23 Jun, 2015

1 commit

  • Pull scheduler updates from Ingo Molnar:
    "The main changes are:

    - lockless wakeup support for futexes and IPC message queues
    (Davidlohr Bueso, Peter Zijlstra)

    - Replace spinlocks with atomics in thread_group_cputimer(), to
    improve scalability (Jason Low)

    - NUMA balancing improvements (Rik van Riel)

    - SCHED_DEADLINE improvements (Wanpeng Li)

    - clean up and reorganize preemption helpers (Frederic Weisbecker)

    - decouple page fault disabling machinery from the preemption
    counter, to improve debuggability and robustness (David
    Hildenbrand)

    - SCHED_DEADLINE documentation updates (Luca Abeni)

    - topology CPU masks cleanups (Bartosz Golaszewski)

    - /proc/sched_debug improvements (Srikar Dronamraju)"

    * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
    sched/deadline: Remove needless parameter in dl_runtime_exceeded()
    sched: Remove superfluous resetting of the p->dl_throttled flag
    sched/deadline: Drop duplicate init_sched_dl_class() declaration
    sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target
    sched/deadline: Make init_sched_dl_class() __init
    sched/deadline: Optimize pull_dl_task()
    sched/preempt: Add static_key() to preempt_notifiers
    sched/preempt: Fix preempt notifiers documentation about hlist_del() within unsafe iteration
    sched/stop_machine: Fix deadlock between multiple stop_two_cpus()
    sched/debug: Add sum_sleep_runtime to /proc//sched
    sched/debug: Replace vruntime with wait_sum in /proc/sched_debug
    sched/debug: Properly format runnable tasks in /proc/sched_debug
    sched/numa: Only consider less busy nodes as numa balancing destinations
    Revert 095bebf61a46 ("sched/numa: Do not move past the balance point if unbalanced")
    sched/fair: Prevent throttling in early pick_next_task_fair()
    preempt: Reorganize the notrace definitions a bit
    preempt: Use preempt_schedule_context() as the official tracing preemption point
    sched: Make preempt_schedule_context() function-tracing safe
    x86: Remove cpu_sibling_mask() and cpu_core_mask()
    x86: Replace cpu_**_mask() with topology_**_cpumask()
    ...

    Linus Torvalds
     

03 Jun, 2015

2 commits

  • strnlen_user() can return a number in a range 0 to count +
    sizeof(unsigned long) - 1. Clarify the comment at the top of the
    function so that users don't think the function returns at most count+1.

    Signed-off-by: Jan Kara
    [ Also added commentary about preferably not using this function ]
    Signed-off-by: Linus Torvalds

    Jan Kara
     
  • If the specified maximum length of the string is a multiple of unsigned
    long, we would load one long behind the specified maximum. If that
    happens to be in a next page, we can hit a page fault although we were
    not expected to.

    Fix the off-by-one bug in the test whether we are at the end of the
    specified range.

    Signed-off-by: Jan Kara
    Cc: stable@vger.kernel.org
    Signed-off-by: Linus Torvalds

    Jan Kara
     

19 May, 2015

1 commit

  • In general, non-atomic variants of user access functions must not sleep
    if pagefaults are disabled.

    Let's update all relevant comments in uaccess code. This also reflects
    the might_sleep() checks in might_fault().

    Reviewed-and-tested-by: Thomas Gleixner
    Signed-off-by: David Hildenbrand
    Signed-off-by: Peter Zijlstra (Intel)
    Cc: David.Laight@ACULAB.COM
    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: airlied@linux.ie
    Cc: akpm@linux-foundation.org
    Cc: benh@kernel.crashing.org
    Cc: bigeasy@linutronix.de
    Cc: borntraeger@de.ibm.com
    Cc: daniel.vetter@intel.com
    Cc: heiko.carstens@de.ibm.com
    Cc: herbert@gondor.apana.org.au
    Cc: hocko@suse.cz
    Cc: hughd@google.com
    Cc: mst@redhat.com
    Cc: paulus@samba.org
    Cc: ralf@linux-mips.org
    Cc: schwidefsky@de.ibm.com
    Cc: yang.shi@windriver.com
    Link: http://lkml.kernel.org/r/1431359540-32227-4-git-send-email-dahi@linux.vnet.ibm.com
    Signed-off-by: Ingo Molnar

    David Hildenbrand
     

28 May, 2012

1 commit


27 May, 2012

1 commit

  • This adds a new generic optimized strnlen_user() function that uses the
    infrastructure to portably do efficient string
    handling.

    In many ways, strnlen is much simpler than strncpy, and in particular we
    can always pre-align the words we load from memory. That means that all
    the worries about alignment etc are a non-issue, so this one can easily
    be used on any architecture. You obviously do have to do the
    appropriate word-at-a-time.h macros.

    Signed-off-by: Linus Torvalds

    Linus Torvalds