[PATCH 0/2] af_unix: Fix priority inversion issue

[Nam Cao]

Hi,

While auditing AF_UNIX sockets, I noticed that the sendmsg() code paths may
block on the garbage collector running as workqueue. This can cause
priority inversion and latency for real-time users.

The implementation does kindly avoid blocking "sane users". However, it is
impossible to tell whether the kernel's definition of "sane users"
accurately describes all users out there.

Digging into history and figuring out the reasons why sendmsg() needs to
wait for garbage collector, it is determined that those reasons no longer
apply.

The first patch remove that block, and the second patch is a simple
post cleanup.

Nam Cao (2):
  af_unix: Do not wait for garbage collector in sendmsg()
  af_unix: Clean up unix_schedule_gc()

 net/unix/af_unix.c |  2 +-
 net/unix/af_unix.h |  2 +-
 net/unix/garbage.c | 16 +---------------
 3 files changed, 3 insertions(+), 17 deletions(-)

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2.47.3