commit 48e8ac2979 upstream.
With recent changes it is possible for the timer handler to detect an
idle interface and not start the timer, but the thread to start an
operation at the same time. The thread will not start the timer in that
instance, resulting in the timer not running.
Instead, move all timer operations under the lock and start the timer in
the thread if it detect non-idle and the timer is not already running.
Moving under locks allows the last timeout to be set in both the thread
and the timer. 'Timer is not running' means that the timer is not
pending and smi_timeout() is not running. So we need a flag to detect
this correctly.
Also fix a few other timeout bugs: setting the last timeout when the
interrupt has to be disabled and the timer started, and setting the last
timeout in check_start_timer_thread possibly racing with the timer
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a94cdd1f4d upstream.
In read_all_bytes, we do
unsigned char i;
...
bt->read_data[0] = BMC2HOST;
bt->read_count = bt->read_data[0];
...
for (i = 1; i <= bt->read_count; i++)
bt->read_data[i] = BMC2HOST;
If bt->read_data[0] == bt->read_count == 255, we loop infinitely in the
'for' loop. Make 'i' an 'int' instead of 'char' to get rid of the
overflow and finish the loop after 255 iterations every time.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-and-debugged-by: Rui Hui Dian <rhdian@novell.com>
Cc: Tomas Cech <tcech@suse.cz>
Cc: Corey Minyard <minyard@acm.org>
Cc: <openipmi-developer@lists.sourceforge.net>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5bbb2ae3d6 upstream.
bind_get() checks the device number it is called with. It uses
MAX_RAW_MINORS for the upper bound. But MAX_RAW_MINORS is set at compile
time while the actual number of raw devices can be set at runtime. This
means the test can either be too strict or too lenient. And if the test
ends up being too lenient bind_get() might try to access memory beyond
what was allocated for "raw_devices".
So check against the runtime value (max_raw_minors) in this function.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 747d35bd9b upstream.
Depending on the implementation strcmp might return the difference between
two strings not only -1,0,1 consequently
if (strcmp (a,b) == -1)
might lead to taking the wrong branch
-> compare with < 0 instead,
which in any case is more canonical.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 85c5e0d451 upstream.
The 'get_burstcount' function can in some circumstances 'return -EBUSY' which
in tpm_stm_i2c_send is stored in an 'u32 burstcnt'
thus converting the signed value into an unsigned value, resulting
in 'burstcnt' being huge.
Changing the type to u32 only does not solve the problem as the signed
value is converted to an unsigned in I2C_WRITE_DATA, resulting in the
same effect.
Thus
-> Change type of burstcnt to u32 (the return type of get_burstcount)
-> Add a check for the return value of 'get_burstcount' and propagate a
potential error.
This makes also sense in the 'I2C_READ_DATA' case, where the there is no
signed/unsigned conversion.
found by coverity
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit df45c712d1 upstream.
In function ppi_callback(), memory allocated by acpi_get_name() will get
leaked when current device isn't the desired TPM device, so fix the
memory leak.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 47d06e532e upstream.
The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason. So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 96f97a8391 upstream.
If a port gets unplugged while a user is blocked on read(), -ENODEV is
returned. However, subsequent read()s returned 0, indicating there's no
host-side connection (but not indicating the device went away).
This also happened when a port was unplugged and the user didn't have
any blocking operation pending. If the user didn't monitor the SIGIO
signal, they won't have a chance to find out if the port went away.
Fix by returning -ENODEV on all read()s after the port gets unplugged.
write() already behaves this way.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 92d3453815 upstream.
SIGIO should be sent when a port gets unplugged. It should only be sent
to prcesses that have the port opened, and have asked for SIGIO to be
delivered. We were clearing out guest_connected before calling
send_sigio_to_port(), resulting in a sigio not getting sent to
processes.
Fix by setting guest_connected to false after invoking the sigio
function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ea3768b438 upstream.
We used to keep the port's char device structs and the /sys entries
around till the last reference to the port was dropped. This is
actually unnecessary, and resulted in buggy behaviour:
1. Open port in guest
2. Hot-unplug port
3. Hot-plug a port with the same 'name' property as the unplugged one
This resulted in hot-plug being unsuccessful, as a port with the same
name already exists (even though it was unplugged).
This behaviour resulted in a warning message like this one:
-------------------8<---------------------------------------
WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted)
Hardware name: KVM
sysfs: cannot create duplicate filename
'/devices/pci0000:00/0000:00:04.0/virtio0/virtio-ports/vport0p1'
Call Trace:
[<ffffffff8106b607>] ? warn_slowpath_common+0x87/0xc0
[<ffffffff8106b6f6>] ? warn_slowpath_fmt+0x46/0x50
[<ffffffff811f2319>] ? sysfs_add_one+0xc9/0x130
[<ffffffff811f23e8>] ? create_dir+0x68/0xb0
[<ffffffff811f2469>] ? sysfs_create_dir+0x39/0x50
[<ffffffff81273129>] ? kobject_add_internal+0xb9/0x260
[<ffffffff812733d8>] ? kobject_add_varg+0x38/0x60
[<ffffffff812734b4>] ? kobject_add+0x44/0x70
[<ffffffff81349de4>] ? get_device_parent+0xf4/0x1d0
[<ffffffff8134b389>] ? device_add+0xc9/0x650
-------------------8<---------------------------------------
Instead of relying on guest applications to release all references to
the ports, we should go ahead and unregister the port from all the core
layers. Any open/read calls on the port will then just return errors,
and an unplug/plug operation on the host will succeed as expected.
This also caused buggy behaviour in case of the device removal (not just
a port): when the device was removed (which means all ports on that
device are removed automatically as well), the ports with active
users would clean up only when the last references were dropped -- and
it would be too late then to be referencing char device pointers,
resulting in oopses:
-------------------8<---------------------------------------
PID: 6162 TASK: ffff8801147ad500 CPU: 0 COMMAND: "cat"
#0 [ffff88011b9d5a90] machine_kexec at ffffffff8103232b
#1 [ffff88011b9d5af0] crash_kexec at ffffffff810b9322
#2 [ffff88011b9d5bc0] oops_end at ffffffff814f4a50
#3 [ffff88011b9d5bf0] die at ffffffff8100f26b
#4 [ffff88011b9d5c20] do_general_protection at ffffffff814f45e2
#5 [ffff88011b9d5c50] general_protection at ffffffff814f3db5
[exception RIP: strlen+2]
RIP: ffffffff81272ae2 RSP: ffff88011b9d5d00 RFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff880118901c18 RCX: 0000000000000000
RDX: ffff88011799982c RSI: 00000000000000d0 RDI: 3a303030302f3030
RBP: ffff88011b9d5d38 R8: 0000000000000006 R9: ffffffffa0134500
R10: 0000000000001000 R11: 0000000000001000 R12: ffff880117a1cc10
R13: 00000000000000d0 R14: 0000000000000017 R15: ffffffff81aff700
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#6 [ffff88011b9d5d00] kobject_get_path at ffffffff8126dc5d
#7 [ffff88011b9d5d40] kobject_uevent_env at ffffffff8126e551
#8 [ffff88011b9d5dd0] kobject_uevent at ffffffff8126e9eb
#9 [ffff88011b9d5de0] device_del at ffffffff813440c7
-------------------8<---------------------------------------
So clean up when we have all the context, and all that's left to do when
the references to the port have dropped is to free up the port struct
itself.
Reported-by: chayang <chayang@redhat.com>
Reported-by: YOGANANTH SUBRAMANIAN <anantyog@in.ibm.com>
Reported-by: FuXiangChun <xfu@redhat.com>
Reported-by: Qunfang Zhang <qzhang@redhat.com>
Reported-by: Sibiao Luo <sluo@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 671bdea2b9 upstream.
Between open() being called and processed, the port can be unplugged.
Check if this happened, and bail out.
A simple test script to reproduce this is:
while true; do for i in $(seq 1 100); do echo $i > /dev/vport0p3; done; done;
This opens and closes the port a lot of times; unplugging the port while
this is happening triggers the bug.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 057b82be3c upstream.
There's a window between find_port_by_devt() returning a port and us
taking a kref on the port, where the port could get unplugged. Fix it
by taking the reference in find_port_by_devt() itself.
Problem reported and analyzed by Mateusz Guzik.
Reported-by: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68c034fefe upstream.
Quit from splice_write if pipe->nrbufs is 0 for avoiding oops in virtio-serial.
When an application was doing splice from a kernel buffer to virtio-serial on
a guest, the application received signal(SIGINT). This situation will normally
happen, but the kernel executed a kernel panic by oops as follows:
BUG: unable to handle kernel paging request at ffff882071c8ef28
IP: [<ffffffff812de48f>] sg_init_table+0x2f/0x50
PGD 1fac067 PUD 0
Oops: 0000 [#1] SMP
Modules linked in: lockd sunrpc bnep bluetooth rfkill ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd microcode virtio_balloon virtio_net pcspkr soundcore i2c_piix4 i2c_core uinput floppy
CPU: 1 PID: 908 Comm: trace-cmd Not tainted 3.10.0+ #49
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
task: ffff880071c64650 ti: ffff88007bf24000 task.ti: ffff88007bf24000
RIP: 0010:[<ffffffff812de48f>] [<ffffffff812de48f>] sg_init_table+0x2f/0x50
RSP: 0018:ffff88007bf25dd8 EFLAGS: 00010286
RAX: 0000001fffffffe0 RBX: ffff882071c8ef28 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880071c8ef48
RBP: ffff88007bf25de8 R08: ffff88007fd15d40 R09: ffff880071c8ef48
R10: ffffea0001c71040 R11: ffffffff8139c555 R12: 0000000000000000
R13: ffff88007506a3c0 R14: ffff88007c862500 R15: ffff880071c8ef00
FS: 00007f0a3646c740(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff882071c8ef28 CR3: 000000007acbb000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff880071c8ef48 ffff88007bf25e20 ffff88007bf25e88 ffffffff8139d6fa
ffff88007bf25e28 ffffffff8127a3f4 0000000000000000 0000000000000000
ffff880071c8ef48 0000100000000000 0000000000000003 ffff88007bf25e08
Call Trace:
[<ffffffff8139d6fa>] port_fops_splice_write+0xaa/0x130
[<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120
[<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0
[<ffffffff811a6fe0>] do_splice_from+0xa0/0x110
[<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0
[<ffffffff8161f8c2>] system_call_fastpath+0x16/0x1b
Code: c1 e2 05 48 89 e5 48 83 ec 10 4c 89 65 f8 41 89 f4 31 f6 48 89 5d f0 48 89 fb e8 8d ce ff ff 41 8d 44 24 ff 48 c1 e0 05 48 01 c3 <48> 8b 03 48 83 e0 fe 48 83 c8 02 48 89 03 48 8b 5d f0 4c 8b 65
RIP [<ffffffff812de48f>] sg_init_table+0x2f/0x50
RSP <ffff88007bf25dd8>
CR2: ffff882071c8ef28
---[ end trace 86323505eb42ea8f ]---
It seems to induce pagefault in sg_init_tabel() when pipe->nrbufs is equal to
zero. This may happen in a following situation:
(1) The application normally does splice(read) from a kernel buffer, then does
splice(write) to virtio-serial.
(2) The application receives SIGINT when is doing splice(read), so splice(read)
is failed by EINTR. However, the application does not finish the operation.
(3) The application tries to do splice(write) without pipe->nrbufs.
(4) The virtio-console driver tries to touch scatterlist structure sgl in
sg_init_table(), but the region is out of bound.
To avoid the case, a kernel should check whether pipe->nrbufs is empty or not
when splice_write is executed in the virtio-console driver.
V3: Add Reviewed-by lines and stable@ line in sign-off area.
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 06f0cce43a upstream.
Allow binding of user memory to the AGP GART on systems with HP
Quicksilver AGP bus. This resolves 'bind memory failed' error seen in
dmesg:
[29.365973] [TTM] AGP Bind memory failed.
…
[29.367030] [drm] Forcing AGP to PCI mode
The system doesn't more fail to bind the memory, and hence not falling
back to the PCI mode (if other failures aren't detected).
This is just a simple write down from the following patches:
agp/amd-k7: Allow binding user memory to the AGP GART
agp/hp-agp: Allow binding user memory to the AGP GART
Signed-off-by: Alex Ivanov <gnidorah@p0n4ik.tk>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 902c098a36 ("random: use lockless techniques in the interrupt
path") turned IRQ path from being spinlock protected into lockless
cmpxchg-retry update.
That commit removed r->lock serialization between crediting entropy bits
from IRQ context and accounting when extracting entropy on userspace
read path, but didn't turn the r->entropy_count reads/updates in
account() to use cmpxchg as well.
It has been observed, that under certain circumstances this leads to
read() on /dev/urandom to return 0 (EOF), as r->entropy_count gets
corrupted and becomes negative, which in turn results in propagating 0
all the way from account() to the actual read() call.
Convert the accounting code to be the proper lockless counterpart of
what has been partially done by 902c098a36.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Greg KH <greg@kroah.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ec8f02da9e ("random: prime last_data value per fips
requirements") added priming of last_data per fips requirements.
Unfortuantely, it did so in a way that can lead to multiple threads all
incrementing nbytes, but only one actually doing anything with the extra
data, which leads to some fun random corruption and panics.
The fix is to simply do everything needed to prime last_data in a single
shot, so there's no window for multiple cpus to increment nbytes -- in
fact, we won't even increment or decrement nbytes anymore, we'll just
extract the needed EXTRACT_SIZE one time per pool and then carry on with
the normal routine.
All these changes have been tested across multiple hosts and
architectures where panics were previously encoutered. The code changes
are are strictly limited to areas only touched when when booted in fips
mode.
This change should also go into 3.8-stable, to make the myriads of fips
users on 3.8.x happy.
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Jan Stodola <jstodola@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull char/misc driver fixes from Greg Kroah-Hartman:
"Here are some small char/misc driver fixes for 3.10-rc2.
Nothing major here, just a number of fixes for things that people have
reported, and a MAINTAINERS update for the recent changes for the
hyperv files that went into 3.10-rc1."
* tag 'char-misc-3.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
ttyprintk: Fix NULL pointer deref by setting tty_port ops after initializing port
uio: UIO_DMEM_GENIRQ should depend on HAS_DMA
MAINTAINERS: update Hyper-V file list
mei: bus: Reset event_cb when disabling a device
Drivers: hv: Fix a bug in get_vp_index()
mei: fix out of array access to me clients array
Char: lp, protect LPGETSTATUS with port_mutex
dummy-irq: require the user to specify an IRQ number
tty_port_init() zeroes out the tty port, which means that we have to set the
ops pointer /after/, not before this call. Otherwise, tty_port_open will crash
when it tries to deref ops, which is now a NULL pointer.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull devm usage cleanup from Wolfram Sang:
"Lately, I have been experimenting how to improve the devm interface to
make writing device drivers easier and less error prone while also
getting rid of its subtle issues. I think it has more potential but
still needs work and definately conistency, especiall in its usage.
The first thing I come up with is a low hanging fruit regarding
devm_ioremap_resouce(). This function already checks if the passed
resource is valid and gives an error message if not. So, we can
remove similar checks from the drivers and get rid of a bit of code
and a number of inconsistent error strings.
This series only removes the unneeded check iff devm_ioremap_resource
follows platform_get_resource directly. The previous version tried to
shuffle code if needed, too, what lead to an embarrasing bug. It
turned out to me that shuffling code for all cases found will make the
automated script too complex, so I am unsure if an automated cleanup
is the proper tool for this case. Removing the easy stuff seems
worthwhile to me, though.
Despite various architectures and platform dependencies, I managed to
compile test 45 out of 57 modified files locally using heuristics and
defconfigs."
Pulled because: 296 deletions, 0 additions.
* 'devm_no_resource_check' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (33 commits)
sound/soc/kirkwood: don't check resource with devm_ioremap_resource
sound/soc/fsl: don't check resource with devm_ioremap_resource
arch/mips/lantiq/xway: don't check resource with devm_ioremap_resource
arch/arm/plat-samsung: don't check resource with devm_ioremap_resource
arch/arm/mach-tegra: don't check resource with devm_ioremap_resource
drivers/watchdog: don't check resource with devm_ioremap_resource
drivers/w1/masters: don't check resource with devm_ioremap_resource
drivers/video/omap2/dss: don't check resource with devm_ioremap_resource
drivers/video/omap2: don't check resource with devm_ioremap_resource
drivers/usb/phy: don't check resource with devm_ioremap_resource
drivers/usb/host: don't check resource with devm_ioremap_resource
drivers/usb/gadget: don't check resource with devm_ioremap_resource
drivers/usb/chipidea: don't check resource with devm_ioremap_resource
drivers/thermal: don't check resource with devm_ioremap_resource
drivers/staging/nvec: don't check resource with devm_ioremap_resource
drivers/staging/dwc2: don't check resource with devm_ioremap_resource
drivers/spi: don't check resource with devm_ioremap_resource
drivers/rtc: don't check resource with devm_ioremap_resource
drivers/pwm: don't check resource with devm_ioremap_resource
drivers/pinctrl: don't check resource with devm_ioremap_resource
...
The patch fixes a problem in the lp driver that can cause oopses as
follows:
process A: calls lp_write, which in turn calls
parport_ieee1284_write_compat, and that invokes
parport_wait_peripheral
process B: meanwhile does an ioctl(LPGETSTATUS), which call
lp_release_parport when done. This function will set
physport->cad = NULL.
process A: parport_wait_peripheral tries to dereference
physport->cad and dies
So, protect that code with the port_mutex in order to protect against
simultaneous calls to lp_read/lp_write.
Similar protection is probably required for ioctl(LPRESET)...
This patch was done by IBM a while back and we (at suse) have that
since at least 2004 in our repos. Let's make it upstream.
Signed-off-by: okir@suse.de
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a 32 bit version of ipmitool is used on a 64 bit kernel, the
ipmi_devintf code fails to correctly acquire ipmi_mutex. This results in
incomplete data being retrieved in some cases, or other possible failures.
Add a wrapper around compat_ipmi_ioctl() to take ipmi_mutex to fix this.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>