02 Nov, 2017
1 commit
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Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
09 Sep, 2017
2 commits
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ipc_findkey() used to scan all objects to look for the wanted key. This
is slow when using a high number of keys. This change adds an rhashtable
of kern_ipc_perm objects in ipc_ids, so that one lookup cease to be O(n).This change gives a 865% improvement of benchmark reaim.jobs_per_min on a
56 threads Intel(R) Xeon(R) CPU E5-2695 v3 @ 2.30GHz with 256G memory [1]Other (more micro) benchmark results, by the author: On an i5 laptop, the
following loop executed right after a reboot took, without and with this
change:for (int i = 0, k=0x424242; i < KEYS; ++i)
semget(k++, 1, IPC_CREAT | 0600);total total max single max single
KEYS without with call without call with1 3.5 4.9 µs 3.5 4.9
10 7.6 8.6 µs 3.7 4.7
32 16.2 15.9 µs 4.3 5.3
100 72.9 41.8 µs 3.7 4.7
1000 5,630.0 502.0 µs * *
10000 1,340,000.0 7,240.0 µs * *
31900 17,600,000.0 22,200.0 µs * **: unreliable measure: high variance
The duration for a lookup-only usage was obtained by the same loop once
the keys are present:total total max single max single
KEYS without with call without call with1 2.1 2.5 µs 2.1 2.5
10 4.5 4.8 µs 2.2 2.3
32 13.0 10.8 µs 2.3 2.8
100 82.9 25.1 µs * 2.3
1000 5,780.0 217.0 µs * *
10000 1,470,000.0 2,520.0 µs * *
31900 17,400,000.0 7,810.0 µs * *Finally, executing each semget() in a new process gave, when still
summing only the durations of these syscalls:creation:
total total
KEYS without with1 3.7 5.0 µs
10 32.9 36.7 µs
32 125.0 109.0 µs
100 523.0 353.0 µs
1000 20,300.0 3,280.0 µs
10000 2,470,000.0 46,700.0 µs
31900 27,800,000.0 219,000.0 µslookup-only:
total total
KEYS without with1 2.5 2.7 µs
10 25.4 24.4 µs
32 106.0 72.6 µs
100 591.0 352.0 µs
1000 22,400.0 2,250.0 µs
10000 2,510,000.0 25,700.0 µs
31900 28,200,000.0 115,000.0 µs[1] http://lkml.kernel.org/r/20170814060507.GE23258@yexl-desktop
Link: http://lkml.kernel.org/r/20170815194954.ck32ta2z35yuzpwp@debix
Signed-off-by: Guillaume Knispel
Reviewed-by: Marc Pardo
Cc: Davidlohr Bueso
Cc: Kees Cook
Cc: Manfred Spraul
Cc: Alexey Dobriyan
Cc: "Eric W. Biederman"
Cc: "Peter Zijlstra (Intel)"
Cc: Ingo Molnar
Cc: Sebastian Andrzej Siewior
Cc: Serge Hallyn
Cc: Andrey Vagin
Cc: Guillaume Knispel
Cc: Marc Pardo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter. This allows to avoid
accidental refcounter overflows that might lead to use-after-free
situations.Link: http://lkml.kernel.org/r/1499417992-3238-2-git-send-email-elena.reshetova@intel.com
Signed-off-by: Elena Reshetova
Signed-off-by: Hans Liljestrand
Signed-off-by: Kees Cook
Signed-off-by: David Windsor
Cc: Peter Zijlstra
Cc: Greg Kroah-Hartman
Cc: "Eric W. Biederman"
Cc: Ingo Molnar
Cc: Alexey Dobriyan
Cc: Serge Hallyn
Cc:
Cc: Davidlohr Bueso
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Mar, 2017
2 commits
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But first update the code that uses these facilities with the
new header.Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar -
Add #include dependencies to all .c files rely on sched.h
doing that for them.Note that even if the count where we need to add extra headers seems high,
it's still a net win, because is included in over
2,200 files ...Acked-by: Linus Torvalds
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
23 Sep, 2016
3 commits
-
From: Andrey Vagin
Each namespace has an owning user namespace and now there is not way
to discover these relationships.Pid and user namepaces are hierarchical. There is no way to discover
parent-child relationships too.Why we may want to know relationships between namespaces?
One use would be visualization, in order to understand the running
system. Another would be to answer the question: what capability does
process X have to perform operations on a resource governed by namespace
Y?One more use-case (which usually called abnormal) is checkpoint/restart.
In CRIU we are going to dump and restore nested namespaces.There [1] was a discussion about which interface to choose to determing
relationships between namespaces.Eric suggested to add two ioctl-s [2]:
> Grumble, Grumble. I think this may actually a case for creating ioctls
> for these two cases. Now that random nsfs file descriptors are bind
> mountable the original reason for using proc files is not as pressing.
>
> One ioctl for the user namespace that owns a file descriptor.
> One ioctl for the parent namespace of a namespace file descriptor.Here is an implementaions of these ioctl-s.
$ man man7/namespaces.7
...
Since Linux 4.X, the following ioctl(2) calls are supported for
namespace file descriptors. The correct syntax is:fd = ioctl(ns_fd, ioctl_type);
where ioctl_type is one of the following:
NS_GET_USERNS
Returns a file descriptor that refers to an owning user names‐
pace.NS_GET_PARENT
Returns a file descriptor that refers to a parent namespace.
This ioctl(2) can be used for pid and user namespaces. For
user namespaces, NS_GET_PARENT and NS_GET_USERNS have the same
meaning.In addition to generic ioctl(2) errors, the following specific ones
can occur:EINVAL NS_GET_PARENT was called for a nonhierarchical namespace.
EPERM The requested namespace is outside of the current namespace
scope.[1] https://lkml.org/lkml/2016/7/6/158
[2] https://lkml.org/lkml/2016/7/9/101Changes for v2:
* don't return ENOENT for init_user_ns and init_pid_ns. There is nothing
outside of the init namespace, so we can return EPERM in this case too.
> The fewer special cases the easier the code is to get
> correct, and the easier it is to read. // EricChanges for v3:
* rename ns->get_owner() to ns->owner(). get_* usually means that it
grabs a reference.Cc: "Eric W. Biederman"
Cc: James Bottomley
Cc: "Michael Kerrisk (man-pages)"
Cc: "W. Trevor King"
Cc: Alexander Viro
Cc: Serge Hallyn -
Return -EPERM if an owning user namespace is outside of a process
current user namespace.v2: In a first version ns_get_owner returned ENOENT for init_user_ns.
This special cases was removed from this version. There is nothing
outside of init_user_ns, so we can return EPERM.
v3: rename ns->get_owner() to ns->owner(). get_* usually means that it
grabs a reference.Acked-by: Serge Hallyn
Signed-off-by: Andrei Vagin
Signed-off-by: Eric W. Biederman -
The current error codes returned when a the per user per user
namespace limit are hit (EINVAL, EUSERS, and ENFILE) are wrong. I
asked for advice on linux-api and it we made clear that those were
the wrong error code, but a correct effor code was not suggested.The best general error code I have found for hitting a resource limit
is ENOSPC. It is not perfect but as it is unambiguous it will serve
until someone comes up with a better error code.Signed-off-by: "Eric W. Biederman"
09 Aug, 2016
1 commit
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Acked-by: Kees Cook
Signed-off-by: "Eric W. Biederman"
03 Aug, 2016
1 commit
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Write-only variable.
Link: http://lkml.kernel.org/r/20160708214356.GA6785@p183.telecom.by
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Jun, 2016
1 commit
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Allow the ipc namespace initialization code to depend on ns->user_ns
being set during initialization.In particular this allows mq_init_ns to use ns->user_ns for permission
checks and initializating s_user_ns while the the mq filesystem is
being mounted.Acked-by: Seth Forshee
Suggested-by: Seth Forshee
Signed-off-by: "Eric W. Biederman"
17 Dec, 2014
1 commit
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Pull vfs pile #2 from Al Viro:
"Next pile (and there'll be one or two more).The large piece in this one is getting rid of /proc/*/ns/* weirdness;
among other things, it allows to (finally) make nameidata completely
opaque outside of fs/namei.c, making for easier further cleanups in
there"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
coda_venus_readdir(): use file_inode()
fs/namei.c: fold link_path_walk() call into path_init()
path_init(): don't bother with LOOKUP_PARENT in argument
fs/namei.c: new helper (path_cleanup())
path_init(): store the "base" pointer to file in nameidata itself
make default ->i_fop have ->open() fail with ENXIO
make nameidata completely opaque outside of fs/namei.c
kill proc_ns completely
take the targets of /proc/*/ns/* symlinks to separate fs
bury struct proc_ns in fs/proc
copy address of proc_ns_ops into ns_common
new helpers: ns_alloc_inum/ns_free_inum
make proc_ns_operations work with struct ns_common * instead of void *
switch the rest of proc_ns_operations to working with &...->ns
netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
common object embedded into various struct ....ns
14 Dec, 2014
1 commit
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SysV can be abused to allocate locked kernel memory. For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.Therefore: increase MSGMNI to the maximum supported.
And: If we ignore the risk of locking too much memory, then an automatic
scaling of MSGMNI doesn't make sense. Therefore the logic can be removed.The code preserves auto_msgmni to avoid breaking any user space applications
that expect that the value exists.Notes:
1) If an administrator must limit the memory allocations, then he can set
MSGMNI as necessary.Or he can disable sysv entirely (as e.g. done by Android).
2) MSGMAX and MSGMNB are intentionally not increased, as these values are used
to control latency vs. throughput:
If MSGMNB is large, then msgsnd() just returns and more messages can be queued
before a task switch to a task that calls msgrcv() is forced.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul
Cc: Davidlohr Bueso
Cc: Rafael Aquini
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Dec, 2014
5 commits
-
Signed-off-by: Al Viro
-
take struct ns_common *, for now simply wrappers around proc_{alloc,free}_inum()
Signed-off-by: Al Viro
-
We can do that now. And kill ->inum(), while we are at it - all instances
are identical.Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
-
for now - just move corresponding ->proc_inum instances over there
Acked-by: "Eric W. Biederman"
Signed-off-by: Al Viro
30 Jul, 2014
1 commit
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The synchronous syncrhonize_rcu in switch_task_namespaces makes setns
a sufficiently expensive system call that people have complained.Upon inspect nsproxy no longer needs rcu protection for remote reads.
remote reads are rare. So optimize for same process reads and write
by switching using rask_lock instead.This yields a simpler to understand lock, and a faster setns system call.
In particular this fixes a performance regression observed
by Rafael David Tinoco .This is effectively a revert of Pavel Emelyanov's commit
cf7b708c8d1d7a27736771bcf4c457b332b0f818 Make access to task's nsproxy lighter
from 2007. The race this originialy fixed no longer exists as
do_notify_parent uses task_active_pid_ns(parent) instead of
parent->nsproxy.Signed-off-by: "Eric W. Biederman"
12 Sep, 2013
2 commits
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After previous cleanups and optimizations, this function is no longer
heavily used and we don't have a good reason to keep it. Update the few
remaining callers and get rid of it.Signed-off-by: Davidlohr Bueso
Cc: Sedat Dilek
Cc: Rik van Riel
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since in some situations the lock can be shared for readers, we shouldn't
be calling it a mutex, rename it to rwsem.Signed-off-by: Davidlohr Bueso
Tested-by: Sedat Dilek
Cc: Rik van Riel
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Aug, 2013
1 commit
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nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and
CAP_SETGID. For the existing users it doesn't noticably simplify things and
from the suggested patches I have seen it encourages people to do the wrong
thing. So remove nsown_capable.Acked-by: Serge Hallyn
Signed-off-by: "Eric W. Biederman"
02 May, 2013
1 commit
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Split the proc namespace stuff out into linux/proc_ns.h.
Signed-off-by: David Howells
cc: netdev@vger.kernel.org
cc: Serge E. Hallyn
cc: Eric W. Biederman
Signed-off-by: Al Viro
15 Dec, 2012
1 commit
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Andy Lutomirski found a nasty little bug in
the permissions of setns. With unprivileged user namespaces it
became possible to create new namespaces without privilege.However the setns calls were relaxed to only require CAP_SYS_ADMIN in
the user nameapce of the targed namespace.Which made the following nasty sequence possible.
pid = clone(CLONE_NEWUSER | CLONE_NEWNS);
if (pid == 0) { /* child */
system("mount --bind /home/me/passwd /etc/passwd");
}
else if (pid != 0) { /* parent */
char path[PATH_MAX];
snprintf(path, sizeof(path), "/proc/%u/ns/mnt");
fd = open(path, O_RDONLY);
setns(fd, 0);
system("su -");
}Prevent this possibility by requiring CAP_SYS_ADMIN
in the current user namespace when joing all but the user namespace.Acked-by: Serge Hallyn
Signed-off-by: "Eric W. Biederman"
20 Nov, 2012
3 commits
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Assign a unique proc inode to each namespace, and use that
inode number to ensure we only allocate at most one proc
inode for every namespace in proc.A single proc inode per namespace allows userspace to test
to see if two processes are in the same namespace.This has been a long requested feature and only blocked because
a naive implementation would put the id in a global space and
would ultimately require having a namespace for the names of
namespaces, making migration and certain virtualization tricks
impossible.We still don't have per superblock inode numbers for proc, which
appears necessary for application unaware checkpoint/restart and
migrations (if the application is using namespace file descriptors)
but that is now allowd by the design if it becomes important.I have preallocated the ipc and uts initial proc inode numbers so
their structures can be statically initialized.Signed-off-by: Eric W. Biederman
-
Modify create_new_namespaces to explicitly take a user namespace
parameter, instead of implicitly through the task_struct.This allows an implementation of unshare(CLONE_NEWUSER) where
the new user namespace is not stored onto the current task_struct
until after all of the namespaces are created.Acked-by: Serge Hallyn
Signed-off-by: "Eric W. Biederman" -
- Push the permission check from the core setns syscall into
the setns install methods where the user namespace of the
target namespace can be determined, and used in a ns_capable
call.Acked-by: Serge Hallyn
Signed-off-by: "Eric W. Biederman"
08 Apr, 2012
1 commit
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Optimize performance and prepare for the removal of the user_ns reference
from user_struct. Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
11 May, 2011
1 commit
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Acked-by: Daniel Lezcano
Signed-off-by: Eric W. Biederman
26 Mar, 2011
1 commit
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commit b515498 ("userns: add a user namespace owner of ipc ns") added a
user namespace owner of ipc ns, but it also introduced a use after free in
free_ipc_ns().Signed-off-by: Xiaotian Feng
Acked-by: "Serge E. Hallyn"
Acked-by: David Howells
Cc: "Eric W. Biederman"
Cc: Daniel Lezcano
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Mar, 2011
2 commits
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CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(),
because the resource comes from current's own ipc namespace.setuid/setgid are to uids in own namespace, so again checks can be against
current_user_ns().Changelog:
Jan 11: Use task_ns_capable() in place of sched_capable().
Jan 11: Use nsown_capable() as suggested by Bastian Blank.
Jan 11: Clarify (hopefully) some logic in futex and sched.c
Feb 15: use ns_capable for ipc, not nsown_capable
Feb 23: let copy_ipcs handle setting ipc_ns->user_ns
Feb 23: pass ns down rather than taking it from current[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge E. Hallyn
Acked-by: "Eric W. Biederman"
Acked-by: Daniel Lezcano
Acked-by: David Howells
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Changelog:
Feb 15: Don't set new ipc->user_ns if we didn't create a new
ipc_ns.
Feb 23: Move extern declaration to ipc_namespace.h, and group
fwd declarations at top.Signed-off-by: Serge E. Hallyn
Acked-by: "Eric W. Biederman"
Acked-by: Daniel Lezcano
Acked-by: David Howells
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Jun, 2009
3 commits
-
Signed-off-by: Alexey Dobriyan
Reviewed-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
clone_ipc_ns() is misnamed, it doesn't clone anything and doesn't use
passed parameter. Rename it.create_ipc_ns() will be used by C/R to create fresh ipcns.
Signed-off-by: Alexey Dobriyan
Acked-by: Serge Hallyn
Reviewed-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
copy_ipcs() doesn't actually copy anything. If new ipcns is created, it's
created from scratch, in this case get/put on old ipcns isn't needed.Signed-off-by: Alexey Dobriyan
Acked-by: Serge Hallyn
Reviewed-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Apr, 2009
2 commits
-
Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.Each ipc ns has a corresponding mqueuefs superblock. When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount. Any
usage of mq_open() and friends will work with the acting task's ipc
namespace. Any actions through the VFS will work with the mqueuefs in
which the file was created. So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.To make this happen, we must protect the ipc reference count when
a) a task exits and drops its ipcns->count, since it might be dropping
it to 0 and freeing the ipcnsb) a task accesses the ipcns through its mqueuefs interface, since it
bumps the ipcns refcount and might race with the last task in the ipcns
exiting.So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.Signed-off-by: Cedric Le Goater
Signed-off-by: Serge E. Hallyn
Cc: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move mqueue vfsmount plus a few tunables into the ipc_namespace struct.
The CONFIG_IPC_NS boolean and the ipc_namespace struct will serve both the
posix message queue namespaces and the SYSV ipc namespaces.The sysctl code will be fixed separately in patch 3. After just this
patch, making a change to posix mqueue tunables always changes the values
in the initial ipc namespace.Signed-off-by: Cedric Le Goater
Signed-off-by: Serge E. Hallyn
Cc: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
3 commits
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Introduce a notification mechanism that aims at recomputing msgmni each time
an ipc namespace is created or removed.The ipc namespace notifier chain already defined for memory hotplug management
is used for that purpose too.Each time a new ipc namespace is allocated or an existing ipc namespace is
removed, the ipcns notifier chain is notified. The callback routine for each
registered ipc namespace is then activated in order to recompute msgmni for
that namespace.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce the registration of a callback routine that recomputes msg_ctlmni
upon memory add / remove.A single notifier block is registered in the hotplug memory chain for all the
ipc namespaces.Since the ipc namespaces are not linked together, they have their own
notification chain: one notifier_block is defined per ipc namespace.Each time an ipc namespace is created (removed) it registers (unregisters) its
notifier block in (from) the ipcns chain. The callback routine registered in
the memory chain invokes the ipcns notifier chain with the IPCNS_LOWMEM event.
Each callback routine registered in the ipcns namespace, in turn, recomputes
msgmni for the owning namespace.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since all the namespaces see the same amount of memory (the total one) this
patch introduces a new variable that counts the ipc namespaces and divides
msg_ctlmni by this counter.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
