Subject: [PATCH 0/2] kvm: use anon_inode_getfd() with O_CLOEXEC flag

From: Yann Droneaud <[email-masked]>
Date: Sat, 24 Aug 2013 22:14:06 +0200

Hi,

Following a patchset asking to change calls to get_unused_flag() [1]
to use O_CLOEXEC, Alex Williamson [2][3] decided to change VFIO
to use the flag.

Since it's a related subsystem to KVM, using O_CLOEXEC for
file descriptors created by KVM might be applicable too.

I'm suggesting to change calls to anon_inode_getfd() to use O_CLOEXEC
as default flag.

This patchset should be reviewed to not break existing userspace program.

BTW, if it's not applicable, I would suggest that new ioctls be added to
KVM subsystem, those ioctls would have a "flag" field added to their arguments.
Such "flag" would let userspace choose the open flag to use.
See for example other APIs using anon_inode_getfd() such as fanotify,
inotify, signalfd and timerfd.

You might be interested to read:

- Secure File Descriptor Handling (Ulrich Drepper, 2008)
  http://udrepper.livejournal.com/20407.html

- Excuse me son, but your code is leaking !!! (Dan Walsh, March 2012) 
  http://danwalsh.livejournal.com/53603.html

Regards.

[1] http://lkml.kernel.org/r/[email-masked]
[2] http://lkml.kernel.org/r/[email-masked]
[3] http://lkml.kernel.org/r/[email-masked]

Yann Droneaud (2):
  kvm: use anon_inode_getfd() with O_CLOEXEC flag
  ppc: kvm: use anon_inode_getfd() with O_CLOEXEC flag

 arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
 arch/powerpc/kvm/book3s_64_vio.c    | 2 +-
 arch/powerpc/kvm/book3s_hv.c        | 2 +-
 virt/kvm/kvm_main.c                 | 6 +++---
 4 files changed, 6 insertions(+), 6 deletions(-)

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1.8.3.1