1. 13 Jun, 2020 20 commits
    • Linus Torvalds's avatar
      Merge tag 'xfs-5.8-merge-9' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux · c5557227
      Linus Torvalds authored
      Pull xfs fix from Darrick Wong:
       "We've settled down into the bugfix phase; this one fixes a resource
        leak on an error bailout path"
      
      * tag 'xfs-5.8-merge-9' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
        xfs: Add the missed xfs_perag_put() for xfs_ifree_cluster()
      c5557227
    • Linus Torvalds's avatar
      Merge tag '9p-for-5.8' of git://github.com/martinetd/linux · 61f3e825
      Linus Torvalds authored
      Pull 9p update from Dominique Martinet:
       "Another very quiet cycle... Only one commit: increase the size of the
        ring used for xen transport"
      
      * tag '9p-for-5.8' of git://github.com/martinetd/linux:
        9p/xen: increase XEN_9PFS_RING_ORDER
      61f3e825
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 08bf1a27
      Linus Torvalds authored
      Pull powerpc fix from Michael Ellerman:
       "One fix for a recent change which broke nested KVM guests on Power9.
      
        Thanks to Alexey Kardashevskiy"
      
      * tag 'powerpc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        KVM: PPC: Fix nested guest RC bits update
      08bf1a27
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm · cfd230b3
      Linus Torvalds authored
      Pull ARM fixes from Russell King:
      
       - fix for "hex" Kconfig default to use 0x0 rather than 0 to allow these
         to be removed from defconfigs
      
       - fix from Ard Biesheuvel for EFI HYP mode booting
      
      * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
        ARM: 8985/1: efi/decompressor: deal with HYP mode boot gracefully
        ARM: 8984/1: Kconfig: set default ZBOOT_ROM_TEXT/BSS value to 0x0
      cfd230b3
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://github.com/openrisc/linux · 56192707
      Linus Torvalds authored
      Pull OpenRISC update from Stafford Horne:
       "One patch found wile I was getting the glibc port ready: fix issue
        with clone TLS arg getting overwritten"
      
      * tag 'for-linus' of git://github.com/openrisc/linux:
        openrisc: Fix issue with argument clobbering for clone/fork
      56192707
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha · 66125d93
      Linus Torvalds authored
      Pull alpha updates from Matt Turner:
       "A few changes for alpha. They're mostly small janitorial fixes but
        there's also a build fix and most notably a patch from Mikulas that
        fixes a hang on boot on the Avanti platform, which required quite a
        bit of work and review"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
        alpha: Fix build around srm_sysrq_reboot_op
        alpha: c_next should increase position index
        alpha: Replace sg++ with sg = sg_next(sg)
        alpha: fix memory barriers so that they conform to the specification
        alpha: remove unneeded semicolon in sys_eiger.c
        alpha: remove unneeded semicolon in osf_sys.c
        alpha: Replace strncmp with str_has_prefix
        alpha: fix rtc port ranges
        alpha: Kconfig: pedantic formatting
      66125d93
    • Linus Torvalds's avatar
      Merge tag 'ras-core-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · a9429089
      Linus Torvalds authored
      Pull x86 RAS updates from Thomas Gleixner:
       "RAS updates from Borislav Petkov:
      
         - Unmap a whole guest page if an MCE is encountered in it to avoid
           follow-on MCEs leading to the guest crashing, by Tony Luck.
      
           This change collided with the entry changes and the merge
           resolution would have been rather unpleasant. To avoid that the
           entry branch was merged in before applying this. The resulting code
           did not change over the rebase.
      
         - AMD MCE error thresholding machinery cleanup and hotplug
           sanitization, by Thomas Gleixner.
      
         - Change the MCE notifiers to denote whether they have handled the
           error and not break the chain early by returning NOTIFY_STOP, thus
           giving the opportunity for the later handlers in the chain to see
           it. By Tony Luck.
      
         - Add AMD family 0x17, models 0x60-6f support, by Alexander Monakov.
      
         - Last but not least, the usual round of fixes and improvements"
      
      * tag 'ras-core-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
        x86/mce/dev-mcelog: Fix -Wstringop-truncation warning about strncpy()
        x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned
        EDAC/amd64: Add AMD family 17h model 60h PCI IDs
        hwmon: (k10temp) Add AMD family 17h model 60h PCI match
        x86/amd_nb: Add AMD family 17h model 60h PCI IDs
        x86/mcelog: Add compat_ioctl for 32-bit mcelog support
        x86/mce: Drop bogus comment about mce.kflags
        x86/mce: Fixup exception only for the correct MCEs
        EDAC: Drop the EDAC report status checks
        x86/mce: Add mce=print_all option
        x86/mce: Change default MCE logger to check mce->kflags
        x86/mce: Fix all mce notifiers to update the mce->kflags bitmask
        x86/mce: Add a struct mce.kflags field
        x86/mce: Convert the CEC to use the MCE notifier
        x86/mce: Rename "first" function as "early"
        x86/mce/amd, edac: Remove report_gart_errors
        x86/mce/amd: Make threshold bank setting hotplug robust
        x86/mce/amd: Cleanup threshold device remove path
        x86/mce/amd: Straighten CPU hotplug path
        x86/mce/amd: Sanitize thresholding device creation hotplug path
        ...
      a9429089
    • Linus Torvalds's avatar
      Merge tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 076f14be
      Linus Torvalds authored
      Pull x86 entry updates from Thomas Gleixner:
       "The x86 entry, exception and interrupt code rework
      
        This all started about 6 month ago with the attempt to move the Posix
        CPU timer heavy lifting out of the timer interrupt code and just have
        lockless quick checks in that code path. Trivial 5 patches.
      
        This unearthed an inconsistency in the KVM handling of task work and
        the review requested to move all of this into generic code so other
        architectures can share.
      
        Valid request and solved with another 25 patches but those unearthed
        inconsistencies vs. RCU and instrumentation.
      
        Digging into this made it obvious that there are quite some
        inconsistencies vs. instrumentation in general. The int3 text poke
        handling in particular was completely unprotected and with the batched
        update of trace events even more likely to expose to endless int3
        recursion.
      
        In parallel the RCU implications of instrumenting fragile entry code
        came up in several discussions.
      
        The conclusion of the x86 maintainer team was to go all the way and
        make the protection against any form of instrumentation of fragile and
        dangerous code pathes enforcable and verifiable by tooling.
      
        A first batch of preparatory work hit mainline with commit
        d5f744f9 ("Pull x86 entry code updates from Thomas Gleixner")
      
        That (almost) full solution introduced a new code section
        '.noinstr.text' into which all code which needs to be protected from
        instrumentation of all sorts goes into. Any call into instrumentable
        code out of this section has to be annotated. objtool has support to
        validate this.
      
        Kprobes now excludes this section fully which also prevents BPF from
        fiddling with it and all 'noinstr' annotated functions also keep
        ftrace off. The section, kprobes and objtool changes are already
        merged.
      
        The major changes coming with this are:
      
          - Preparatory cleanups
      
          - Annotating of relevant functions to move them into the
            noinstr.text section or enforcing inlining by marking them
            __always_inline so the compiler cannot misplace or instrument
            them.
      
          - Splitting and simplifying the idtentry macro maze so that it is
            now clearly separated into simple exception entries and the more
            interesting ones which use interrupt stacks and have the paranoid
            handling vs. CR3 and GS.
      
          - Move quite some of the low level ASM functionality into C code:
      
             - enter_from and exit to user space handling. The ASM code now
               calls into C after doing the really necessary ASM handling and
               the return path goes back out without bells and whistels in
               ASM.
      
             - exception entry/exit got the equivivalent treatment
      
             - move all IRQ tracepoints from ASM to C so they can be placed as
               appropriate which is especially important for the int3
               recursion issue.
      
          - Consolidate the declaration and definition of entry points between
            32 and 64 bit. They share a common header and macros now.
      
          - Remove the extra device interrupt entry maze and just use the
            regular exception entry code.
      
          - All ASM entry points except NMI are now generated from the shared
            header file and the corresponding macros in the 32 and 64 bit
            entry ASM.
      
          - The C code entry points are consolidated as well with the help of
            DEFINE_IDTENTRY*() macros. This allows to ensure at one central
            point that all corresponding entry points share the same
            semantics. The actual function body for most entry points is in an
            instrumentable and sane state.
      
            There are special macros for the more sensitive entry points, e.g.
            INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF.
            They allow to put the whole entry instrumentation and RCU handling
            into safe places instead of the previous pray that it is correct
            approach.
      
          - The INT3 text poke handling is now completely isolated and the
            recursion issue banned. Aside of the entry rework this required
            other isolation work, e.g. the ability to force inline bsearch.
      
          - Prevent #DB on fragile entry code, entry relevant memory and
            disable it on NMI, #MC entry, which allowed to get rid of the
            nested #DB IST stack shifting hackery.
      
          - A few other cleanups and enhancements which have been made
            possible through this and already merged changes, e.g.
            consolidating and further restricting the IDT code so the IDT
            table becomes RO after init which removes yet another popular
            attack vector
      
          - About 680 lines of ASM maze are gone.
      
        There are a few open issues:
      
         - An escape out of the noinstr section in the MCE handler which needs
           some more thought but under the aspect that MCE is a complete
           trainwreck by design and the propability to survive it is low, this
           was not high on the priority list.
      
         - Paravirtualization
      
           When PV is enabled then objtool complains about a bunch of indirect
           calls out of the noinstr section. There are a few straight forward
           ways to fix this, but the other issues vs. general correctness were
           more pressing than parawitz.
      
         - KVM
      
           KVM is inconsistent as well. Patches have been posted, but they
           have not yet been commented on or picked up by the KVM folks.
      
         - IDLE
      
           Pretty much the same problems can be found in the low level idle
           code especially the parts where RCU stopped watching. This was
           beyond the scope of the more obvious and exposable problems and is
           on the todo list.
      
        The lesson learned from this brain melting exercise to morph the
        evolved code base into something which can be validated and understood
        is that once again the violation of the most important engineering
        principle "correctness first" has caused quite a few people to spend
        valuable time on problems which could have been avoided in the first
        place. The "features first" tinkering mindset really has to stop.
      
        With that I want to say thanks to everyone involved in contributing to
        this effort. Special thanks go to the following people (alphabetical
        order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian
        Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai
        Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra,
        Vitaly Kuznetsov, and Will Deacon"
      
      * tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits)
        x86/entry: Force rcu_irq_enter() when in idle task
        x86/entry: Make NMI use IDTENTRY_RAW
        x86/entry: Treat BUG/WARN as NMI-like entries
        x86/entry: Unbreak __irqentry_text_start/end magic
        x86/entry: __always_inline CR2 for noinstr
        lockdep: __always_inline more for noinstr
        x86/entry: Re-order #DB handler to avoid *SAN instrumentation
        x86/entry: __always_inline arch_atomic_* for noinstr
        x86/entry: __always_inline irqflags for noinstr
        x86/entry: __always_inline debugreg for noinstr
        x86/idt: Consolidate idt functionality
        x86/idt: Cleanup trap_init()
        x86/idt: Use proper constants for table size
        x86/idt: Add comments about early #PF handling
        x86/idt: Mark init only functions __init
        x86/entry: Rename trace_hardirqs_off_prepare()
        x86/entry: Clarify irq_{enter,exit}_rcu()
        x86/entry: Remove DBn stacks
        x86/entry: Remove debug IDT frobbing
        x86/entry: Optimize local_db_save() for virt
        ...
      076f14be
    • Linus Torvalds's avatar
      Merge tag 'notifications-20200601' of... · 6c329784
      Linus Torvalds authored
      Merge tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
      
      Pull notification queue from David Howells:
       "This adds a general notification queue concept and adds an event
        source for keys/keyrings, such as linking and unlinking keys and
        changing their attributes.
      
        Thanks to Debarshi Ray, we do have a pull request to use this to fix a
        problem with gnome-online-accounts - as mentioned last time:
      
           https://gitlab.gnome.org/GNOME/gnome-online-accounts/merge_requests/47
      
        Without this, g-o-a has to constantly poll a keyring-based kerberos
        cache to find out if kinit has changed anything.
      
        [ There are other notification pending: mount/sb fsinfo notifications
          for libmount that Karel Zak and Ian Kent have been working on, and
          Christian Brauner would like to use them in lxc, but let's see how
          this one works first ]
      
        LSM hooks are included:
      
         - A set of hooks are provided that allow an LSM to rule on whether or
           not a watch may be set. Each of these hooks takes a different
           "watched object" parameter, so they're not really shareable. The
           LSM should use current's credentials. [Wanted by SELinux & Smack]
      
         - A hook is provided to allow an LSM to rule on whether or not a
           particular message may be posted to a particular queue. This is
           given the credentials from the event generator (which may be the
           system) and the watch setter. [Wanted by Smack]
      
        I've provided SELinux and Smack with implementations of some of these
        hooks.
      
        WHY
        ===
      
        Key/keyring notifications are desirable because if you have your
        kerberos tickets in a file/directory, your Gnome desktop will monitor
        that using something like fanotify and tell you if your credentials
        cache changes.
      
        However, we also have the ability to cache your kerberos tickets in
        the session, user or persistent keyring so that it isn't left around
        on disk across a reboot or logout. Keyrings, however, cannot currently
        be monitored asynchronously, so the desktop has to poll for it - not
        so good on a laptop. This facility will allow the desktop to avoid the
        need to poll.
      
        DESIGN DECISIONS
        ================
      
         - The notification queue is built on top of a standard pipe. Messages
           are effectively spliced in. The pipe is opened with a special flag:
      
              pipe2(fds, O_NOTIFICATION_PIPE);
      
           The special flag has the same value as O_EXCL (which doesn't seem
           like it will ever be applicable in this context)[?]. It is given up
           front to make it a lot easier to prohibit splice&co from accessing
           the pipe.
      
           [?] Should this be done some other way?  I'd rather not use up a new
               O_* flag if I can avoid it - should I add a pipe3() system call
               instead?
      
           The pipe is then configured::
      
              ioctl(fds[1], IOC_WATCH_QUEUE_SET_SIZE, queue_depth);
              ioctl(fds[1], IOC_WATCH_QUEUE_SET_FILTER, &filter);
      
           Messages are then read out of the pipe using read().
      
         - It should be possible to allow write() to insert data into the
           notification pipes too, but this is currently disabled as the
           kernel has to be able to insert messages into the pipe *without*
           holding pipe->mutex and the code to make this work needs careful
           auditing.
      
         - sendfile(), splice() and vmsplice() are disabled on notification
           pipes because of the pipe->mutex issue and also because they
           sometimes want to revert what they just did - but one or more
           notification messages might've been interleaved in the ring.
      
         - The kernel inserts messages with the wait queue spinlock held. This
           means that pipe_read() and pipe_write() have to take the spinlock
           to update the queue pointers.
      
         - Records in the buffer are binary, typed and have a length so that
           they can be of varying size.
      
           This allows multiple heterogeneous sources to share a common
           buffer; there are 16 million types available, of which I've used
           just a few, so there is scope for others to be used. Tags may be
           specified when a watchpoint is created to help distinguish the
           sources.
      
         - Records are filterable as types have up to 256 subtypes that can be
           individually filtered. Other filtration is also available.
      
         - Notification pipes don't interfere with each other; each may be
           bound to a different set of watches. Any particular notification
           will be copied to all the queues that are currently watching for it
           - and only those that are watching for it.
      
         - When recording a notification, the kernel will not sleep, but will
           rather mark a queue as having lost a message if there's
           insufficient space. read() will fabricate a loss notification
           message at an appropriate point later.
      
         - The notification pipe is created and then watchpoints are attached
           to it, using one of:
      
              keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fds[1], 0x01);
              watch_mount(AT_FDCWD, "/", 0, fd, 0x02);
              watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x03);
      
           where in both cases, fd indicates the queue and the number after is
           a tag between 0 and 255.
      
         - Watches are removed if either the notification pipe is destroyed or
           the watched object is destroyed. In the latter case, a message will
           be generated indicating the enforced watch removal.
      
        Things I want to avoid:
      
         - Introducing features that make the core VFS dependent on the
           network stack or networking namespaces (ie. usage of netlink).
      
         - Dumping all this stuff into dmesg and having a daemon that sits
           there parsing the output and distributing it as this then puts the
           responsibility for security into userspace and makes handling
           namespaces tricky. Further, dmesg might not exist or might be
           inaccessible inside a container.
      
         - Letting users see events they shouldn't be able to see.
      
        TESTING AND MANPAGES
        ====================
      
         - The keyutils tree has a pipe-watch branch that has keyctl commands
           for making use of notifications. Proposed manual pages can also be
           found on this branch, though a couple of them really need to go to
           the main manpages repository instead.
      
           If the kernel supports the watching of keys, then running "make
           test" on that branch will cause the testing infrastructure to spawn
           a monitoring process on the side that monitors a notifications pipe
           for all the key/keyring changes induced by the tests and they'll
           all be checked off to make sure they happened.
      
              https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/keyutils.git/log/?h=pipe-watch
      
         - A test program is provided (samples/watch_queue/watch_test) that
           can be used to monitor for keyrings, mount and superblock events.
           Information on the notifications is simply logged to stdout"
      
      * tag 'notifications-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
        smack: Implement the watch_key and post_notification hooks
        selinux: Implement the watch_key security hook
        keys: Make the KEY_NEED_* perms an enum rather than a mask
        pipe: Add notification lossage handling
        pipe: Allow buffers to be marked read-whole-or-error for notifications
        Add sample notification program
        watch_queue: Add a key/keyring notification facility
        security: Add hooks to rule on setting a watch
        pipe: Add general notification queue support
        pipe: Add O_NOTIFICATION_PIPE
        security: Add a hook for the point of notification insertion
        uapi: General notification queue definitions
      6c329784
    • Ard Biesheuvel's avatar
      ARM: 8985/1: efi/decompressor: deal with HYP mode boot gracefully · db227c19
      Ard Biesheuvel authored
      EFI on ARM only supports short descriptors, and given that it mandates
      that the MMU and caches are on, it is implied that booting in HYP mode
      is not supported.
      
      However, implementations of EFI exist (i.e., U-Boot) that ignore this
      requirement, which is not entirely unreasonable, given that it makes
      HYP mode inaccessible to the operating system.
      
      So let's make sure that we can deal with this condition gracefully.
      We already tolerate booting the EFI stub with the caches off (even
      though this violates the EFI spec as well), and so we should deal
      with HYP mode boot with MMU and caches either on or off.
      
      - When the MMU and caches are on, we can ignore the HYP stub altogether,
        since we can carry on executing at HYP. We do need to ensure that we
        disable the MMU at HYP before entering the kernel proper.
      
      - When the MMU and caches are off, we have to drop to SVC mode so that
        we can set up the page tables using short descriptors. In this case,
        we need to install the HYP stub as usual, so that we can return to HYP
        mode before handing over to the kernel proper.
      Tested-by: default avatarHeinrich Schuchardt <xypron.glpk@gmx.de>
      Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
      Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      db227c19
    • Chris Packham's avatar
      ARM: 8984/1: Kconfig: set default ZBOOT_ROM_TEXT/BSS value to 0x0 · 39c3e304
      Chris Packham authored
      ZBOOT_ROM_TEXT and ZBOOT_ROM_BSS are defined as 'hex' but had a default
      of "0". Kconfig will helpfully expand a text entry of 0 to 0x0 but
      because this is not the same as the default value it was treated as
      being explicitly set when running 'make savedefconfig' so most arm
      defconfigs have CONFIG_ZBOOT_ROM_TEXT=0x0 and CONFIG_ZBOOT_ROM_BSS=0x0.
      
      Change the default to 0x0 which will mean next time the defconfigs are
      re-generated the spurious config entries will be removed.
      Signed-off-by: default avatarChris Packham <chris.packham@alliedtelesis.co.nz>
      Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      39c3e304
    • Joerg Roedel's avatar
      alpha: Fix build around srm_sysrq_reboot_op · 777747f6
      Joerg Roedel authored
      The patch introducing the struct was probably never compile tested,
      because it sets a handler with a wrong function signature. Wrap the
      handler into a functions with the correct signature to fix the build.
      
      Fixes: 0f1c9688 ("tty/sysrq: alpha: export and use __sysrq_get_key_op()")
      Cc: Emil Velikov <emil.l.velikov@gmail.com>
      Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      777747f6
    • Matt Turner's avatar
      alpha: c_next should increase position index · 7812193c
      Matt Turner authored
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      7812193c
    • Xu Wang's avatar
      alpha: Replace sg++ with sg = sg_next(sg) · e66dd01e
      Xu Wang authored
      Replace sg++ with sg = sg_next(sg).
      Signed-off-by: default avatarXu Wang <vulab@iscas.ac.cn>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      e66dd01e
    • Mikulas Patocka's avatar
      alpha: fix memory barriers so that they conform to the specification · 54505a1e
      Mikulas Patocka authored
      The commits cd0e00c1 and 92d7223a broke boot on the Alpha Avanti
      platform. The patches move memory barriers after a write before the write.
      The result is that if there's iowrite followed by ioread, there is no
      barrier between them.
      
      The Alpha architecture allows reordering of the accesses to the I/O space,
      and the missing barrier between write and read causes hang with serial
      port and real time clock.
      
      This patch makes barriers confiorm to the specification.
      
      1. We add mb() before readX_relaxed and writeX_relaxed -
         memory-barriers.txt claims that these functions must be ordered w.r.t.
         each other. Alpha doesn't order them, so we need an explicit barrier.
      2. We add mb() before reads from the I/O space - so that if there's a
         write followed by a read, there should be a barrier between them.
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Fixes: cd0e00c1 ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering")
      Fixes: 92d7223a ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2")
      Cc: stable@vger.kernel.org      # v4.17+
      Acked-by: default avatarIvan Kokshaysky <ink@jurassic.park.msu.ru>
      Reviewed-by: default avatarMaciej W. Rozycki <macro@linux-mips.org>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      54505a1e
    • Jason Yan's avatar
      alpha: remove unneeded semicolon in sys_eiger.c · c0ebf715
      Jason Yan authored
      Fix the following coccicheck warning:
      
      arch/alpha/kernel/sys_eiger.c:179:2-3: Unneeded semicolon
      Signed-off-by: default avatarJason Yan <yanaijie@huawei.com>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      c0ebf715
    • Jason Yan's avatar
      alpha: remove unneeded semicolon in osf_sys.c · a466a5cf
      Jason Yan authored
      Fix the following coccicheck warning:
      
      arch/alpha/kernel/osf_sys.c:680:2-3: Unneeded semicolon
      Signed-off-by: default avatarJason Yan <yanaijie@huawei.com>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      a466a5cf
    • Chuhong Yuan's avatar
      alpha: Replace strncmp with str_has_prefix · 5f14596e
      Chuhong Yuan authored
      In commit b6b27355
      ("tracing: Use str_has_prefix() instead of using fixed sizes")
      the newly introduced str_has_prefix() was used
      to replace error-prone strncmp(str, const, len).
      Here fix codes with the same pattern.
      Signed-off-by: default avatarChuhong Yuan <hslester96@gmail.com>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      5f14596e
    • Mikulas Patocka's avatar
      alpha: fix rtc port ranges · 5bea3044
      Mikulas Patocka authored
      Alpha incorrectly reports "0070-0080 : rtc" in /proc/ioports.
      Fix this, so that it is "0070-007f".
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      5bea3044
    • Enrico Weigelt, metux IT consult's avatar
      alpha: Kconfig: pedantic formatting · 8b3ebda6
      Enrico Weigelt, metux IT consult authored
      Formatting of Kconfig files doesn't look so pretty, so let the
      Great White Handkerchief come around and clean it up.
      Signed-off-by: default avatarEnrico Weigelt, metux IT consult <info@metux.net>
      Signed-off-by: default avatarMatt Turner <mattst88@gmail.com>
      8b3ebda6
  2. 12 Jun, 2020 20 commits
    • Linus Torvalds's avatar
      Merge tag 'thermal-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux · df2fbf5b
      Linus Torvalds authored
      Pull thermal updates from Daniel Lezcano:
      
       - Add the hwmon support on the i.MX SC (Anson Huang)
      
       - Thermal framework cleanups (self-encapsulation, pointless stubs,
         private structures) (Daniel Lezcano)
      
       - Use the PM QoS frequency changes for the devfreq cooling device
         (Matthias Kaehlcke)
      
       - Remove duplicate error messages from platform_get_irq() error
         handling (Markus Elfring)
      
       - Add support for the bandgap sensors (Keerthy)
      
       - Statically initialize .get_mode/.set_mode ops (Andrzej Pietrasiewicz)
      
       - Add Renesas R-Car maintainer entry (Niklas Söderlund)
      
       - Fix error checking after calling ti_bandgap_get_sensor_data() for the
         TI SoC thermal (Sudip Mukherjee)
      
       - Add latency constraint for the idle injection, the DT binding and the
         change the registering function (Daniel Lezcano)
      
       - Convert the thermal framework binding to the Yaml schema (Amit
         Kucheria)
      
       - Replace zero-length array with flexible-array on i.MX 8MM (Gustavo A.
         R. Silva)
      
       - Thermal framework cleanups (alphabetic order for heads, replace
         module.h by export.h, make file naming consistent) (Amit Kucheria)
      
       - Merge tsens-common into the tsens driver (Amit Kucheria)
      
       - Fix platform dependency for the Qoriq driver (Geert Uytterhoeven)
      
       - Clean up the rcar_thermal_update_temp() function in the rcar thermal
         driver (Niklas Söderlund)
      
       - Fix the TMSAR register for the TMUv2 on the Qoriq platform (Yuantian
         Tang)
      
       - Export GDDV, OEM vendor variables, and don't require IDSP for the
         int340x thermal driver - trivial conflicts fixed (Matthew Garrett)
      
      * tag 'thermal-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux: (48 commits)
        thermal/int340x_thermal: Don't require IDSP to exist
        thermal/int340x_thermal: Export OEM vendor variables
        thermal/int340x_thermal: Export GDDV
        thermal: qoriq: Update the settings for TMUv2
        thermal: rcar_thermal: Clean up rcar_thermal_update_temp()
        thermal: qoriq: Add platform dependencies
        drivers: thermal: tsens: Merge tsens-common.c into tsens.c
        thermal/of: Rename of-thermal.c
        thermal/governors: Prefix all source files with gov_
        thermal/drivers/user_space: Sort headers alphabetically
        thermal/drivers/of-thermal: Sort headers alphabetically
        thermal/drivers/cpufreq_cooling: Replace module.h with export.h
        thermal/drivers/cpufreq_cooling: Sort headers alphabetically
        thermal/drivers/clock_cooling: Include export.h
        thermal/drivers/clock_cooling: Sort headers alphabetically
        thermal/drivers/thermal_hwmon: Include export.h
        thermal/drivers/thermal_hwmon: Sort headers alphabetically
        thermal/drivers/thermal_helpers: Include export.h
        thermal/drivers/thermal_helpers: Sort headers alphabetically
        thermal/core: Replace module.h with export.h
        ...
      df2fbf5b
    • Linus Torvalds's avatar
      Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace · 44ebe016
      Linus Torvalds authored
      Pull proc fix from Eric Biederman:
       "Much to my surprise syzbot found a very old bug in proc that the
        recent changes made easier to reproce. This bug is subtle enough it
        looks like it fooled everyone who should know better"
      
      * 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
        proc: Use new_inode not new_inode_pseudo
      44ebe016
    • Thomas Gleixner's avatar
      x86/entry: Force rcu_irq_enter() when in idle task · 0bf3924b
      Thomas Gleixner authored
      The idea of conditionally calling into rcu_irq_enter() only when RCU is
      not watching turned out to be not completely thought through.
      
      Paul noticed occasional premature end of grace periods in RCU torture
      testing. Bisection led to the commit which made the invocation of
      rcu_irq_enter() conditional on !rcu_is_watching().
      
      It turned out that this conditional breaks RCU assumptions about the idle
      task when the scheduler tick happens to be a nested interrupt. Nested
      interrupts can happen when the first interrupt invokes softirq processing
      on return which enables interrupts.
      
      If that nested tick interrupt does not invoke rcu_irq_enter() then the
      RCU's irq-nesting checks will believe that this interrupt came directly
      from idle, which will cause RCU to report a quiescent state.  Because this
      interrupt instead came from a softirq handler which might have been
      executing an RCU read-side critical section, this can cause the grace
      period to end prematurely.
      
      Change the condition from !rcu_is_watching() to is_idle_task(current) which
      enforces that interrupts in the idle task unconditionally invoke
      rcu_irq_enter() independent of the RCU state.
      
      This is also correct vs. user mode entries in NOHZ full scenarios because
      user mode entries bring RCU out of EQS and force the RCU irq nesting state
      accounting to nested. As only the first interrupt can enter from user mode
      a nested tick interrupt will enter from kernel mode and as the nesting
      state accounting is forced to nesting it will not do anything stupid even
      if rcu_irq_enter() has not been invoked.
      
      Fixes: 3eeec385 ("x86/entry: Provide idtentry_entry/exit_cond_rcu()")
      Reported-by: default avatar"Paul E. McKenney" <paulmck@kernel.org>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatar"Paul E. McKenney" <paulmck@kernel.org>
      Reviewed-by: default avatar"Paul E. McKenney" <paulmck@kernel.org>
      Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
      Acked-by: default avatarFrederic Weisbecker <frederic@kernel.org>
      Link: https://lkml.kernel.org/r/87wo4cxubv.fsf@nanos.tec.linutronix.de
      0bf3924b
    • Linus Torvalds's avatar
      Merge tag 'pwm/for-5.8-rc1' of... · 9433a51e
      Linus Torvalds authored
      Merge tag 'pwm/for-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
      
      Pull pwm updates from Thierry Reding:
       "Nothing too exciting for this cycle. A couple of fixes across the
        board, and Lee volunteered to help with patch review"
      
      * tag 'pwm/for-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
        pwm: Add missing "CONFIG_" prefix
        MAINTAINERS: Add Lee Jones as reviewer for the PWM subsystem
        pwm: imx27: Fix rounding behavior
        pwm: rockchip: Simplify rockchip_pwm_get_state()
        pwm: img: Call pm_runtime_put() in pm_runtime_get_sync() failed case
        pwm: tegra: Support dynamic clock frequency configuration
        pwm: jz4740: Add support for the JZ4725B
        pwm: jz4740: Make PWM start with the active part
        pwm: jz4740: Enhance precision in calculation of duty cycle
        pwm: jz4740: Drop dependency on MACH_INGENIC
        pwm: lpss: Fix get_state runtime-pm reference handling
        pwm: sun4i: Support direct clock output on Allwinner A64
        pwm: Add support for Azoteq IQS620A PWM generator
        dt-bindings: pwm: rcar: add r8a77961 support
        pwm: Add missing '\n' in log messages
      9433a51e
    • Linus Torvalds's avatar
      Merge tag 'iommu-drivers-move-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu · 8f02f363
      Linus Torvalds authored
      Pull iommu driver directory structure cleanup from Joerg Roedel:
       "Move the Intel and AMD IOMMU drivers into their own subdirectory.
      
        Both drivers consist of several files by now and giving them their own
        directory unclutters the IOMMU top-level directory a bit"
      
      * tag 'iommu-drivers-move-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
        iommu/vt-d: Move Intel IOMMU driver into subdirectory
        iommu/amd: Move AMD IOMMU driver into subdirectory
      8f02f363
    • Linus Torvalds's avatar
      Merge tag 'printk-for-5.8-kdb-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux · 5c2fb57a
      Linus Torvalds authored
      Pull printk fix from Petr Mladek:
       "One more printk change for 5.8: make sure that messages printed from
        KDB context are redirected to KDB console handlers. It did not work
        when KDB interrupted NMI or printk_safe contexts.
      
        Arm people started hitting this problem more often recently. I forgot
        to add the fix into the previous pull request by mistake"
      
      * tag 'printk-for-5.8-kdb-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
        printk/kdb: Redirect printk messages into kdb in any context
      5c2fb57a
    • Eric W. Biederman's avatar
      proc: Use new_inode not new_inode_pseudo · ef1548ad
      Eric W. Biederman authored
      Recently syzbot reported that unmounting proc when there is an ongoing
      inotify watch on the root directory of proc could result in a use
      after free when the watch is removed after the unmount of proc
      when the watcher exits.
      
      Commit 69879c01 ("proc: Remove the now unnecessary internal mount
      of proc") made it easier to unmount proc and allowed syzbot to see the
      problem, but looking at the code it has been around for a long time.
      
      Looking at the code the fsnotify watch should have been removed by
      fsnotify_sb_delete in generic_shutdown_super.  Unfortunately the inode
      was allocated with new_inode_pseudo instead of new_inode so the inode
      was not on the sb->s_inodes list.  Which prevented
      fsnotify_unmount_inodes from finding the inode and removing the watch
      as well as made it so the "VFS: Busy inodes after unmount" warning
      could not find the inodes to warn about them.
      
      Make all of the inodes in proc visible to generic_shutdown_super,
      and fsnotify_sb_delete by using new_inode instead of new_inode_pseudo.
      The only functional difference is that new_inode places the inodes
      on the sb->s_inodes list.
      
      I wrote a small test program and I can verify that without changes it
      can trigger this issue, and by replacing new_inode_pseudo with
      new_inode the issues goes away.
      
      Cc: stable@vger.kernel.org
      Link: https://lkml.kernel.org/r/000000000000d788c905a7dfa3f4@google.com
      Reported-by: syzbot+7d2debdcdb3cb93c1e5e@syzkaller.appspotmail.com
      Fixes: 0097875b ("proc: Implement /proc/thread-self to point at the directory of the current thread")
      Fixes: 021ada7d ("procfs: switch /proc/self away from proc_dir_entry")
      Fixes: 51f0885e ("vfs,proc: guarantee unique inodes in /proc")
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      ef1548ad
    • Linus Torvalds's avatar
      Merge tag 'integrity-v5.8-fix' of... · 923ea163
      Linus Torvalds authored
      Merge tag 'integrity-v5.8-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
      
      Pull integrity fix from Mimi Zohar:
       "ima mprotect performance fix"
      
      * tag 'integrity-v5.8-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
        ima: fix mprotect checking
      923ea163
    • Linus Torvalds's avatar
      Merge tag 'devicetree-fixes-for-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux · 4071b856
      Linus Torvalds authored
      Pull Devicetree fixes from Rob Herring:
      
       - Another round of whack-a-mole removing 'allOf', redundant cases of
         'maxItems' and incorrect 'reg' sizes
      
       - Fix support for yaml.h in non-standard paths
      
      * tag 'devicetree-fixes-for-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
        dt-bindings: Remove redundant 'maxItems'
        dt-bindings: Fix more incorrect 'reg' property sizes in examples
        dt-bindings: phy: qcom: Fix missing 'ranges' and example addresses
        dt-bindings: Remove more cases of 'allOf' containing a '$ref'
        scripts/dtc: use pkg-config to include <yaml.h> in non-standard path
      4071b856
    • Linus Torvalds's avatar
      Merge tag 'nios2-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2 · 7de26c41
      Linus Torvalds authored
      Pull nios2 update from Ley Foon Tan:
       "Mark expected switch fall-through in signal handling"
      
      * tag 'nios2-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
        nios2: signal: Mark expected switch fall-through
      7de26c41
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 52cd0d97
      Linus Torvalds authored
      Pull more KVM updates from Paolo Bonzini:
       "The guest side of the asynchronous page fault work has been delayed to
        5.9 in order to sync with Thomas's interrupt entry rework, but here's
        the rest of the KVM updates for this merge window.
      
        MIPS:
         - Loongson port
      
        PPC:
         - Fixes
      
        ARM:
         - Fixes
      
        x86:
         - KVM_SET_USER_MEMORY_REGION optimizations
         - Fixes
         - Selftest fixes"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (62 commits)
        KVM: x86: do not pass poisoned hva to __kvm_set_memory_region
        KVM: selftests: fix sync_with_host() in smm_test
        KVM: async_pf: Inject 'page ready' event only if 'page not present' was previously injected
        KVM: async_pf: Cleanup kvm_setup_async_pf()
        kvm: i8254: remove redundant assignment to pointer s
        KVM: x86: respect singlestep when emulating instruction
        KVM: selftests: Don't probe KVM_CAP_HYPERV_ENLIGHTENED_VMCS when nested VMX is unsupported
        KVM: selftests: do not substitute SVM/VMX check with KVM_CAP_NESTED_STATE check
        KVM: nVMX: Consult only the "basic" exit reason when routing nested exit
        KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h
        KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception
        KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts
        KVM: arm64: Remove host_cpu_context member from vcpu structure
        KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr
        KVM: arm64: Handle PtrAuth traps early
        KVM: x86: Unexport x86_fpu_cache and make it static
        KVM: selftests: Ignore KVM 5-level paging support for VM_MODE_PXXV48_4K
        KVM: arm64: Save the host's PtrAuth keys in non-preemptible context
        KVM: arm64: Stop save/restoring ACTLR_EL1
        KVM: arm64: Add emulation for 32bit guests accessing ACTLR2
        ...
      52cd0d97
    • Linus Torvalds's avatar
      Merge tag 'for-linus-5.8b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip · d2d5439d
      Linus Torvalds authored
      Pull xen updates from Juergen Gross:
      
       - several smaller cleanups
      
       - a fix for a Xen guest regression with CPU offlining
      
       - a small fix in the xen pvcalls backend driver
      
       - an update of MAINTAINERS
      
      * tag 'for-linus-5.8b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
        MAINTAINERS: Update PARAVIRT_OPS_INTERFACE and VMWARE_HYPERVISOR_INTERFACE
        xen/pci: Get rid of verbose_request and use dev_dbg() instead
        xenbus: Use dev_printk() when possible
        xen-pciback: Use dev_printk() when possible
        xen: enable BALLOON_MEMORY_HOTPLUG by default
        xen: expand BALLOON_MEMORY_HOTPLUG description
        xen/pvcalls: Make pvcalls_back_global static
        xen/cpuhotplug: Fix initial CPU offlining for PV(H) guests
        xen-platform: Constify dev_pm_ops
        xen/pvcalls-back: test for errors when calling backend_connect()
      d2d5439d
    • Rob Herring's avatar
      8440d4a7
    • Rob Herring's avatar
      dt-bindings: Remove redundant 'maxItems' · 44761570
      Rob Herring authored
      There's no need to specify 'maxItems' with the same value as the number
      of entries in 'items'. A meta-schema update will catch future cases.
      
      Cc: Shawn Guo <shawnguo@kernel.org>
      Cc: Sascha Hauer <s.hauer@pengutronix.de>
      Cc: Anson Huang <Anson.Huang@nxp.com>
      Cc: linux-clk@vger.kernel.org
      Cc: linux-pwm@vger.kernel.org
      Cc: linux-usb@vger.kernel.org
      Reviewed-by: Stephen Boyd <sboyd@kernel.org> # clk
      Acked-by: default avatarThierry Reding <thierry.reding@gmail.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
      44761570
    • Mimi Zohar's avatar
      ima: fix mprotect checking · 4235b1a4
      Mimi Zohar authored
      Make sure IMA is enabled before checking mprotect change.  Addresses
      report of a 3.7% regression of boot-time.dhcp.
      
      Fixes: 8eb613c0 ("ima: verify mprotect change is consistent with mmap policy")
      Reported-by: default avatarkernel test robot <rong.a.chen@intel.com>
      Reviewed-by: default avatarLakshmi Ramasubramanian <nramas@linux.microsoft.com>
      Tested-by: default avatarXing Zhengjun <zhengjun.xing@linux.intel.com>
      Signed-off-by: default avatarMimi Zohar <zohar@linux.ibm.com>
      4235b1a4
    • Thomas Gleixner's avatar
      x86/entry: Make NMI use IDTENTRY_RAW · 71ed49d8
      Thomas Gleixner authored
      For no reason other than beginning brainmelt, IDTENTRY_NMI was mapped to
      IDTENTRY_IST.
      
      This is not a problem on 64bit because the IST default entry point maps to
      IDTENTRY_RAW which does not any entry handling. The surplus function
      declaration for the noist C entry point is unused and as there is no ASM
      code emitted for NMI this went unnoticed.
      
      On 32bit IDTENTRY_IST maps to a regular IDTENTRY which does the normal
      entry handling. That is clearly the wrong thing to do for NMI.
      
      Map it to IDTENTRY_RAW to unbreak it. The IDTENTRY_NMI mapping needs to
      stay to avoid emitting ASM code.
      
      Fixes: 6271fef0 ("x86/entry: Convert NMI to IDTENTRY_NMI")
      Reported-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
      Debugged-by: default avatarAndy Lutomirski <luto@kernel.org>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Link: https://lkml.kernel.org/r/CA+G9fYvF3cyrY+-iw_SZtpN-i2qA2BruHg4M=QYECU2-dNdsMw@mail.gmail.com
      71ed49d8
    • Andy Lutomirski's avatar
      x86/entry: Treat BUG/WARN as NMI-like entries · 15a416e8
      Andy Lutomirski authored
      BUG/WARN are cleverly optimized using UD2 to handle the BUG/WARN out of
      line in an exception fixup.
      
      But if BUG or WARN is issued in a funny RCU context, then the
      idtentry_enter...() path might helpfully WARN that the RCU context is
      invalid, which results in infinite recursion.
      
      Split the BUG/WARN handling into an nmi_enter()/nmi_exit() path in
      exc_invalid_op() to increase the chance to survive the experience.
      
      [ tglx: Make the declaration match the implementation ]
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Link: https://lkml.kernel.org/r/f8fe40e0088749734b4435b554f73eee53dcf7a8.1591932307.git.luto@kernel.org
      15a416e8
    • Alexey Kardashevskiy's avatar
      KVM: PPC: Fix nested guest RC bits update · e881bfaf
      Alexey Kardashevskiy authored
      Before commit 6cdf3037 ("powerpc/kvm/book3s: Use kvm helpers
      to walk shadow or secondary table") we called __find_linux_pte() with
      a page table pointer from a kvm_nested_guest struct but
      now we rely on kvmhv_find_nested() which takes an L1 LPID and returns
      a kvm_nested_guest pointer, however we pass a L0 LPID there and
      the L2 guest hangs.
      
      This fixes the LPID passed to kvmppc_hv_handle_set_rc().
      
      Fixes: 6cdf3037 ("powerpc/kvm/book3s: Use kvm helpers to walk shadow or secondary table")
      Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/20200611030559.75257-1-aik@ozlabs.ru
      e881bfaf
    • Ley Foon Tan's avatar
      nios2: signal: Mark expected switch fall-through · 6b57fa4d
      Ley Foon Tan authored
      Mark switch cases where we are expecting to fall through.
      
      Fix the following warning through the use of the new the new
      pseudo-keyword fallthrough;
      
      arch/nios2/kernel/signal.c:254:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
        254 |    restart = -2;
            |    ~~~~~~~~^~~~
      arch/nios2/kernel/signal.c:255:3: note: here
        255 |   case ERESTARTNOHAND:
            |   ^~~~
      Reported-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
      Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
      Signed-off-by: default avatarLey Foon Tan <ley.foon.tan@intel.com>
      6b57fa4d
    • Linus Torvalds's avatar
      Merge tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · b791d1bd
      Linus Torvalds authored
      Pull the Kernel Concurrency Sanitizer from Thomas Gleixner:
       "The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector,
        which relies on compile-time instrumentation, and uses a
        watchpoint-based sampling approach to detect races.
      
        The feature was under development for quite some time and has already
        found legitimate bugs.
      
        Unfortunately it comes with a limitation, which was only understood
        late in the development cycle:
      
           It requires an up to date CLANG-11 compiler
      
        CLANG-11 is not yet released (scheduled for June), but it's the only
        compiler today which handles the kernel requirements and especially
        the annotations of functions to exclude them from KCSAN
        instrumentation correctly.
      
        These annotations really need to work so that low level entry code and
        especially int3 text poke handling can be completely isolated.
      
        A detailed discussion of the requirements and compiler issues can be
        found here:
      
          https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/
      
        We came to the conclusion that trying to work around compiler
        limitations and bugs again would end up in a major trainwreck, so
        requiring a working compiler seemed to be the best choice.
      
        For Continous Integration purposes the compiler restriction is
        manageable and that's where most xxSAN reports come from.
      
        For a change this limitation might make GCC people actually look at
        their bugs. Some issues with CSAN in GCC are 7 years old and one has
        been 'fixed' 3 years ago with a half baken solution which 'solved' the
        reported issue but not the underlying problem.
      
        The KCSAN developers also ponder to use a GCC plugin to become
        independent, but that's not something which will show up in a few
        days.
      
        Blocking KCSAN until wide spread compiler support is available is not
        a really good alternative because the continuous growth of lockless
        optimizations in the kernel demands proper tooling support"
      
      * tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
        compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining
        compiler.h: Move function attributes to compiler_types.h
        compiler.h: Avoid nested statement expression in data_race()
        compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE()
        kcsan: Update Documentation to change supported compilers
        kcsan: Remove 'noinline' from __no_kcsan_or_inline
        kcsan: Pass option tsan-instrument-read-before-write to Clang
        kcsan: Support distinguishing volatile accesses
        kcsan: Restrict supported compilers
        kcsan: Avoid inserting __tsan_func_entry/exit if possible
        ubsan, kcsan: Don't combine sanitizer with kcov on clang
        objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn()
        kcsan: Add __kcsan_{enable,disable}_current() variants
        checkpatch: Warn about data_race() without comment
        kcsan: Use GFP_ATOMIC under spin lock
        Improve KCSAN documentation a bit
        kcsan: Make reporting aware of KCSAN tests
        kcsan: Fix function matching in report
        kcsan: Change data_race() to no longer require marking racing accesses
        kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h
        ...
      b791d1bd