved to kernel graphics drivers. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm: enhance region_is_ram() to region_intersects()Dan Williams2015-08-111-25/+36
| | | | | | | | | | | | | | | | | | | | | | region_is_ram() is used to prevent the establishment of aliased mappings to physical "System RAM" with incompatible cache settings. However, it uses "-1" to indicate both "unknown" memory ranges (ranges not described by platform firmware) and "mixed" ranges (where the parameters describe a range that partially overlaps "System RAM"). Fix this up by explicitly tracking the "unknown" vs "mixed" resource cases and returning REGION_INTERSECTS, REGION_MIXED, or REGION_DISJOINT. This re-write also adds support for detecting when the requested region completely eclipses all of a resource. Note, the implementation treats overlaps between "unknown" and the requested memory type as REGION_INTERSECTS. Finally, other memory types can be passed in by name, for now the only usage "System RAM". Suggested-by: Luis R. Rodriguez <mcgrof@suse.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mm: Fix bugs in region_is_ram()Toshi Kani2015-07-221-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | region_is_ram() looks up the iomem_resource table to check if a target range is in RAM. However, it always returns with -1 due to invalid range checks. It always breaks the loop at the first entry of the table. Another issue is that it compares p->flags and flags, but it always fails. flags is declared as int, which makes it as a negative value with IORESOURCE_BUSY (0x80000000) set while p->flags is unsigned long. Fix the range check and flags so that region_is_ram() works as advertised. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Mike Travis <travis@sgi.com> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Roland Dreier <roland@purestorage.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1437088996-28511-4-git-send-email-toshi.kani@hp.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* kernel/resource.c: remove deprecated __check_region() and friendsJakub Sitnicki2015-04-161-32/+0
| | | | | | | | | | | | | | | | | | All users of __check_region(), check_region(), and check_mem_region() are gone. We got rid of the last user in v4.0-rc1. Remove them. bloat-o-meter on x86_64 shows: add/remove: 0/3 grow/shrink: 0/0 up/down: 0/-102 (-102) function old new delta __kstrtab___check_region 15 - -15 __ksymtab___check_region 16 - -16 __check_region 71 - -71 Signed-off-by: Jakub Sitnicki <jsitnicki@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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