Age | Commit message (Collapse) | Author | Files | Lines |
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Allow filesystems to return ENOSYS from opendir, preventing the kernel from
sending opendir and releasedir messages in the future. This avoids
userspace transitions when filesystems don't need to keep track of state
per directory handle.
A new capability flag, FUSE_NO_OPENDIR_SUPPORT, parallels
FUSE_NO_OPEN_SUPPORT, indicating the new semantics for returning ENOSYS
from opendir.
Signed-off-by: Chad Austin <chadaustin@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Bad inode checks were done done in various places, and move them into
fuse_file_{read|write}_iter().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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This is cleanup, as well as allowing switching between I/O modes while the
file is open in the future.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Nothing preventing copy_file_range to work on files opened with
FOPEN_DIRECT_IO.
Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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The default splice implementation is grossly inefficient and the iter based
ones work just fine, so use those instead. I've measured an 8x speedup for
splice write (with len = 128k).
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Switch to using the async directo IO code path in fuse_direct_read_iter()
and fuse_direct_write_iter(). This is especially important in connection
with loop devices with direct IO enabled as loop assumes async direct io is
actually async.
Signed-off-by: Martin Raiber <martin@urbackup.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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...to get rid of one more fc->lock use.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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The only caller that needs fc->aborted set is fuse_conn_abort_write().
Setting fc->aborted is now racy (fuse_abort_conn() may already be in
progress or finished) but there's no reason to care.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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This is rather natural action after previous patches, and it just decreases
load of fc->lock.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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This continues previous patch and introduces the same protection for
nlookup field.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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To minimize contention of fc->lock, this patch introduces a new spinlock
for protection fuse_inode metadata:
fuse_inode:
writectr
writepages
write_files
queued_writes
attr_version
inode:
i_size
i_nlink
i_mtime
i_ctime
Also, it protects the fields changed in fuse_change_attributes_common()
(too many to list).
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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This patch makes fc->attr_version of atomic64_t type, so fc->lock won't be
needed to read or modify it anymore.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Here is preparation for next patches, which introduce new fi->lock for
protection of ff->write_entry linked into fi->write_files.
This patch just passes new argument to the function.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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When queue_interrupt() is called from fuse_dev_do_write(), it came from
userspace directly. Userspace may pass any request id, even the request's
we have not interrupted (or even background's request). This patch adds
sanity check to make kernel safe against that.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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This is needed for next patch.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Currently, we wait on req->waitq in request_wait_answer() function only,
and it's never used for background requests. Since wake_up() is not a
light-weight macros, instead of this, it unfolds in really called function,
which makes locking operations taking some cpu cycles, let's avoid its call
for the case we definitely know it's completely useless.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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We take global fiq->waitq.lock every time, when we are in this function,
but interrupted requests are just small subset of all requests. This patch
optimizes request_end() and makes it to take the lock when it's really
needed.
queue_interrupt() needs small change for that. After req is linked to
interrupt list, we do smp_mb() and check for FR_FINISHED again. In case of
FR_FINISHED bit has appeared, we remove req and leave the function:
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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We should sent signal only in case of interrupt is really queued. Not a
real problem, but this makes the code clearer and intuitive.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Function end_requests() does not take fc->lock.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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It looks like we can optimize page replacement and avoid copying by simple
updating the request's page.
[SzM: swap with new request's tmp page to avoid use after free.]
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Auxiliary requests chained on req->misc.write.next may be leaked on
truncate. Free these as well if the parent request was truncated off.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Don't reuse the queued request, even if it only contains a single page.
This is needed because previous locking changes (spliting out
fiq->waitq.lock from fc->lock) broke the assumption that request will
remain in FR_PENDING at least until the new page contents are copied.
This fix removes a slight optimization for a rare corner case, so we really
shoudln't care.
Reported-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Fixes: fd22d62ed0c3 ("fuse: no fc->lock for iqueue parts")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Restructure the function to better separate the locked and the unlocked
parts. Use the "old_req" local variable to mean only the queued request,
and not any auxiliary requests added onto its misc.write.next list. These
changes are in preparation for the following patch.
Also turn BUG_ON instances into WARN_ON and add a header comment explaining
what the function does.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Call this from fuse_range_is_writeback() and fuse_writepage_in_flight().
Turn a BUG_ON() into a WARN_ON() in the process.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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set_pmd_at() calls native_set_pmd() unconditionally on x86. This was
fine as long as only huge page entries were written via set_pmd_at(),
as Xen pv guests don't support those.
Commit 2c91bd4a4e2e53 ("mm: speed up mremap by 20x on large regions")
introduced a usage of set_pmd_at() possible on pv guests, leading to
failures like:
BUG: unable to handle kernel paging request at ffff888023e26778
#PF error: [PROT] [WRITE]
RIP: e030:move_page_tables+0x7c1/0xae0
move_vma.isra.3+0xd1/0x2d0
__se_sys_mremap+0x3c6/0x5b0
do_syscall_64+0x49/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Make set_pmd_at() paravirt aware by just letting it use set_pmd().
Fixes: 2c91bd4a4e2e53 ("mm: speed up mremap by 20x on large regions")
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Cc: sstabellini@kernel.org
Cc: hpa@zytor.com
Cc: bp@alien8.de
Cc: torvalds@linux-foundation.org
Link: https://lkml.kernel.org/r/20190210074056.11842-1-jgross@suse.com
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The listed maintainer has not been responding to emails for a while.
Add myself as a second maintainer.
Add the platform data include file, which was not listed.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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As the prototype has been defined in "include/linux/blk-mq.h", the one
in "block/blk-mq.h" can be removed then.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This is to catch any unexpected negative value of inflight IO counter.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Our test reported the following stack, and vmcore showed that
->inflight counter is -1.
[ffffc9003fcc38d0] __schedule at ffffffff8173d95d
[ffffc9003fcc3958] schedule at ffffffff8173de26
[ffffc9003fcc3970] io_schedule at ffffffff810bb6b6
[ffffc9003fcc3988] blkcg_iolatency_throttle at ffffffff813911cb
[ffffc9003fcc3a20] rq_qos_throttle at ffffffff813847f3
[ffffc9003fcc3a48] blk_mq_make_request at ffffffff8137468a
[ffffc9003fcc3b08] generic_make_request at ffffffff81368b49
[ffffc9003fcc3b68] submit_bio at ffffffff81368d7d
[ffffc9003fcc3bb8] ext4_io_submit at ffffffffa031be00 [ext4]
[ffffc9003fcc3c00] ext4_writepages at ffffffffa03163de [ext4]
[ffffc9003fcc3d68] do_writepages at ffffffff811c49ae
[ffffc9003fcc3d78] __filemap_fdatawrite_range at ffffffff811b6188
[ffffc9003fcc3e30] filemap_write_and_wait_range at ffffffff811b6301
[ffffc9003fcc3e60] ext4_sync_file at ffffffffa030cee8 [ext4]
[ffffc9003fcc3ea8] vfs_fsync_range at ffffffff8128594b
[ffffc9003fcc3ee8] do_fsync at ffffffff81285abd
[ffffc9003fcc3f18] sys_fsync at ffffffff81285d50
[ffffc9003fcc3f28] do_syscall_64 at ffffffff81003c04
[ffffc9003fcc3f50] entry_SYSCALL_64_after_swapgs at ffffffff81742b8e
The ->inflight counter may be negative (-1) if
1) blk-iolatency was disabled when the IO was issued,
2) blk-iolatency was enabled before this IO reached its endio,
3) the ->inflight counter is decreased from 0 to -1 in endio()
In fact the hang can be easily reproduced by the below script,
H=/sys/fs/cgroup/unified/
P=/sys/fs/cgroup/unified/test
echo "+io" > $H/cgroup.subtree_control
mkdir -p $P
echo $$ > $P/cgroup.procs
xfs_io -f -d -c "pwrite 0 4k" /dev/sdg
echo "`cat /sys/block/sdg/dev` target=1000000" > $P/io.latency
xfs_io -f -d -c "pwrite 0 4k" /dev/sdg
This fixes the problem by freezing the queue so that while
enabling/disabling iolatency, there is no inflight rq running.
Note that quiesce_queue is not needed as this only updating iolatency
configuration about which dispatching request_queue doesn't care.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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In the linux kernel MAINTAINERS file, largely
"xen-devel@lists.xenproject.org (moderated for non-subscribers)"
is used to refer to the xen-devel mailing list.
The DRM DRIVERS FOR XEN section entry mentions
xen-devel@lists.xen.org instead, but that is just the same
mailing list as the mailing list above.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
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The recent commit fe0937b24ff5 ("x86/mm/cpa: Fold cpa_flush_range() and
cpa_flush_array() into a single cpa_flush() function") accidentally made
the call to make_addr_canonical_again() go away, which breaks
set_mce_nospec().
Re-instate the call to convert the address back into canonical form right
before invoking either CLFLUSH or INVLPG. Rename the function while at it
to be shorter (and less MAGA).
Fixes: fe0937b24ff5 ("x86/mm/cpa: Fold cpa_flush_range() and cpa_flush_array() into a single cpa_flush() function")
Reported-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lkml.kernel.org/r/20190208120859.GH32511@hirez.programming.kicks-ass.net
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commit 56222b212e8e ("futex: Drop hb->lock before enqueueing on the
rtmutex") changed the locking rules in the futex code so that the hash
bucket lock is not longer held while the waiter is enqueued into the
rtmutex wait list. This made the lock and the unlock path symmetric, but
unfortunately the possible early exit from __rt_mutex_proxy_start() due to
a detected deadlock was not updated accordingly. That allows a concurrent
unlocker to observe inconsitent state which triggers the warning in the
unlock path.
futex_lock_pi() futex_unlock_pi()
lock(hb->lock)
queue(hb_waiter) lock(hb->lock)
lock(rtmutex->wait_lock)
unlock(hb->lock)
// acquired hb->lock
hb_waiter = futex_top_waiter()
lock(rtmutex->wait_lock)
__rt_mutex_proxy_start()
---> fail
remove(rtmutex_waiter);
---> returns -EDEADLOCK
unlock(rtmutex->wait_lock)
// acquired wait_lock
wake_futex_pi()
rt_mutex_next_owner()
--> returns NULL
--> WARN
lock(hb->lock)
unqueue(hb_waiter)
The problem is caused by the remove(rtmutex_waiter) in the failure case of
__rt_mutex_proxy_start() as this lets the unlocker observe a waiter in the
hash bucket but no waiter on the rtmutex, i.e. inconsistent state.
The original commit handles this correctly for the other early return cases
(timeout, signal) by delaying the removal of the rtmutex waiter until the
returning task reacquired the hash bucket lock.
Treat the failure case of __rt_mutex_proxy_start() in the same way and let
the existing cleanup code handle the eventual handover of the rtmutex
gracefully. The regular rt_mutex_proxy_start() gains the rtmutex waiter
removal for the failure case, so that the other callsites are still
operating correctly.
Add proper comments to the code so all these details are fully documented.
Thanks to Peter for helping with the analysis and writing the really
valuable code comments.
Fixes: 56222b212e8e ("futex: Drop hb->lock before enqueueing on the rtmutex")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Stefan Liebler <stli@linux.ibm.com>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1901292311410.1950@nanos.tec.linutronix.de
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The current comment for the barrier that guarantees that waiter increment
is always before taking the hb spinlock (barrier (A)) needs to be fixed as
it is misplaced.
This is obviously referring to hb_waiters_inc, which is a full barrier.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190206185602.949-1-dave@stgolabs.net
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Fixes the issues with non BCM58XX chips in the b53 driver
failing, when the irq is not specified in the device tree.
Removed the check for BCM58XX in b53_srab_prepare_irq(),
so the 'port->irq' will be set to '-EXIO' if the irq is not
specified in the device tree.
Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Fixes: b2ddc48a81b5 ("net: dsa: b53: Do not fail when IRQ are not initialized")
Signed-off-by: Arun Parameswaran <arun.parameswaran@broadcom.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently, blktrace will not show requests that don't have any data as
rq->__sector is initialized to -1 which is out of device range and thus
discarded by act_log_check(). This is most notably the case for cache
flush requests sent to the device. Fix the problem by making
blk_rq_trace_sector() return 0 for requests without initialized sector.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Accordingly to the documentation
---cut---
The GCR_ERROR_CAUSE.ERR_TYPE field and the GCR_ERROR_MULT.ERR_TYPE
fields can be cleared by either a reset or by writing the current
value of GCR_ERROR_CAUSE.ERR_TYPE to the
GCR_ERROR_CAUSE.ERR_TYPE register.
---cut---
Do exactly this. Original value of cm_error may be safely written back;
it clears error cause and keeps other bits untouched.
Fixes: 3885c2b463f6 ("MIPS: CM: Add support for reporting CM cache errors")
Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@linux.intel.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v4.3+
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On my Yeeloong 8089, I noticed the machine fails to shutdown
properly, and often, the function mach_prepare_reboot() is
unexpectedly executed, thus the machine reboots instead. A
wait loop is needed to ensure the system is in a well-defined
state before going down.
In commit 997e93d4df16 ("MIPS: Hang more efficiently on
halt/powerdown/restart"), a general superset of the wait loop for all
platforms is already provided, so we don't need to implement our own.
This commit simply removes the unreachable() compiler marco after
mach_prepare_reboot(), thus allowing the execution of machine_hang().
My test shows that the machine is now able to shutdown successfully.
Please note that there are two different bugs preventing the machine
from shutting down, another work-in-progress commit is needed to
fix a lockup in cpufreq / i8259 driver, please read Reference, this
commit does not fix that bug.
Reference: https://lkml.org/lkml/2019/2/5/908
Signed-off-by: Yifeng Li <tomli@tomli.me>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org # v4.17+
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If we disabled IPv6 from the kernel command line (ipv6.disable=1), we should
not call ip6_err_gen_icmpv6_unreach(). This:
ip link add sit1 type sit local 192.0.2.1 remote 192.0.2.2 ttl 1
ip link set sit1 up
ip addr add 198.51.100.1/24 dev sit1
ping 198.51.100.2
if IPv6 is disabled at boot time, will crash the kernel.
v2: there's no need to use in6_dev_get(), use __in6_dev_get() instead,
as we only need to check that idev exists and we are under
rcu_read_lock() (from netif_receive_skb_internal()).
Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: ca15a078bd90 ("sit: generate icmpv6 error when receiving icmpv4 error")
Cc: Oussama Ghorbel <ghorbel@pivasoftware.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When we add a new GENEVE device with IPv6 remote, checking only for
IS_ENABLED(CONFIG_IPV6) is not enough as we may disable IPv6 in the
kernel command line (ipv6.disable=1), and calling rt6_lookup() would
cause a NULL pointer dereference.
v2:
- don't mix declarations and code (reported by Stefano Brivio, Eric Dumazet)
- there's no need to use in6_dev_get() as we only need to check that
idev exists (reported by David Ahern). This is under RTNL, so we can
simply use __in6_dev_get() instead (Stefano, Eric).
Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: c40e89fd358e9 ("geneve: configure MTU based on a lower device")
Cc: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Bugzilla: 1671904
There are multiple code paths where an hrtimer may have been started to
emulate an L1 VMX preemption timer that can result in a call to free_nested
without an intervening L2 exit where the hrtimer is normally
cancelled. Unconditionally cancel in free_nested to cover all cases.
Embargoed until Feb 7th 2019.
Signed-off-by: Peter Shier <pshier@google.com>
Reported-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Cc: stable@kernel.org
Message-Id: <20181011184646.154065-1-pshier@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Bugzilla: 1671930
Emulation of certain instructions (VMXON, VMCLEAR, VMPTRLD, VMWRITE with
memory operand, INVEPT, INVVPID) can incorrectly inject a page fault
when passed an operand that points to an MMIO address. The page fault
will use uninitialized kernel stack memory as the CR2 and error code.
The right behavior would be to abort the VM with a KVM_EXIT_INTERNAL_ERROR
exit to userspace; however, it is not an easy fix, so for now just
ensure that the error code and CR2 are zero.
Embargoed until Feb 7th 2019.
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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kvm_ioctl_create_device() does the following:
1. creates a device that holds a reference to the VM object (with a borrowed
reference, the VM's refcount has not been bumped yet)
2. initializes the device
3. transfers the reference to the device to the caller's file descriptor table
4. calls kvm_get_kvm() to turn the borrowed reference to the VM into a real
reference
The ownership transfer in step 3 must not happen before the reference to the VM
becomes a proper, non-borrowed reference, which only happens in step 4.
After step 3, an attacker can close the file descriptor and drop the borrowed
reference, which can cause the refcount of the kvm object to drop to zero.
This means that we need to grab a reference for the device before
anon_inode_getfd(), otherwise the VM can disappear from under us.
Fixes: 852b6d57dc7f ("kvm: add device control API")
Cc: stable@kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Recently syzkaller was able to create unkillablle processes by
creating a timer that is delivered as a thread local signal on SIGHUP,
and receiving SIGHUP SA_NODEFERER. Ultimately causing a loop failing
to deliver SIGHUP but always trying.
When the stack overflows delivery of SIGHUP fails and force_sigsegv is
called. Unfortunately because SIGSEGV is numerically higher than
SIGHUP next_signal tries again to deliver a SIGHUP.
From a quality of implementation standpoint attempting to deliver the
timer SIGHUP signal is wrong. We should attempt to deliver the
synchronous SIGSEGV signal we just forced.
We can make that happening in a fairly straight forward manner by
instead of just looking at the signal number we also look at the
si_code. In particular for exceptions (aka synchronous signals) the
si_code is always greater than 0.
That still has the potential to pick up a number of asynchronous
signals as in a few cases the same si_codes that are used
for synchronous signals are also used for asynchronous signals,
and SI_KERNEL is also included in the list of possible si_codes.
Still the heuristic is much better and timer signals are definitely
excluded. Which is enough to prevent all known ways for someone
sending a process signals fast enough to cause unexpected and
arguably incorrect behavior.
Cc: stable@vger.kernel.org
Fixes: a27341cd5fcb ("Prioritize synchronous signals over 'normal' signals")
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Recently syzkaller was able to create unkillablle processes by
creating a timer that is delivered as a thread local signal on SIGHUP,
and receiving SIGHUP SA_NODEFERER. Ultimately causing a loop
failing to deliver SIGHUP but always trying.
Upon examination it turns out part of the problem is actually most of
the solution. Since 2.5 signal delivery has found all fatal signals,
marked the signal group for death, and queued SIGKILL in every threads
thread queue relying on signal->group_exit_code to preserve the
information of which was the actual fatal signal.
The conversion of all fatal signals to SIGKILL results in the
synchronous signal heuristic in next_signal kicking in and preferring
SIGHUP to SIGKILL. Which is especially problematic as all
fatal signals have already been transformed into SIGKILL.
Instead of dequeueing signals and depending upon SIGKILL to
be the first signal dequeued, first test if the signal group
has already been marked for death. This guarantees that
nothing in the signal queue can prevent a process that needs
to exit from exiting.
Cc: stable@vger.kernel.org
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Ref: ebf5ebe31d2c ("[PATCH] signal-fixes-2.5.59-A4")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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There was a divergence between Linux and ACPICA on the definition of
ACPI_DEBUG_DEFAULT. This divergence was solved by taking ACPICA's
definition in 4c1379d7bb42. After resolving the divergence, it was
clear that Linux users wanted to use their old set of debug flags.
This change fixes the divergence by setting these debug flags during
acpi_early_init() rather than during global variable initialization
in acpixf.h (owned by ACPICA).
Fixes: 4c1379d7bb42 ("ACPICA: Debug output: Add option to display method/object evaluation")
Reported-by: Michael J Ruhl <michael.j.ruhl@intel.com>
Reported-by: Alex Gagniuc <Alex_Gagniuc@Dellteam.com>
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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8c56df372bc1 ("net: add support for Cavium PTP coprocessor") added the
Cavium PTP coprocessor driver and enabled it by default. Remove the
"default y" because the driver only applies to Cavium ThunderX processors.
Fixes: 8c56df372bc1 ("net: add support for Cavium PTP coprocessor")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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dev_consume_skb_irq() should be called in sbdma_tx_process() when
skb xmit done. It makes drop profiles(dropwatch, perf) more
friendly.
Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
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dev_consume_skb_irq() should be called in velocity_free_tx_buf()
when skb xmit done. It makes drop profiles(dropwatch, perf) more
friendly.
Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
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dev_consume_skb_irq() should be called in bdx_tx_cleanup() when skb
xmit done. It makes drop profiles(dropwatch, perf) more friendly.
Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
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