commit b383a42ca5 upstream.
INVALL CMD specifies that the ITS must ensure any caching associated with
the interrupt collection defined by ICID is consistent with the LPI
configuration tables held in memory for all Redistributors. SYNC is
required to ensure that INVALL is executed.
Currently, LPI configuration data may be inconsistent with that in the
memory within a short period of time after the INVALL command is executed.
Signed-off-by: Wudi Wang <wangwudi@hisilicon.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Fixes: cc2d3216f5 ("irqchip: GICv3: ITS command queue")
Link: https://lore.kernel.org/r/20211208015429.5007-1-zhangshaokun@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d0a553502e upstream.
irq-armada-370-xp driver already sets MSI_FLAG_MULTI_PCI_MSI flag into
msi_domain_info structure. But allocated interrupt numbers for Multi-MSI
needs to be properly aligned otherwise devices send MSI interrupt with
wrong number.
Fix this issue by using function bitmap_find_free_region() instead of
bitmap_find_next_zero_area() to allocate aligned interrupt numbers.
Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: a71b9412c9 ("irqchip/armada-370-xp: Allow allocation of multiple MSIs")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211125130057.26705-2-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67fe29583e upstream.
IIO trigger handlers must call iio_trigger_notify_done() when done. This
must be done even when an error occurred. Otherwise the trigger will be
seen as busy indefinitely and the trigger handler will never be called
again.
The itg3200 driver neglects to call iio_trigger_notify_done() when there is
an error reading the gyro data. Fix this by making sure that
iio_trigger_notify_done() is included in the error exit path.
Fixes: 9dbf091da0 ("iio: gyro: Add itg3200")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211101144055.13858-1-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 45febe0d63 upstream.
IIO trigger handlers need to return one of the irqreturn_t values.
Returning an error code is not supported.
The kxsd9 interrupt handler returns an error code if reading the data
registers fails. In addition when exiting due to an error the trigger
handler does not call `iio_trigger_notify_done()`. Which when not done
keeps the triggered disabled forever.
Modify the code so that the function returns a valid irqreturn_t value as
well as calling `iio_trigger_notify_done()` on all exit paths.
Since we can't return the error code make sure to at least log it as part
of the error message.
Fixes: 0427a106a9 ("iio: accel: kxsd9: Add triggered buffer handling")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20211024171251.22896-2-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef9d67fa72 upstream.
IIO trigger handlers need to return one of the irqreturn_t values.
Returning an error code is not supported.
The ltr501 interrupt handler gets this right for most error paths, but
there is one case where it returns the error code.
In addition for this particular case the trigger handler does not call
`iio_trigger_notify_done()`. Which when not done keeps the triggered
disabled forever.
Modify the code so that the function returns a valid irqreturn_t value as
well as calling `iio_trigger_notify_done()` on all exit paths.
Fixes: 2690be9051 ("iio: Add Lite-On ltr501 ambient light / proximity sensor driver")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211024171251.22896-1-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cd00822357 upstream.
The mma8452 driver directly assigns a trigger to the struct iio_dev. The
IIO core when done using this trigger will call `iio_trigger_put()` to drop
the reference count by 1.
Without the matching `iio_trigger_get()` in the driver the reference count
can reach 0 too early, the trigger gets freed while still in use and a
use-after-free occurs.
Fix this by getting a reference to the trigger before assigning it to the
IIO device.
Fixes: ae6d9ce056 ("iio: mma8452: Add support for interrupt driven triggers.")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211024092700.6844-1-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 86ebbc11bb upstream.
Under some conditions, USB gadget devices can show allocated buffer
contents to a host. Fix this up by zero-allocating them so that any
extra data will all just be zeros.
Reported-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Tested-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 153a2d7e33 upstream.
Sometimes USB hosts can ask for buffers that are too large from endpoint
0, which should not be allowed. If this happens for OUT requests, stall
the endpoint, but for IN requests, trim the request size to the endpoint
buffer size.
Co-developed-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d17b9737c2 upstream.
The ql_wait_for_drvr_lock() fails and returns false, then this
function should return an error code instead of returning success.
The other problem is that the success path prints an error message
netdev_err(ndev, "Releasing driver lock\n"); Delete that and
re-order the code a little to make it more clear.
Fixes: 5a4faa8737 ("[PATCH] qla3xxx NIC driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211207082416.GA16110@kili
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5bd95d171 upstream.
Background:
We have a customer is running a Profinet stack on the 8MM which receives and
responds PNIO packets every 4ms and PNIO-CM packets every 40ms. However, from
time to time the received PNIO-CM package is "stock" and is only handled when
receiving a new PNIO-CM or DCERPC-Ping packet (tcpdump shows the PNIO-CM and
the DCERPC-Ping packet at the same time but the PNIO-CM HW timestamp is from
the expected 40 ms and not the 2s delay of the DCERPC-Ping).
After debugging, we noticed PNIO, PNIO-CM and DCERPC-Ping packets would
be handled by different RX queues.
The root cause should be driver ack all queues' interrupt when handle a
specific queue in fec_enet_rx_queue(). The blamed patch is introduced to
receive as much packets as possible once to avoid interrupt flooding.
But it's unreasonable to clear other queues'interrupt when handling one
queue, this patch tries to fix it.
Fixes: ed63f1dcd5 (net: fec: clear receive interrupts before processing a packet)
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Reported-by: Nicolas Diaz <nicolas.diaz@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20211206135457.15946-1-qiangqing.zhang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit badd7857f5 upstream.
There are two error paths which accidentally return success instead of
a negative error code.
Fixes: bbd2190ce9 ("Altera TSE: Add main and header file for Altera Ethernet Driver")
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 2be6d4d16a upstream.
Currently, due to the sequential use of min_t() and clamp_t() macros,
in cdc_ncm_check_tx_max(), if dwNtbOutMaxSize is not set, the logic
sets tx_max to 0. This is then used to allocate the data area of the
SKB requested later in cdc_ncm_fill_tx_frame().
This does not cause an issue presently because when memory is
allocated during initialisation phase of SKB creation, more memory
(512b) is allocated than is required for the SKB headers alone (320b),
leaving some space (512b - 320b = 192b) for CDC data (172b).
However, if more elements (for example 3 x u64 = [24b]) were added to
one of the SKB header structs, say 'struct skb_shared_info',
increasing its original size (320b [320b aligned]) to something larger
(344b [384b aligned]), then suddenly the CDC data (172b) no longer
fits in the spare SKB data area (512b - 384b = 128b).
Consequently the SKB bounds checking semantics fails and panics:
skbuff: skb_over_panic: text:ffffffff830a5b5f len:184 put:172 \
head:ffff888119227c00 data:ffff888119227c00 tail:0xb8 end:0x80 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:110!
RIP: 0010:skb_panic+0x14f/0x160 net/core/skbuff.c:106
<snip>
Call Trace:
<IRQ>
skb_over_panic+0x2c/0x30 net/core/skbuff.c:115
skb_put+0x205/0x210 net/core/skbuff.c:1877
skb_put_zero include/linux/skbuff.h:2270 [inline]
cdc_ncm_ndp16 drivers/net/usb/cdc_ncm.c:1116 [inline]
cdc_ncm_fill_tx_frame+0x127f/0x3d50 drivers/net/usb/cdc_ncm.c:1293
cdc_ncm_tx_fixup+0x98/0xf0 drivers/net/usb/cdc_ncm.c:1514
By overriding the max value with the default CDC_NCM_NTB_MAX_SIZE_TX
when not offered through the system provided params, we ensure enough
data space is allocated to handle the CDC data, meaning no crash will
occur.
Cc: Oliver Neukum <oliver@neukum.org>
Fixes: 289507d336 ("net: cdc_ncm: use sysfs for rx/tx aggregation tuning")
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Bjørn Mork <bjorn@mork.no>
Link: https://lore.kernel.org/r/20211202143437.1411410-1-lee.jones@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 48b27b6b51 upstream.
As people have been asking to allow non-root processes to have access to
the tracefs directory, it was considered best to only allow groups to have
access to the directory, where it is easier to just set the tracefs file
system to a specific group (as other would be too dangerous), and that way
the admins could pick which processes would have access to tracefs.
Unfortunately, this broke tooling on Android that expected the other bit
to be set. For some special cases, for non-root tools to trace the system,
tracefs would be mounted and change the permissions of the top level
directory which gave access to all running tasks permission to the
tracing directory. Even though this would be dangerous to do in a
production environment, for testing environments this can be useful.
Now with the new changes to not allow other (which is still the proper
thing to do), it breaks the testing tooling. Now more code needs to be
loaded on the system to change ownership of the tracing directory.
The real solution is to have tracefs honor the gid=xxx option when
mounting. That is,
(tracing group tracing has value 1003)
mount -t tracefs -o gid=1003 tracefs /sys/kernel/tracing
should have it that all files in the tracing directory should be of the
given group.
Copy the logic from d_walk() from dcache.c and simplify it for the mount
case of tracefs if gid is set. All the files in tracefs will be walked and
their group will be set to the value passed in.
Link: https://lkml.kernel.org/r/20211207171729.2a54e1b3@gandalf.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Kalesh Singh <kaleshsingh@google.com>
Reported-by: Yabin Cui <yabinc@google.com>
Fixes: 49d67e4457 ("tracefs: Have tracefs directories not set OTH permission bits by default")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 42288cb44c upstream.
Several ->poll() implementations are special in that they use a
waitqueue whose lifetime is the current task, rather than the struct
file as is normally the case. This is okay for blocking polls, since a
blocking poll occurs within one task; however, non-blocking polls
require another solution. This solution is for the queue to be cleared
before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'.
However, that has a bug: wake_up_poll() calls __wake_up() with
nr_exclusive=1. Therefore, if there are multiple "exclusive" waiters,
and the wakeup function for the first one returns a positive value, only
that one will be called. That's *not* what's needed for POLLFREE;
POLLFREE is special in that it really needs to wake up everyone.
Considering the three non-blocking poll systems:
- io_uring poll doesn't handle POLLFREE at all, so it is broken anyway.
- aio poll is unaffected, since it doesn't support exclusive waits.
However, that's fragile, as someone could add this feature later.
- epoll doesn't appear to be broken by this, since its wakeup function
returns 0 when it sees POLLFREE. But this is fragile.
Although there is a workaround (see epoll), it's better to define a
function which always sends POLLFREE to all waiters. Add such a
function. Also make it verify that the queue really becomes empty after
all waiters have been woken up.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a66307d473 upstream.
The ASMedia 1092 has a configuration mode which will present a
dummy device; sadly the implementation falsely claims to provide
a device with 100M which doesn't actually exist.
So disable this device to avoid errors during boot.
Cc: stable@vger.kernel.org
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b6409dd6bd upstream.
When control_compat.c:copy_ctl_value_to_user() is used, by
ctl_elem_read_user() & ctl_elem_write_user(), it must also copy back the
snd_ctl_elem_id value that may have been updated (filled in) by the call
to snd_ctl_elem_read/snd_ctl_elem_write().
This matches the functionality provided by snd_ctl_elem_read_user() and
snd_ctl_elem_write_user(), via snd_ctl_build_ioff().
Without this, and without making additional calls to snd_ctl_info()
which are unnecessary when using the non-compat calls, a userspace
application will not know the numid value for the element and
consequently will not be able to use the poll/read interface on the
control file to determine which elements have updates.
Signed-off-by: Alan Young <consult.awy@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211202150607.543389-1-consult.awy@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fc2237a724 upstream.
Although HID itself is transport-agnostic, occasionally a driver may
want to interact with the low-level transport that a device is connected
through. To do this, we need to know what kind of bus is in use. The
first guess may be to look at the 'bus' field of the 'struct hid_device',
but this field may be emulated in some cases (e.g. uhid).
More ideally, we can check which ll_driver a device is using. This
function introduces a 'hid_is_using_ll_driver' function and makes the
'struct hid_ll_driver' of the four most common transports accessible
through hid.h.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00de977f9e upstream.
Commit 761ed4a945 ("tty: serial_core: convert uart_close to use
tty_port_close") converted serial core to use tty_port_close() but
failed to notice that the transmit buffer still needs to be freed on
final close.
Not freeing the transmit buffer means that the buffer is no longer
cleared on next open so that any ioctl() waiting for the buffer to drain
might wait indefinitely (e.g. on termios changes) or that stale data can
end up being transmitted in case tx is restarted.
Furthermore, the buffer of any port that has been opened would leak on
driver unbind.
Note that the port lock is held when clearing the buffer pointer due to
the ldisc race worked around by commit a5ba1d95e4 ("uart: fix race
between uart_put_char() and uart_shutdown()").
Also note that the tty-port shutdown() callback is not called for
console ports so it is not strictly necessary to free the buffer page
after releasing the lock (cf. d72402145a ("tty/serial: do not free
trasnmit buffer page under port lock")).
Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il
Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Cc: stable@vger.kernel.org # 4.9
Cc: Rob Herring <robh@kernel.org>
Reported-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ac442a077a upstream.
The document 'ACPI for Arm Components 1.0' defines the following
_HID mappings:
-'Prime cell UART (PL011)': ARMH0011
-'SBSA UART': ARMHB000
Use the sbsa-uart driver when a device is described with
the 'ARMHB000' _HID.
Note:
PL011 devices currently use the sbsa-uart driver instead of the
uart-pl011 driver. Indeed, PL011 devices are not bound to a clock
in ACPI. It is not possible to change their baudrate.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Link: https://lore.kernel.org/r/20211109172248.19061-1-Pierre.Gondois@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7492ffc90f upstream.
The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of
setup, it is often sharing a serial device with the normal system console.
This is usually no problem because the polling helpers can consume input
values directly (when in kgdb context) and the normal Linux handlers can
only consume new input values after kgdb switched back.
This is not true anymore when RX DMA is enabled for UARTDM controllers.
Single input values can no longer be received correctly. Instead following
seems to happen:
* on 1. input, some old input is read (continuously)
* on 2. input, two old inputs are read (continuously)
* on 3. input, three old input values are read (continuously)
* on 4. input, 4 previous inputs are received
This repeats then for each group of 4 input values.
This behavior changes slightly depending on what state the controller was
when the first input was received. But this makes working with kgdb
basically impossible because control messages are always corrupted when
kgdboc tries to parse them.
RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid
these kind of problems. No such problem was noticed for TX DMA.
Fixes: 9969394501 ("tty: serial: msm: Add RX DMA support")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3dfac26e2e upstream.
Fix a division by zero in `vgacon_resize' with a backtrace like:
vgacon_resize
vc_do_resize
vgacon_init
do_bind_con_driver
do_unbind_con_driver
fbcon_fb_unbind
do_unregister_framebuffer
do_register_framebuffer
register_framebuffer
__drm_fb_helper_initial_config_and_unlock
drm_helper_hpd_irq_event
dw_hdmi_irq
irq_thread
kthread
caused by `c->vc_cell_height' not having been initialized. This has
only started to trigger with commit 860dafa902 ("vt: Fix character
height handling with VT_RESIZEX"), however the ultimate offender is
commit 50ec42edd9 ("[PATCH] Detaching fbcon: fix vgacon to allow
retaking of the console").
Said commit has added a call to `vc_resize' whenever `vgacon_init' is
called with the `init' argument set to 0, which did not happen before.
And the call is made before a key vgacon boot parameter retrieved in
`vgacon_startup' has been propagated in `vgacon_init' for `vc_resize' to
use to the console structure being worked on. Previously the parameter
was `c->vc_font.height' and now it is `c->vc_cell_height'.
In this particular scenario the registration of fbcon has failed and vt
resorts to vgacon. Now fbcon does have initialized `c->vc_font.height'
somehow, unlike `c->vc_cell_height', which is why this code did not
crash before, but either way the boot parameters should have been copied
to the console structure ahead of the call to `vc_resize' rather than
afterwards, so that first the call has a chance to use them and second
they do not change the console structure to something possibly different
from what was used by `vc_resize'.
Move the propagation of the vgacon boot parameters ahead of the call to
`vc_resize' then. Adjust the comment accordingly.
Fixes: 50ec42edd9 ("[PATCH] Detaching fbcon: fix vgacon to allow retaking of the console")
Cc: stable@vger.kernel.org # v2.6.18+
Reported-by: Wim Osterholt <wim@djo.tudelft.nl>
Reported-by: Pavel V. Panteleev <panteleev_p@mcst.ru>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2110252317110.58149@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0f9fee4cde upstream.
On newer debian releases the debian-provided "installkernel" script is
installed in /usr/sbin. Fix the kernel install.sh script to look for the
script in this directory as well.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 19f36edf14 upstream.
Correct an error where setting /proc/sys/net/rds/tcp/rds_tcp_rcvbuf would
instead modify the socket's sk_sndbuf and would leave sk_rcvbuf untouched.
Fixes: c6a58ffed5 ("RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket")
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f7e5b9bfa6 upstream.
On ARM v6 and later, we define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
because the ordinary load/store instructions (ldr, ldrh, ldrb) can
tolerate any misalignment of the memory address. However, load/store
double and load/store multiple instructions (ldrd, ldm) may still only
be used on memory addresses that are 32-bit aligned, and so we have to
use the CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS macro with care, or we
may end up with a severe performance hit due to alignment traps that
require fixups by the kernel. Testing shows that this currently happens
with clang-13 but not gcc-11. In theory, any compiler version can
produce this bug or other problems, as we are dealing with undefined
behavior in C99 even on architectures that support this in hardware,
see also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363.
Fortunately, the get_unaligned() accessors do the right thing: when
building for ARMv6 or later, the compiler will emit unaligned accesses
using the ordinary load/store instructions (but avoid the ones that
require 32-bit alignment). When building for older ARM, those accessors
will emit the appropriate sequence of ldrb/mov/orr instructions. And on
architectures that can truly tolerate any kind of misalignment, the
get_unaligned() accessors resolve to the leXX_to_cpup accessors that
operate on aligned addresses.
Since the compiler will in fact emit ldrd or ldm instructions when
building this code for ARM v6 or later, the solution is to use the
unaligned accessors unconditionally on architectures where this is
known to be fast. The _aligned version of the hash function is
however still needed to get the best performance on architectures
that cannot do any unaligned access in hardware.
This new version avoids the undefined behavior and should produce
the fastest hash on all architectures we support.
Link: https://lore.kernel.org/linux-arm-kernel/20181008211554.5355-4-ard.biesheuvel@linaro.org/
Link: https://lore.kernel.org/linux-crypto/CAK8P3a2KfmmGDbVHULWevB0hv71P2oi2ZCHEAqT=8dQfa0=cqQ@mail.gmail.com/
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Fixes: 2c956a6077 ("siphash: add cryptographically secure PRF")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
