History log of /linux/ipc/ (Results 1 – 25 of 841)
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Revision tags: v5.9-rc6, v5.9-rc5, v5.9-rc4
fff1662c04-Sep-2020 Tobias Klauser

ipc: adjust proc_ipc_sem_dointvec definition to match prototype

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel poi

ipc: adjust proc_ipc_sem_dointvec definition to match prototype

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer. Adjust the
signature of proc_ipc_sem_dointvec to match ctl_table.proc_handler which
fixes the following sparse error/warning:

ipc/ipc_sysctl.c:94:47: warning: incorrect type in argument 3 (different address spaces)
ipc/ipc_sysctl.c:94:47: expected void *buffer
ipc/ipc_sysctl.c:94:47: got void [noderef] __user *buffer
ipc/ipc_sysctl.c:194:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
ipc/ipc_sysctl.c:194:35: expected int ( [usertype] *proc_handler )( ... )
ipc/ipc_sysctl.c:194:35: got int ( * )( ... )

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200825105846.5193-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Revision tags: v5.9-rc3
df561f6623-Aug-2020 Gustavo A. R. Silva

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

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Revision tags: v5.9-rc2, v5.9-rc1
ce14489c12-Aug-2020 Liao Pingfang

ipc/shm.c: remove the superfluous break

Remove the superfuous break, as there is a 'return' before it.

Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Yi

ipc/shm.c: remove the superfluous break

Remove the superfuous break, as there is a 'return' before it.

Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1594724361-11525-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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00898e8512-Aug-2020 Alexey Dobriyan

ipc: uninline functions

Two functions are only called via function pointers, don't bother
inlining them.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by:

ipc: uninline functions

Two functions are only called via function pointers, don't bother
inlining them.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: http://lkml.kernel.org/r/20200710200312.GA960353@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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45e5530007-Aug-2020 Peter Collingbourne

mm: remove unnecessary wrapper function do_mmap_pgoff()

The current split between do_mmap() and do_mmap_pgoff() was introduced in
commit 1fcfd8db7f82 ("mm, mpx: add "vm_flags_t vm_flags"

mm: remove unnecessary wrapper function do_mmap_pgoff()

The current split between do_mmap() and do_mmap_pgoff() was introduced in
commit 1fcfd8db7f82 ("mm, mpx: add "vm_flags_t vm_flags" arg to
do_mmap_pgoff()") to support MPX.

The wrapper function do_mmap_pgoff() always passed 0 as the value of the
vm_flags argument to do_mmap(). However, MPX support has subsequently
been removed from the kernel and there were no more direct callers of
do_mmap(); all calls were going via do_mmap_pgoff().

Simplify the code by removing do_mmap_pgoff() and changing all callers to
directly call do_mmap(), which now no longer takes a vm_flags argument.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200727194109.1371462-1-pcc@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Revision tags: v5.8, v5.8-rc7, v5.8-rc6, v5.8-rc5, v5.8-rc4, v5.8-rc3, v5.8-rc2, v5.8-rc1
d8ed45c509-Jun-2020 Michel Lespinasse

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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e1eb26fa08-Jun-2020 Giuseppe Scrivano

ipc/namespace.c: use a work queue to free_ipc

the reason is to avoid a delay caused by the synchronize_rcu() call in
kern_umount() when the mqueue mount is freed.

the code:

ipc/namespace.c: use a work queue to free_ipc

the reason is to avoid a delay caused by the synchronize_rcu() call in
kern_umount() when the mqueue mount is freed.

the code:

#define _GNU_SOURCE
#include <sched.h>
#include <error.h>
#include <errno.h>
#include <stdlib.h>

int main()
{
int i;

for (i = 0; i < 1000; i++)
if (unshare(CLONE_NEWIPC) < 0)
error(EXIT_FAILURE, errno, "unshare");
}

goes from

Command being timed: "./ipc-namespace"
User time (seconds): 0.00
System time (seconds): 0.06
Percent of CPU this job got: 0%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:08.05

to

Command being timed: "./ipc-namespace"
User time (seconds): 0.00
System time (seconds): 0.02
Percent of CPU this job got: 96%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.03

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Link: http://lkml.kernel.org/r/20200225145419.527994-1-gscrivan@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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4b78e20108-Jun-2020 Jules Irenge

ipc/msg: add missing annotation for freeque()

Sparse reports a warning at freeque()

warning: context imbalance in freeque() - unexpected unlock

The root cause is the missin

ipc/msg: add missing annotation for freeque()

Sparse reports a warning at freeque()

warning: context imbalance in freeque() - unexpected unlock

The root cause is the missing annotation at freeque()

Add the missing __releases(RCU) annotation
Add the missing __releases(&msq->q_perm) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Lu Shuaibing <shuaibinglu@126.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: http://lkml.kernel.org/r/20200403160505.2832-2-jbi.octave@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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cb8e59cc03-Jun-2020 Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from David Miller:

1) Allow setting bluetooth L2CAP modes via socket option, from Luiz

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from David Miller:

1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
Augusto von Dentz.

2) Add GSO partial support to igc, from Sasha Neftin.

3) Several cleanups and improvements to r8169 from Heiner Kallweit.

4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
device self-test. From Andrew Lunn.

5) Start moving away from custom driver versions, use the globally
defined kernel version instead, from Leon Romanovsky.

6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.

7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.

8) Add sriov and vf support to hinic, from Luo bin.

9) Support Media Redundancy Protocol (MRP) in the bridging code, from
Horatiu Vultur.

10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.

11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
Dubroca. Also add ipv6 support for espintcp.

12) Lots of ReST conversions of the networking documentation, from Mauro
Carvalho Chehab.

13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
from Doug Berger.

14) Allow to dump cgroup id and filter by it in inet_diag code, from
Dmitry Yakunin.

15) Add infrastructure to export netlink attribute policies to
userspace, from Johannes Berg.

16) Several optimizations to sch_fq scheduler, from Eric Dumazet.

17) Fallback to the default qdisc if qdisc init fails because otherwise
a packet scheduler init failure will make a device inoperative. From
Jesper Dangaard Brouer.

18) Several RISCV bpf jit optimizations, from Luke Nelson.

19) Correct the return type of the ->ndo_start_xmit() method in several
drivers, it's netdev_tx_t but many drivers were using
'int'. From Yunjian Wang.

20) Add an ethtool interface for PHY master/slave config, from Oleksij
Rempel.

21) Add BPF iterators, from Yonghang Song.

22) Add cable test infrastructure, including ethool interfaces, from
Andrew Lunn. Marvell PHY driver is the first to support this
facility.

23) Remove zero-length arrays all over, from Gustavo A. R. Silva.

24) Calculate and maintain an explicit frame size in XDP, from Jesper
Dangaard Brouer.

25) Add CAP_BPF, from Alexei Starovoitov.

26) Support terse dumps in the packet scheduler, from Vlad Buslov.

27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.

28) Add devm_register_netdev(), from Bartosz Golaszewski.

29) Minimize qdisc resets, from Cong Wang.

30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
eliminate set_fs/get_fs calls. From Christoph Hellwig.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
selftests: net: ip_defrag: ignore EPERM
net_failover: fixed rollback in net_failover_open()
Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
vmxnet3: allow rx flow hash ops only when rss is enabled
hinic: add set_channels ethtool_ops support
selftests/bpf: Add a default $(CXX) value
tools/bpf: Don't use $(COMPILE.c)
bpf, selftests: Use bpf_probe_read_kernel
s390/bpf: Use bcr 0,%0 as tail call nop filler
s390/bpf: Maintain 8-byte stack alignment
selftests/bpf: Fix verifier test
selftests/bpf: Fix sample_cnt shared between two threads
bpf, selftests: Adapt cls_redirect to call csum_level helper
bpf: Add csum_level helper for fixing up csum levels
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
crypto/chtls: IPv6 support for inline TLS
Crypto/chcr: Fixes a coccinile check error
Crypto/chcr: Fixes compilations warnings
...

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e7c93cbf03-Jun-2020 Linus Torvalds

Merge tag 'threads-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread updates from Christian Brauner:
"We have been discussing using pidfds to attach to na

Merge tag 'threads-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread updates from Christian Brauner:
"We have been discussing using pidfds to attach to namespaces for quite
a while and the patches have in one form or another already existed
for about a year. But I wanted to wait to see how the general api
would be received and adopted.

This contains the changes to make it possible to use pidfds to attach
to the namespaces of a process, i.e. they can be passed as the first
argument to the setns() syscall.

When only a single namespace type is specified the semantics are
equivalent to passing an nsfd. That means setns(nsfd, CLONE_NEWNET)
equals setns(pidfd, CLONE_NEWNET).

However, when a pidfd is passed, multiple namespace flags can be
specified in the second setns() argument and setns() will attach the
caller to all the specified namespaces all at once or to none of them.

Specifying 0 is not valid together with a pidfd. Here are just two
obvious examples:

setns(pidfd, CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWNET);
setns(pidfd, CLONE_NEWUSER);

Allowing to also attach subsets of namespaces supports various
use-cases where callers setns to a subset of namespaces to retain
privilege, perform an action and then re-attach another subset of
namespaces.

Apart from significantly reducing the number of syscalls needed to
attach to all currently supported namespaces (eight "open+setns"
sequences vs just a single "setns()"), this also allows atomic setns
to a set of namespaces, i.e. either attaching to all namespaces
succeeds or we fail without having changed anything.

This is centered around a new internal struct nsset which holds all
information necessary for a task to switch to a new set of namespaces
atomically. Fwiw, with this change a pidfd becomes the only token
needed to interact with a container. I'm expecting this to be
picked-up by util-linux for nsenter rather soon.

Associated with this change is a shiny new test-suite dedicated to
setns() (for pidfds and nsfds alike)"

* tag 'threads-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
selftests/pidfd: add pidfd setns tests
nsproxy: attach to namespaces via pidfds
nsproxy: add struct nsset

show more ...


Revision tags: v5.7, v5.7-rc7, v5.7-rc6
da07f52d15-May-2020 David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic,

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.

Signed-off-by: David S. Miller <davem@davemloft.net>

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5e69822214-May-2020 Vasily Averin

ipc/util.c: sysvipc_find_ipc() incorrectly updates position index

Commit 89163f93c6f9 ("ipc/util.c: sysvipc_find_ipc() should increase
position index") is causing this bug (seen on 5.6.8

ipc/util.c: sysvipc_find_ipc() incorrectly updates position index

Commit 89163f93c6f9 ("ipc/util.c: sysvipc_find_ipc() should increase
position index") is causing this bug (seen on 5.6.8):

# ipcs -q

------ Message Queues --------
key msqid owner perms used-bytes messages

# ipcmk -Q
Message queue id: 0
# ipcs -q

------ Message Queues --------
key msqid owner perms used-bytes messages
0x82db8127 0 root 644 0 0

# ipcmk -Q
Message queue id: 1
# ipcs -q

------ Message Queues --------
key msqid owner perms used-bytes messages
0x82db8127 0 root 644 0 0
0x76d1fb2a 1 root 644 0 0

# ipcrm -q 0
# ipcs -q

------ Message Queues --------
key msqid owner perms used-bytes messages
0x76d1fb2a 1 root 644 0 0
0x76d1fb2a 1 root 644 0 0

# ipcmk -Q
Message queue id: 2
# ipcrm -q 2
# ipcs -q

------ Message Queues --------
key msqid owner perms used-bytes messages
0x76d1fb2a 1 root 644 0 0
0x76d1fb2a 1 root 644 0 0

# ipcmk -Q
Message queue id: 3
# ipcrm -q 1
# ipcs -q

------ Message Queues --------
key msqid owner perms used-bytes messages
0x7c982867 3 root 644 0 0
0x7c982867 3 root 644 0 0
0x7c982867 3 root 644 0 0
0x7c982867 3 root 644 0 0

Whenever an IPC item with a low id is deleted, the items with higher ids
are duplicated, as if filling a hole.

new_pos should jump through hole of unused ids, pos can be updated
inside "for" cycle.

Fixes: 89163f93c6f9 ("ipc/util.c: sysvipc_find_ipc() should increase position index")
Reported-by: Andreas Schwab <schwab@suse.de>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/4921fe9b-9385-a2b4-1dc4-1099be6d2e39@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Revision tags: v5.7-rc5
f2a8d52e05-May-2020 Christian Brauner

nsproxy: add struct nsset

Add a simple struct nsset. It holds all necessary pieces to switch to a new
set of namespaces without leaving a task in a half-switched state which we
will

nsproxy: add struct nsset

Add a simple struct nsset. It holds all necessary pieces to switch to a new
set of namespaces without leaving a task in a half-switched state which we
will make use of in the next patch. This patch switches the existing setns
logic over without causing a change in setns() behavior. This brings
setns() closer to how unshare() works(). The prepare_ns() function is
responsible to prepare all necessary information. This has two reasons.
First it minimizes dependencies between individual namespaces, i.e. all
install handler can expect that all fields are properly initialized
independent in what order they are called in. Second, this makes the code
easier to maintain and easier to follow if it needs to be changed.

The prepare_ns() helper will only be switched over to use a flags argument
in the next patch. Here it will still use nstype as a simple integer
argument which was argued would be clearer. I'm not particularly
opinionated about this if it really helps or not. The struct nsset itself
already contains the flags field since its name already indicates that it
can contain information required by different namespaces. None of this
should have functional consequences.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Jann Horn <jannh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20200505140432.181565-2-christian.brauner@ubuntu.com

show more ...

b5f2006108-May-2020 Oleg Nesterov

ipc/mqueue.c: change __do_notify() to bypass check_kill_permission()

Commit cc731525f26a ("signal: Remove kernel interal si_code magic")
changed the value of SI_FROMUSER(SI_MESGQ), this

ipc/mqueue.c: change __do_notify() to bypass check_kill_permission()

Commit cc731525f26a ("signal: Remove kernel interal si_code magic")
changed the value of SI_FROMUSER(SI_MESGQ), this means that mq_notify() no
longer works if the sender doesn't have rights to send a signal.

Change __do_notify() to use do_send_sig_info() instead of kill_pid_info()
to avoid check_kill_permission().

This needs the additional notify.sigev_signo != 0 check, shouldn't we
change do_mq_notify() to deny sigev_signo == 0 ?

Test-case:

#include <signal.h>
#include <mqueue.h>
#include <unistd.h>
#include <sys/wait.h>
#include <assert.h>

static int notified;

static void sigh(int sig)
{
notified = 1;
}

int main(void)
{
signal(SIGIO, sigh);

int fd = mq_open("/mq", O_RDWR|O_CREAT, 0666, NULL);
assert(fd >= 0);

struct sigevent se = {
.sigev_notify = SIGEV_SIGNAL,
.sigev_signo = SIGIO,
};
assert(mq_notify(fd, &se) == 0);

if (!fork()) {
assert(setuid(1) == 0);
mq_send(fd, "",1,0);
return 0;
}

wait(NULL);
mq_unlink("/mq");
assert(notified);
return 0;
}

[manfred@colorfullife.com: 1) Add self_exec_id evaluation so that the implementation matches do_notify_parent 2) use PIDTYPE_TGID everywhere]
Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
Reported-by: Yoji <yoji.fujihar.min@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Cc: <1vier1@web.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/e2a782e4-eab9-4f5c-c749-c07a8f7a4e66@colorfullife.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Revision tags: v5.7-rc4, v5.7-rc3
3292739324-Apr-2020 Christoph Hellwig

sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to

sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

show more ...

Revision tags: v5.7-rc2, v5.7-rc1
89163f9310-Apr-2020 Vasily Averin

ipc/util.c: sysvipc_find_ipc() should increase position index

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

ht

ipc/util.c: sysvipc_find_ipc() should increase position index

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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1cd377ba07-Apr-2020 Jason Yan

ipc/shm.c: make compat_ksys_shmctl() static

Fix the following sparse warning:

ipc/shm.c:1335:6: warning: symbol 'compat_ksys_shmctl' was not declared.
Should it be static?

ipc/shm.c: make compat_ksys_shmctl() static

Fix the following sparse warning:

ipc/shm.c:1335:6: warning: symbol 'compat_ksys_shmctl' was not declared.
Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200403063933.24785-1-yanaijie@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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43afe4d307-Apr-2020 Somala Swaraj

ipc/mqueue.c: fix a brace coding style issue

Signed-off-by: somala swaraj <somalaswaraj@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.o

ipc/mqueue.c: fix a brace coding style issue

Signed-off-by: somala swaraj <somalaswaraj@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200301135530.18340-1-somalaswaraj@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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d919b33d07-Apr-2020 Alexey Dobriyan

proc: faster open/read/close with "permanent" files

Now that "struct proc_ops" exist we can start putting there stuff which
could not fly with VFS "struct file_operations"...

Mo

proc: faster open/read/close with "permanent" files

Now that "struct proc_ops" exist we can start putting there stuff which
could not fly with VFS "struct file_operations"...

Most of fs/proc/inode.c file is dedicated to make open/read/.../close
reliable in the event of disappearing /proc entries which usually happens
if module is getting removed. Files like /proc/cpuinfo which never
disappear simply do not need such protection.

Save 2 atomic ops, 1 allocation, 1 free per open/read/close sequence for such
"permanent" files.

Enable "permanent" flag for

/proc/cpuinfo
/proc/kmsg
/proc/modules
/proc/slabinfo
/proc/stat
/proc/sysvipc/*
/proc/swaps

More will come once I figure out foolproof way to prevent out module
authors from marking their stuff "permanent" for performance reasons
when it is not.

This should help with scalability: benchmark is "read /proc/cpuinfo R times
by N threads scattered over the system".

N R t, s (before) t, s (after)
-----------------------------------------------------
64 4096 1.582458 1.530502 -3.2%
256 4096 6.371926 6.125168 -3.9%
1024 4096 25.64888 24.47528 -4.6%

Benchmark source:

#include <chrono>
#include <iostream>
#include <thread>
#include <vector>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

const int NR_CPUS = sysconf(_SC_NPROCESSORS_ONLN);
int N;
const char *filename;
int R;

int xxx = 0;

int glue(int n)
{
cpu_set_t m;
CPU_ZERO(&m);
CPU_SET(n, &m);
return sched_setaffinity(0, sizeof(cpu_set_t), &m);
}

void f(int n)
{
glue(n % NR_CPUS);

while (*(volatile int *)&xxx == 0) {
}

for (int i = 0; i < R; i++) {
int fd = open(filename, O_RDONLY);
char buf[4096];
ssize_t rv = read(fd, buf, sizeof(buf));
asm volatile ("" :: "g" (rv));
close(fd);
}
}

int main(int argc, char *argv[])
{
if (argc < 4) {
std::cerr << "usage: " << argv[0] << ' ' << "N /proc/filename R
";
return 1;
}

N = atoi(argv[1]);
filename = argv[2];
R = atoi(argv[3]);

for (int i = 0; i < NR_CPUS; i++) {
if (glue(i) == 0)
break;
}

std::vector<std::thread> T;
T.reserve(N);
for (int i = 0; i < N; i++) {
T.emplace_back(f, i);
}

auto t0 = std::chrono::system_clock::now();
{
*(volatile int *)&xxx = 1;
for (auto& t: T) {
t.join();
}
}
auto t1 = std::chrono::system_clock::now();
std::chrono::duration<double> dt = t1 - t0;
std::cout << dt.count() << '
';

return 0;
}

P.S.:
Explicit randomization marker is added because adding non-function pointer
will silently disable structure layout randomization.

[akpm@linux-foundation.org: coding style fixes]
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200222201539.GA22576@avx2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Revision tags: v5.6, v5.6-rc7, v5.6-rc6, v5.6-rc5, v5.6-rc4, v5.6-rc3
edf28f4021-Feb-2020 Ioanna Alifieraki

Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()"

This reverts commit a97955844807e327df11aa33869009d14d6b7de0.

Commit a97955844807 ("ipc,sem: remove uneeded s

Revert "ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()"

This reverts commit a97955844807e327df11aa33869009d14d6b7de0.

Commit a97955844807 ("ipc,sem: remove uneeded sem_undo_list lock usage
in exit_sem()") removes a lock that is needed. This leads to a process
looping infinitely in exit_sem() and can also lead to a crash. There is
a reproducer available in [1] and with the commit reverted the issue
does not reproduce anymore.

Using the reproducer found in [1] is fairly easy to reach a point where
one of the child processes is looping infinitely in exit_sem between
for(;;) and if (semid == -1) block, while it's trying to free its last
sem_undo structure which has already been freed by freeary().

Each sem_undo struct is on two lists: one per semaphore set (list_id)
and one per process (list_proc). The list_id list tracks undos by
semaphore set, and the list_proc by process.

Undo structures are removed either by freeary() or by exit_sem(). The
freeary function is invoked when the user invokes a syscall to remove a
semaphore set. During this operation freeary() traverses the list_id
associated with the semaphore set and removes the undo structures from
both the list_id and list_proc lists.

For this case, exit_sem() is called at process exit. Each process
contains a struct sem_undo_list (referred to as "ulp") which contains
the head for the list_proc list. When the process exits, exit_sem()
traverses this list to remove each sem_undo struct. As in freeary(),
whenever a sem_undo struct is removed from list_proc, it is also removed
from the list_id list.

Removing elements from list_id is safe for both exit_sem() and freeary()
due to sem_lock(). Removing elements from list_proc is not safe;
freeary() locks &un->ulp->lock when it performs
list_del_rcu(&un->list_proc) but exit_sem() does not (locking was
removed by commit a97955844807 ("ipc,sem: remove uneeded sem_undo_list
lock usage in exit_sem()").

This can result in the following situation while executing the
reproducer [1] : Consider a child process in exit_sem() and the parent
in freeary() (because of semctl(sid[i], NSEM, IPC_RMID)).

- The list_proc for the child contains the last two undo structs A and
B (the rest have been removed either by exit_sem() or freeary()).

- The semid for A is 1 and semid for B is 2.

- exit_sem() removes A and at the same time freeary() removes B.

- Since A and B have different semid sem_lock() will acquire different
locks for each process and both can proceed.

The bug is that they remove A and B from the same list_proc at the same
time because only freeary() acquires the ulp lock. When exit_sem()
removes A it makes ulp->list_proc.next to point at B and at the same
time freeary() removes B setting B->semid=-1.

At the next iteration of for(;;) loop exit_sem() will try to remove B.

The only way to break from for(;;) is for (&un->list_proc ==
&ulp->list_proc) to be true which is not. Then exit_sem() will check if
B->semid=-1 which is and will continue looping in for(;;) until the
memory for B is reallocated and the value at B->semid is changed.

At that point, exit_sem() will crash attempting to unlink B from the
lists (this can be easily triggered by running the reproducer [1] a
second time).

To prove this scenario instrumentation was added to keep information
about each sem_undo (un) struct that is removed per process and per
semaphore set (sma).

CPU0 CPU1
[caller holds sem_lock(sma for A)] ...
freeary() exit_sem()
... ...
... sem_lock(sma for B)
spin_lock(A->ulp->lock) ...
list_del_rcu(un_A->list_proc) list_del_rcu(un_B->list_proc)

Undo structures A and B have different semid and sem_lock() operations
proceed. However they belong to the same list_proc list and they are
removed at the same time. This results into ulp->list_proc.next
pointing to the address of B which is already removed.

After reverting commit a97955844807 ("ipc,sem: remove uneeded
sem_undo_list lock usage in exit_sem()") the issue was no longer
reproducible.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1694779

Link: http://lkml.kernel.org/r/20191211191318.11860-1-ioanna-maria.alifieraki@canonical.com
Fixes: a97955844807 ("ipc,sem: remove uneeded sem_undo_list lock usage in exit_sem()")
Signed-off-by: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Herton R. Krzesinski <herton@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: <malat@debian.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jay Vosburgh <jay.vosburgh@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Revision tags: v5.6-rc2, v5.6-rc1
97a3253904-Feb-2020 Alexey Dobriyan

proc: convert everything to "struct proc_ops"

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

llseek =>

proc: convert everything to "struct proc_ops"

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

llseek => proc_lseek
unlocked_ioctl => proc_ioctl

xxx => proc_xxx

delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

889b331704-Feb-2020 Lu Shuaibing

ipc/msg.c: consolidate all xxxctl_down() functions

A use of uninitialized memory in msgctl_down() because msqid64 in
ksys_msgctl hasn't been initialized. The local | msqid64 | is create

ipc/msg.c: consolidate all xxxctl_down() functions

A use of uninitialized memory in msgctl_down() because msqid64 in
ksys_msgctl hasn't been initialized. The local | msqid64 | is created in
ksys_msgctl() and then passed into msgctl_down(). Along the way msqid64
is never initialized before msgctl_down() checks msqid64->msg_qbytes.

KUMSAN(KernelUninitializedMemorySantizer, a new error detection tool)
reports:

==================================================================
BUG: KUMSAN: use of uninitialized memory in msgctl_down+0x94/0x300
Read of size 8 at addr ffff88806bb97eb8 by task syz-executor707/2022

CPU: 0 PID: 2022 Comm: syz-executor707 Not tainted 5.2.0-rc4+ #63
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
Call Trace:
dump_stack+0x75/0xae
__kumsan_report+0x17c/0x3e6
kumsan_report+0xe/0x20
msgctl_down+0x94/0x300
ksys_msgctl.constprop.14+0xef/0x260
do_syscall_64+0x7e/0x1f0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4400e9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd869e0598 EFLAGS: 00000246 ORIG_RAX: 0000000000000047
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400e9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401970
R13: 0000000000401a00 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0001aee5c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x100000000000000()
raw: 0100000000000000 0000000000000000 ffffffff01ae0101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kumsan: bad access detected
==================================================================

Syzkaller reproducer:
msgctl$IPC_RMID(0x0, 0x0)

C reproducer:
// autogenerated by syzkaller (https://github.com/google/syzkaller)

int main(void)
{
syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
syscall(__NR_msgctl, 0, 0, 0);
return 0;
}

[natechancellor@gmail.com: adjust indentation in ksys_msgctl]
Link: https://github.com/ClangBuiltLinux/linux/issues/829
Link: http://lkml.kernel.org/r/20191218032932.37479-1-natechancellor@gmail.com
Link: http://lkml.kernel.org/r/20190613014044.24234-1-shuaibinglu@126.com
Signed-off-by: Lu Shuaibing <shuaibinglu@126.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: NeilBrown <neilb@suse.com>
From: Andrew Morton <akpm@linux-foundation.org>
Subject: drivers/block/null_blk_main.c: fix layout

Each line here overflows 80 cols by exactly one character. Delete one tab
per line to fix.

Cc: Shaohua Li <shli@fb.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

8116b54e04-Feb-2020 Manfred Spraul

ipc/sem.c: document and update memory barriers

Document and update the memory barriers in ipc/sem.c:

- Add smp_store_release() to wake_up_sem_queue_prepare() and
document why

ipc/sem.c: document and update memory barriers

Document and update the memory barriers in ipc/sem.c:

- Add smp_store_release() to wake_up_sem_queue_prepare() and
document why it is needed.

- Read q->status using READ_ONCE+smp_acquire__after_ctrl_dep().
as the pair for the barrier inside wake_up_sem_queue_prepare().

- Add comments to all barriers, and mention the rules in the block
regarding locking.

- Switch to using wake_q_add_safe().

Link: http://lkml.kernel.org/r/20191020123305.14715-6-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

0d97a82b04-Feb-2020 Manfred Spraul

ipc/msg.c: update and document memory barriers

Transfer findings from ipc/mqueue.c:

- A control barrier was missing for the lockless receive case So in
theory, not yet initial

ipc/msg.c: update and document memory barriers

Transfer findings from ipc/mqueue.c:

- A control barrier was missing for the lockless receive case So in
theory, not yet initialized data may have been copied to user space -
obviously only for architectures where control barriers are not NOP.

- use smp_store_release(). In theory, the refount may have been
decreased to 0 already when wake_q_add() tries to get a reference.

Link: http://lkml.kernel.org/r/20191020123305.14715-5-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

c5b2cbdb04-Feb-2020 Manfred Spraul

ipc/mqueue.c: update/document memory barriers

Update and document memory barriers for mqueue.c:

- ewp->state is read without any locks, thus READ_ONCE is required.

- add sm

ipc/mqueue.c: update/document memory barriers

Update and document memory barriers for mqueue.c:

- ewp->state is read without any locks, thus READ_ONCE is required.

- add smp_aquire__after_ctrl_dep() after the READ_ONCE, we need
acquire semantics if the value is STATE_READY.

- use wake_q_add_safe()

- document why __set_current_state() may be used:
Reading task->state cannot happen before the wake_q_add() call,
which happens while holding info->lock. Thus the spin_unlock()
is the RELEASE, and the spin_lock() is the ACQUIRE.

For completeness: there is also a 3 CPU scenario, if the to be woken
up task is already on another wake_q.
Then:
- CPU1: spin_unlock() of the task that goes to sleep is the RELEASE
- CPU2: the spin_lock() of the waker is the ACQUIRE
- CPU2: smp_mb__before_atomic inside wake_q_add() is the RELEASE
- CPU3: smp_mb__after_spinlock() inside try_to_wake_up() is the ACQUIRE

Link: http://lkml.kernel.org/r/20191020123305.14715-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Waiman Long <longman@redhat.com>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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