1. 14 Jul, 2015 2 commits
    • Aleksa Sarai's avatar
      cgroup: implement the PIDs subsystem · 49b786ea
      Aleksa Sarai authored
      Adds a new single-purpose PIDs subsystem to limit the number of
      tasks that can be forked inside a cgroup. Essentially this is an
      implementation of RLIMIT_NPROC that applies to a cgroup rather than a
      process tree.
      However, it should be noted that organisational operations (adding and
      removing tasks from a PIDs hierarchy) will *not* be prevented. Rather,
      the number of tasks in the hierarchy cannot exceed the limit through
      forking. This is due to the fact that, in the unified hierarchy, attach
      cannot fail (and it is not possible for a task to overcome its PIDs
      cgroup policy limit by attaching to a child cgroup -- even if migrating
      mid-fork it must be able to fork in the parent first).
      PIDs are fundamentally a global resource, and it is possible to reach
      PID exhaustion inside a cgroup without hitting any reasonable kmemcg
      policy. Once you've hit PID exhaustion, you're only in a marginally
      better state than OOM. This subsystem allows PID exhaustion inside a
      cgroup to be prevented.
      Signed-off-by: default avatarAleksa Sarai <cyphar@cyphar.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    • Aleksa Sarai's avatar
      cgroup: allow a cgroup subsystem to reject a fork · 7e47682e
      Aleksa Sarai authored
      Add a new cgroup subsystem callback can_fork that conditionally
      states whether or not the fork is accepted or rejected by a cgroup
      policy. In addition, add a cancel_fork callback so that if an error
      occurs later in the forking process, any state modified by can_fork can
      be reverted.
      Allow for a private opaque pointer to be passed from cgroup_can_fork to
      cgroup_post_fork, allowing for the fork state to be stored by each
      subsystem separately.
      Also add a tagging system for cgroup_subsys.h to allow for CGROUP_<TAG>
      enumerations to be be defined and used. In addition, explicitly add a
      CGROUP_CANFORK_COUNT macro to make arrays easier to define.
      This is in preparation for implementing the pids cgroup subsystem.
      Signed-off-by: default avatarAleksa Sarai <cyphar@cyphar.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
  2. 05 Jul, 2015 4 commits
    • Linus Torvalds's avatar
      Linux 4.2-rc1 · d770e558
      Linus Torvalds authored
    • Linus Torvalds's avatar
      Merge tag 'platform-drivers-x86-v4.2-2' of... · a585d2b7
      Linus Torvalds authored
      Merge tag 'platform-drivers-x86-v4.2-2' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86
      Pull late x86 platform driver updates from Darren Hart:
       "The following came in a bit later and I wanted them to bake in next a
        few more days before submitting, thus the second pull.
        A new intel_pmc_ipc driver, a symmetrical allocation and free fix in
        dell-laptop, a couple minor fixes, and some updated documentation in
        the dell-laptop comments.
         - Add Intel Apollo Lake PMC IPC driver
         - Delete an unnecessary check before the function call "kfree"
         - Fix allocating & freeing SMI buffer page
         - Show info about WiGig and UWB in debugfs
         - Update information about wireless control"
      * tag 'platform-drivers-x86-v4.2-2' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
        intel_pmc_ipc: Add Intel Apollo Lake PMC IPC driver
        tc1100-wmi: Delete an unnecessary check before the function call "kfree"
        dell-laptop: Fix allocating & freeing SMI buffer page
        dell-laptop: Show info about WiGig and UWB in debugfs
        dell-laptop: Update information about wireless control
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 1dc51b82
      Linus Torvalds authored
      Pull more vfs updates from Al Viro:
       "Assorted VFS fixes and related cleanups (IMO the most interesting in
        that part are f_path-related things and Eric's descriptor-related
        stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
        fs-cache series, DAX patches, Jan's file_remove_suid() work"
      [ I'd say this is much more than "fixes and related cleanups".  The
        file_table locking rule change by Eric Dumazet is a rather big and
        fundamental update even if the patch isn't huge.   - Linus ]
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
        9p: cope with bogus responses from server in p9_client_{read,write}
        p9_client_write(): avoid double p9_free_req()
        9p: forgetting to cancel request on interrupted zero-copy RPC
        dax: bdev_direct_access() may sleep
        block: Add support for DAX reads/writes to block devices
        dax: Use copy_from_iter_nocache
        dax: Add block size note to documentation
        fs/file.c: __fget() and dup2() atomicity rules
        fs/file.c: don't acquire files->file_lock in fd_install()
        fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
        vfs: avoid creation of inode number 0 in get_next_ino
        namei: make set_root_rcu() return void
        make simple_positive() public
        ufs: use dir_pages instead of ufs_dir_pages()
        pagemap.h: move dir_pages() over there
        remove the pointless include of lglock.h
        fs: cleanup slight list_entry abuse
        xfs: Correctly lock inode when removing suid and file capabilities
        fs: Call security_ops->inode_killpriv on truncate
        fs: Provide function telling whether file_remove_privs() will do anything
    • Linus Torvalds's avatar
      bluetooth: fix list handling · 9b284cbd
      Linus Torvalds authored
      Commit 835a6a2f ("Bluetooth: Stop sabotaging list poisoning")
      thought that the code was sabotaging the list poisoning when NULL'ing
      out the list pointers and removed it.
      But what was going on was that the bluetooth code was using NULL
      pointers for the list as a way to mark it empty, and that commit just
      broke it (and replaced the test with NULL with a "list_empty()" test on
      a uninitialized list instead, breaking things even further).
      So fix it all up to use the regular and real list_empty() handling
      (which does not use NULL, but a pointer to itself), also making sure to
      initialize the list properly (the previous NULL case was initialized
      implicitly by the session being allocated with kzalloc())
      This is a combination of patches by Marcel Holtmann and Tedd Ho-Jeong
      [ I would normally expect to get this through the bt tree, but I'm going
        to release -rc1, so I'm just committing this directly   - Linus ]
      Reported-and-tested-by: default avatarJörg Otte <jrg.otte@gmail.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Original-by: default avatarTedd Ho-Jeong An <tedd.an@intel.com>
      Original-by: Marcel Holtmann <marcel@holtmann.org>:
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  3. 04 Jul, 2015 34 commits