linux/include
Yann Droneaud a21b0b354d perf: Introduce a flag to enable close-on-exec in perf_event_open()
Unlike recent modern userspace API such as:

  epoll_create1 (EPOLL_CLOEXEC), eventfd (EFD_CLOEXEC),
  fanotify_init (FAN_CLOEXEC), inotify_init1 (IN_CLOEXEC),
  signalfd (SFD_CLOEXEC), timerfd_create (TFD_CLOEXEC),
  or the venerable general purpose open (O_CLOEXEC),

perf_event_open() syscall lack a flag to atomically set FD_CLOEXEC
(eg. close-on-exec) flag on file descriptor it returns to userspace.

The present patch adds a PERF_FLAG_FD_CLOEXEC flag to allow
perf_event_open() syscall to atomically set close-on-exec.

Having this flag will enable userspace to remove the file descriptor
from the list of file descriptors being inherited across exec,
without the need to call fcntl(fd, F_SETFD, FD_CLOEXEC) and the
associated race condition between the current thread and another
thread calling fork(2) then execve(2).

Links:

 - 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

 - Notes in DMA buffer sharing: leak and security hole
   http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/dma-buf-sharing.txt?id=v3.13-rc3#n428

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/8c03f54e1598b1727c19706f3af03f98685d9fe6.1388952061.git.ydroneaud@opteya.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-12 10:16:59 +01:00
..
acpi Merge branch 'acpica' 2013-11-27 01:03:27 +01:00
asm-generic word-at-a-time: provide generic big-endian zero_bytemask implementation 2013-12-12 10:39:01 -08:00
clocksource
crypto crypto: scatterwalk - Use sg_chain_ptr on chain entries 2013-12-09 19:58:52 +08:00
drm Merge branch 'ttm-fixes-3.13' of git://people.freedesktop.org/~thomash/linux into drm-fixes 2013-11-21 18:46:56 +10:00
dt-bindings For the 3.13 merge window we have a couple of new drivers for the AMS 2013-11-15 16:37:40 -08:00
keys
kvm
linux perf/x86: Fix active_entry initialization 2014-01-12 10:16:07 +01:00
math-emu
media [media] videobuf2: Add support for file access mode flags for DMABUF exporting 2013-12-09 14:50:50 -02:00
memory
misc
net sctp: properly latch and use autoclose value from sock to association 2013-12-10 22:41:26 -05:00
pcmcia
ras
rdma Merge branches 'cma', 'cxgb4', 'flowsteer', 'ipoib', 'misc', 'mlx4', 'mlx5', 'nes', 'ocrdma', 'qib' and 'srp' into for-next 2013-11-17 08:22:19 -08:00
rxrpc
scsi [SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers 2013-11-29 08:48:39 +04:00
sound ALSA: memalloc.h - fix wrong truncation of dma_addr_t 2013-12-10 15:30:46 +01:00
target target_core_alua: Store supported ALUA states 2013-11-20 11:26:37 -08:00
trace Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-12-02 10:13:09 -08:00
uapi perf: Introduce a flag to enable close-on-exec in perf_event_open() 2014-01-12 10:16:59 +01:00
video fbdev changes for 3.13 2013-11-14 14:44:20 +09:00
xen Features: 2013-11-15 13:34:37 +09:00
Kbuild