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2018-06-13alpha: Remove custom dec_and_lock() implementationSebastian Andrzej Siewior3-51/+0
Alpha provides a custom implementation of dec_and_lock(). The functions is split into two parts: - atomic_add_unless() + return 0 (fast path in assembly) - remaining part including locking (slow path in C) Comparing the result of the alpha implementation with the generic implementation compiled by gcc it looks like the fast path is optimized by avoiding a stack frame (and reloading the GP), register store and all this. This is only done in the slowpath. After marking the slowpath (atomic_dec_and_lock_1()) as "noinline" and doing the slowpath in C (the atomic_add_unless(atomic, -1, 1) part) I noticed differences in the resulting assembly: - the GP is still reloaded - atomic_add_unless() adds more memory barriers compared to the custom assembly - the custom assembly here does "load, sub, beq" while atomic_add_unless() does "load, cmpeq, add, bne". This is okay because it compares against zero after subtraction while the generic code compares against 1 before. I'm not sure if avoiding the stack frame (and GP reloading) brings a lot in terms of performance. Regarding the different barriers, Peter Zijlstra says: |refcount decrement needs to be a RELEASE operation, such that all the |load/stores to the object happen before we decrement the refcount. | |Otherwise things like: | | obj->foo = 5; | refcnt_dec(&obj->ref); | |can be re-ordered, which then allows fun scenarios like: | | CPU0 CPU1 | | refcnt_dec(&obj->ref); | if (dec_and_test(&obj->ref)) | free(obj); | obj->foo = 5; // oops UaF | | |This means (for alpha) that there should be a memory barrier _before_ |the decrement, however the dec_and_lock asm thing only has one _after_, |which, per the above, is too late. | |The generic version using add_unless will result in memory barrier |before and after (because that is the rule for atomic ops with a return |value) which is strictly too many barriers for the refcount story, but |who knows what other ordering requirements code has. Remove the custom alpha implementation of dec_and_lock() and if it is an issue (performance wise) then the fast path could still be inlined. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org Link: https://lkml.kernel.org/r/20180606115918.GG12198@hirez.programming.kicks-ass.net Link: https://lkml.kernel.org/r20180612161621.22645-2-bigeasy@linutronix.de
2018-06-06Merge tag 'kbuild-v4.18' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - improve fixdep to coalesce consecutive slashes in dep-files - fix some issues of the maintainer string generation in deb-pkg script - remove unused CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX and clean-up several tools and linker scripts - clean-up modpost - allow to enable the dead code/data elimination for PowerPC in EXPERT mode - improve two coccinelle scripts for better performance - pass endianness and machine size flags to sparse for all architecture - misc fixes * tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits) kbuild: add machine size to CHECKFLAGS kbuild: add endianness flag to CHEKCFLAGS kbuild: $(CHECK) doesnt need NOSTDINC_FLAGS twice scripts: Fixed printf format mismatch scripts/tags.sh: use `find` for $ALLSOURCE_ARCHS generation coccinelle: deref_null: improve performance coccinelle: mini_lock: improve performance powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled kbuild: LD_DEAD_CODE_DATA_ELIMINATION no -ffunction-sections/-fdata-sections for module build kbuild: Fix asm-generic/vmlinux.lds.h for LD_DEAD_CODE_DATA_ELIMINATION modpost: constify *modname function argument where possible modpost: remove redundant is_vmlinux() test modpost: use strstarts() helper more widely modpost: pass struct elf_info pointer to get_modinfo() checkpatch: remove VMLINUX_SYMBOL() check vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL() kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX export.h: remove code for prefixing symbols with underscore depmod.sh: remove symbol prefix support ...
2018-06-05Merge branch 'timers-2038-for-linus' of ↵Linus Torvalds5-92/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull time/Y2038 updates from Thomas Gleixner: - Consolidate SySV IPC UAPI headers - Convert SySV IPC to the new COMPAT_32BIT_TIME mechanism - Cleanup the core interfaces and standardize on the ktime_get_* naming convention. - Convert the X86 platform ops to timespec64 - Remove the ugly temporary timespec64 hack * 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86: Convert x86_platform_ops to timespec64 timekeeping: Add more coarse clocktai/boottime interfaces timekeeping: Add ktime_get_coarse_with_offset timekeeping: Standardize on ktime_get_*() naming timekeeping: Clean up ktime_get_real_ts64 timekeeping: Remove timespec64 hack y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop y2038: ipc: Enable COMPAT_32BIT_TIME y2038: ipc: Use __kernel_timespec y2038: ipc: Report long times to user space y2038: ipc: Use ktime_get_real_seconds consistently y2038: xtensa: Extend sysvipc data structures y2038: powerpc: Extend sysvipc data structures y2038: sparc: Extend sysvipc data structures y2038: parisc: Extend sysvipc data structures y2038: mips: Extend sysvipc data structures y2038: arm64: Extend sysvipc compat data structures y2038: s390: Remove unneeded ipc uapi header files y2038: ia64: Remove unneeded ipc uapi header files y2038: alpha: Remove unneeded ipc uapi header files ...
2018-06-05Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timers and timekeeping updates from Thomas Gleixner: - Core infrastucture work for Y2038 to address the COMPAT interfaces: + Add a new Y2038 safe __kernel_timespec and use it in the core code + Introduce config switches which allow to control the various compat mechanisms + Use the new config switch in the posix timer code to control the 32bit compat syscall implementation. - Prevent bogus selection of CPU local clocksources which causes an endless reselection loop - Remove the extra kthread in the clocksource code which has no value and just adds another level of indirection - The usual bunch of trivial updates, cleanups and fixlets all over the place - More SPDX conversions * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) clocksource/drivers/mxs_timer: Switch to SPDX identifier clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier clocksource/drivers/timer-imx-gpt: Remove outdated file path clocksource/drivers/arc_timer: Add comments about locking while read GFRC clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages clocksource/drivers/sprd: Fix Kconfig dependency clocksource: Move inline keyword to the beginning of function declarations timer_list: Remove unused function pointer typedef timers: Adjust a kernel-doc comment tick: Prefer a lower rating device only if it's CPU local device clocksource: Remove kthread time: Change nanosleep to safe __kernel_* types time: Change types to new y2038 safe __kernel_* types time: Fix get_timespec64() for y2038 safe compat interfaces time: Add new y2038 safe __kernel_timespec posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME time: Introduce CONFIG_COMPAT_32BIT_TIME time: Introduce CONFIG_64BIT_TIME in architectures compat: Enable compat_get/put_timespec64 always ...
2018-06-05Merge branch 'siginfo-linus' of ↵Linus Torvalds5-107/+30
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull siginfo updates from Eric Biederman: "This set of changes close the known issues with setting si_code to an invalid value, and with not fully initializing struct siginfo. There remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64 and x86 to get the code that generates siginfo into a simpler and more maintainable state. Most of that work involves refactoring the signal handling code and thus careful code review. Also not included is the work to shrink the in kernel version of struct siginfo. That depends on getting the number of places that directly manipulate struct siginfo under control, as it requires the introduction of struct kernel_siginfo for the in kernel things. Overall this set of changes looks like it is making good progress, and with a little luck I will be wrapping up the siginfo work next development cycle" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) signal/sh: Stop gcc warning about an impossible case in do_divide_error signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions signal/um: More carefully relay signals in relay_signal. signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR} signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code signal/signalfd: Add support for SIGSYS signal/signalfd: Remove __put_user from signalfd_copyinfo signal/xtensa: Use force_sig_fault where appropriate signal/xtensa: Consistenly use SIGBUS in do_unaligned_user signal/um: Use force_sig_fault where appropriate signal/sparc: Use force_sig_fault where appropriate signal/sparc: Use send_sig_fault where appropriate signal/sh: Use force_sig_fault where appropriate signal/s390: Use force_sig_fault where appropriate signal/riscv: Replace do_trap_siginfo with force_sig_fault signal/riscv: Use force_sig_fault where appropriate signal/parisc: Use force_sig_fault where appropriate signal/parisc: Use force_sig_mceerr where appropriate signal/openrisc: Use force_sig_fault where appropriate signal/nios2: Use force_sig_fault where appropriate ...
2018-06-04Merge tag 'docs-4.18' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "There's been a fair amount of work in the docs tree this time around, including: - Extensive RST conversions and organizational work in the memory-management docs thanks to Mike Rapoport. - An update of Documentation/features from Andrea Parri and a script to keep it updated. - Various LICENSES updates from Thomas, along with a script to check SPDX tags. - Work to fix dangling references to documentation files; this involved a fair number of one-liner comment changes outside of Documentation/ ... and the usual list of documentation improvements, typo fixes, etc" * tag 'docs-4.18' of git://git.lwn.net/linux: (103 commits) Documentation: document hung_task_panic kernel parameter docs/admin-guide/mm: add high level concepts overview docs/vm: move ksm and transhuge from "user" to "internals" section. docs: Use the kerneldoc comments for memalloc_no*() doc: document scope NOFS, NOIO APIs docs: update kernel versions and dates in tables docs/vm: transhuge: split userspace bits to admin-guide/mm/transhuge docs/vm: transhuge: minor updates docs/vm: transhuge: change sections order Documentation: arm: clean up Marvell Berlin family info Documentation: gpio: driver: Fix a typo and some odd grammar docs: ranoops.rst: fix location of ramoops.txt scripts/documentation-file-ref-check: rewrite it in perl with auto-fix mode docs: uio-howto.rst: use a code block to solve a warning mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback w1: w1_io.c: fix a kernel-doc warning Documentation/process/posting: wrap text at 80 cols docs: admin-guide: add cgroup-v2 documentation Revert "Documentation/features/vm: Remove arch support status file for 'pte_special'" Documentation: refcount-vs-atomic: Update reference to LKMM doc. ...
2018-06-04Merge tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2-17/+2
Pull dma-mapping updates from Christoph Hellwig: - replace the force_dma flag with a dma_configure bus method. (Nipun Gupta, although one patch is іncorrectly attributed to me due to a git rebase bug) - use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai) - remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the right thing for bounce buffering. - move dma-debug initialization to common code, and apply a few cleanups to the dma-debug code. - cleanup the Kconfig mess around swiotlb selection - swiotlb comment fixup (Yisheng Xie) - a trivial swiotlb fix. (Dan Carpenter) - support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt) - add a new generic dma-noncoherent dma_map_ops implementation and use it for arc, c6x and nds32. - improve scatterlist validity checking in dma-debug. (Robin Murphy) - add a struct device quirk to limit the dma-mask to 32-bit due to bridge/system issues, and switch x86 to use it instead of a local hack for VIA bridges. - handle devices without a dma_mask more gracefully in the dma-direct code. * tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits) dma-direct: don't crash on device without dma_mask nds32: use generic dma_noncoherent_ops nds32: implement the unmap_sg DMA operation nds32: consolidate DMA cache maintainance routines x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag x86/pci-dma: remove the explicit nodac and allowdac option x86/pci-dma: remove the experimental forcesac boot option Documentation/x86: remove a stray reference to pci-nommu.c core, dma-direct: add a flag 32-bit dma limits dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs dma-debug: check scatterlist segments c6x: use generic dma_noncoherent_ops arc: use generic dma_noncoherent_ops arc: fix arc_dma_{map,unmap}_page arc: fix arc_dma_sync_sg_for_{cpu,device} arc: simplify arc_dma_sync_single_for_{cpu,device} dma-mapping: provide a generic dma-noncoherent implementation dma-mapping: simplify Kconfig dependencies riscv: add swiotlb support riscv: only enable ZONE_DMA32 for 64-bit ...
2018-06-01kbuild: add machine size to CHECKFLAGSLuc Van Oostenryck1-1/+1
By default, sparse assumes a 64bit machine when compiled on x86-64 and 32bit when compiled on anything else. This can of course create all sort of problems for the other archs, like issuing false warnings ('shift too big (32) for type unsigned long'), or worse, failing to emit legitimate warnings. Fix this by adding the -m32/-m64 flag, depending on CONFIG_64BIT, to CHECKFLAGS in the main Makefile (and so for all archs). Also, remove the now unneeded -m32/-m64 in arch specific Makefiles. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-23alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2Sinan Kaya1-7/+7
memory-barriers.txt has been updated with the following requirement. "When using writel(), a prior wmb() is not needed to guarantee that the cache coherent memory writes have completed before writing to the MMIO region." Current writeX() and iowriteX() implementations on alpha are not satisfying this requirement as the barrier is after the register write. Move mb() in writeX() and iowriteX() functions to guarantee that HW observes memory changes before performing register operations. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-05-23alpha: simplify get_arch_dma_opsChristoph Hellwig2-5/+3
Remove the dma_ops indirection. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-05-23alpha: use dma_direct_ops for jensenChristoph Hellwig3-33/+5
The generic dma_direct implementation does the same thing as the alpha pci-noop implementation, just with more bells and whistles. And unlike the current code it at least has a theoretical chance to actually compile. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-05-09arch: define the ARCH_DMA_ADDR_T_64BIT config symbol in lib/KconfigChristoph Hellwig1-3/+0
Define this symbol if the architecture either uses 64-bit pointers or the PHYS_ADDR_T_64BIT is set. This covers 95% of the old arch magic. We only need an additional select for Xen on ARM (why anyway?), and we now always set ARCH_DMA_ADDR_T_64BIT on mips boards with 64-bit physical addressing instead of only doing it when highmem is set. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: James Hogan <jhogan@kernel.org>
2018-05-09dma-mapping: move the NEED_DMA_MAP_STATE config symbol to lib/KconfigChristoph Hellwig1-3/+1
This way we have one central definition of it, and user can select it as needed. Note that we now also always select it when CONFIG_DMA_API_DEBUG is select, which fixes some incorrect checks in a few network drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2018-05-09scatterlist: move the NEED_SG_DMA_LENGTH config symbol to lib/KconfigChristoph Hellwig1-3/+1
This way we have one central definition of it, and user can select it as needed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
2018-05-09iommu-helper: mark iommu_is_span_boundary as inlineChristoph Hellwig1-3/+0
This avoids selecting IOMMU_HELPER just for this function. And we only use it once or twice in normal builds so this often even is a size reduction. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-07PCI: remove PCI_DMA_BUS_IS_PHYSChristoph Hellwig1-5/+0
This was used by the ide, scsi and networking code in the past to determine if they should bounce payloads. Now that the dma mapping always have to support dma to all physical memory (thanks to swiotlb for non-iommu systems) there is no need to this crude hack any more. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Palmer Dabbelt <palmer@sifive.com> (for riscv) Reviewed-by: Jens Axboe <axboe@kernel.dk>
2018-04-25signal/alpha: Use force_sig_fault where appropriateEric W. Biederman2-21/+3
Filling in struct siginfo before calling force_sig_info a tedious and error prone process, where once in a great while the wrong fields are filled out, and siginfo has been inconsistently cleared. Simplify this process by using the helper force_sig_fault. Which takes as a parameters all of the information it needs, ensures all of the fiddly bits of filling in struct siginfo are done properly and then calls force_sig_info. In short about a 5 line reduction in code for every time force_sig_info is called, which makes the calling function clearer. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: linux-alpha@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25signal/alpha: Use send_sig_fault where appropriateEric W. Biederman3-79/+24
Filling in struct siginfo before calling send_sig_info a tedious and error prone process, where once in a great while the wrong fields are filled out, and siginfo has been inconsistently cleared. Simplify this process by using the helper send_sig_fault. Which takes as a parameters all of the information it needs, ensures all of the fiddly bits of filling in struct siginfo are done properly and then calls send_sig_info. In short about a 5 line reduction in code for every time send_sig_info is called, which makes the calling function clearer. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: linux-alpha@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25signal/alpha: Replace TRAP_FIXME with TRAP_UNKEric W. Biederman2-9/+2
Using an si_code of 0 that aliases with SI_USER is clearly the wrong thing to do, and causes problems in interesting ways. For it really is not clear to me if using TRAP_UNK bugcheck or the default case of gentrap is really the best way to handle things. There is certainly enough information that that a more specific si_code could potentially be used. That said TRAP_UNK is definitely an improvement over 0 as it removes the ambiguiuty of what si_code of 0 with SIGTRAP means on alpha. Recent history suggests no actually cares about crazy corner cases of the kernel behavior like this so I don't expect any regressions from changing this. However if something does happen this change is easy to revert. Cc: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org Fixes: 0a635c7a84cf ("Fill in siginfo_t.") History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25signal/alpha: Replace FPE_FIXME with FPE_FLTUNKEric W. Biederman3-9/+2
Using an si_code of 0 that aliases with SI_USER is clearly the wrong thing todo, and causes problems in interesting ways. The newly defined FPE_FLTUNK semantically appears to fit the bill so use it instead. Given recent experience in this area odds are it will not break anything. Fixing it removes a hazard to kernel maintenance. Cc: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Fixes: 0a635c7a84cf ("Fill in siginfo_t.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25signal: Ensure every siginfo we send has all bits initializedEric W. Biederman4-0/+10
Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-20y2038: alpha: Remove unneeded ipc uapi header filesArnd Bergmann5-92/+4
The alpha ipcbuf/msgbuf/sembuf/shmbuf header files are all identical to the version from asm-generic. This patch removes the files and replaces them with 'generic-y' statements as part of the y2038 series. Since there is no 32-bit syscall support for alpha, we don't need the other changes, but it's good to have clean this up anyway. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-19time: Add an asm-generic/compat.h fileArnd Bergmann1-0/+1
We have a couple of files that try to include asm/compat.h on architectures where this is available. Those should generally use the higher-level linux/compat.h file, but that in turn fails to include asm/compat.h when CONFIG_COMPAT is disabled, unless we can provide that header on all architectures. This adds the asm/compat.h for all remaining architectures to simplify the dependencies. Architectures that are getting removed in linux-4.17 are not changed here, to avoid needless conflicts with the removal patches. Those architectures are broken by this patch, but we have already shown that they have no users. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-18signal/alpha: Document a conflict with SI_USER for SIGFPEEric W. Biederman1-1/+1
Setting si_code to 0 is the same as setting si_code to SI_USER. This is the same si_code as SI_USER. Posix and common sense requires that SI_USER not be a signal specific si_code. As such this use of 0 for the si_code is a pretty horribly broken ABI. Cc: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Ref: 0a635c7a84cf ("Fill in siginfo_t.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-16Merge branch 'mm-rst' into docs-nextJonathan Corbet1-1/+1
Mike Rapoport says: These patches convert files in Documentation/vm to ReST format, add an initial index and link it to the top level documentation. There are no contents changes in the documentation, except few spelling fixes. The relatively large diffstat stems from the indentation and paragraph wrapping changes. I've tried to keep the formatting as consistent as possible, but I could miss some places that needed markup and add some markup where it was not necessary. [jc: significant conflicts in vm/hmm.rst]
2018-04-16docs/vm: rename documentation files to .rstMike Rapoport1-1/+1
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-11mm: introduce MAP_FIXED_NOREPLACEMichal Hocko1-0/+1
Patch series "mm: introduce MAP_FIXED_NOREPLACE", v2. This has started as a follow up discussion [3][4] resulting in the runtime failure caused by hardening patch [5] which removes MAP_FIXED from the elf loader because MAP_FIXED is inherently dangerous as it might silently clobber an existing underlying mapping (e.g. stack). The reason for the failure is that some architectures enforce an alignment for the given address hint without MAP_FIXED used (e.g. for shared or file backed mappings). One way around this would be excluding those archs which do alignment tricks from the hardening [6]. The patch is really trivial but it has been objected, rightfully so, that this screams for a more generic solution. We basically want a non-destructive MAP_FIXED. The first patch introduced MAP_FIXED_NOREPLACE which enforces the given address but unlike MAP_FIXED it fails with EEXIST if the given range conflicts with an existing one. The flag is introduced as a completely new one rather than a MAP_FIXED extension because of the backward compatibility. We really want a never-clobber semantic even on older kernels which do not recognize the flag. Unfortunately mmap sucks wrt flags evaluation because we do not EINVAL on unknown flags. On those kernels we would simply use the traditional hint based semantic so the caller can still get a different address (which sucks) but at least not silently corrupt an existing mapping. I do not see a good way around that. Except we won't export expose the new semantic to the userspace at all. It seems there are users who would like to have something like that. Jemalloc has been mentioned by Michael Ellerman [7] Florian Weimer has mentioned the following: : glibc ld.so currently maps DSOs without hints. This means that the kernel : will map right next to each other, and the offsets between them a completely : predictable. We would like to change that and supply a random address in a : window of the address space. If there is a conflict, we do not want the : kernel to pick a non-random address. Instead, we would try again with a : random address. John Hubbard has mentioned CUDA example : a) Searches /proc/<pid>/maps for a "suitable" region of available : VA space. "Suitable" generally means it has to have a base address : within a certain limited range (a particular device model might : have odd limitations, for example), it has to be large enough, and : alignment has to be large enough (again, various devices may have : constraints that lead us to do this). : : This is of course subject to races with other threads in the process. : : Let's say it finds a region starting at va. : : b) Next it does: : p = mmap(va, ...) : : *without* setting MAP_FIXED, of course (so va is just a hint), to : attempt to safely reserve that region. If p != va, then in most cases, : this is a failure (almost certainly due to another thread getting a : mapping from that region before we did), and so this layer now has to : call munmap(), before returning a "failure: retry" to upper layers. : : IMPROVEMENT: --> if instead, we could call this: : : p = mmap(va, ... MAP_FIXED_NOREPLACE ...) : : , then we could skip the munmap() call upon failure. This : is a small thing, but it is useful here. (Thanks to Piotr : Jaroszynski and Mark Hairgrove for helping me get that detail : exactly right, btw.) : : c) After that, CUDA suballocates from p, via: : : q = mmap(sub_region_start, ... MAP_FIXED ...) : : Interestingly enough, "freeing" is also done via MAP_FIXED, and : setting PROT_NONE to the subregion. Anyway, I just included (c) for : general interest. Atomic address range probing in the multithreaded programs in general sounds like an interesting thing to me. The second patch simply replaces MAP_FIXED use in elf loader by MAP_FIXED_NOREPLACE. I believe other places which rely on MAP_FIXED should follow. Actually real MAP_FIXED usages should be docummented properly and they should be more of an exception. [1] http://lkml.kernel.org/r/20171116101900.13621-1-mhocko@kernel.org [2] http://lkml.kernel.org/r/20171129144219.22867-1-mhocko@kernel.org [3] http://lkml.kernel.org/r/20171107162217.382cd754@canb.auug.org.au [4] http://lkml.kernel.org/r/1510048229.12079.7.camel@abdul.in.ibm.com [5] http://lkml.kernel.org/r/20171023082608.6167-1-mhocko@kernel.org [6] http://lkml.kernel.org/r/20171113094203.aofz2e7kueitk55y@dhcp22.suse.cz [7] http://lkml.kernel.org/r/87efp1w7vy.fsf@concordia.ellerman.id.au This patch (of 2): MAP_FIXED is used quite often to enforce mapping at the particular range. The main problem of this flag is, however, that it is inherently dangerous because it unmaps existing mappings covered by the requested range. This can cause silent memory corruptions. Some of them even with serious security implications. While the current semantic might be really desiderable in many cases there are others which would want to enforce the given range but rather see a failure than a silent memory corruption on a clashing range. Please note that there is no guarantee that a given range is obeyed by the mmap even when it is free - e.g. arch specific code is allowed to apply an alignment. Introduce a new MAP_FIXED_NOREPLACE flag for mmap to achieve this behavior. It has the same semantic as MAP_FIXED wrt. the given address request with a single exception that it fails with EEXIST if the requested address is already covered by an existing mapping. We still do rely on get_unmaped_area to handle all the arch specific MAP_FIXED treatment and check for a conflicting vma after it returns. The flag is introduced as a completely new one rather than a MAP_FIXED extension because of the backward compatibility. We really want a never-clobber semantic even on older kernels which do not recognize the flag. Unfortunately mmap sucks wrt. flags evaluation because we do not EINVAL on unknown flags. On those kernels we would simply use the traditional hint based semantic so the caller can still get a different address (which sucks) but at least not silently corrupt an existing mapping. I do not see a good way around that. [mpe@ellerman.id.au: fix whitespace] [fail on clashing range with EEXIST as per Florian Weimer] [set MAP_FIXED before round_hint_to_min as per Khalid Aziz] Link: http://lkml.kernel.org/r/20171213092550.2774-2-mhocko@kernel.org Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Russell King - ARM Linux <linux@armlinux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Joel Stanley <joel@jms.id.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Jason Evans <jasone@google.com> Cc: David Goldblatt <davidtgoldblatt@gmail.com> Cc: Edward Tomasz Napierała <trasz@FreeBSD.org> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-08alpha: io: reorder barriers to guarantee writeX() and iowriteX() orderingSinan Kaya1-7/+7
memory-barriers.txt has been updated with the following requirement. "When using writel(), a prior wmb() is not needed to guarantee that the cache coherent memory writes have completed before writing to the MMIO region." Current writeX() and iowriteX() implementations on alpha are not satisfying this requirement as the barrier is after the register write. Move mb() in writeX() and iowriteX() functions to guarantee that HW observes memory changes before performing register operations. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-04-08alpha: Implement CPU vulnerabilities sysfs functions.Michael Cree3-1/+47
Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and spectre_v2 on Alpha. Tests on XP1000 (EV67/667MHz) and ES45 (EV68CB/1.25GHz) show them to be vulnerable to Meltdown and Spectre V1. In the case of Meltdown I saw a 1 to 2% success rate in reading bytes on the XP1000 and 50 to 60% success rate on the ES45. (This compares to 99.97% success reported for Intel CPUs.) Report EV6 and later CPUs as vulnerable. Tests on PWS600au (EV56/600MHz) for Spectre V1 attack were unsuccessful (though I did not try particularly hard) so mark EV4 through to EV56 as not vulnerable. Signed-off-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-04-08alpha: rtc: stop validating rtc_time in .read_timeAlexandre Belloni1-1/+1
The RTC core is always calling rtc_valid_tm after the read_time callback. It is not necessary to call it just before returning from the callback. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-04-08alpha: rtc: remove unused set_mmss opsAlexandre Belloni1-99/+0
The .set_mmss and .setmmss64 ops are only called when the RTC is not providing an implementation for the .set_time callback. On alpha, .set_time is provided so .set_mmss64 is never called. Remove the unused code. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Matt Turner <mattst88@gmail.com>
2018-04-08Merge branch 'misc.compat' of ↵Linus Torvalds3-11/+10
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull alpha syscall cleanups from Al Viro: "A couple of SYSCALL_DEFINE conversions and removal of pointless (and bitrotted) piece stuck in ret_from_kernel_thread since the kernel_exceve/kernel_thread conversions six years ago" * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: alpha: get rid of pointless insn in ret_from_kernel_thread alpha: switch pci syscalls to SYSCALL_DEFINE
2018-04-03Merge branch 'syscalls-next' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux Pull removal of in-kernel calls to syscalls from Dominik Brodowski: "System calls are interaction points between userspace and the kernel. Therefore, system call functions such as sys_xyzzy() or compat_sys_xyzzy() should only be called from userspace via the syscall table, but not from elsewhere in the kernel. At least on 64-bit x86, it will likely be a hard requirement from v4.17 onwards to not call system call functions in the kernel: It is better to use use a different calling convention for system calls there, where struct pt_regs is decoded on-the-fly in a syscall wrapper which then hands processing over to the actual syscall function. This means that only those parameters which are actually needed for a specific syscall are passed on during syscall entry, instead of filling in six CPU registers with random user space content all the time (which may cause serious trouble down the call chain). Those x86-specific patches will be pushed through the x86 tree in the near future. Moreover, rules on how data may be accessed may differ between kernel data and user data. This is another reason why calling sys_xyzzy() is generally a bad idea, and -- at most -- acceptable in arch-specific code. This patchset removes all in-kernel calls to syscall functions in the kernel with the exception of arch/. On top of this, it cleans up the three places where many syscalls are referenced or prototyped, namely kernel/sys_ni.c, include/linux/syscalls.h and include/linux/compat.h" * 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux: (109 commits) bpf: whitelist all syscalls for error injection kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions kernel/sys_ni: sort cond_syscall() entries syscalls/x86: auto-create compat_sys_*() prototypes syscalls: sort syscall prototypes in include/linux/compat.h net: remove compat_sys_*() prototypes from net/compat.h syscalls: sort syscall prototypes in include/linux/syscalls.h kexec: move sys_kexec_load() prototype to syscalls.h x86/sigreturn: use SYSCALL_DEFINE0 x86: fix sys_sigreturn() return type to be long, not unsigned long x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead() mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff() mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64() fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate() fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate() fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid() kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare() ...
2018-04-02mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()Dominik Brodowski1-1/+1
Using this helper allows us to avoid the in-kernel calls to the sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_mmap_pgoff(). This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main kernel side changes were: - Modernize the kprobe and uprobe creation/destruction tooling ABIs: The existing text based APIs (kprobe_events and uprobe_events in tracefs), are naive, limited ABIs in that they require user-space to clean up after themselves, which is both difficult and fragile if the tool is buggy or exits unexpectedly. In other words they are not really suited for modern, robust tooling. So introduce a modern, file descriptor based ABI that does not have these limitations: introduce the 'perf_kprobe' and 'perf_uprobe' PMUs and extend the perf_event_open() syscall to create events with a kprobe/uprobe attached to them. These [k,u]probe are associated with this file descriptor, so they are not available in tracefs. (Song Liu) - Intel Cannon Lake CPU support (Harry Pan) - Intel PT cleanups (Alexander Shishkin) - Improve the performance of pinned/flexible event groups by using RB trees (Alexey Budankov) - Add PERF_EVENT_IOC_MODIFY_ATTRIBUTES which allows the modification of hardware breakpoints, which new ABI variant massively speeds up existing tooling that uses hardware breakpoints to instrument (and debug) memory usage. (Milind Chabbi, Jiri Olsa) - Various Intel PEBS handling fixes and improvements, and other Intel PMU improvements (Kan Liang) - Various perf core improvements and optimizations (Peter Zijlstra) - ... misc cleanups, fixes and updates. There's over 200 tooling commits, here's an (imperfect) list of highlights: - 'perf annotate' improvements: * Recognize and handle jumps to other functions as calls, which improves the navigation along jumps and back. (Arnaldo Carvalho de Melo) * Add the 'P' hotkey in TUI annotation to dump annotation output into a file, to ease e-mail reporting of annotation details. (Arnaldo Carvalho de Melo) * Add an IPC/cycles column to the TUI (Jin Yao) * Improve s390 assembly annotation (Thomas Richter) * Refactor the output formatting logic to better separate it into interactive and non-interactive features and add the --stdio2 output variant to demonstrate this. (Arnaldo Carvalho de Melo) - 'perf script' improvements: * Add Python 3 support (Jaroslav Škarvada) * Add --show-round-event (Jiri Olsa) - 'perf c2c' improvements: * Add NUMA analysis support (Jiri Olsa) - 'perf trace' improvements: * Improve PowerPC support (Ravi Bangoria) - 'perf inject' improvements: * Integrate ARM CoreSight traces (Robert Walker) - 'perf stat' improvements: * Add the --interval-count option (yuzhoujian) * Add the --timeout option (yuzhoujian) - 'perf sched' improvements (Changbin Du) - Vendor events improvements : * Add IBM s390 vendor events (Thomas Richter) * Add and improve arm64 vendor events (John Garry, Ganapatrao Kulkarni) * Update POWER9 vendor events (Sukadev Bhattiprolu) - Intel PT tooling improvements (Adrian Hunter) - PMU handling improvements (Agustin Vega-Frias) - Record machine topology in perf.data (Jiri Olsa) - Various overwrite related cleanups (Kan Liang) - Add arm64 dwarf post unwind support (Kim Phillips, Jean Pihet) - ... and lots of other changes, cleanups and fixes, see the shortlog and Git history for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (262 commits) perf/x86/intel: Enable C-state residency events for Cannon Lake perf/x86/intel: Add Cannon Lake support for RAPL profiling perf/x86/pt, coresight: Clean up address filter structure perf vendor events s390: Add JSON files for IBM z14 perf vendor events s390: Add JSON files for IBM z13 perf vendor events s390: Add JSON files for IBM zEC12 zBC12 perf vendor events s390: Add JSON files for IBM z196 perf vendor events s390: Add JSON files for IBM z10EC z10BC perf mmap: Be consistent when checking for an unmaped ring buffer perf mmap: Fix accessing unmapped mmap in perf_mmap__read_done() perf build: Fix check-headers.sh opts assignment perf/x86: Update rdpmc_always_available static key to the modern API perf annotate: Use absolute addresses to calculate jump target offsets perf annotate: Defer searching for comma in raw line till it is needed perf annotate: Support jumping from one function to another perf annotate: Add "_local" to jump/offset validation routines perf python: Reference Py_None before returning it perf annotate: Mark jumps to outher functions with the call arrow perf annotate: Pass function descriptor to its instruction parsing routines perf annotate: No need to calculate notes->start twice ...
2018-03-28alpha: get rid of pointless insn in ret_from_kernel_threadAl Viro1-1/+0
It used to clear a3, so that signal handling on return to userland would've passed zero r0 to do_work_pending(), preventing the syscall restart logics from triggering. It had been pointless all along, since we only go there after successful do_execve(). Which does clear regs->r0 on alpha, preventing the syscall restart logics just fine, no extra help needed. Good thing, that, since back in 2012 do_work_pending() has lost the second argument, shifting the registers used to pass that thing from a3 to a2. Commit that had done that adjusted the entry.S code accordingly, but missed that one. As the result, we were left with useless insn in ret_from_kernel_thread and confusing comment to go with it. Get rid of both... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-28alpha: switch pci syscalls to SYSCALL_DEFINEAl Viro2-10/+10
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-16perf: Fix sibling iterationPeter Zijlstra1-1/+1
Mark noticed that the change to sibling_list changed some iteration semantics; because previously we used group_list as list entry, sibling events would always have an empty sibling_list. But because we now use sibling_list for both list head and list entry, siblings will report as having siblings. Fix this with a custom for_each_sibling_event() iterator. Fixes: 8343aae66167 ("perf/core: Remove perf_event::group_entry") Reported-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: vincent.weaver@maine.edu Cc: alexander.shishkin@linux.intel.com Cc: torvalds@linux-foundation.org Cc: alexey.budankov@linux.intel.com Cc: valery.cherepennikov@intel.com Cc: eranian@google.com Cc: acme@redhat.com Cc: linux-tip-commits@vger.kernel.org Cc: davidcc@google.com Cc: kan.liang@intel.com Cc: Dmitry.Prohorov@intel.com Cc: jolsa@redhat.com Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net
2018-03-12perf/core: Remove perf_event::group_entryPeter Zijlstra1-1/+1
Now that all the grouping is done with RB trees, we no longer need group_entry and can replace the whole thing with sibling_list. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Valery Cherepennikov <valery.cherepennikov@intel.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12locking/xchg/alpha: Remove superfluous memory barriers from the _local() ↵Andrea Parri2-31/+16
variants The following two commits: 79d442461df74 ("locking/xchg/alpha: Clean up barrier usage by using smp_mb() in place of __ASM__MB") 472e8c55cf662 ("locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugs") ... ended up adding unnecessary barriers to the _local() variants on Alpha, which the previous code took care to avoid. Fix them by adding the smp_mb() into the cmpxchg() macro rather than into the ____cmpxchg() variants. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-alpha@vger.kernel.org Fixes: 472e8c55cf662 ("locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugs") Fixes: 79d442461df74 ("locking/xchg/alpha: Clean up barrier usage by using smp_mb() in place of __ASM__MB") Link: http://lkml.kernel.org/r/1519704058-13430-1-git-send-email-parri.andrea@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-23locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugsAndrea Parri1-3/+18
Successful RMW operations are supposed to be fully ordered, but Alpha's xchg() and cmpxchg() do not meet this requirement. Will Deacon noticed the bug: > So MP using xchg: > > WRITE_ONCE(x, 1) > xchg(y, 1) > > smp_load_acquire(y) == 1 > READ_ONCE(x) == 0 > > would be allowed. ... which thus violates the above requirement. Fix it by adding a leading smp_mb() to the xchg() and cmpxchg() implementations. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-alpha@vger.kernel.org Link: http://lkml.kernel.org/r/1519291488-5752-1-git-send-email-parri.andrea@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-23locking/xchg/alpha: Clean up barrier usage by using smp_mb() in place of ↵Andrea Parri2-14/+8
__ASM__MB Replace each occurrence of __ASM__MB with a (trailing) smp_mb() in xchg(), cmpxchg(), and remove the now unused __ASM__MB definitions; this improves readability, with no additional synchronization cost. Suggested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-alpha@vger.kernel.org Link: http://lkml.kernel.org/r/1519291469-5702-1-git-send-email-parri.andrea@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21locking/xchg/alpha: Add unconditional memory barrier to cmpxchg()Andrea Parri1-8/+7
Continuing along with the fight against smp_read_barrier_depends() [1] (or rather, against its improper use), add an unconditional barrier to cmpxchg. This guarantees that dependency ordering is preserved when a dependency is headed by an unsuccessful cmpxchg. As it turns out, the change could enable further simplification of LKMM as proposed in [2]. [1] https://marc.info/?l=linux-kernel&m=150884953419377&w=2 https://marc.info/?l=linux-kernel&m=150884946319353&w=2 https://marc.info/?l=linux-kernel&m=151215810824468&w=2 https://marc.info/?l=linux-kernel&m=151215816324484&w=2 [2] https://marc.info/?l=linux-kernel&m=151881978314872&w=2 Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-alpha@vger.kernel.org Link: http://lkml.kernel.org/r/1519152356-4804-1-git-send-email-parri.andrea@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-06Merge tag 'pci-v4.16-changes' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: - skip AER driver error recovery callbacks for correctable errors reported via ACPI APEI, as we already do for errors reported via the native path (Tyler Baicar) - fix DPC shared interrupt handling (Alex Williamson) - print full DPC interrupt number (Keith Busch) - enable DPC only if AER is available (Keith Busch) - simplify DPC code (Bjorn Helgaas) - calculate ASPM L1 substate parameter instead of hardcoding it (Bjorn Helgaas) - enable Latency Tolerance Reporting for ASPM L1 substates (Bjorn Helgaas) - move ASPM internal interfaces out of public header (Bjorn Helgaas) - allow hot-removal of VGA devices (Mika Westerberg) - speed up unplug and shutdown by assuming Thunderbolt controllers don't support Command Completed events (Lukas Wunner) - add AtomicOps support for GPU and Infiniband drivers (Felix Kuehling, Jay Cornwall) - expose "ari_enabled" in sysfs to help NIC naming (Stuart Hayes) - clean up PCI DMA interface usage (Christoph Hellwig) - remove PCI pool API (replaced with DMA pool) (Romain Perier) - deprecate pci_get_bus_and_slot(), which assumed PCI domain 0 (Sinan Kaya) - move DT PCI code from drivers/of/ to drivers/pci/ (Rob Herring) - add PCI-specific wrappers for dev_info(), etc (Frederick Lawler) - remove warnings on sysfs mmap failure (Bjorn Helgaas) - quiet ROM validation messages (Alex Deucher) - remove redundant memory alloc failure messages (Markus Elfring) - fill in types for compile-time VGA and other I/O port resources (Bjorn Helgaas) - make "pci=pcie_scan_all" work for Root Ports as well as Downstream Ports to help AmigaOne X1000 (Bjorn Helgaas) - add SPDX tags to all PCI files (Bjorn Helgaas) - quirk Marvell 9128 DMA aliases (Alex Williamson) - quirk broken INTx disable on Ceton InfiniTV4 (Bjorn Helgaas) - fix CONFIG_PCI=n build by adding dummy pci_irqd_intx_xlate() (Niklas Cassel) - use DMA API to get MSI address for DesignWare IP (Niklas Cassel) - fix endpoint-mode DMA mask configuration (Kishon Vijay Abraham I) - fix ARTPEC-6 incorrect IS_ERR() usage (Wei Yongjun) - add support for ARTPEC-7 SoC (Niklas Cassel) - add endpoint-mode support for ARTPEC (Niklas Cassel) - add Cadence PCIe host and endpoint controller driver (Cyrille Pitchen) - handle multiple INTx status bits being set in dra7xx (Vignesh R) - translate dra7xx hwirq range to fix INTD handling (Vignesh R) - remove deprecated Exynos PHY initialization code (Jaehoon Chung) - fix MSI erratum workaround for HiSilicon Hip06/Hip07 (Dongdong Liu) - fix NULL pointer dereference in iProc BCMA driver (Ray Jui) - fix Keystone interrupt-controller-node lookup (Johan Hovold) - constify qcom driver structures (Julia Lawall) - rework Tegra config space mapping to increase space available for endpoints (Vidya Sagar) - simplify Tegra driver by using bus->sysdata (Manikanta Maddireddy) - remove PCI_REASSIGN_ALL_BUS usage on Tegra (Manikanta Maddireddy) - add support for Global Fabric Manager Server (GFMS) event to Microsemi Switchtec switch driver (Logan Gunthorpe) - add IDs for Switchtec PSX 24xG3 and PSX 48xG3 (Kelvin Cao) * tag 'pci-v4.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (140 commits) PCI: cadence: Add EndPoint Controller driver for Cadence PCIe controller dt-bindings: PCI: cadence: Add DT bindings for Cadence PCIe endpoint controller PCI: endpoint: Fix EPF device name to support multi-function devices PCI: endpoint: Add the function number as argument to EPC ops PCI: cadence: Add host driver for Cadence PCIe controller dt-bindings: PCI: cadence: Add DT bindings for Cadence PCIe host controller PCI: Add vendor ID for Cadence PCI: Add generic function to probe PCI host controllers PCI: generic: fix missing call of pci_free_resource_list() PCI: OF: Add generic function to parse and allocate PCI resources PCI: Regroup all PCI related entries into drivers/pci/Makefile PCI/DPC: Reformat DPC register definitions PCI/DPC: Add and use DPC Status register field definitions PCI/DPC: Squash dpc_rp_pio_get_info() into dpc_process_rp_pio_error() PCI/DPC: Remove unnecessary RP PIO register structs PCI/DPC: Push dpc->rp_pio_status assignment into dpc_rp_pio_get_info() PCI/DPC: Squash dpc_rp_pio_print_error() into dpc_rp_pio_get_info() PCI/DPC: Make RP PIO log size check more generic PCI/DPC: Rename local "status" to "dpc_status" PCI/DPC: Squash dpc_rp_pio_print_tlp_header() into dpc_rp_pio_print_error() ...
2018-02-03Merge branch 'for-linus' of ↵Linus Torvalds8-18/+26
git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha Pull alpha updates from Matt Turner: "A few small fixes and clean ups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha: alpha: fix crash if pthread_create races with signal delivery alpha: fix formating of stack content alpha: fix reboot on Avanti platform alpha: deprecate pci_get_bus_and_slot() alpha: Fix mixed up args in EXC macro in futex operations alpha: osf_sys.c: use timespec64 where appropriate alpha: osf_sys.c: fix put_tv32 regression alpha: make thread_saved_pc static alpha: make XTABS equivalent to TAB3
2018-02-02Merge tag 'clk-for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux Pull clk updates from Stephen Boyd: "The core framework has a handful of patches this time around, mostly due to the clk rate protection support added by Jerome Brunet. This feature will allow consumers to lock in a certain rate on the output of a clk so that things like audio playback don't hear pops when the clk frequency changes due to shared parent clks changing rates. Currently the clk API doesn't guarantee the rate of a clk stays at the rate you request after clk_set_rate() is called, so this new API will allow drivers to express that requirement. Beyond this, the core got some debugfs pretty printing patches and a couple minor non-critical fixes. Looking outside of the core framework diff we have some new driver additions and the removal of a legacy TI clk driver. Both of these hit high in the dirstat. Also, the removal of the asm-generic/clkdev.h file causes small one-liners in all the architecture Kbuild files. Overall, the driver diff seems to be the normal stuff that comes all the time to fix little problems here and there and to support new hardware. Summary: Core: - Clk rate protection - Symbolic clk flags in debugfs output - Clk registration enabled clks while doing bookkeeping updates New Drivers: - Spreadtrum SC9860 - HiSilicon hi3660 stub - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS - Amlogic Meson-AXG - ASPEED BMC Removed Drivers: - TI OMAP 3xxx legacy clk (non-DT) support - asm*/clkdev.h got removed (not really a driver) Updates: - Renesas FDP1-0 module clock on R-Car M3-W - Renesas LVDS module clock on R-Car V3M - Misc fixes to pr_err() prints - Qualcomm MSM8916 audio fixes - Qualcomm IPQ8074 rounded out support for more peripherals - Qualcomm Alpha PLL variants - Divider code was using container_of() on bad pointers - Allwinner DE2 clks on H3 - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED - Mediatek clk driver compile test support - AT91 PMC clk suspend/resume restoration support - PLL issues fixed on si5351 - Broadcom IProc PLL calculation updates - DVFS support for Armada mvebu CPU clks - Allwinner fixed post-divider support - TI clkctrl fixes and support for newer SoCs" * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (125 commits) clk: aspeed: Handle inverse polarity of USB port 1 clock gate clk: aspeed: Fix return value check in aspeed_cc_init() clk: aspeed: Add reset controller clk: aspeed: Register gated clocks clk: aspeed: Add platform driver and register PLLs clk: aspeed: Register core clocks clk: Add clock driver for ASPEED BMC SoCs clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built clk: fix reentrancy of clk_enable() on UP systems clk: meson-axg: fix potential NULL dereference in axg_clkc_probe() clk: Simplify debugfs registration clk: Fix debugfs_create_*() usage clk: Show symbolic clock flags in debugfs clk: renesas: r8a7796: Add FDP clock clk: Move __clk_{get,put}() into private clk.h API clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks clk: Improve flags doc for of_clk_detect_critical() arch: Remove clkdev.h asm-generic from Kbuild clk: sunxi-ng: a83t: Add M divider to TCON1 clock clk: Prepare to remove asm-generic/clkdev.h ...
2018-02-01Merge branch 'work.whack-a-mole' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull asm/uaccess.h whack-a-mole from Al Viro: "It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop cropping up..." * 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h riscv: use linux/uaccess.h, not asm/uaccess.h... ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h
2018-01-31Merge tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds1-0/+1
Pull dma mapping updates from Christoph Hellwig: "Except for a runtime warning fix from Christian this is all about consolidation of the generic no-IOMMU code, a well as the glue code for swiotlb. All the code is based on the x86 implementation with hooks to allow all architectures that aren't cache coherent to use it. The x86 conversion itself has been deferred because the x86 maintainers were a little busy in the last months" * tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits) MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb arm64: use swiotlb_alloc and swiotlb_free arm64: replace ZONE_DMA with ZONE_DMA32 mips: use swiotlb_{alloc,free} mips/netlogic: remove swiotlb support tile: use generic swiotlb_ops tile: replace ZONE_DMA with ZONE_DMA32 unicore32: use generic swiotlb_ops ia64: remove an ifdef around the content of pci-dma.c ia64: clean up swiotlb support ia64: use generic swiotlb_ops ia64: replace ZONE_DMA with ZONE_DMA32 swiotlb: remove various exports swiotlb: refactor coherent buffer allocation swiotlb: refactor coherent buffer freeing swiotlb: wire up ->dma_supported in swiotlb_dma_ops swiotlb: add common swiotlb_map_ops swiotlb: rename swiotlb_free to swiotlb_exit x86: rename swiotlb_dma_ops powerpc: rename swiotlb_dma_ops ...
2018-01-31Merge branch 'work.misc' of ↵Linus Torvalds1-36/+36
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of misc stuff, without any unifying topic, from various people. Neil's d_anon patch, several bugfixes, introduction of kvmalloc analogue of kmemdup_user(), extending bitfield.h to deal with fixed-endians, assorted cleanups all over the place..." * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) alpha: osf_sys.c: use timespec64 where appropriate alpha: osf_sys.c: fix put_tv32 regression jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path dcache: delete unused d_hash_mask dcache: subtract d_hash_shift from 32 in advance fs/buffer.c: fold init_buffer() into init_page_buffers() fs: fold __inode_permission() into inode_permission() fs: add RWF_APPEND sctp: use vmemdup_user() rather than badly open-coding memdup_user() snd_ctl_elem_init_enum_names(): switch to vmemdup_user() replace_user_tlv(): switch to vmemdup_user() new primitive: vmemdup_user() memdup_user(): switch to GFP_USER eventfd: fold eventfd_ctx_get() into eventfd_ctx_fileget() eventfd: fold eventfd_ctx_read() into eventfd_read() eventfd: convert to use anon_inode_getfd() nfs4file: get rid of pointless include of btrfs.h uvc_v4l2: clean copyin/copyout up vme_user: don't use __copy_..._user() usx2y: don't bother with memdup_user() for 16-byte structure ...
2018-01-31Merge branch 'pci/resource' into nextBjorn Helgaas1-0/+1
* pci/resource: PCI: tegra: Remove PCI_REASSIGN_ALL_BUS use on Tegra resource: Set type when reserving new regions resource: Set type of "reserve=" user-specified resources irqchip/i8259: Set I/O port resource types correctly powerpc: Set I/O port resource types correctly MIPS: Set I/O port resource types correctly vgacon: Set VGA struct resource types PCI: Use dev_info() rather than dev_err() for ROM validation PCI: Remove PCI_REASSIGN_ALL_RSRC use on arm and arm64 PCI: Remove sysfs resource mmap warning Conflicts: drivers/pci/rom.c