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2017-12-17xtensa: print kernel sections info in mem_initMax Filippov
Output virtual addresses and sizes occupied by the main kernel sections: .text, .rodata, .data, .init and .bss. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-17xtensa: use generic strncpy_from_user with KASANMax Filippov
This enables KASAN check of the destination buffer. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: use __memset in __xtensa_clear_userMax Filippov
memset on xtensa is capable of accessing user memory, but KASAN checks if memset function is actually used for that and reports it as an error: ================================================================== BUG: KASAN: user-memory-access in padzero+0x4d/0x58 Write of size 519 at addr 0049ddf9 by task init/1 Call Trace: [<b0189978>] kasan_report+0x160/0x238 [<b0188818>] check_memory_region+0xf8/0x100 [<b018891c>] memset+0x20/0x34 [<b0238b71>] padzero+0x4d/0x58 ================================================================== Use __memset in __xtensa_clear_user to avoid that. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: add support for KASANMax Filippov
Cover kernel addresses above 0x90000000 by the shadow map. Enable HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills shadow map with writable copies of kasan_zero_page. Call kasan_early_init right after mmu initialization in the setup_arch. Provide kasan_init that allocates proper shadow map pages from the memblock and puts these pages into the shadow map for addresses from VMALLOC area to the end of KSEG. Call kasan_init right after memblock initialization. Don't use KASAN for the boot code, MMU and KASAN initialization and page fault handler. Make kernel stack size 4 times larger when KASAN is enabled to avoid stack overflows. GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: move fixmap and kmap just above the KSEGMax Filippov
The virtual address space between the page table and the VMALLOC region is big enough to host KASAN shadow map and there's enough space between the VMALLOC area and KSEG for the fixmap and kmap. Move fixmap and kmap to the gap between VMALLOC area and KSEG, just above the KSEG. Reorder entries in the kernel memory layout printing code. Drop duplicate PGTABLE_START definition, use XCHAL_PAGE_TABLE_VADDR instead. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: don't clear swapper_pg_dir in paging_initMax Filippov
swapper_pg_dir is located in the .bss, so it's zero-initialized anyway. With KASAN enabled paging_init will be called after KASAN initialization, it must not erase page directory entries set up for KASAN shadow map. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: extract init_kioMax Filippov
KIO region placement may be specified in the device tree, that's why it's initialized with the rest of MMU after the early_init_devtree. In order to support KASAN the MMU must be initialized earlier. Separate KIO initialization from the rest of MMU initialization. Reinitialize KIO if its location is specified in the device tree. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: implement early_trap_initMax Filippov
Paging on xtensa architecture requires functioning exception handling because hardware cannot transparently access page tables that are not currently mapped by TLB. Exception handling is set up late in the initialization process, but working paging is needed for KASAN. Provide early_trap_init that sets up minimal exception handling sufficient for KASAN to work. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: clean up exception handling structureMax Filippov
Instead of using flat array of longs use normal C structure and generate EXC_TABLE_* constants in the asm-offsets.c Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: clean up custom-controlled debug outputMax Filippov
Replace #ifdef'fed/commented out debug printk statements with pr_debug. Replace printk statements with pr_* equivalents. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-16xtensa: enable stack protectorMax Filippov
The implementation is adopted from the ARM arch. GCC 7.3, 8 or newer is required for building the xtensa kernel with SSP. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: print hardware config ID on startupMax Filippov
Print hardware config ID on startup and config ID recorded in the configuration if it doesn't match one read from the hardware. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: consolidate kernel stack size related definitionsMax Filippov
Define kernel stack size in kmem_layout and use it in current_thread_info, GET_THREAD_INFO, THREAD_SIZE and THERAD_SIZE_ORDER definitions. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: clean up functions in assembly codeMax Filippov
Use ENTRY and ENDPROC throughout arch/xtensa/lib assembly sources. Introduce asm/linkage.h and define xtensa-specific __ALIGN macro there. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: clean up word alignment macros in assembly codeMax Filippov
Remove duplicate definitions of ALIGN/src_b/__src_b and SSA8/ssa8/__ssa8 from assembly sources and put single definition into asm/asmmacro.h Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: clean up fixups in assembly codeMax Filippov
Remove duplicate definitions of EX() and similar TRY/CATCH and SRC/DST macros from assembly sources and put single definition into asm/asmmacro.h Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: use call instead of callx in assembly codeMax Filippov
Now that xtensa assembly sources are compiled with -mlongcalls let the assembler and linker relax call instructions into l32r + callx where needed. This change makes the code cleaner and potentially a bit faster. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10xtensa: build kernel with text-section-literalsMax Filippov
vmlinux.lds.S doesn't do anything special with literals, so instead of keeping them separate put them into the corresponding text sections. Drop explicit .literal sections from the vmlinux.lds.S, use standard section macros. Mark literal pool locations in the assembly sources. Unfortunately assembler doesn't put literals into .init sections and external libgcc may still have .literal sections, so sed transformation to the linker script is still needed. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-09xtensa: add -mno-serialize-volatile to CFLAGSMax Filippov
By default xtensa gcc inserts memw for all volatile object accesses. This is too pessimistic for the kernel: there should be no "normal" volatile objects, and all special objects, like MMIO or objects shared between CPUs should have explicit barriers. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-05bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program typeHendrik Brueckner
Commit 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") introduced the bpf_perf_event_data structure which exports the pt_regs structure. This is OK for multiple architectures but fail for s390 and arm64 which do not export pt_regs. Programs using them, for example, the bpf selftest fail to compile on these architectures. For s390, exporting the pt_regs is not an option because s390 wants to allow changes to it. For arm64, there is a user_pt_regs structure that covers parts of the pt_regs structure for use by user space. To solve the broken uapi for s390 and arm64, introduce an abstract type for pt_regs and add an asm/bpf_perf_event.h file that concretes the type. An asm-generic header file covers the architectures that export pt_regs today. The arch-specific enablement for s390 and arm64 follows in separate commits. Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Fixes: 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-29make kernel-side POLL... arch-independentAl Viro
mangle/demangle on the way to/from userland Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27define __poll_t, annotate constantsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-17Merge tag 'libnvdimm-for-4.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm and dax updates from Dan Williams: "Save for a few late fixes, all of these commits have shipped in -next releases since before the merge window opened, and 0day has given a build success notification. The ext4 touches came from Jan, and the xfs touches have Darrick's reviewed-by. An xfstest for the MAP_SYNC feature has been through a few round of reviews and is on track to be merged. - Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable 'userspace flush' of persistent memory updates via filesystem-dax mappings. It arranges for any filesystem metadata updates that may be required to satisfy a write fault to also be flushed ("on disk") before the kernel returns to userspace from the fault handler. Effectively every write-fault that dirties metadata completes an fsync() before returning from the fault handler. The new MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag is validated as supported by the filesystem's ->mmap() file operation. - Add support for the standard ACPI 6.2 label access methods that replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods. This enables interoperability with environments that only implement the standardized methods. - Add support for the ACPI 6.2 NVDIMM media error injection methods. - Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for latch last shutdown status, firmware update, SMART error injection, and SMART alarm threshold control. - Cleanup physical address information disclosures to be root-only. - Fix revalidation of the DIMM "locked label area" status to support dynamic unlock of the label area. - Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA (system-physical-address) command and error injection commands. Acknowledgements that came after the commits were pushed to -next: - 957ac8c421ad ("dax: fix PMD faults on zero-length files"): Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> - a39e596baa07 ("xfs: support for synchronous DAX faults") and 7b565c9f965b ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()") Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>" * tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits) acpi, nfit: add 'Enable Latch System Shutdown Status' command support dax: fix general protection fault in dax_alloc_inode dax: fix PMD faults on zero-length files dax: stop requiring a live device for dax_flush() brd: remove dax support dax: quiet bdev_dax_supported() fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core tools/testing/nvdimm: unit test clear-error commands acpi, nfit: validate commands against the device type tools/testing/nvdimm: stricter bounds checking for error injection commands xfs: support for synchronous DAX faults xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault() ext4: Support for synchronous DAX faults ext4: Simplify error handling in ext4_dax_huge_fault() dax: Implement dax_finish_sync_fault() dax, iomap: Add support for synchronous faults mm: Define MAP_SYNC and VM_SYNC flags dax: Allow tuning whether dax_insert_mapping_entry() dirties entry dax: Allow dax_iomap_fault() to return pfn dax: Fix comment describing dax_iomap_fault() ...
2017-11-15Merge tag 'pci-v4.15-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: - detach driver before tearing down procfs/sysfs (Alex Williamson) - disable PCIe services during shutdown (Sinan Kaya) - fix ASPM oops on systems with no Root Ports (Ard Biesheuvel) - fix ASPM LTR_L1.2_THRESHOLD programming (Bjorn Helgaas) - fix ASPM Common_Mode_Restore_Time computation (Bjorn Helgaas) - fix portdrv MSI/MSI-X vector allocation (Dongdong Liu, Bjorn Helgaas) - report non-fatal AER errors only to the affected endpoint (Gabriele Paoloni) - distribute bus numbers, MMIO, and I/O space among hotplug bridges to allow more devices to be hot-added (Mika Westerberg) - fix pciehp races during initialization and surprise link down (Mika Westerberg) - handle surprise-removed devices in PME handling (Qiang) - support resizable BARs for large graphics devices (Christian König) - expose SR-IOV offset, stride, and VF device ID via sysfs (Filippo Sironi) - create SR-IOV virtfn/physfn sysfs links before attaching driver (Stuart Hayes) - fix SR-IOV "ARI Capable Hierarchy" restore issue (Tony Nguyen) - enforce Kconfig IOV/REALLOC dependency (Sascha El-Sharkawy) - avoid slot reset if bridge itself is broken (Jan Glauber) - clean up pci_reset_function() path (Jan H. Schönherr) - make pci_map_rom() fail if the option ROM is invalid (Changbin Du) - convert timers to timer_setup() (Kees Cook) - move PCI_QUIRKS to PCI bus Kconfig menu (Randy Dunlap) - constify pci_dev_type and intel_mid_pci_ops (Bhumika Goyal) - remove unnecessary pci_dev, pci_bus, resource, pcibios_set_master() declarations (Bjorn Helgaas) - fix endpoint framework overflows and BUG()s (Dan Carpenter) - fix endpoint framework issues (Kishon Vijay Abraham I) - avoid broken Cavium CN8xxx bus reset behavior (David Daney) - extend Cavium ACS capability quirks (Vadim Lomovtsev) - support Synopsys DesignWare RC in ECAM mode (Ard Biesheuvel) - turn off dra7xx clocks cleanly on shutdown (Keerthy) - fix Faraday probe error path (Wei Yongjun) - support HiSilicon STB SoC PCIe host controller (Jianguo Sun) - fix Hyper-V interrupt affinity issue (Dexuan Cui) - remove useless ACPI warning for Hyper-V pass-through devices (Vitaly Kuznetsov) - support multiple MSI on iProc (Sandor Bodo-Merle) - support Layerscape LS1012a and LS1046a PCIe host controllers (Hou Zhiqiang) - fix Layerscape default error response (Minghuan Lian) - support MSI on Tango host controller (Marc Gonzalez) - support Tegra186 PCIe host controller (Manikanta Maddireddy) - use generic accessors on Tegra when possible (Thierry Reding) - support V3 Semiconductor PCI host controller (Linus Walleij) * tag 'pci-v4.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (85 commits) PCI/ASPM: Add L1 Substates definitions PCI/ASPM: Reformat ASPM register definitions PCI/ASPM: Use correct capability pointer to program LTR_L1.2_THRESHOLD PCI/ASPM: Account for downstream device's Port Common_Mode_Restore_Time PCI: xgene: Rename xgene_pcie_probe_bridge() to xgene_pcie_probe() PCI: xilinx: Rename xilinx_pcie_link_is_up() to xilinx_pcie_link_up() PCI: altera: Rename altera_pcie_link_is_up() to altera_pcie_link_up() PCI: Fix kernel-doc build warning PCI: Fail pci_map_rom() if the option ROM is invalid PCI: Move pci_map_rom() error path PCI: Move PCI_QUIRKS to the PCI bus menu alpha/PCI: Make pdev_save_srm_config() static PCI: Remove unused declarations PCI: Remove redundant pci_dev, pci_bus, resource declarations PCI: Remove redundant pcibios_set_master() declarations PCI/PME: Handle invalid data when reading Root Status PCI: hv: Use effective affinity mask PCI: pciehp: Do not clear Presence Detect Changed during initialization PCI: pciehp: Fix race condition handling surprise link down PCI: Distribute available resources to hotplug-capable bridges ...
2017-11-15Merge branch 'for-linus' of ↵Linus Torvalds
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "The usual rocket-science from trivial tree for 4.15" * 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: MAINTAINERS: relinquish kconfig MAINTAINERS: Update my email address treewide: Fix typos in Kconfig kfifo: Fix comments init/Kconfig: Fix module signing document location misc: ibmasm: Return error on error path HID: logitech-hidpp: fix mistake in printk, "feeback" -> "feedback" MAINTAINERS: Correct path to uDraw PS3 driver tracing: Fix doc mistakes in trace sample tracing: Kconfig text fixes for CONFIG_HWLAT_TRACER MIPS: Alchemy: Remove reverted CONFIG_NETLINK_MMAP from db1xxx_defconfig mm/huge_memory.c: fixup grammar in comment lib/xz: Add fall-through comments to a switch statement
2017-11-14Merge tag 'devicetree-for-4.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull DeviceTree updates from Rob Herring: "A bigger diffstat than usual with the kbuild changes and a tree wide fix in the binding documentation. Summary: - kbuild cleanups and improvements for dtbs - Code clean-up of overlay code and fixing for some long standing memory leak and race condition in applying overlays - Improvements to DT memory usage making sysfs/kobjects optional and skipping unflattening of disabled nodes. This is part of kernel tinification efforts. - Final piece of removing storing the full path for every DT node. The prerequisite conversion of printk's to use device_node format specifier happened in 4.14. - Sync with current upstream dtc. This brings additional checks to dtb compiling. - Binding doc tree wide removal of leading 0s from examples - RTC binding documentation adding missing devices and some consolidation of duplicated bindings - Vendor prefix documentation for nutsboard, Silicon Storage Technology, shimafuji, Tecon Microprocessor Technologies, DH electronics GmbH, Opal Kelly, and Next Thing" * tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (55 commits) dt-bindings: usb: add #phy-cells to usb-nop-xceiv dt-bindings: Remove leading zeros from bindings notation kbuild: handle dtb-y and CONFIG_OF_ALL_DTBS natively in Makefile.lib MIPS: dts: remove bogus bcm96358nb4ser.dtb from dtb-y entry kbuild: clean up *.dtb and *.dtb.S patterns from top-level Makefile .gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignore .gitignore: sort normal pattern rules alphabetically dt-bindings: add vendor prefix for Next Thing Co. scripts/dtc: Update to upstream version v1.4.5-6-gc1e55a5513e9 of: dynamic: fix memory leak related to properties of __of_node_dup of: overlay: make pr_err() string unique of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove of: overlay: remove unneeded check for NULL kbasename() of: overlay: remove a dependency on device node full_name of: overlay: simplify applying symbols from an overlay of: overlay: avoid race condition between applying multiple overlays of: overlay: loosen overly strict phandle clash check of: overlay: expand check of whether overlay changeset can be removed of: overlay: detect cases where device tree may become corrupt of: overlay: minor restructuring ...
2017-11-14Merge tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping updates from Christoph Hellwig: - turn dma_cache_sync into a dma_map_ops instance and remove implementation that purely are dead because the architecture doesn't support noncoherent allocations - add a flag for busses that need DMA configuration (Robin Murphy) * tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mapping: dma-mapping: turn dma_cache_sync into a dma_map_ops method sh: make dma_cache_sync a no-op xtensa: make dma_cache_sync a no-op unicore32: make dma_cache_sync a no-op powerpc: make dma_cache_sync a no-op mn10300: make dma_cache_sync a no-op microblaze: make dma_cache_sync a no-op ia64: make dma_cache_sync a no-op frv: make dma_cache_sync a no-op x86: make dma_cache_sync a no-op floppy: consolidate the dummy fd_cacheflush definition drivers: flag buses which demand DMA configuration
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-13Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Yet another big pile of changes: - More year 2038 work from Arnd slowly reaching the point where we need to think about the syscalls themself. - A new timer function which allows to conditionally (re)arm a timer only when it's either not running or the new expiry time is sooner than the armed expiry time. This allows to use a single timer for multiple timeout requirements w/o caring about the first expiry time at the call site. - A new NMI safe accessor to clock real time for the printk timestamp work. Can be used by tracing, perf as well if required. - A large number of timer setup conversions from Kees which got collected here because either maintainers requested so or they simply got ignored. As Kees pointed out already there are a few trivial merge conflicts and some redundant commits which was unavoidable due to the size of this conversion effort. - Avoid a redundant iteration in the timer wheel softirq processing. - Provide a mechanism to treat RTC implementations depending on their hardware properties, i.e. don't inflict the write at the 0.5 seconds boundary which originates from the PC CMOS RTC to all RTCs. No functional change as drivers need to be updated separately. - The usual small updates to core code clocksource drivers. Nothing really exciting" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (111 commits) timers: Add a function to start/reduce a timer pstore: Use ktime_get_real_fast_ns() instead of __getnstimeofday() timer: Prepare to change all DEFINE_TIMER() callbacks netfilter: ipvs: Convert timers to use timer_setup() scsi: qla2xxx: Convert timers to use timer_setup() block/aoe: discover_timer: Convert timers to use timer_setup() ide: Convert timers to use timer_setup() drbd: Convert timers to use timer_setup() mailbox: Convert timers to use timer_setup() crypto: Convert timers to use timer_setup() drivers/pcmcia: omap1: Fix error in automated timer conversion ARM: footbridge: Fix typo in timer conversion drivers/sgi-xp: Convert timers to use timer_setup() drivers/pcmcia: Convert timers to use timer_setup() drivers/memstick: Convert timers to use timer_setup() drivers/macintosh: Convert timers to use timer_setup() hwrng/xgene-rng: Convert timers to use timer_setup() auxdisplay: Convert timers to use timer_setup() sparc/led: Convert timers to use timer_setup() mips: ip22/32: Convert timers to use timer_setup() ...
2017-11-10xtensa/simdisk: fix compile errorChristoph Hellwig
Fixes: d004a5e7d4dd ("block: remove __bio_kmap_atomic") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block: remove __bio_kmap_atomicChristoph Hellwig
This helper doesn't buy us much over calling kmap_atomic directly. In fact in the only caller it does a bit of useless work as the caller already has the bvec at hand, and said caller would even buggy for a multi-segment bio due to the use of this helper. So just remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-09kbuild: handle dtb-y and CONFIG_OF_ALL_DTBS natively in Makefile.libMasahiro Yamada
If CONFIG_OF_ALL_DTBS is enabled, "make ARCH=arm64 dtbs" compiles each DTB twice; one from arch/arm64/boot/dts/*/Makefile and the other from the dtb-$(CONFIG_OF_ALL_DTBS) line in arch/arm64/boot/dts/Makefile. It could be a race problem when building DTBS in parallel. Another minor issue is CONFIG_OF_ALL_DTBS covers only *.dts in vendor sub-directories, so this broke when Broadcom added one more hierarchy in arch/arm64/boot/dts/broadcom/<soc>/. One idea to fix the issues in a clean way is to move DTB handling to Kbuild core scripts. Makefile.dtbinst already recognizes dtb-y natively, so it should not hurt to do so. Add $(dtb-y) to extra-y, and $(dtb-) as well if CONFIG_OF_ALL_DTBS is enabled. All clutter things in Makefiles go away. As a bonus clean-up, I also removed dts-dirs. Just use subdir-y directly to traverse sub-directories. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Arnd Bergmann <arnd@arndb.de> [robh: corrected BUILTIN_DTB to CONFIG_BUILTIN_DTB] Signed-off-by: Rob Herring <robh@kernel.org>
2017-11-08kbuild: clean up *.dtb and *.dtb.S patterns from top-level MakefileMasahiro Yamada
We need to add "clean-files" in Makfiles to clean up DT blobs, but we often miss to do so. Since there are no source files that end with .dtb or .dtb.S, so we can clean-up those files from the top-level Makefile. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rob Herring <robh@kernel.org>
2017-11-08.gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignoreMasahiro Yamada
Most of DT files are compiled under arch/*/boot/dts/, but we have some other directories, like drivers/of/unittest-data/. We often miss to add gitignore patterns per directory. Since there are no source files that end with .dtb or .dtb.S, we can ignore the patterns globally. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-11-07PCI: Remove redundant pci_dev, pci_bus, resource declarationsBjorn Helgaas
<linux/pci.h> defines struct pci_bus and struct pci_dev and includes the struct resource definition before including <asm/pci.h>. Nobody includes <asm/pci.h> directly, so they don't need their own declarations. Remove the redundant struct pci_dev, pci_bus, resource declarations. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> # CRIS Acked-by: Ralf Baechle <ralf@linux-mips.org> # MIPS
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-03mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flagsDan Williams
The mmap(2) syscall suffers from the ABI anti-pattern of not validating unknown flags. However, proposals like MAP_SYNC need a mechanism to define new behavior that is known to fail on older kernels without the support. Define a new MAP_SHARED_VALIDATE flag pattern that is guaranteed to fail on all legacy mmap implementations. It is worth noting that the original proposal was for a standalone MAP_VALIDATE flag. However, when that could not be supported by all archs Linus observed: I see why you *think* you want a bitmap. You think you want a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC etc, so that people can do ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_SYNC, fd, 0); and "know" that MAP_SYNC actually takes. And I'm saying that whole wish is bogus. You're fundamentally depending on special semantics, just make it explicit. It's already not portable, so don't try to make it so. Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value of 0x3, and make people do ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE | MAP_SYNC, fd, 0); and then the kernel side is easier too (none of that random garbage playing games with looking at the "MAP_VALIDATE bit", but just another case statement in that map type thing. Boom. Done. Similar to ->fallocate() we also want the ability to validate the support for new flags on a per ->mmap() 'struct file_operations' instance basis. Towards that end arrange for flags to be generically validated against a mmap_supported_flags exported by 'struct file_operations'. By default all existing flags are implicitly supported, but new flags require MAP_SHARED_VALIDATE and per-instance-opt-in. Cc: Jan Kara <jack@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Suggested-by: Christoph Hellwig <hch@lst.de> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-02xtensa: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Kees Cook <keescook@chromium.org>
2017-11-02License cleanup: add SPDX license identifier to uapi header files with a licenseGreg Kroah-Hartman
Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02License cleanup: add SPDX license identifier to uapi header files with no ↵Greg Kroah-Hartman
license Many user space API headers are missing licensing information, which makes it hard for compliance tools to determine the correct license. By default are files without license information under the default license of the kernel, which is GPLV2. Marking them GPLV2 would exclude them from being included in non GPLV2 code, which is obviously not intended. The user space API headers fall under the syscall exception which is in the kernels COPYING file: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". otherwise syscall usage would not be possible. Update the files which contain no license information with an SPDX license identifier. The chosen identifier is 'GPL-2.0 WITH Linux-syscall-note' which is the officially assigned identifier for the Linux syscall exception. SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-19dma-mapping: turn dma_cache_sync into a dma_map_ops methodChristoph Hellwig
After we removed all the dead wood it turns out only two architectures actually implement dma_cache_sync as a real op: mips and parisc. Add a cache_sync method to struct dma_map_ops and implement it for the mips defualt DMA ops, and the parisc pa11 ops. Note that arm, arc and openrisc support DMA_ATTR_NON_CONSISTENT, but never provided a functional dma_cache_sync implementations, which seems somewhat odd. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2017-10-19xtensa: make dma_cache_sync a no-opChristoph Hellwig
xtensa does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't make any sense to do any work in dma_cache_sync given that it must be a no-op when dma_alloc_attrs returns coherent memory. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2017-10-12treewide: Fix typos in KconfigMasanari Iida
This patch fixes some spelling typos found in Kconfig files. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-10-10locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementationsWill Deacon
The arch_{read,spin,write}_lock_flags() macros are simply mapped to the non-flags versions by the majority of architectures, so do this in core code and remove the dummy implementations. Also remove the implementation in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call local_irq_save(flags) anyway. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10locking/core: Remove {read,spin,write}_can_lock()Will Deacon
Outside of the locking code itself, {read,spin,write}_can_lock() have no users in tree. Apparmor (the last remaining user of write_can_lock()) got moved over to lockdep by the previous patch. This patch removes the use of {read,spin,write}_can_lock() from the BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the lock status, and subsequently removes the unused macros altogether. They aren't guaranteed to work in a concurrent environment and can give incorrect results in the case of qrwlock. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-22arch: remove unused *_segments() macros/functionsTobias Klauser
Some architectures define the no-op macros/functions copy_segments, release_segments and forget_segments. These are used nowhere in the tree, so removed them. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Vineet Gupta <vgupta@synopsys.com> [for arch/arc] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - various misc bits - DAX updates - OCFS2 - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits) mm,fork: introduce MADV_WIPEONFORK x86,mpx: make mpx depend on x86-64 to free up VMA flag mm: add /proc/pid/smaps_rollup mm: hugetlb: clear target sub-page last when clearing huge page mm: oom: let oom_reap_task and exit_mmap run concurrently swap: choose swap device according to numa node mm: replace TIF_MEMDIE checks by tsk_is_oom_victim mm, oom: do not rely on TIF_MEMDIE for memory reserves access z3fold: use per-cpu unbuddied lists mm, swap: don't use VMA based swap readahead if HDD is used as swap mm, swap: add sysfs interface for VMA based swap readahead mm, swap: VMA based swap readahead mm, swap: fix swap readahead marking mm, swap: add swap readahead hit statistics mm/vmalloc.c: don't reinvent the wheel but use existing llist API mm/vmstat.c: fix wrong comment selftests/memfd: add memfd_create hugetlbfs selftest mm/shmem: add hugetlbfs support to memfd_create() mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas() ...
2017-09-06mm,fork: introduce MADV_WIPEONFORKRik van Riel
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty in the child process after fork. This differs from MADV_DONTFORK in one important way. If a child process accesses memory that was MADV_WIPEONFORK, it will get zeroes. The address ranges are still valid, they are just empty. If a child process accesses memory that was MADV_DONTFORK, it will get a segmentation fault, since those address ranges are no longer valid in the child after fork. Since MADV_DONTFORK also seems to be used to allow very large programs to fork in systems with strict memory overcommit restrictions, changing the semantics of MADV_DONTFORK might break existing programs. MADV_WIPEONFORK only works on private, anonymous VMAs. The use case is libraries that store or cache information, and want to know that they need to regenerate it in the child process after fork. Examples of this would be: - systemd/pulseaudio API checks (fail after fork) (replacing a getpid check, which is too slow without a PID cache) - PKCS#11 API reinitialization check (mandated by specification) - glibc's upcoming PRNG (reseed after fork) - OpenSSL PRNG (reseed after fork) The security benefits of a forking server having a re-inialized PRNG in every child process are pretty obvious. However, due to libraries having all kinds of internal state, and programs getting compiled with many different versions of each library, it is unreasonable to expect calling programs to re-initialize everything manually after fork. A further complication is the proliferation of clone flags, programs bypassing glibc's functions to call clone directly, and programs calling unshare, causing the glibc pthread_atfork hook to not get called. It would be better to have the kernel take care of this automatically. The patch also adds MADV_KEEPONFORK, to undo the effects of a prior MADV_WIPEONFORK. This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO: https://man.openbsd.org/minherit.2 [akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines] Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Florian Weimer <fweimer@redhat.com> Reported-by: Colm MacCártaigh <colm@allcosts.net> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>