Fix a braino in F_DUPFD_CLOEXEC; f_dupfd() expects flags for alloc_fd(),
get_unused_fd() etc and there clone-on-exec if O_CLOEXEC, not
FD_CLOEXEC.
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... except for one in android, where the check is different
and already done in caller. No need to recalculate rlimit
many times in alloc_fd() either.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When we restore file descriptors we would like them to look exactly as
they were at dumping time.
With help of fcntl it's almost possible, the missing snippet is file
owners UIDs.
To be able to read their values the F_GETOWNER_UIDS is introduced.
This option is valid iif CONFIG_CHECKPOINT_RESTORE is turned on, otherwise
returning -EINVAL.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wrap accesses to the fd_sets in struct fdtable (for recording open files and
close-on-exec flags) so that we can move away from using fd_sets since we
abuse the fd_set structs by not allocating the full-sized structure under
normal circumstances and by non-core code looking at the internals of the
fd_sets.
The first abuse means that use of FD_ZERO() on these fd_sets is not permitted,
since that cannot be told about their abnormal lengths.
This introduces six wrapper functions for setting, clearing and testing
close-on-exec flags and fd-is-open flags:
void __set_close_on_exec(int fd, struct fdtable *fdt);
void __clear_close_on_exec(int fd, struct fdtable *fdt);
bool close_on_exec(int fd, const struct fdtable *fdt);
void __set_open_fd(int fd, struct fdtable *fdt);
void __clear_open_fd(int fd, struct fdtable *fdt);
bool fd_is_open(int fd, const struct fdtable *fdt);
Note that I've prepended '__' to the names of the set/clear functions because
they require the caller to hold a lock to use them.
Note also that I haven't added wrappers for looking behind the scenes at the
the array. Possibly that should exist too.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.uk
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
And give it a kernel-doc comment.
[akpm@linux-foundation.org: btrfs changed in linux-next]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
New flag for open(2) - O_PATH. Semantics:
* pathname is resolved, but the file itself is _NOT_ opened
as far as filesystem is concerned.
* almost all operations on the resulting descriptors shall
fail with -EBADF. Exceptions are:
1) operations on descriptors themselves (i.e.
close(), dup(), dup2(), dup3(), fcntl(fd, F_DUPFD),
fcntl(fd, F_DUPFD_CLOEXEC, ...), fcntl(fd, F_GETFD),
fcntl(fd, F_SETFD, ...))
2) fcntl(fd, F_GETFL), for a common non-destructive way to
check if descriptor is open
3) "dfd" arguments of ...at(2) syscalls, i.e. the starting
points of pathname resolution
* closing such descriptor does *NOT* affect dnotify or
posix locks.
* permissions are checked as usual along the way to file;
no permission checks are applied to the file itself. Of course,
giving such thing to syscall will result in permission checks (at
the moment it means checking that starting point of ....at() is
a directory and caller has exec permissions on it).
fget() and fget_light() return NULL on such descriptors; use of
fget_raw() and fget_raw_light() is needed to get them. That protects
existing code from dealing with those things.
There are two things still missing (they come in the next commits):
one is handling of symlinks (right now we refuse to open them that
way; see the next commit for semantics related to those) and another
is descriptor passing via SCM_RIGHTS datagrams.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
FMODE_EXEC is a constant type of fmode_t but was used with normal integer
constants. This results in following warnings from sparse. Fix it using
new macro __FMODE_EXEC.
fs/exec.c:116:58: warning: restricted fmode_t degrades to integer
fs/exec.c:689:58: warning: restricted fmode_t degrades to integer
fs/fcntl.c:777:9: warning: restricted fmode_t degrades to integer
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit f7347ce4ee ("fasync: re-organize fasync entry insertion to
allow it under a spinlock") Arnd took an earlier patch of mine that had
the comment about the FASYNC flag above the wrong function.
When the fasync_add_entry() function was split to introduce the new
fasync_insert_entry() helper function, the code that actually cares
about the FASYNC bit moved to that new helper.
So just move the comment to the right point.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
You currently cannot use "fasync_helper()" in an atomic environment to
insert a new fasync entry, because it will need to allocate the new
"struct fasync_struct".
Yet fcntl_setlease() wants to call this under lock_flocks(), which is in
the process of being converted from the BKL to a spinlock.
In order to fix this, this abstracts out the actual fasync list
insertion and the fasync allocations into functions of their own, and
teaches fs/locks.c to pre-allocate the fasync_struct entry. That way
the actual list insertion can happen while holding the required
spinlock.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bfields@redhat.com: rebase on top of my changes to Arnd's patch]
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
O_NONBLOCK on parisc has a dual value:
#define O_NONBLOCK 000200004 /* HPUX has separate NDELAY & NONBLOCK */
It is caught by the O_* bits uniqueness check and leads to a parisc
compile error. The fix would be to take O_NONBLOCK out.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Cc: Jamie Lokier <jamie@shareable.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
copy_to_user() returns the number of bytes remaining, but we want to
return -EFAULT.
ret = fcntl(fd, F_SETOWN_EX, NULL);
With the original code ret would be 8 here.
V2: Takuya Yoshikawa pointed out a similar issue in f_getown_ex()
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
kill_fasync() uses a central rwlock, candidate for RCU conversion, to
avoid cache line ping pongs on SMP.
fasync_remove_entry() and fasync_add_entry() can disable IRQS on a short
section instead during whole list scan.
Use a spinlock per fasync_struct to synchronize kill_fasync_rcu() and
fasync_{remove|add}_entry(). This spinlock is IRQ safe, so sock_fasync()
doesnt need its own implementation and can use fasync_helper(), to
reduce code size and complexity.
We can remove __kill_fasync() direct use in net/socket.c, and rename it
to kill_fasync_rcu().
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sure compiler won't do weird things with limits. E.g. fetching them
twice may return 2 different values after writable limits are implemented.
I.e. either use rlimit helpers added in commit 3e10e716ab ("resource:
add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
