commit 6f457819e8343ae097b7122a57694d26d4ce13b0
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sat Oct 21 17:07:27 2017 +0200
Linux 3.18.77
commit 3cde552980e99d537ff88352202932f8c0bc12e4
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu Oct 19 15:28:08 2017 +0200
Revert "tty: goldfish: Fix a parameter of a call to free_irq"
This reverts commit 0961072120f3e40fe98c2bb49c45549ca3f042dc which is
commit 1a5c2d1de7d35f5eb9793266237903348989502b upstream.
Ben writes:
This fixes a bug introduced in 4.6 by commit 465893e18878 "tty:
goldfish: support platform_device with id -1". For earlier
kernel versions, it *introduces* a bug.
So let's drop it.
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
commit e524bfab417cb2c109eb9b8e900f98a944dbf494
Author: Varun Prakash <varun@chelsio.com>
Date: Fri Jan 20 16:44:33 2017 +0530
target/iscsi: Fix unsolicited data seq_end_offset calculation
[ Upstream commit 4d65491c269729a1e3b375c45e73213f49103d33 ]
In case of unsolicited data for the first sequence
seq_end_offset must be set to minimum of total data length
and FirstBurstLength, so do not add cmd->write_data_done
to the min of total data length and FirstBurstLength.
This patch avoids that with ImmediateData=Yes, InitialR2T=No,
MaxXmitDataSegmentLength < FirstBurstLength that a WRITE command
with IO size above FirstBurstLength triggers sequence error
messages, for example
Set following parameters on target (linux-4.8.12)
ImmediateData = Yes
InitialR2T = No
MaxXmitDataSegmentLength = 8k
FirstBurstLength = 64k
Log in from Open iSCSI initiator and execute
dd if=/dev/zero of=/dev/sdb bs=128k count=1 oflag=direct
Error messages on target
Command ITT: 0x00000035 with Offset: 65536, Length: 8192 outside
of Sequence 73728:131072 while DataSequenceInOrder=Yes.
Command ITT: 0x00000035, received DataSN: 0x00000001 higher than
expected 0x00000000.
Unable to perform within-command recovery while ERL=0.
Signed-off-by: Varun Prakash <varun@chelsio.com>
[ bvanassche: Use min() instead of open-coding it / edited patch description ]
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1405b8e763e6634f0c7503c47184509ba3911387
Author: Dmitry V. Levin <ldv@altlinux.org>
Date: Thu Feb 16 18:04:29 2017 +0300
uapi: fix linux/mroute6.h userspace compilation errors
[ Upstream commit 72aa107df6a275cf03359934ca5799a2be7a1bf7 ]
Include <linux/in6.h> to fix the following linux/mroute6.h userspace
compilation errors:
/usr/include/linux/mroute6.h:80:22: error: field 'mf6cc_origin' has incomplete type
struct sockaddr_in6 mf6cc_origin; /* Origin of mcast */
/usr/include/linux/mroute6.h:81:22: error: field 'mf6cc_mcastgrp' has incomplete type
struct sockaddr_in6 mf6cc_mcastgrp; /* Group in question */
/usr/include/linux/mroute6.h:91:22: error: field 'src' has incomplete type
struct sockaddr_in6 src;
/usr/include/linux/mroute6.h:92:22: error: field 'grp' has incomplete type
struct sockaddr_in6 grp;
/usr/include/linux/mroute6.h:132:18: error: field 'im6_src' has incomplete type
struct in6_addr im6_src, im6_dst;
/usr/include/linux/mroute6.h:132:27: error: field 'im6_dst' has incomplete type
struct in6_addr im6_src, im6_dst;
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d090846a538dc4081140b4b76fbbe6b806611f7f
Author: Dmitry V. Levin <ldv@altlinux.org>
Date: Thu Feb 16 18:05:45 2017 +0300
uapi: fix linux/rds.h userspace compilation errors
[ Upstream commit feb0869d90e51ce8b6fd8a46588465b1b5a26d09 ]
Consistently use types from linux/types.h to fix the following
linux/rds.h userspace compilation errors:
/usr/include/linux/rds.h:106:2: error: unknown type name 'uint8_t'
uint8_t name[32];
/usr/include/linux/rds.h:107:2: error: unknown type name 'uint64_t'
uint64_t value;
/usr/include/linux/rds.h:117:2: error: unknown type name 'uint64_t'
uint64_t next_tx_seq;
/usr/include/linux/rds.h:118:2: error: unknown type name 'uint64_t'
uint64_t next_rx_seq;
/usr/include/linux/rds.h:121:2: error: unknown type name 'uint8_t'
uint8_t transport[TRANSNAMSIZ]; /* null term ascii */
/usr/include/linux/rds.h:122:2: error: unknown type name 'uint8_t'
uint8_t flags;
/usr/include/linux/rds.h:129:2: error: unknown type name 'uint64_t'
uint64_t seq;
/usr/include/linux/rds.h:130:2: error: unknown type name 'uint32_t'
uint32_t len;
/usr/include/linux/rds.h:135:2: error: unknown type name 'uint8_t'
uint8_t flags;
/usr/include/linux/rds.h:139:2: error: unknown type name 'uint32_t'
uint32_t sndbuf;
/usr/include/linux/rds.h:144:2: error: unknown type name 'uint32_t'
uint32_t rcvbuf;
/usr/include/linux/rds.h:145:2: error: unknown type name 'uint64_t'
uint64_t inum;
/usr/include/linux/rds.h:153:2: error: unknown type name 'uint64_t'
uint64_t hdr_rem;
/usr/include/linux/rds.h:154:2: error: unknown type name 'uint64_t'
uint64_t data_rem;
/usr/include/linux/rds.h:155:2: error: unknown type name 'uint32_t'
uint32_t last_sent_nxt;
/usr/include/linux/rds.h:156:2: error: unknown type name 'uint32_t'
uint32_t last_expected_una;
/usr/include/linux/rds.h:157:2: error: unknown type name 'uint32_t'
uint32_t last_seen_una;
/usr/include/linux/rds.h:164:2: error: unknown type name 'uint8_t'
uint8_t src_gid[RDS_IB_GID_LEN];
/usr/include/linux/rds.h:165:2: error: unknown type name 'uint8_t'
uint8_t dst_gid[RDS_IB_GID_LEN];
/usr/include/linux/rds.h:167:2: error: unknown type name 'uint32_t'
uint32_t max_send_wr;
/usr/include/linux/rds.h:168:2: error: unknown type name 'uint32_t'
uint32_t max_recv_wr;
/usr/include/linux/rds.h:169:2: error: unknown type name 'uint32_t'
uint32_t max_send_sge;
/usr/include/linux/rds.h:170:2: error: unknown type name 'uint32_t'
uint32_t rdma_mr_max;
/usr/include/linux/rds.h:171:2: error: unknown type name 'uint32_t'
uint32_t rdma_mr_size;
/usr/include/linux/rds.h:212:9: error: unknown type name 'uint64_t'
typedef uint64_t rds_rdma_cookie_t;
/usr/include/linux/rds.h:215:2: error: unknown type name 'uint64_t'
uint64_t addr;
/usr/include/linux/rds.h:216:2: error: unknown type name 'uint64_t'
uint64_t bytes;
/usr/include/linux/rds.h:221:2: error: unknown type name 'uint64_t'
uint64_t cookie_addr;
/usr/include/linux/rds.h:222:2: error: unknown type name 'uint64_t'
uint64_t flags;
/usr/include/linux/rds.h:228:2: error: unknown type name 'uint64_t'
uint64_t cookie_addr;
/usr/include/linux/rds.h:229:2: error: unknown type name 'uint64_t'
uint64_t flags;
/usr/include/linux/rds.h:234:2: error: unknown type name 'uint64_t'
uint64_t flags;
/usr/include/linux/rds.h:240:2: error: unknown type name 'uint64_t'
uint64_t local_vec_addr;
/usr/include/linux/rds.h:241:2: error: unknown type name 'uint64_t'
uint64_t nr_local;
/usr/include/linux/rds.h:242:2: error: unknown type name 'uint64_t'
uint64_t flags;
/usr/include/linux/rds.h:243:2: error: unknown type name 'uint64_t'
uint64_t user_token;
/usr/include/linux/rds.h:248:2: error: unknown type name 'uint64_t'
uint64_t local_addr;
/usr/include/linux/rds.h:249:2: error: unknown type name 'uint64_t'
uint64_t remote_addr;
/usr/include/linux/rds.h:252:4: error: unknown type name 'uint64_t'
uint64_t compare;
/usr/include/linux/rds.h:253:4: error: unknown type name 'uint64_t'
uint64_t swap;
/usr/include/linux/rds.h:256:4: error: unknown type name 'uint64_t'
uint64_t add;
/usr/include/linux/rds.h:259:4: error: unknown type name 'uint64_t'
uint64_t compare;
/usr/include/linux/rds.h:260:4: error: unknown type name 'uint64_t'
uint64_t swap;
/usr/include/linux/rds.h:261:4: error: unknown type name 'uint64_t'
uint64_t compare_mask;
/usr/include/linux/rds.h:262:4: error: unknown type name 'uint64_t'
uint64_t swap_mask;
/usr/include/linux/rds.h:265:4: error: unknown type name 'uint64_t'
uint64_t add;
/usr/include/linux/rds.h:266:4: error: unknown type name 'uint64_t'
uint64_t nocarry_mask;
/usr/include/linux/rds.h:269:2: error: unknown type name 'uint64_t'
uint64_t flags;
/usr/include/linux/rds.h:270:2: error: unknown type name 'uint64_t'
uint64_t user_token;
/usr/include/linux/rds.h:274:2: error: unknown type name 'uint64_t'
uint64_t user_token;
/usr/include/linux/rds.h:275:2: error: unknown type name 'int32_t'
int32_t status;
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ffc669a3af00c8c3a9ceeb1b30a55f89cf38d2ce
Author: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue Feb 21 21:46:37 2017 +0300
scsi: scsi_dh_emc: return success in clariion_std_inquiry()
[ Upstream commit 4d7d39a18b8b81511f0b893b7d2203790bf8a58b ]
We accidentally return an uninitialized variable on success.
Fixes: b6ff1b14cdf4 ("[SCSI] scsi_dh: Update EMC handler")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b370a0378091e31f8c6a4eb708dfd22be314f7c0
Author: Eric Ren <zren@suse.com>
Date: Wed Feb 22 15:40:41 2017 -0800
ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lock
[ Upstream commit 439a36b8ef38657f765b80b775e2885338d72451 ]
We are in the situation that we have to avoid recursive cluster locking,
but there is no way to check if a cluster lock has been taken by a precess
already.
Mostly, we can avoid recursive locking by writing code carefully.
However, we found that it's very hard to handle the routines that are
invoked directly by vfs code. For instance:
const struct inode_operations ocfs2_file_iops = {
.permission = ocfs2_permission,
.get_acl = ocfs2_iop_get_acl,
.set_acl = ocfs2_iop_set_acl,
};
Both ocfs2_permission() and ocfs2_iop_get_acl() call ocfs2_inode_lock(PR):
do_sys_open
may_open
inode_permission
ocfs2_permission
ocfs2_inode_lock() <=== first time
generic_permission
get_acl
ocfs2_iop_get_acl
ocfs2_inode_lock() <=== recursive one
A deadlock will occur if a remote EX request comes in between two of
ocfs2_inode_lock(). Briefly describe how the deadlock is formed:
On one hand, OCFS2_LOCK_BLOCKED flag of this lockres is set in
BAST(ocfs2_generic_handle_bast) when downconvert is started on behalf of
the remote EX lock request. Another hand, the recursive cluster lock
(the second one) will be blocked in in __ocfs2_cluster_lock() because of
OCFS2_LOCK_BLOCKED. But, the downconvert never complete, why? because
there is no chance for the first cluster lock on this node to be
unlocked - we block ourselves in the code path.
The idea to fix this issue is mostly taken from gfs2 code.
1. introduce a new field: struct ocfs2_lock_res.l_holders, to keep track
of the processes' pid who has taken the cluster lock of this lock
resource;
2. introduce a new flag for ocfs2_inode_lock_full:
OCFS2_META_LOCK_GETBH; it means just getting back disk inode bh for
us if we've got cluster lock.
3. export a helper: ocfs2_is_locked_by_me() is used to check if we have
got the cluster lock in the upper code path.
The tracking logic should be used by some of the ocfs2 vfs's callbacks,
to solve the recursive locking issue cuased by the fact that vfs
routines can call into each other.
The performance penalty of processing the holder list should only be
seen at a few cases where the tracking logic is used, such as get/set
acl.
You may ask what if the first time we got a PR lock, and the second time
we want a EX lock? fortunately, this case never happens in the real
world, as far as I can see, including permission check,
(get|set)_(acl|attr), and the gfs2 code also do so.
[sfr@canb.auug.org.au remove some inlines]
Link: http://lkml.kernel.org/r/20170117100948.11657-2-zren@suse.com
Signed-off-by: Eric Ren <zren@suse.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7cab7260362320e26243925c60d731552a0280a7
Author: Milan Broz <gmazyland@gmail.com>
Date: Thu Feb 23 08:38:26 2017 +0100
crypto: xts - Add ECB dependency
[ Upstream commit 12cb3a1c4184f891d965d1f39f8cfcc9ef617647 ]
Since the
commit f1c131b45410a202eb45cc55980a7a9e4e4b4f40
crypto: xts - Convert to skcipher
the XTS mode is based on ECB, so the mode must select
ECB otherwise it can fail to initialize.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bcd17067a2311847ea05bc62aae0ba297e740e0d
Author: Majd Dibbiny <majd@mellanox.com>
Date: Thu Feb 23 12:02:43 2017 +0200
net/mlx4_core: Fix VF overwrite of module param which disables DMFS on new probed PFs
[ Upstream commit 95f1ba9a24af9769f6e20dfe9a77c863f253f311 ]
In the VF driver, module parameter mlx4_log_num_mgm_entry_size was
mistakenly overwritten -- and in a manner which overrode the
device-managed flow steering option encoded in the parameter.
log_num_mgm_entry_size is a global module parameter which
affects all ConnectX-3 PFs installed on that host.
If a VF changes log_num_mgm_entry_size, this will affect all PFs
which are probed subsequent to the change (by disabling DMFS for
those PFs).
Fixes: 3c439b5586e9 ("mlx4_core: Allow choosing flow steering mode")
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2d9e4b59c8fa8e0983bff7432ddf26c42762cf6f
Author: Robbie Ko <robbieko@synology.com>
Date: Thu Jan 5 16:24:55 2017 +0800
Btrfs: send, fix failure to rename top level inode due to name collision
[ Upstream commit 4dd9920d991745c4a16f53a8f615f706fbe4b3f7 ]
Under certain situations, an incremental send operation can fail due to a
premature attempt to create a new top level inode (a direct child of the
subvolume/snapshot root) whose name collides with another inode that was
removed from the send snapshot.
Consider the following example scenario.
Parent snapshot:
. (ino 256, gen 8)
|---- a1/ (ino 257, gen 9)
|---- a2/ (ino 258, gen 9)
Send snapshot:
. (ino 256, gen 3)
|---- a2/ (ino 257, gen 7)
In this scenario, when receiving the incremental send stream, the btrfs
receive command fails like this (ran in verbose mode, -vv argument):
rmdir a1
mkfile o257-7-0
rename o257-7-0 -> a2
ERROR: rename o257-7-0 -> a2 failed: Is a directory
What happens when computing the incremental send stream is:
1) An operation to remove the directory with inode number 257 and
generation 9 is issued.
2) An operation to create the inode with number 257 and generation 7 is
issued. This creates the inode with an orphanized name of "o257-7-0".
3) An operation rename the new inode 257 to its final name, "a2", is
issued. This is incorrect because inode 258, which has the same name
and it's a child of the same parent (root inode 256), was not yet
processed and therefore no rmdir operation for it was yet issued.
The rename operation is issued because we fail to detect that the
name of the new inode 257 collides with inode 258, because their
parent, a subvolume/snapshot root (inode 256) has a different
generation in both snapshots.
So fix this by ignoring the generation value of a parent directory that
matches a root inode (number 256) when we are checking if the name of the
inode currently being processed collides with the name of some other
inode that was not yet processed.
We can achieve this scenario of different inodes with the same number but
different generation values either by mounting a filesystem with the inode
cache option (-o inode_cache) or by creating and sending snapshots across
different filesystems, like in the following example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/a1
$ mkdir /mnt/a2
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ touch /mnt/a2
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs receive /mnt -f /tmp/1.snap
# Take note that once the filesystem is created, its current
# generation has value 7 so the inode from the second snapshot has
# a generation value of 7. And after receiving the first snapshot
# the filesystem is at a generation value of 10, because the call to
# create the second snapshot bumps the generation to 8 (the snapshot
# creation ioctl does a transaction commit), the receive command calls
# the snapshot creation ioctl to create the first snapshot, which bumps
# the filesystem's generation to 9, and finally when the receive
# operation finishes it calls an ioctl to transition the first snapshot
# (snap1) from RW mode to RO mode, which does another transaction commit
# and bumps the filesystem's generation to 10.
$ rm -f /tmp/1.snap
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdd /mnt
$ btrfs receive /mnt /tmp/1.snap
# Receive of snapshot snap2 used to fail.
$ btrfs receive /mnt /tmp/2.snap
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[Rewrote changelog to be more precise and clear]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 21bf570719a5e5c9c8082601175fa32be83e43d5
Author: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Tue Feb 21 07:34:00 2017 +0100
iio: adc: xilinx: Fix error handling
[ Upstream commit ca1c39ef76376b67303d01f94fe98bb68bb3861a ]
Reorder error handling labels in order to match the way resources have
been allocated.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a5043741109f5318638cc79de0a1a28b78b25b9
Author: Jarno Rajahalme <jarno@ovn.org>
Date: Thu Feb 23 17:08:54 2017 -0800
netfilter: nf_ct_expect: Change __nf_ct_expect_check() return value.
[ Upstream commit 4b86c459c7bee3acaf92f0e2b4c6ac803eaa1a58 ]
Commit 4dee62b1b9b4 ("netfilter: nf_ct_expect: nf_ct_expect_insert()
returns void") inadvertently changed the successful return value of
nf_ct_expect_related_report() from 0 to 1 due to
__nf_ct_expect_check() returning 1 on success. Prevent this
regression in the future by changing the return value of
__nf_ct_expect_check() to 0 on success.
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Joe Stringer <joe@ovn.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef0423167be6c11d68bfcbd1190f508727f1d042
Author: Franck Demathieu <fdemathieu@gmail.com>
Date: Thu Feb 23 10:48:55 2017 +0100
irqchip/crossbar: Fix incorrect type of local variables
[ Upstream commit b28ace12661fbcfd90959c1e84ff5a85113a82a1 ]
The max and entry variables are unsigned according to the dt-bindings.
Fix following 3 sparse issues (-Wtypesign):
drivers/irqchip/irq-crossbar.c:222:52: warning: incorrect type in argument 3 (different signedness)
drivers/irqchip/irq-crossbar.c:222:52: expected unsigned int [usertype] *out_value
drivers/irqchip/irq-crossbar.c:222:52: got int *<noident>
drivers/irqchip/irq-crossbar.c:245:56: warning: incorrect type in argument 4 (different signedness)
drivers/irqchip/irq-crossbar.c:245:56: expected unsigned int [usertype] *out_value
drivers/irqchip/irq-crossbar.c:245:56: got int *<noident>
drivers/irqchip/irq-crossbar.c:263:56: warning: incorrect type in argument 4 (different signedness)
drivers/irqchip/irq-crossbar.c:263:56: expected unsigned int [usertype] *out_value
drivers/irqchip/irq-crossbar.c:263:56: got int *<noident>
Signed-off-by: Franck Demathieu <fdemathieu@gmail.com>
Cc: marc.zyngier@arm.com
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/20170223094855.6546-1-fdemathieu@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5961adefd0f361deaf925d3c4bff80bc9e87de50
Author: Arnd Bergmann <arnd@arndb.de>
Date: Wed Mar 1 10:15:29 2017 +0100
watchdog: kempld: fix gcc-4.3 build
[ Upstream commit 3736d4eb6af37492aeded7fec0072dedd959c842 ]
gcc-4.3 can't decide whether the constant value in
kempld_prescaler[PRESCALER_21] is built-time constant or
not, and gets confused by the logic in do_div():
drivers/watchdog/kempld_wdt.o: In function `kempld_wdt_set_stage_timeout':
kempld_wdt.c:(.text.kempld_wdt_set_stage_timeout+0x130): undefined reference to `__aeabi_uldivmod'
This adds a call to ACCESS_ONCE() to force it to not consider
it to be constant, and leaves the more efficient normal case
in place for modern compilers, using an #ifdef to annotate
why we do this hack.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 981199076d96effa8f26321372240a2dbaa3561e
Author: Peter Zijlstra <peterz@infradead.org>
Date: Wed Mar 1 16:23:30 2017 +0100
locking/lockdep: Add nest_lock integrity test
[ Upstream commit 7fb4a2cea6b18dab56d609530d077f168169ed6b ]
Boqun reported that hlock->references can overflow. Add a debug test
for that to generate a clear error when this happens.
Without this, lockdep is likely to report a mysterious failure on
unlock.
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicolai Hähnle <Nicolai.Haehnle@amd.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4a8a916d932e719fba2725ea144e5c5803ee6cb0
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu Oct 19 14:55:29 2017 +0200
Revert "bsg-lib: don't free job in bsg_prepare_job"
This reverts commit d9100405a20a71dd620843e0380e38fc50731108 which was
commit f507b54dccfd8000c517d740bc45f20c74532d18 upstream.
Ben reports:
That function doesn't exist here (it was introduced in 4.13).
Instead, this backport has modified bsg_create_job(), creating a
leak. Please revert this on the 3.18, 4.4 and 4.9 stable
branches.
So I'm dropping it from here.
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
commit bc8a5a45208d335de143643e51358c8299bce0f3
Author: Christoph Paasch <cpaasch@apple.com>
Date: Tue Sep 26 17:38:50 2017 -0700
net: Set sk_prot_creator when cloning sockets to the right proto
[ Upstream commit 9d538fa60bad4f7b23193c89e843797a1cf71ef3 ]
sk->sk_prot and sk->sk_prot_creator can differ when the app uses
IPV6_ADDRFORM (transforming an IPv6-socket to an IPv4-one).
Which is why sk_prot_creator is there to make sure that sk_prot_free()
does the kmem_cache_free() on the right kmem_cache slab.
Now, if such a socket gets transformed back to a listening socket (using
connect() with AF_UNSPEC) we will allocate an IPv4 tcp_sock through
sk_clone_lock() when a new connection comes in. But sk_prot_creator will
still point to the IPv6 kmem_cache (as everything got copied in
sk_clone_lock()). When freeing, we will thus put this
memory back into the IPv6 kmem_cache although it was allocated in the
IPv4 cache. I have seen memory corruption happening because of this.
With slub-debugging and MEMCG_KMEM enabled this gives the warning
"cache_from_obj: Wrong slab cache. TCPv6 but object is from TCP"
A C-program to trigger this:
void main(void)
{
int fd = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
int new_fd, newest_fd, client_fd;
struct sockaddr_in6 bind_addr;
struct sockaddr_in bind_addr4, client_addr1, client_addr2;
struct sockaddr unsp;
int val;
memset(&bind_addr, 0, sizeof(bind_addr));
bind_addr.sin6_family = AF_INET6;
bind_addr.sin6_port = ntohs(42424);
memset(&client_addr1, 0, sizeof(client_addr1));
client_addr1.sin_family = AF_INET;
client_addr1.sin_port = ntohs(42424);
client_addr1.sin_addr.s_addr = inet_addr("127.0.0.1");
memset(&client_addr2, 0, sizeof(client_addr2));
client_addr2.sin_family = AF_INET;
client_addr2.sin_port = ntohs(42421);
client_addr2.sin_addr.s_addr = inet_addr("127.0.0.1");
memset(&unsp, 0, sizeof(unsp));
unsp.sa_family = AF_UNSPEC;
bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr));
listen(fd, 5);
client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
connect(client_fd, (struct sockaddr *)&client_addr1, sizeof(client_addr1));
new_fd = accept(fd, NULL, NULL);
close(fd);
val = AF_INET;
setsockopt(new_fd, SOL_IPV6, IPV6_ADDRFORM, &val, sizeof(val));
connect(new_fd, &unsp, sizeof(unsp));
memset(&bind_addr4, 0, sizeof(bind_addr4));
bind_addr4.sin_family = AF_INET;
bind_addr4.sin_port = ntohs(42421);
bind(new_fd, (struct sockaddr *)&bind_addr4, sizeof(bind_addr4));
listen(new_fd, 5);
client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
connect(client_fd, (struct sockaddr *)&client_addr2, sizeof(client_addr2));
newest_fd = accept(new_fd, NULL, NULL);
close(new_fd);
close(client_fd);
close(new_fd);
}
As far as I can see, this bug has been there since the beginning of the
git-days.
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b0763909b4538894bb47614656c75f2a233c40d2
Author: Willem de Bruijn <willemb@google.com>
Date: Tue Sep 26 12:19:37 2017 -0400
packet: in packet_do_bind, test fanout with bind_lock held
[ Upstream commit 4971613c1639d8e5f102c4e797c3bf8f83a5a69e ]
Once a socket has po->fanout set, it remains a member of the group
until it is destroyed. The prot_hook must be constant and identical
across sockets in the group.
If fanout_add races with packet_do_bind between the test of po->fanout
and taking the lock, the bind call may make type or dev inconsistent
with that of the fanout group.
Hold po->bind_lock when testing po->fanout to avoid this race.
I had to introduce artificial delay (local_bh_enable) to actually
observe the race.
Fixes: dc99f600698d ("packet: Add fanout support.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5eaafe649af94c12164bb43f81d85cbc7cfe6778
Author: Sabrina Dubroca <sd@queasysnail.net>
Date: Tue Sep 26 16:16:43 2017 +0200
l2tp: fix race condition in l2tp_tunnel_delete
[ Upstream commit 62b982eeb4589b2e6d7c01a90590e3a4c2b2ca19 ]
If we try to delete the same tunnel twice, the first delete operation
does a lookup (l2tp_tunnel_get), finds the tunnel, calls
l2tp_tunnel_delete, which queues it for deletion by
l2tp_tunnel_del_work.
The second delete operation also finds the tunnel and calls
l2tp_tunnel_delete. If the workqueue has already fired and started
running l2tp_tunnel_del_work, then l2tp_tunnel_delete will queue the
same tunnel a second time, and try to free the socket again.
Add a dead flag to prevent firing the workqueue twice. Then we can
remove the check of queue_work's result that was meant to prevent that
race but doesn't.
Reproducer:
ip l2tp add tunnel tunnel_id 3000 peer_tunnel_id 4000 local 192.168.0.2 remote 192.168.0.1 encap udp udp_sport 5000 udp_dport 6000
ip l2tp add session name l2tp1 tunnel_id 3000 session_id 1000 peer_session_id 2000
ip link set l2tp1 up
ip l2tp del tunnel tunnel_id 3000
ip l2tp del tunnel tunnel_id 3000
Fixes: f8ccac0e4493 ("l2tp: put tunnel socket release on a workqueue")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 88db37f8e4de97702da5f53c09cdbff0382f9bdd
Author: Ridge Kennedy <ridge.kennedy@alliedtelesis.co.nz>
Date: Wed Feb 22 14:59:49 2017 +1300
l2tp: Avoid schedule while atomic in exit_net
[ Upstream commit 12d656af4e3d2781b9b9f52538593e1717e7c979 ]
While destroying a network namespace that contains a L2TP tunnel a
"BUG: scheduling while atomic" can be observed.
Enabling lockdep shows that this is happening because l2tp_exit_net()
is calling l2tp_tunnel_closeall() (via l2tp_tunnel_delete()) from
within an RCU critical section.
l2tp_exit_net() takes rcu_read_lock_bh()
<< list_for_each_entry_rcu() >>
l2tp_tunnel_delete()
l2tp_tunnel_closeall()
__l2tp_session_unhash()
synchronize_rcu() << Illegal inside RCU critical section >>
BUG: sleeping function called from invalid context
in_atomic(): 1, irqs_disabled(): 0, pid: 86, name: kworker/u16:2
INFO: lockdep is turned off.
CPU: 2 PID: 86 Comm: kworker/u16:2 Tainted: G W O 4.4.6-at1 #2
Hardware name: Xen HVM domU, BIOS 4.6.1-xs125300 05/09/2016
Workqueue: netns cleanup_net
0000000000000000 ffff880202417b90 ffffffff812b0013 ffff880202410ac0
ffffffff81870de8 ffff880202417bb8 ffffffff8107aee8 ffffffff81870de8
0000000000000c51 0000000000000000 ffff880202417be0 ffffffff8107b024
Call Trace:
[<ffffffff812b0013>] dump_stack+0x85/0xc2
[<ffffffff8107aee8>] ___might_sleep+0x148/0x240
[<ffffffff8107b024>] __might_sleep+0x44/0x80
[<ffffffff810b21bd>] synchronize_sched+0x2d/0xe0
[<ffffffff8109be6d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff8105c7bb>] ? __local_bh_enable_ip+0x6b/0xc0
[<ffffffff816a1b00>] ? _raw_spin_unlock_bh+0x30/0x40
[<ffffffff81667482>] __l2tp_session_unhash+0x172/0x220
[<ffffffff81667397>] ? __l2tp_session_unhash+0x87/0x220
[<ffffffff8166888b>] l2tp_tunnel_closeall+0x9b/0x140
[<ffffffff81668c74>] l2tp_tunnel_delete+0x14/0x60
[<ffffffff81668dd0>] l2tp_exit_net+0x110/0x270
[<ffffffff81668d5c>] ? l2tp_exit_net+0x9c/0x270
[<ffffffff815001c3>] ops_exit_list.isra.6+0x33/0x60
[<ffffffff81501166>] cleanup_net+0x1b6/0x280
...
This bug can easily be reproduced with a few steps:
$ sudo unshare -n bash # Create a shell in a new namespace
# ip link set lo up
# ip addr add 127.0.0.1 dev lo
# ip l2tp add tunnel remote 127.0.0.1 local 127.0.0.1 tunnel_id 1 \
peer_tunnel_id 1 udp_sport 50000 udp_dport 50000
# ip l2tp add session name foo tunnel_id 1 session_id 1 \
peer_session_id 1
# ip link set foo up
# exit # Exit the shell, in turn exiting the namespace
$ dmesg
...
[942121.089216] BUG: scheduling while atomic: kworker/u16:3/13872/0x00000200
...
To fix this, move the call to l2tp_tunnel_closeall() out of the RCU
critical section, and instead call it from l2tp_tunnel_del_work(), which
is running from the l2tp_wq workqueue.
Fixes: 2b551c6e7d5b ("l2tp: close sessions before initiating tunnel delete")
Signed-off-by: Ridge Kennedy <ridge.kennedy@alliedtelesis.co.nz>
Acked-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6132b4ff8fbd56613a8342e75a8b82b6b011a837
Author: Alexey Kodanev <alexey.kodanev@oracle.com>
Date: Tue Sep 26 15:14:29 2017 +0300
vti: fix use after free in vti_tunnel_xmit/vti6_tnl_xmit
[ Upstream commit 36f6ee22d2d66046e369757ec6bbe1c482957ba6 ]
When running LTP IPsec tests, KASan might report:
BUG: KASAN: use-after-free in vti_tunnel_xmit+0xeee/0xff0 [ip_vti]
Read of size 4 at addr ffff880dc6ad1980 by task swapper/0/0
...
Call Trace:
<IRQ>
dump_stack+0x63/0x89
print_address_description+0x7c/0x290
kasan_report+0x28d/0x370
? vti_tunnel_xmit+0xeee/0xff0 [ip_vti]
__asan_report_load4_noabort+0x19/0x20
vti_tunnel_xmit+0xeee/0xff0 [ip_vti]
? vti_init_net+0x190/0x190 [ip_vti]
? save_stack_trace+0x1b/0x20
? save_stack+0x46/0xd0
dev_hard_start_xmit+0x147/0x510
? icmp_echo.part.24+0x1f0/0x210
__dev_queue_xmit+0x1394/0x1c60
...
Freed by task 0:
save_stack_trace+0x1b/0x20
save_stack+0x46/0xd0
kasan_slab_free+0x70/0xc0
kmem_cache_free+0x81/0x1e0
kfree_skbmem+0xb1/0xe0
kfree_skb+0x75/0x170
kfree_skb_list+0x3e/0x60
__dev_queue_xmit+0x1298/0x1c60
dev_queue_xmit+0x10/0x20
neigh_resolve_output+0x3a8/0x740
ip_finish_output2+0x5c0/0xe70
ip_finish_output+0x4ba/0x680
ip_output+0x1c1/0x3a0
xfrm_output_resume+0xc65/0x13d0
xfrm_output+0x1e4/0x380
xfrm4_output_finish+0x5c/0x70
Can be fixed if we get skb->len before dst_output().
Fixes: b9959fd3b0fa ("vti: switch to new ip tunnel code")
Fixes: 22e1b23dafa8 ("vti6: Support inter address family tunneling.")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ba554fc7dc2b4189ccfc412853c578cf0d613c3b
Author: Meng Xu <mengxu.gatech@gmail.com>
Date: Tue Sep 19 21:49:55 2017 -0400
isdn/i4l: fetch the ppp_write buffer in one shot
[ Upstream commit 02388bf87f72e1d47174cd8f81c34443920eb5a0 ]
In isdn_ppp_write(), the header (i.e., protobuf) of the buffer is
fetched twice from userspace. The first fetch is used to peek at the
protocol of the message and reset the huptimer if necessary; while the
second fetch copies in the whole buffer. However, given that buf resides
in userspace memory, a user process can race to change its memory content
across fetches. By doing so, we can either avoid resetting the huptimer
for any type of packets (by first setting proto to PPP_LCP and later
change to the actual type) or force resetting the huptimer for LCP
packets.
This patch changes this double-fetch behavior into two single fetches
decided by condition (lp->isdn_device < 0 || lp->isdn_channel <0).
A more detailed discussion can be found at
https://marc.info/?l=linux-kernel&m=150586376926123&w=2
Signed-off-by: Meng Xu <mengxu.gatech@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e4ffdf9ead59a909f2824a4270356909d6d64380
Author: Willem de Bruijn <willemb@google.com>
Date: Thu Sep 14 17:14:41 2017 -0400
packet: hold bind lock when rebinding to fanout hook
[ Upstream commit 008ba2a13f2d04c947adc536d19debb8fe66f110 ]
Packet socket bind operations must hold the po->bind_lock. This keeps
po->running consistent with whether the socket is actually on a ptype
list to receive packets.
fanout_add unbinds a socket and its packet_rcv/tpacket_rcv call, then
binds the fanout object to receive through packet_rcv_fanout.
Make it hold the po->bind_lock when testing po->running and rebinding.
Else, it can race with other rebind operations, such as that in
packet_set_ring from packet_rcv to tpacket_rcv. Concurrent updates
can result in a socket being added to a fanout group twice, causing
use-after-free KASAN bug reports, among others.
Reported independently by both trinity and syzkaller.
Verified that the syzkaller reproducer passes after this patch.
Fixes: dc99f600698d ("packet: Add fanout support.")
Reported-by: nixioaming <nixiaoming@huawei.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 63692f8b33bd8167169e600350b1d5a3102a71ad
Author: Edward Cree <ecree@solarflare.com>
Date: Fri Sep 15 14:37:38 2017 +0100
bpf/verifier: reject BPF_ALU64|BPF_END
[ Upstream commit e67b8a685c7c984e834e3181ef4619cd7025a136 ]
Neither ___bpf_prog_run nor the JITs accept it.
Also adds a new test case.
Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit db27397942aa3f3c7b02a28d52878468923834bd
Author: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu Sep 14 02:00:54 2017 +0300
sctp: potential read out of bounds in sctp_ulpevent_type_enabled()
[ Upstream commit fa5f7b51fc3080c2b195fa87c7eca7c05e56f673 ]
This code causes a static checker warning because Smatch doesn't trust
anything that comes from skb->data. I've reviewed this code and I do
think skb->data can be controlled by the user here.
The sctp_event_subscribe struct has 13 __u8 fields and we want to see
if ours is non-zero. sn_type can be any value in the 0-USHRT_MAX range.
We're subtracting SCTP_SN_TYPE_BASE which is 1 << 15 so we could read
either before the start of the struct or after the end.
This is a very old bug and it's surprising that it would go undetected
for so long but my theory is that it just doesn't have a big impact so
it would be hard to notice.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1512129452b835f342c7e0bffac71172d0ac39f3
Author: Jan Kara <jack@suse.cz>
Date: Thu Aug 11 12:38:55 2016 -0400
ext4: avoid deadlock when expanding inode size
[ Upstream commit 2e81a4eeedcaa66e35f58b81e0755b87057ce392 ]
When we need to move xattrs into external xattr block, we call
ext4_xattr_block_set() from ext4_expand_extra_isize_ea(). That may end
up calling ext4_mark_inode_dirty() again which will recurse back into
the inode expansion code leading to deadlocks.
Protect from recursion using EXT4_STATE_NO_EXPAND inode flag and move
its management into ext4_expand_extra_isize_ea() since its manipulation
is safe there (due to xattr_sem) from possible races with
ext4_xattr_set_handle() which plays with it as well.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9b7e3d75f8c3a704d8bba9ee9049e41371489815
Author: Harry Wentland <harry.wentland@amd.com>
Date: Mon Dec 7 13:55:52 2015 -0500
drm/dp/mst: save vcpi with payloads
commit 6cecdf7a161d2b909dc7c8979176bbc4f0669968 upstream.
This makes it possibly for drivers to find the associated
mst_port by looking at the payload allocation table.
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449514552-10236-3-git-send-email-harry.wentland@amd.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Kai Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 608c3080b00944769a3cf898d5e54dca64511dea
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri Aug 5 15:37:39 2016 +0200
x86/mm: Disable preemption during CR3 read+write
commit 5cf0791da5c162ebc14b01eb01631cfa7ed4fa6e upstream.
There's a subtle preemption race on UP kernels:
Usually current->mm (and therefore mm->pgd) stays the same during the
lifetime of a task so it does not matter if a task gets preempted during
the read and write of the CR3.
But then, there is this scenario on x86-UP:
TaskA is in do_exit() and exit_mm() sets current->mm = NULL followed by:
-> mmput()
-> exit_mmap()
-> tlb_finish_mmu()
-> tlb_flush_mmu()
-> tlb_flush_mmu_tlbonly()
-> tlb_flush()
-> flush_tlb_mm_range()
-> __flush_tlb_up()
-> __flush_tlb()
-> __native_flush_tlb()
At this point current->mm is NULL but current->active_mm still points to
the "old" mm.
Let's preempt taskA _after_ native_read_cr3() by taskB. TaskB has its
own mm so CR3 has changed.
Now preempt back to taskA. TaskA has no ->mm set so it borrows taskB's
mm and so CR3 remains unchanged. Once taskA gets active it continues
where it was interrupted and that means it writes its old CR3 value
back. Everything is fine because userland won't need its memory
anymore.
Now the fun part:
Let's preempt taskA one more time and get back to taskB. This
time switch_mm() won't do a thing because oldmm (->active_mm)
is the same as mm (as per context_switch()). So we remain
with a bad CR3 / PGD and return to userland.
The next thing that happens is handle_mm_fault() with an address for
the execution of its code in userland. handle_mm_fault() realizes that
it has a PTE with proper rights so it returns doing nothing. But the
CPU looks at the wrong PGD and insists that something is wrong and
faults again. And again. And one more time…
This pagefault circle continues until the scheduler gets tired of it and
puts another task on the CPU. It gets little difficult if the task is a
RT task with a high priority. The system will either freeze or it gets
fixed by the software watchdog thread which usually runs at RT-max prio.
But waiting for the watchdog will increase the latency of the RT task
which is no good.
Fix this by disabling preemption across the critical code section.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1470404259-26290-1-git-send-email-bigeasy@linutronix.de
[ Prettified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Bernhard Kaindl <bernhard.kaindl@thalesgroup.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>