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
..
callchain.c	perf: Roll back callchain buffer refcount under the callchain mutex	2013-08-16 17:55:50 +02:00
core.c	perf: Introduce a flag to enable close-on-exec in perf_event_open()	2014-01-12 10:16:59 +01:00
hw_breakpoint.c	hw_breakpoint: Introduce "struct bp_cpuinfo"	2013-06-20 17:58:57 +02:00
internal.h	perf: Fix arch_perf_out_copy_user default	2013-11-06 12:34:25 +01:00
Makefile	uprobes: Move to kernel/events/	2012-02-22 11:08:00 +01:00
ring_buffer.c	perf: Optimize ring-buffer write by depending on control dependencies	2013-12-11 15:53:22 +01:00
uprobes.c	uprobes: Document xol_area and arch_uprobe->insn/ixol	2013-11-20 16:31:07 +01:00