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2017-07-07vfs: fix flock compat thinkoLinus Torvalds1-15/+15
Michael Ellerman reported that commit 8c6657cb50cb ("Switch flock copyin/copyout primitives to copy_{from,to}_user()") broke his networking on a bunch of PPC machines (64-bit kernel, 32-bit userspace). The reason is a brown-paper bug by that commit, which had the arguments to "copy_flock_fields()" in the wrong order, breaking the compat handling for file locking. Apparently very few people run 32-bit user space on x86 any more, so the PPC people got the honor of noticing this "feature". Michael also sent a minimal diff that just changed the order of the arguments in that macro. This is not that minimal diff. This not only changes the order of the arguments in the macro, it also changes them to be pointers (to be consistent with all the other uses of those pointers), and makes the functions that do all of this also have the proper "const" attribution on the source pointers in order to make issues like that (using the source as a destination) be really obvious. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-05Merge branch 'work.misc-set_fs' of ↵Linus Torvalds1-93/+138
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc user access cleanups from Al Viro: "The first pile is assorted getting rid of cargo-culted access_ok(), cargo-culted set_fs() and field-by-field copyouts. The same description applies to a lot of stuff in other branches - this is just the stuff that didn't fit into a more specific topical branch" * 'work.misc-set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: Switch flock copyin/copyout primitives to copy_{from,to}_user() fs/fcntl: return -ESRCH in f_setown when pid/pgid can't be found fs/fcntl: f_setown, avoid undefined behaviour fs/fcntl: f_setown, allow returning error lpfc debugfs: get rid of pointless access_ok() adb: get rid of pointless access_ok() isdn: get rid of pointless access_ok() compat statfs: switch to copy_to_user() fs/locks: don't mess with the address limit in compat_fcntl64 nfsd_readlink(): switch to vfs_get_link() drbd: ->sendpage() never needed set_fs() fs/locks: pass kernel struct flock to fcntl_getlk/setlk fs: locks: Fix some troubles at kernel-doc comments
2017-06-28fs/fcntl: use copy_to/from_user() for u64 typesJens Axboe1-4/+9
Some architectures (at least PPC) doesn't like get/put_user with 64-bit types on a 32-bit system. Use the variably sized copy to/from user variants instead. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: c75b1d9421f8 ("fs: add fcntl() interface for setting/getting write life time hints") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27fs: add fcntl() interface for setting/getting write life time hintsJens Axboe1-0/+62
Define a set of write life time hints: RWH_WRITE_LIFE_NOT_SET No hint information set RWH_WRITE_LIFE_NONE No hints about write life time RWH_WRITE_LIFE_SHORT Data written has a short life time RWH_WRITE_LIFE_MEDIUM Data written has a medium life time RWH_WRITE_LIFE_LONG Data written has a long life time RWH_WRITE_LIFE_EXTREME Data written has an extremely long life time The intent is for these values to be relative to each other, no absolute meaning should be attached to these flag names. Add an fcntl interface for querying these flags, and also for setting them as well: F_GET_RW_HINT Returns the read/write hint set on the underlying inode. F_SET_RW_HINT Set one of the above write hints on the underlying inode. F_GET_FILE_RW_HINT Returns the read/write hint set on the file descriptor. F_SET_FILE_RW_HINT Set one of the above write hints on the file descriptor. The user passes in a 64-bit pointer to get/set these values, and the interface returns 0/-1 on success/error. Sample program testing/implementing basic setting/getting of write hints is below. Add support for storing the write life time hint in the inode flags and in struct file as well, and pass them to the kiocb flags. If both a file and its corresponding inode has a write hint, then we use the one in the file, if available. The file hint can be used for sync/direct IO, for buffered writeback only the inode hint is available. This is in preparation for utilizing these hints in the block layer, to guide on-media data placement. /* * writehint.c: get or set an inode write hint */ #include <stdio.h> #include <fcntl.h> #include <stdlib.h> #include <unistd.h> #include <stdbool.h> #include <inttypes.h> #ifndef F_GET_RW_HINT #define F_LINUX_SPECIFIC_BASE 1024 #define F_GET_RW_HINT (F_LINUX_SPECIFIC_BASE + 11) #define F_SET_RW_HINT (F_LINUX_SPECIFIC_BASE + 12) #endif static char *str[] = { "RWF_WRITE_LIFE_NOT_SET", "RWH_WRITE_LIFE_NONE", "RWH_WRITE_LIFE_SHORT", "RWH_WRITE_LIFE_MEDIUM", "RWH_WRITE_LIFE_LONG", "RWH_WRITE_LIFE_EXTREME" }; int main(int argc, char *argv[]) { uint64_t hint; int fd, ret; if (argc < 2) { fprintf(stderr, "%s: file <hint>\n", argv[0]); return 1; } fd = open(argv[1], O_RDONLY); if (fd < 0) { perror("open"); return 2; } if (argc > 2) { hint = atoi(argv[2]); ret = fcntl(fd, F_SET_RW_HINT, &hint); if (ret < 0) { perror("fcntl: F_SET_RW_HINT"); return 4; } } ret = fcntl(fd, F_GET_RW_HINT, &hint); if (ret < 0) { perror("fcntl: F_GET_RW_HINT"); return 3; } printf("%s: hint %s\n", argv[1], str[hint]); close(fd); return 0; } Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26Switch flock copyin/copyout primitives to copy_{from,to}_user()Al Viro1-30/+29
... and lose HAVE_ARCH_...; if copy_{to,from}_user() on an architecture sucks badly enough to make it a problem, we have a worse problem. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14fs/fcntl: return -ESRCH in f_setown when pid/pgid can't be foundJeff Layton1-5/+13
The current implementation of F_SETOWN doesn't properly vet the argument passed in and only returns an error if INT_MIN is passed in. If the argument doesn't specify a valid pid/pgid, then we just end up cleaning out the file->f_owner structure. What we really want is to only clean that out only in the case where userland passed in an argument of 0. For anything else, we want to return ESRCH if it doesn't refer to a valid pid. The relevant POSIX spec page is here: http://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html Cc: Jiri Slaby <jslaby@suse.cz> Cc: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-06-14fs/fcntl: f_setown, avoid undefined behaviourJiri Slaby1-0/+4
fcntl(0, F_SETOWN, 0x80000000) triggers: UBSAN: Undefined behaviour in fs/fcntl.c:118:7 negation of -2147483648 cannot be represented in type 'int': CPU: 1 PID: 18261 Comm: syz-executor Not tainted 4.8.1-0-syzkaller #1 ... Call Trace: ... [<ffffffffad8f0868>] ? f_setown+0x1d8/0x200 [<ffffffffad8f19a9>] ? SyS_fcntl+0x999/0xf30 [<ffffffffaed1fb00>] ? entry_SYSCALL_64_fastpath+0x23/0xc1 Fix that by checking the arg parameter properly (against INT_MAX) before "who = -who". And return immediatelly with -EINVAL in case it is wrong. Note that according to POSIX we can return EINVAL: http://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html [EINVAL] The cmd argument is F_SETOWN and the value of the argument is not valid as a process or process group identifier. [v2] returns an error, v1 used to fail silently [v3] implement proper check for the bad value INT_MIN Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-06-14fs/fcntl: f_setown, allow returning errorJiri Slaby1-3/+4
Allow f_setown to return an error value. We will fail in the next patch with EINVAL for bad input to f_setown, so tile the path for the later patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Jeff Layton <jlayton@redhat.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-06-01fs/locks: don't mess with the address limit in compat_fcntl64Christoph Hellwig1-51/+67
Instead write a proper compat syscall that calls common helpers. [ jlayton: fix pointer dereferencing in fixup_compat_flock ] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-05-27fs/locks: pass kernel struct flock to fcntl_getlk/setlkChristoph Hellwig1-5/+22
This will make it easier to implement a sane compat fcntl syscall. [ jlayton: fix undeclared identifiers in 32-bit fcntl64 syscall handler ] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-05-09Merge branch 'work.misc' of ↵Linus Torvalds1-10/+4
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted bits and pieces from various people. No common topic in this pile, sorry" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs/affs: add rename exchange fs/affs: add rename2 to prepare multiple methods Make stat/lstat/fstatat pass AT_NO_AUTOMOUNT to vfs_statx() fs: don't set *REFERENCED on single use objects fs: compat: Remove warning from COMPATIBLE_IOCTL remove pointless extern of atime_need_update_rcu() fs: completely ignore unknown open flags fs: add a VALID_OPEN_FLAGS fs: remove _submit_bh() fs: constify tree_descr arrays passed to simple_fill_super() fs: drop duplicate header percpu-rwsem.h fs/affs: bugfix: Write files greater than page size on OFS fs/affs: bugfix: enable writes on OFS disks fs/affs: remove node generation check fs/affs: import amigaffs.h fs/affs: bugfix: make symbolic links work again
2017-04-27fs: add a VALID_OPEN_FLAGSChristoph Hellwig1-10/+4
Add a central define for all valid open flags, and use it in the uniqueness check. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-17fcntl: move compat syscalls from compat.cAl Viro1-0/+157
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+1
<linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-04don't open-code file_inode()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-09fcntl: allow to set O_DIRECT flag on pipeStanislav Kinsburskiy1-1/+2
With packetized mode for pipes, it's not possible to set O_DIRECT on pipe file via sys_fcntl, because of unsupported sanity checks. Ability to set this flag will be used by CRIU to migrate packetized pipes. v2: Fixed typos and mode variable to check. Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-08vfs: renumber FMODE_NONOTIFY and add to uniqueness checkDavid Drysdale1-2/+3
Fix clashing values for O_PATH and FMODE_NONOTIFY on sparc. The clashing O_PATH value was added in commit 5229645bdc35 ("vfs: add nonconflicting values for O_PATH") but this can't be changed as it is user-visible. FMODE_NONOTIFY is only used internally in the kernel, but it is in the same numbering space as the other O_* flags, as indicated by the comment at the top of include/uapi/asm-generic/fcntl.h (and its use in fs/notify/fanotify/fanotify_user.c). So renumber it to avoid the clash. All of this has happened before (commit 12ed2e36c98a: "fanotify: FMODE_NONOTIFY and __O_SYNC in sparc conflict"), and all of this will happen again -- so update the uniqueness check in fcntl_init() to include __FMODE_NONOTIFY. Signed-off-by: David Drysdale <drysdale@google.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Jan Kara <jack@suse.cz> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-09security: make security_file_set_fowner, f_setown and __f_setown void returnJeff Layton1-14/+7
security_file_set_fowner always returns 0, so make it f_setown and __f_setown void return functions and fix up the error handling in the callers. Cc: linux-security-module@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-08-08shm: add sealing APIDavid Herrmann1-0/+5
If two processes share a common memory region, they usually want some guarantees to allow safe access. This often includes: - one side cannot overwrite data while the other reads it - one side cannot shrink the buffer while the other accesses it - one side cannot grow the buffer beyond previously set boundaries If there is a trust-relationship between both parties, there is no need for policy enforcement. However, if there's no trust relationship (eg., for general-purpose IPC) sharing memory-regions is highly fragile and often not possible without local copies. Look at the following two use-cases: 1) A graphics client wants to share its rendering-buffer with a graphics-server. The memory-region is allocated by the client for read/write access and a second FD is passed to the server. While scanning out from the memory region, the server has no guarantee that the client doesn't shrink the buffer at any time, requiring rather cumbersome SIGBUS handling. 2) A process wants to perform an RPC on another process. To avoid huge bandwidth consumption, zero-copy is preferred. After a message is assembled in-memory and a FD is passed to the remote side, both sides want to be sure that neither modifies this shared copy, anymore. The source may have put sensible data into the message without a separate copy and the target may want to parse the message inline, to avoid a local copy. While SIGBUS handling, POSIX mandatory locking and MAP_DENYWRITE provide ways to achieve most of this, the first one is unproportionally ugly to use in libraries and the latter two are broken/racy or even disabled due to denial of service attacks. This patch introduces the concept of SEALING. If you seal a file, a specific set of operations is blocked on that file forever. Unlike locks, seals can only be set, never removed. Hence, once you verified a specific set of seals is set, you're guaranteed that no-one can perform the blocked operations on this file, anymore. An initial set of SEALS is introduced by this patch: - SHRINK: If SEAL_SHRINK is set, the file in question cannot be reduced in size. This affects ftruncate() and open(O_TRUNC). - GROW: If SEAL_GROW is set, the file in question cannot be increased in size. This affects ftruncate(), fallocate() and write(). - WRITE: If SEAL_WRITE is set, no write operations (besides resizing) are possible. This affects fallocate(PUNCH_HOLE), mmap() and write(). - SEAL: If SEAL_SEAL is set, no further seals can be added to a file. This basically prevents the F_ADD_SEAL operation on a file and can be set to prevent others from adding further seals that you don't want. The described use-cases can easily use these seals to provide safe use without any trust-relationship: 1) The graphics server can verify that a passed file-descriptor has SEAL_SHRINK set. This allows safe scanout, while the client is allowed to increase buffer size for window-resizing on-the-fly. Concurrent writes are explicitly allowed. 2) For general-purpose IPC, both processes can verify that SEAL_SHRINK, SEAL_GROW and SEAL_WRITE are set. This guarantees that neither process can modify the data while the other side parses it. Furthermore, it guarantees that even with writable FDs passed to the peer, it cannot increase the size to hit memory-limits of the source process (in case the file-storage is accounted to the source). The new API is an extension to fcntl(), adding two new commands: F_GET_SEALS: Return a bitset describing the seals on the file. This can be called on any FD if the underlying file supports sealing. F_ADD_SEALS: Change the seals of a given file. This requires WRITE access to the file and F_SEAL_SEAL may not already be set. Furthermore, the underlying file must support sealing and there may not be any existing shared mapping of that file. Otherwise, EBADF/EPERM is returned. The given seals are _added_ to the existing set of seals on the file. You cannot remove seals again. The fcntl() handler is currently specific to shmem and disabled on all files. A file needs to explicitly support sealing for this interface to work. A separate syscall is added in a follow-up, which creates files that support sealing. There is no intention to support this on other file-systems. Semantics are unclear for non-volatile files and we lack any use-case right now. Therefore, the implementation is specific to shmem. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-22locks: rename file-private locks to "open file description locks"Jeff Layton1-6/+6
File-private locks have been merged into Linux for v3.15, and *now* people are commenting that the name and macro definitions for the new file-private locks suck. ...and I can't even disagree. The names and command macros do suck. We're going to have to live with these for a long time, so it's important that we be happy with the names before we're stuck with them. The consensus on the lists so far is that they should be rechristened as "open file description locks". The name isn't a big deal for the kernel, but the command macros are not visually distinct enough from the traditional POSIX lock macros. The glibc and documentation folks are recommending that we change them to look like F_OFD_{GETLK|SETLK|SETLKW}. That lessens the chance that a programmer will typo one of the commands wrong, and also makes it easier to spot this difference when reading code. This patch makes the following changes that I think are necessary before v3.15 ships: 1) rename the command macros to their new names. These end up in the uapi headers and so are part of the external-facing API. It turns out that glibc doesn't actually use the fcntl.h uapi header, but it's hard to be sure that something else won't. Changing it now is safest. 2) make the the /proc/locks output display these as type "OFDLCK" Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Carlos O'Donell <carlos@redhat.com> Cc: Stefan Metzmacher <metze@samba.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frank Filz <ffilzlnx@mindspring.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2014-03-31locks: add new fcntl cmd values for handling file private locksJeff Layton1-11/+24
Due to some unfortunate history, POSIX locks have very strange and unhelpful semantics. The thing that usually catches people by surprise is that they are dropped whenever the process closes any file descriptor associated with the inode. This is extremely problematic for people developing file servers that need to implement byte-range locks. Developers often need a "lock management" facility to ensure that file descriptors are not closed until all of the locks associated with the inode are finished. Additionally, "classic" POSIX locks are owned by the process. Locks taken between threads within the same process won't conflict with one another, which renders them useless for synchronization between threads. This patchset adds a new type of lock that attempts to address these issues. These locks conflict with classic POSIX read/write locks, but have semantics that are more like BSD locks with respect to inheritance and behavior on close. This is implemented primarily by changing how fl_owner field is set for these locks. Instead of having them owned by the files_struct of the process, they are instead owned by the filp on which they were acquired. Thus, they are inherited across fork() and are only released when the last reference to a filp is put. These new semantics prevent them from being merged with classic POSIX locks, even if they are acquired by the same process. These locks will also conflict with classic POSIX locks even if they are acquired by the same process or on the same file descriptor. The new locks are managed using a new set of cmd values to the fcntl() syscall. The initial implementation of this converts these values to "classic" cmd values at a fairly high level, and the details are not exposed to the underlying filesystem. We may eventually want to push this handing out to the lower filesystem code but for now I don't see any need for it. Also, note that with this implementation the new cmd values are only available via fcntl64() on 32-bit arches. There's little need to add support for legacy apps on a new interface like this. Signed-off-by: Jeff Layton <jlayton@redhat.com>
2014-03-31locks: pass the cmd value to fcntl_getlk/getlk64Jeff Layton1-2/+2
Once we introduce file private locks, we'll need to know what cmd value was used, as that affects the ownership and whether a conflict would arise. Signed-off-by: Jeff Layton <jlayton@redhat.com>
2013-10-24file->f_op is never NULL...Al Viro1-3/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-08-05vfs: add missing check for __O_TMPFILE in fcntl_init()Zheng Liu1-2/+2
As comment in include/uapi/asm-generic/fcntl.h described, when introducing new O_* bits, we need to check its uniqueness in fcntl_init(). But __O_TMPFILE bit is missing. So fix it. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22new helper: file_inode(file)Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-09Fix F_DUPFD_CLOEXEC breakageAl Viro1-1/+1
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>
2012-09-26fcntl: fix misannotationsAl Viro1-3/+3
__user * != * __user... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26switch simple cases of fget_light to fdgetAl Viro1-18/+14
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26take purely descriptor-related stuff from fcntl.c to file.cAl Viro1-128/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26take rlimit check to callers of expand_files()Al Viro1-0/+3
... 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>
2012-07-30c/r: fcntl: add F_GETOWNER_UIDS optionCyrill Gorcunov1-0/+29
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>
2012-05-29switch fcntl to fget_raw_light/fput_lightAl Viro1-25/+17
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-03userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfsEric W. Biederman1-3/+3
Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-02-19Wrap accesses to the fd_sets in struct fdtableDavid Howells1-9/+9
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>
2011-03-23userns: rename is_owner_or_cap to inode_owner_or_capableSerge E. Hallyn1-1/+1
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>
2011-03-15New kind of open files - "location only".Al Viro1-5/+32
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>
2011-02-02vfs: sparse: add __FMODE_EXECNamhyung Kim1-1/+1
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>
2010-10-27fasync: Fix placement of FASYNC flag commentLinus Torvalds1-3/+3
In commit f7347ce4ee7c ("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>
2010-10-27fasync: re-organize fasync entry insertion to allow it under a spinlockLinus Torvalds1-16/+50
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>
2010-09-09vfs: take O_NONBLOCK out of the O_* uniqueness testJames Bottomley1-3/+7
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>
2010-08-11vfs: O_* bit numbers uniqueness checkWu Fengguang1-2/+13
The O_* bit numbers are defined in 20+ arch/*, and can silently overlap. Add a compile time check to ensure the uniqueness as suggested by David Miller. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Eric Paris <eparis@redhat.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Jamie Lokier <jamie@shareable.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-29fs/fcntl.c:kill_fasync_rcu() fa_lock must be IRQ-safeAndrew Morton1-2/+4
Fix a lockdep-splat-causing regression introduced by commit 989a2979205d ("fasync: RCU and fine grained locking"). kill_fasync() can be called from both process and hard-irq context, so fa_lock must be taken with IRQs disabled. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16230 Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Tested-by: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Maciej Rutecki <maciej.rutecki@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-04fcntl: return -EFAULT if copy_to_user failsDan Carpenter1-2/+5
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>
2010-05-21Merge branch 'master' into for-2.6.35Jens Axboe1-24/+42
Conflicts: fs/ext3/fsync.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21pipe: add support for shrinking and growing pipesJens Axboe1-0/+5
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>
2010-04-21fasync: RCU and fine grained lockingEric Dumazet1-24/+42
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>
2010-03-06fs: use rlimit helpersJiri Slaby1-1/+1
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 3e10e716abf3 ("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>
2010-02-07Fix race in tty_fasync() properlyLinus Torvalds1-4/+2
This reverts commit 703625118069 ("tty: fix race in tty_fasync") and commit b04da8bfdfbb ("fnctl: f_modown should call write_lock_irqsave/ restore") that tried to fix up some of the fallout but was incomplete. It turns out that we really cannot hold 'tty->ctrl_lock' over calling __f_setown, because not only did that cause problems with interrupt disables (which the second commit fixed), it also causes a potential ABBA deadlock due to lock ordering. Thanks to Tetsuo Handa for following up on the issue, and running lockdep to show the problem. It goes roughly like this: - f_getown gets filp->f_owner.lock for reading without interrupts disabled, so an interrupt that happens while that lock is held can cause a lockdep chain from f_owner.lock -> sighand->siglock. - at the same time, the tty->ctrl_lock -> f_owner.lock chain that commit 703625118069 introduced, together with the pre-existing sighand->siglock -> tty->ctrl_lock chain means that we have a lock dependency the other way too. So instead of extending tty->ctrl_lock over the whole __f_setown() call, we now just take a reference to the 'pid' structure while holding the lock, and then release it after having done the __f_setown. That still guarantees that 'struct pid' won't go away from under us, which is all we really ever needed. Reported-and-tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Américo Wang <xiyou.wangcong@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-26fnctl: f_modown should call write_lock_irqsave/restoreGreg Kroah-Hartman1-2/+4
Commit 703625118069f9f8960d356676662d3db5a9d116 exposed that f_modown() should call write_lock_irqsave instead of just write_lock_irq so that because a caller could have a spinlock held and it would not be good to renable interrupts. Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Tavis Ormandy <taviso@google.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>