linux/security
Linus Torvalds 6a965666b7 Pipework for general notification queue
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Merge tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull pipe rework from David Howells:
 "This is my set of preparatory patches for building a general
  notification queue on top of pipes. It makes a number of significant
  changes:

   - It removes the nr_exclusive argument from __wake_up_sync_key() as
     this is always 1. This prepares for the next step:

   - Adds wake_up_interruptible_sync_poll_locked() so that poll can be
     woken up from a function that's holding the poll waitqueue
     spinlock.

   - Change the pipe buffer ring to be managed in terms of unbounded
     head and tail indices rather than bounded index and length. This
     means that reading the pipe only needs to modify one index, not
     two.

   - A selection of helper functions are provided to query the state of
     the pipe buffer, plus a couple to apply updates to the pipe
     indices.

   - The pipe ring is allowed to have kernel-reserved slots. This allows
     many notification messages to be spliced in by the kernel without
     allowing userspace to pin too many pages if it writes to the same
     pipe.

   - Advance the head and tail indices inside the pipe waitqueue lock
     and use wake_up_interruptible_sync_poll_locked() to poke poll
     without having to take the lock twice.

   - Rearrange pipe_write() to preallocate the buffer it is going to
     write into and then drop the spinlock. This allows kernel
     notifications to then be added the ring whilst it is filling the
     buffer it allocated. The read side is stalled because the pipe
     mutex is still held.

   - Don't wake up readers on a pipe if there was already data in it
     when we added more.

   - Don't wake up writers on a pipe if the ring wasn't full before we
     removed a buffer"

* tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  pipe: Remove sync on wake_ups
  pipe: Increase the writer-wakeup threshold to reduce context-switch count
  pipe: Check for ring full inside of the spinlock in pipe_write()
  pipe: Remove redundant wakeup from pipe_write()
  pipe: Rearrange sequence in pipe_write() to preallocate slot
  pipe: Conditionalise wakeup in pipe_read()
  pipe: Advance tail pointer inside of wait spinlock in pipe_read()
  pipe: Allow pipes to have kernel-reserved slots
  pipe: Use head and tail pointers for the ring, not cursor and length
  Add wake_up_interruptible_sync_poll_locked()
  Remove the nr_exclusive argument from __wake_up_sync_key()
  pipe: Reduce #inclusion of pipe_fs_i.h
2019-11-30 14:12:13 -08:00
..
apparmor Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
integrity integrity: remove pointless subdir-$(CONFIG_...) 2019-10-05 15:29:49 +09:00
keys KEYS: trusted: Remove set but not used variable 'keyhndl' 2019-11-12 21:45:37 +02:00
loadpin proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
lockdown efi/efi_test: Lock down /dev/efi_test and require CAP_SYS_ADMIN 2019-10-31 09:40:21 +01:00
safesetid security/safesetid: Replace rcu_swap_protected() with rcu_replace_pointer() 2019-10-30 08:45:57 -07:00
selinux Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-27 17:17:40 -08:00
smack pipe: Reduce #inclusion of pipe_fs_i.h 2019-10-23 17:02:34 +01:00
tomoyo treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
yama proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
commoncap.c Merge branch 'next-lsm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-07-09 12:24:21 -07:00
device_cgroup.c device_cgroup: Export devcgroup_check_permission 2019-10-07 15:11:38 -05:00
inode.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
Kconfig Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Kconfig.hardening meminit fix 2019-07-28 12:33:15 -07:00
lsm_audit.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Makefile security: Add a static lockdown policy LSM 2019-08-19 21:54:15 -07:00
min_addr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
security.c perf_event: Add support for LSM and SELinux checks 2019-10-17 21:31:55 +02:00