diff options
| author |   Jann Horn <jannh@google.com> | 2019-07-16 17:20:47 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-07-25 15:37:05 +0200 |
| commit | cb361d8cdef69990f6b4504dc1fd9a594d983c97 (patch) | |
| tree | cde527557b6259487a11df5f30a652ab965cda41 /include/linux/sched.h | |
| parent | sched/fair: Don't free p->numa_faults with concurrent readers (diff) | |
| download | linux-dev-cb361d8cdef69990f6b4504dc1fd9a594d983c97.tar.xz linux-dev-cb361d8cdef69990f6b4504dc1fd9a594d983c97.zip | |
sched/fair: Use RCU accessors consistently for ->numa_group
The old code used RCU annotations and accessors inconsistently for
->numa_group, which can lead to use-after-frees and NULL dereferences.
Let all accesses to ->numa_group use proper RCU helpers to prevent such
issues.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 8c8a743c5087 ("sched/numa: Use {cpu, pid} to create task groups for shared faults")
Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | include/linux/sched.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 8dc1811487f5..9f51932bd543 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1092,7 +1092,15 @@ struct task_struct { u64 last_sum_exec_runtime; struct callback_head numa_work; - struct numa_group *numa_group; + /* + * This pointer is only modified for current in syscall and + * pagefault context (and for tasks being destroyed), so it can be read + * from any of the following contexts: + * - RCU read-side critical section + * - current->numa_group from everywhere + * - task's runqueue locked, task not running + */ + struct numa_group __rcu *numa_group; /* * numa_faults is an array split into four regions: |