lkml.org 
[lkml]   [2020]   [Dec]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v5 09/15] sched: Reject CPU affinity changes based on task_cpu_possible_mask()
    Date
    Reject explicit requests to change the affinity mask of a task via
    set_cpus_allowed_ptr() if the requested mask is not a subset of the
    mask returned by task_cpu_possible_mask(). This ensures that the
    'cpus_mask' for a given task cannot contain CPUs which are incapable of
    executing it, except in cases where the affinity is forced.

    Reviewed-by: Quentin Perret <qperret@google.com>
    Signed-off-by: Will Deacon <will@kernel.org>
    ---
    kernel/sched/core.c | 4 ++++
    1 file changed, 4 insertions(+)

    diff --git a/kernel/sched/core.c b/kernel/sched/core.c
    index 58474569a2ea..92ac3e53f50a 100644
    --- a/kernel/sched/core.c
    +++ b/kernel/sched/core.c
    @@ -1875,6 +1875,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
    const struct cpumask *new_mask, bool check)
    {
    const struct cpumask *cpu_valid_mask = cpu_active_mask;
    + const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p);
    unsigned int dest_cpu;
    struct rq_flags rf;
    struct rq *rq;
    @@ -1888,6 +1889,9 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
    * Kernel threads are allowed on online && !active CPUs
    */
    cpu_valid_mask = cpu_online_mask;
    + } else if (!cpumask_subset(new_mask, cpu_allowed_mask)) {
    + ret = -EINVAL;
    + goto out;
    }

    /*
    --
    2.29.2.576.ga3fc446d84-goog
    \
     
     \ /
      Last update: 2020-12-08 14:31    [W:6.820 / U:0.076 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site