When the zoned mode is enabled in null_blk, Serializing read, write
and zone management operations for each zone is necessary to protect
device level information for managing zone resources (zone open and
closed counters) as well as each zone condition and write pointer
position. Commit 35bc10b2eafb ("null_blk: synchronization fix for
zoned device") introduced a spinlock to implement this serialization.
However, when memory backing is also enabled, GFP_NOIO memory
allocations are executed under the spinlock, resulting in might_sleep()
warnings. Furthermore, the zone_lock spinlock is locked/unlocked using
spin_lock_irq/spin_unlock_irq, similarly to the memory backing code with
the nullb->lock spinlock. This nested use of irq locks wrecks the irq
enabled/disabled state.
Fix all this by introducing a bitmap for per-zone lock, with locking
implemented using wait_on_bit_lock_io() and clear_and_wake_up_bit().
This locking mechanism allows keeping a zone locked while executing
null_process_cmd(), serializing all operations to the zone while
allowing to sleep during memory backing allocation with GFP_NOIO.
Device level zone resource management information is protected using
a spinlock which is not held while executing null_process_cmd();
Fixes: 35bc10b2eafb ("null_blk: synchronization fix for zoned device") Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the cae of the REQ_OP_ZONE_RESET_ALL operation, the command sector is
ignored and the operation is applied to all sequential zones. For these
commands, tracing the effect of the command using the command sector to
determine the target zone is thus incorrect.
Fix null_zone_mgmt() zone condition tracing in the case of
REQ_OP_ZONE_RESET_ALL to apply tracing to all sequential zones that are
not already empty.
Fixes: 766c3297d7e1 ("null_blk: add trace in null_blk_zoned.c") Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since sched_clock_read_begin() and sched_clock_read_retry() are called
by notrace function sched_clock(), they shouldn't be traceable either,
or else ftrace_graph_caller will run into a dead loop on the path
as below (arm for instance):
Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow: 17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
timespec64_to_ns include/linux/time64.h:127 [inline]
set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
__x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295
Commit bd40a175769d ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.
Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.
[ tglx: Added comment and adjusted the fixes tag ]
Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64") Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because sugov_update_next_freq() may skip a frequency update even if
the need_freq_update flag has been set for the policy at hand, policy
limits updates may not take effect as expected.
For example, if the intel_pstate driver operates in the passive mode
with HWP enabled, it needs to update the HWP min and max limits when
the policy min and max limits change, respectively, but that may not
happen if the target frequency does not change along with the limit
at hand. In particular, if the policy min is changed first, causing
the target frequency to be adjusted to it, and the policy max limit
is changed later to the same value, the HWP max limit will not be
updated to follow it as expected, because the target frequency is
still equal to the policy min limit and it will not change until
that limit is updated.
To address this issue, modify get_next_freq() to let the driver
callback run if the CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag
is set regardless of whether or not the new frequency to set is
equal to the previous one.
Currently in case of alignment or FCS error if the packet cannot be
corrected it's still not dropped. Report the error properly and drop the
packet while making the code around a little bit more readable.
The "cb_pcidas" driver supports asynchronous commands on the analog
output (AO) subdevice for those boards that have an AO FIFO. The code
(in `cb_pcidas_ao_check_chanlist()` and `cb_pcidas_ao_cmd()`) to
validate and set up the command supports output to a single channel or
to two channels simultaneously (the boards have two AO channels).
However, the code in `cb_pcidas_auto_attach()` that initializes the
subdevices neglects to initialize the AO subdevice's `len_chanlist`
member, leaving it set to 0, but the Comedi core will "correct" it to 1
if the driver neglected to set it. This limits commands to use a single
channel (either channel 0 or 1), but the limit should be two channels.
Set the AO subdevice's `len_chanlist` member to be the same value as the
`n_chan` member, which will be 2.
Some architectures assume that the stopped CPUs don't make function calls
to traceable functions when they are in the stopped state. See also commit cb9d7fd51d9f ("watchdog: Mark watchdog touch functions as notrace").
Violating this assumption causes kernel crashes when switching tracer on
RISC-V.
Mark rcu_momentary_dyntick_idle() and stop_machine_yield() notrace to
prevent this.
Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Fixes: 366237e7b083 ("stop_machine: Provide RCU quiescent state in multi_cpu_stop()") Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Atish Patra <atish.patra@wdc.com> Tested-by: Colin Ian King <colin.king@canonical.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201021073839.43935-1-zong.li@sifive.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DBGD{CCINT,SCRext} and DBGVCR register entries in the cp14 array
are missing their target register, resulting in all accesses being
targetted at the guard sysreg (indexed by __INVALID_SYSREG__).
Point the emulation code at the actual register entries.
The newly introduced kvm_msr_ignored_check() tries to print error or
debug messages via vcpu_*() macros, but those may cause Oops when NULL
vcpu is passed for KVM_GET_MSRS ioctl.
Fix it by replacing the print calls with kvm_*() macros.
(Note that this will leave vcpu argument completely unused in the
function, but I didn't touch it to make the fix as small as
possible. A clean up may be applied later.)
Fixes: 12bc2132b15e ("KVM: X86: Do the same ignore_msrs check for feature msrs") BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1178280 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Message-Id: <20201030151414.20165-1-tiwai@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It appears that firmware nodes can be shared between devices. In such case
when a (child) device is about to be deleted, its firmware node may be shared
and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
of the shared primary firmware node.
In order to prevent that, check, if the device has a parent and parent's
firmware node is shared with its child, and avoid crashing the link.
Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") Reported-by: Ferry Toth <fntoth@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Tested-by: Ferry Toth <fntoth@gmail.com> Cc: 5.9+ <stable@vger.kernel.org> # 5.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Behind primary and secondary we understand the type of the nodes
which might define their ordering. However, if primary node gone,
we can't maintain the ordering by definition of the linked list.
Thus, by ordering secondary node becomes first in the list.
But in this case the meaning of it is still secondary (or auxiliary).
The type of the node is maintained by the secondary pointer in it:
secondary pointer Meaning
NULL or valid primary node
ERR_PTR(-ENODEV) secondary node
So, if by some reason we do the following sequence of calls
This concept is supported by the description of set_primary_fwnode()
along with implementation of set_secondary_fwnode(). Hence, fix
the commit c15e1bdda436 to follow this as well.
Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") Cc: Ferry Toth <fntoth@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Tested-by: Ferry Toth <fntoth@gmail.com> Cc: 5.9+ <stable@vger.kernel.org> # 5.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Parallel write,read,zone-mgmt operations accessing/altering zone state
and write-pointer may get into race. Avoid the situation by using a new
spinlock for zoned device.
Concurrent zone-appends (on a zone) returning same write-pointer issue
is also avoided using this lock.
Cc: stable@vger.kernel.org Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND") Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Espressobin boards have 3 ethernet ports and some of them got assigned more
then one MAC address. MAC addresses are stored in U-Boot environment.
Since commit a2c7023f7075c ("net: dsa: read mac address from DT for slave
device") kernel can use MAC addresses from DT for particular DSA port.
Currently Espressobin DTS file contains alias just for ethernet0.
This patch defines additional ethernet aliases in Espressobin DTS files, so
bootloader can fill correct MAC address for DSA switch ports if more MAC
addresses were specified.
DT alias ethernet1 is used for wan port, DT aliases ethernet2 and ethernet3
are used for lan ports for both Espressobin revisions (V5 and V7).
Commit 39d114ddc682 ("arm64: add KASAN support") added .weak directives to
arch/arm64/lib/mem*.S instead of changing the existing SYM_FUNC_START_PI
macros. This can lead to the assembly snippet `.weak memcpy ... .globl
memcpy` which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL
memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since
https://reviews.llvm.org/D90108) will error on such an overridden symbol
binding.
Use the appropriate SYM_FUNC_START_WEAK_PI instead.
Fixes: 39d114ddc682 ("arm64: add KASAN support") Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201029181951.1866093-1-maskray@google.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f6361c6b3880 ("ARM: S3C24XX: remove separate restart code")
removed usage of the watchdog reset platform code in favor of the
Samsung SoC watchdog driver. However the latter was not selected thus
S3C24xx platforms lost reset abilities.
Cc: <stable@vger.kernel.org> Fixes: f6361c6b3880 ("ARM: S3C24XX: remove separate restart code") Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Selecting CONFIG_SAMSUNG_PM_DEBUG (depending on CONFIG_DEBUG_LL) but
without CONFIG_MMU leads to build errors:
arch/arm/plat-samsung/pm-debug.c: In function ‘s3c_pm_uart_base’:
arch/arm/plat-samsung/pm-debug.c:57:2: error:
implicit declaration of function ‘debug_ll_addr’ [-Werror=implicit-function-declaration]
Fixes: 99b2fc2b8b40 ("ARM: SAMSUNG: Use debug_ll_addr() to get UART base address") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200910154150.3318-1-krzk@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the 5.7 merge window the media kconfig was restructued. For most
platforms these changes set CONFIG_MEDIA_SUPPORT_FILTER=y which keeps
unwanted drivers disabled.
The exception is if a config sets EMBEDDED or EXPERT (see b0cd4fb27665).
In that case the filter is set to =n, causing a bunch of DVB tuner drivers
(MEDIA_TUNER_*) to be accidentally enabled. This was noticed as it blew
out the build time for the Aspeed defconfigs.
Enabling the filter means the Aspeed config also needs to set
CONFIG_MEDIA_PLATFORM_SUPPORT=y in order to have the CONFIG_VIDEO_ASPEED
driver enabled.
Fixes: 06b93644f4d1 ("media: Kconfig: add an option to filter in/out platform drivers") Fixes: b0cd4fb27665 ("media: Kconfig: on !EMBEDDED && !EXPERT, enable driver filtering") Signed-off-by: Joel Stanley <joel@jms.id.au> Cc: stable@vger.kernel.org CC: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix typo in pinctrl property of "vibrator-en" fixed regulator in Aries
family of boards. The error caused lack of pin configuration for the
GPIO used in vibrator.
Fixes: 04568cb58a43 ("ARM: dts: s5pv210: Disable pull for vibrator enable GPIO on Aries boards") Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200907161141.31034-5-krzk@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A feature was added to the aspeed vuart driver to configure the vuart
interrupt (sirq) polarity according to the LPC/eSPI strapping register.
Systems that depend on a active low behaviour (sirq_polarity set to 0)
such as OpenPower boxes also use LPC, so this relationship does not
hold. Jeremy confirms that the s2600st which is strapped for eSPI also
does not have this relationship.
The property was added for a Tyan S7106 system which is not supported
in the kernel tree. Should this or other systems wish to use this
feature of the driver they should add it to the machine specific device
tree.
Fixes: c791fc76bc72 ("arm: dts: aspeed: Add vuart aspeed,sirq-polarity-sense...") Signed-off-by: Joel Stanley <joel@jms.id.au> Tested-by: Jeremy Kerr <jk@ozlabs.org> Reviewed-by: Jeremy Kerr <jk@ozlabs.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200812112400.2406734-1-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When starting a HP machine with HIL driver but without an HIL keyboard
or HIL mouse attached, it may happen that data written to the HIL loop
gets stuck (e.g. because the transaction queue is full). Usually one
will then have to reboot the machine because all you see is and endless
output of:
Transaction add failed: transaction already queued?
In the higher layers hp_sdc_enqueue_transaction() is called to queued up
a HIL packet. This function returns an error code, and this patch adds
the necessary checks for this return code and disables the HIL driver if
further packets can't be sent.
Some of the font tty ioctl's always used the current foreground VC for
their operations. Don't do that then.
This fixes a data race on fg_console.
Side note: both Michael Ellerman and Jiri Slaby point out that all these
ioctls are deprecated, and should probably have been removed long ago,
and everything seems to be using the KDFONTOP ioctl instead.
In fact, Michael points out that it looks like busybox's loadfont
program seems to have switched over to using KDFONTOP exactly _because_
of this bug (ahem.. 12 years ago ;-).
Stop registering the SMU i2c bus on navi1x. This leads to instability
issues when userspace processes mess with the bus and also seems to
cause display stability issues in some cases.
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1314
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1341 Reviewed-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For all commands except FUTEX_WAIT, the timeout is interpreted as an
absolute value. This absolute value is inside the task's time namespace and
has to be converted to the host's time.
Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets") Reported-by: Hans van der Laan <j.h.vanderlaan@student.utwente.nl> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201015160020.293748-1-avagin@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In brcmstb_dpfe_download_firmware(), memory is allocated to variable fw by
firmware_request_nowarn(), but never released. Fix up to release fw on
all return paths.
Cc: <stable@vger.kernel.org> Fixes: 2f330caff577 ("memory: brcmstb: Add driver for DPFE") Signed-off-by: Alex Dewar <alex.dewar90@gmail.com> Acked-by: Markus Mayer <mmayer@broadcom.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20200820172118.781324-1-alex.dewar90@gmail.com Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 63a613fdb16c ("memory: tegra: Add gr2d and gr3d to DRM IOMMU
group") added the GPU to the DRM IOMMU group, which doesn't make any
sense. This causes problems when Nouveau tries to attach to the SMMU
and causes it to fall back to using the DMA API.
Remove the GPU from the DRM groups to restore the old behaviour. The
GPU should always have its own IOMMU domain to make sure it can map
buffers into contiguous chunks (for big page support) without getting
in the way of mappings from the DRM group.
sdhci-of-dwcmshc meets an eMMC read performance regression with below
command after commit 427b6514d095 ("mmc: sdhci: Add Auto CMD Auto
Select support"):
Before the commit, the above command gives 120MB/s
After the commit, the above command gives 51.3 MB/s
So it looks like sdhci-of-dwcmshc expects Version 4 Mode for Auto
CMD Auto Select. Fix the performance degradation by ensuring v4_mode
is true to use Auto CMD Auto Select.
Fixes: 427b6514d095 ("mmc: sdhci: Add Auto CMD Auto Select support") Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201015174115.4cf2c19a@xhacker.debian Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mmc0: Tuning timeout, falling back to fixed sampling clock
There are SD cards which takes a significant longer time to reply to the
first CMD19 command. The eSDHC takes the data timeout value into account
during the tuning period. The SDHCI core doesn't explicitly set this
timeout for the tuning procedure. Thus on the slow cards, there might be
a spurious "Buffer Read Ready" interrupt, which in turn triggers a wrong
sequence of events. In the end this will lead to an unsuccessful tuning
procedure and to the above error.
To workaround this, set the timeout to the maximum value (which is the
best we can do) and the SDHCI core will take care of the proper timeout
handling.
For eMMC HS400 mode initialization, the DLL reset is a required step
if DLL is enabled to use previously, like in bootloader.
This step has not been documented in reference manual, but the RM will
be fixed sooner or later.
This patch is to add the step of DLL reset, and make sure delay chain
locked for HS400.
ext4_ext_search_right() will read more extent blocks and call put_bh
after we get the information we need. However, ret_ex will break this
and may cause use-after-free once pagecache has been freed. Fix it by
copying the extent structure if needed.
left shifting m_lblk by blkbits was causing value overflow and hence
it was not able to convert unwritten to written extent.
So, make sure we typecast it to loff_t before do left shift operation.
Also in func ext4_convert_unwritten_io_end_vec(), make sure to initialize
ret variable to avoid accidentally returning an uninitialized ret.
This patch fixes the issue reported in ext4 for bs < ps with
dioread_nolock mount option.
Fixes: c8cc88163f40df39e50c ("ext4: Add support for blocksize < pagesize in dioread_nolock") Cc: stable@kernel.org Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/af902b5db99e8b73980c795d84ad7bb417487e76.1602168865.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Consider a situation when a filesystem was uncleanly shutdown and the
orphan list is not empty and a read-only mount is attempted. The orphan
list cleanup during mount will fail with:
ext4_check_bdev_write_error:193: comm mount: Error while async write back metadata
This happens because sbi->s_bdev_wb_err is not initialized when mounting
the filesystem in read only mode and so ext4_check_bdev_write_error()
falsely triggers.
Initialize sbi->s_bdev_wb_err unconditionally to avoid this problem.
Fixes: bc71726c7257 ("ext4: abort the filesystem if failed to async write metadata buffer") Cc: stable@kernel.org Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200928020556.710971-1-zhangxiaoxu5@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The metadata buffer is no longer trusted after we read it from disk
again because it is not uptodate for some reasons (e.g. failed to write
back). Otherwise we may get below memory corruption problem in
ext4_ext_split()->memset() if we read stale data from the newly
allocated extent block on disk which has been failed to async write
out but miss verify again since the verified bit has already been set
on the buffer.
During the stability test, there are some errors:
ext4_lookup:1590: inode #6967: comm fsstress: iget: checksum invalid.
If the inode->i_iblocks too big and doesn't set huge file flag, checksum
will not be recalculated when update the inode information to it's buffer.
If other inode marks the buffer dirty, then the inconsistent inode will
be flushed to disk.
Fix this problem by checking i_blocks in advance.
Cc: stable@kernel.org Signed-off-by: Luo Meng <luomeng12@huawei.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20201020013631.3796673-1-luomeng12@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After moving ext4's bmap to iomap interface, swapon functionality
on files created using fallocate (which creates unwritten extents) are
failing. This is since iomap_bmap interface returns 0 for unwritten
extents and thus generic_swapfile_activate considers this as holes
and hence bail out with below kernel msg :-
[340.915835] swapon: swapfile has holes
To fix this we need to implement ->swap_activate aops in ext4
which will use ext4_iomap_report_ops. Since we only need to return
the list of extents so ext4_iomap_report_ops should be enough.
If riov and wiov are both defined and they point to different
objects, only riov is initialized. If the wiov is not initialized
by the caller, the function fails returning -EINVAL and printing
"Readable desc 0x... after writable" error message.
This issue happens when descriptors have both readable and writable
buffers (eg. virtio-blk devices has virtio_blk_outhdr in the readable
buffer and status as last byte of writable buffer) and we call
__vringh_iov() to get both type of buffers in two different iovecs.
Let's replace the 'else if' clause with 'if' to initialize both
riov and wiov if they are not NULL.
As checkpatch pointed out, we also avoid crashing the kernel
when riov and wiov are both NULL, replacing BUG() with WARN_ON()
and returning -EINVAL.
Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/20201008204256.162292-1-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the cpufreq policy max limit is changed when intel_pstate operates
in the passive mode with HWP enabled and the "powersave" governor is
used on top of it, the HWP max limit is not updated as appropriate.
Namely, in the "powersave" governor case, the target P-state
is always equal to the policy min limit, so if the latter does
not change, intel_cpufreq_adjust_hwp() is not invoked to update
the HWP Request MSR due to the "target_pstate != old_pstate" check
in intel_cpufreq_update_pstate(), so the HWP max limit is not
updated as a result.
Also, if the CPUFREQ_NEED_UPDATE_LIMITS flag is not set for the
driver and the target frequency does not change along with the
policy max limit, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents the driver's ->target() callback
from being invoked at all, so the HWP max limit is not updated.
To prevent that occurring, set the CPUFREQ_NEED_UPDATE_LIMITS flag
in the intel_cpufreq driver structure if HWP is enabled and modify
intel_cpufreq_update_pstate() to do the "target_pstate != old_pstate"
check only in the non-HWP case and let intel_cpufreq_adjust_hwp()
always run in the HWP case (it will update HWP Request only if the
cached value of the register is different from the new one including
the limits, so if neither the target P-state value nor the max limit
changes, the register write will still be avoided).
Generally, a cpufreq driver may need to update some internal upper
and lower frequency boundaries on policy max and min changes,
respectively, but currently this does not work if the target
frequency does not change along with the policy limit.
Namely, if the target frequency does not change along with the
policy min or max, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents driver callbacks from being
invoked and they do not even have a chance to update the
corresponding internal boundary.
This particularly affects the "powersave" and "performance"
governors that always set the target frequency to one of the
policy limits and it never changes when the other limit is updated.
To allow cpufreq the drivers needing to update internal frequency
boundaries on policy limits changes to avoid this issue, introduce
a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will
neutralize the check mentioned above.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 33aa46f252c7 ("cpufreq: intel_pstate: Use passive mode by
default without HWP") was meant to cause intel_pstate to be used
in the passive mode with the schedutil governor on top of it, but
it missed the case in which either "ondemand" or "conservative"
was selected as the default governor in the existing kernel config,
in which case the previous old governor configuration would be used,
causing the default legacy governor to be used on top of intel_pstate
instead of schedutil.
Address this by preventing "ondemand" and "conservative" from being
configured as the default cpufreq governor in the case when schedutil
is the default choice for the default governor setting.
[Note that the default cpufreq governor can still be set via the
kernel command line if need be and that choice is not limited,
so if anyone really wants to use one of the legacy governors by
default, it can be achieved this way.]
Fixes: 33aa46f252c7 ("cpufreq: intel_pstate: Use passive mode by default without HWP") Reported-by: Julia Lawall <julia.lawall@inria.fr> Cc: 5.8+ <stable@vger.kernel.org> # 5.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently intel_idle driver gets the c-state information from ACPI
_CST if the processor model is not recognized by it. However the
c-state in _CST starts with index 1 which is different from the
index in intel_idle driver's internal c-state table.
While intel_idle_max_cstate_reached() was previously introduced to
deal with intel_idle driver's internal c-state table, re-using
this function directly on _CST is incorrect.
Fix this by subtracting 1 from the index when checking max_cstate
in the _CST case.
For example, append intel_idle.max_cstate=1 in boot command line,
Before the patch:
grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
POLL
After the patch:
grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
/sys/devices/system/cpu/cpu0/cpuidle/state0/name:POLL
/sys/devices/system/cpu/cpu0/cpuidle/state1/name:C1_ACPI
Fixes: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables") Reported-by: Pengfei Xu <pengfei.xu@intel.com> Cc: 5.6+ <stable@vger.kernel.org> # 5.6+ Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
e6d4f08a6776 ("intel_idle: Use ACPI _CST on server systems") avoids
enabling c-states that have been disabled by the platform with the
exception of C1E.
Unfortunately, BIOS implementations are not always consistent in terms
of how capabilities are advertised and control cannot always be handed
over. If control cannot be handed over then intel_idle reports that "ACPI
_CST not found or not usable" but does not clear acpi_state_table.count
meaning the information is still partially used.
This patch ignores ACPI information if CST control cannot be requested from
the platform. This was only observed on a number of Haswell platforms that
had identical CPUs but not identical BIOS versions. While this problem
may be rare overall, 24 separate test cases bisected to this specific
commit across 4 separate test machines and is worth addressing. If the
situation occurs, the kernel behaves as it did before commit e6d4f08a6776
and uses any c-states that are discovered.
The affected test cases were all ones that involved a small number of
processes -- exec microbenchmark, pipe microbenchmark, git test suite,
netperf, tbench with one client and system call microbenchmark. Each
case benefits from being able to use turboboost which is prevented if the
lower c-states are unavailable. This may mask real regressions specific
to older hardware so it is worth addressing.
We don't need to check the new buffer size, and the return value
had confused resize_buffer_duplicate_size().
...
ret = ring_buffer_resize(trace_buf->buffer,
per_cpu_ptr(size_buf->data,cpu_id)->entries, cpu_id);
if (ret == 0)
per_cpu_ptr(trace_buf->data, cpu_id)->entries =
per_cpu_ptr(size_buf->data, cpu_id)->entries;
...
Link: https://lkml.kernel.org/r/20201019142242.11560-1-hqjagain@gmail.com Cc: stable@vger.kernel.org Fixes: d60da506cbeb3 ("tracing: Add a resize function to make one buffer equivalent to another buffer") Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Qsdk U-Boot can incorrectly leave the PCIe interface in an undefined
state if bootm command is used instead of bootipq. This is caused by the
not deinit of PCIe when bootm is called. Reset the PCIe before init
anyway to fix this U-Boot bug.
Fix returning value for sysctl sunrpc.transports.
Return error code from sysctl proc_handler function proc_do_xprt instead of number of the written bytes.
Otherwise sysctl returns random garbage for this key.
Since v1:
- Handle negative returned value from memory_read_from_buffer as an error
Signed-off-by: Artur Molchanov <arturmolchanov@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
con->out_msg must be cleared on Policy::stateful_server
(!CEPH_MSG_CONNECT_LOSSY) faults. Not doing so botches the
reconnection attempt, because after writing the banner the
messenger moves on to writing the data section of that message
(either from where it got interrupted by the connection reset or
from the beginning) instead of writing struct ceph_msg_connect.
This results in a bizarre error message because the server
sends CEPH_MSGR_TAG_BADPROTOVER but we think we wrote struct
ceph_msg_connect:
libceph: mds0 (1)172.21.15.45:6828 socket error on write
ceph: mds0 reconnect start
libceph: mds0 (1)172.21.15.45:6829 socket closed (con state OPEN)
libceph: mds0 (1)172.21.15.45:6829 protocol version mismatch, my 32 != server's 32
libceph: mds0 (1)172.21.15.45:6829 protocol version mismatch
AFAICT this bug goes back to the dawn of the kernel client.
The reason it survived for so long is that only MDS sessions
are stateful and only two MDS messages have a data section:
CEPH_MSG_CLIENT_RECONNECT (always, but reconnecting is rare)
and CEPH_MSG_CLIENT_REQUEST (only when xattrs are involved).
The connection has to get reset precisely when such message
is being sent -- in this case it was the former.
Currently both error code paths handled in dal_gpio_open_ex() issues
ASSERT_CRITICAL(), and this leads to a kernel panic unnecessarily if
CONFIG_KGDB is enabled. Since basically both are non-critical errors
and can be recovered, drop those assert calls and use a safer one,
BREAK_TO_DEBUGGER(), for allowing the debugging, instead.
BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1177973 Cc: <stable@vger.kernel.org> Acked-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ASSERT_CRITICAL() invokes kgdb_breakpoint() whenever either
CONFIG_KGDB or CONFIG_HAVE_KGDB is set. This, however, may lead to a
kernel panic when no kdb stuff is attached, since the
kgdb_breakpoint() call issues INT3. It's nothing but a surprise for
normal end-users.
For avoiding the pitfall, make the kgdb_breakpoint() call only when
CONFIG_DEBUG_KERNEL_DC is set.
https://bugzilla.opensuse.org/show_bug.cgi?id=1177973 Cc: <stable@vger.kernel.org> Acked-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On connector destruction call drm_dp_mst_topology_mgr_destroy
to release resources allocated in drm_dp_mst_topology_mgr_init.
Do it only if MST manager was initilized before otherwsie a crash
is seen on driver unload/device unplug.
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Synchronize the ring usage for vcn1 and jpeg1 to workaround a hardware bug.
Signed-off-by: Veerabadhran Gopalakrishnan <veerabadhran.gopalakrishnan@amd.com> Acked-by: Christian König <christian.koenig@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Christian König <christian.koenig@amd.com> Signed-off-by: Madhav Chauhan <madhav.chauhan@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If interrupt comes late, during probe error path or device remove (could
be triggered with CONFIG_DEBUG_SHIRQ), the interrupt handler
i2c_imx_isr() will access registers with the clock being disabled. This
leads to external abort on non-linefetch on Toradex Colibri VF50 module
(with Vybrid VF5xx):
Unhandled fault: external abort on non-linefetch (0x1008) at 0x8882d003
Internal error: : 1008 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0 #607
Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
(i2c_imx_isr) from [<8017009c>] (free_irq+0x25c/0x3b0)
(free_irq) from [<805844ec>] (release_nodes+0x178/0x284)
(release_nodes) from [<80580030>] (really_probe+0x10c/0x348)
(really_probe) from [<80580380>] (driver_probe_device+0x60/0x170)
(driver_probe_device) from [<80580630>] (device_driver_attach+0x58/0x60)
(device_driver_attach) from [<805806bc>] (__driver_attach+0x84/0xc0)
(__driver_attach) from [<8057e228>] (bus_for_each_dev+0x68/0xb4)
(bus_for_each_dev) from [<8057f3ec>] (bus_add_driver+0x144/0x1ec)
(bus_add_driver) from [<80581320>] (driver_register+0x78/0x110)
(driver_register) from [<8010213c>] (do_one_initcall+0xa8/0x2f4)
(do_one_initcall) from [<80c0100c>] (kernel_init_freeable+0x178/0x1dc)
(kernel_init_freeable) from [<80807048>] (kernel_init+0x8/0x110)
(kernel_init) from [<80100114>] (ret_from_fork+0x14/0x20)
Additionally, the i2c_imx_isr() could wake up the wait queue
(imx_i2c_struct->queue) before its initialization happens.
The resource-managed framework should not be used for interrupt handling,
because the resource will be released too late - after disabling clocks.
The interrupt handler is not prepared for such case.
Fixes: 1c4b6c3bcf30 ("i2c: imx: implement bus recovery") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The way the driver is implemented is buggy for the (admittedly unlikely)
use case where there are two RTCs with one having an interrupt configured
and the second not. This is caused by the fact that we use a global
rtc_class_ops struct which we modify depending on whether the irq number
is present or not.
Fix it by using two const ops structs with and without alarm operations.
While at it: not being able to request a configured interrupt is an error
so don't ignore it and bail out of probe().
Fix linkage error when CONFIG_BINFMT_ELF is selected but CONFIG_COREDUMP
is not:
ia64-linux-ld: arch/ia64/kernel/elfcore.o: in function `elf_core_write_extra_phdrs':
elfcore.c:(.text+0x172): undefined reference to `dump_emit'
ia64-linux-ld: arch/ia64/kernel/elfcore.o: in function `elf_core_write_extra_data':
elfcore.c:(.text+0x2b2): undefined reference to `dump_emit'
Fixes: 1fcccbac89f5 ("elf coredump: replace ELF_CORE_EXTRA_* macros by functions") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200819064146.12529-1-krzk@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A detach hung is possible when a race occurs between the detach process
and the ubi background thread. The following sequences outline the race:
ubi thread: if (list_empty(&ubi->works)...
ubi detach: set_bit(KTHREAD_SHOULD_STOP, &kthread->flags)
=> by kthread_stop()
wake_up_process()
=> ubi thread is still running, so 0 is returned
ubi thread: set_current_state(TASK_INTERRUPTIBLE)
schedule()
=> ubi thread will never be scheduled again
ubi detach: wait_for_completion()
=> hung task!
To fix that, we need to check kthread_should_stop() after we set the
task state, so the ubi thread will either see the stop bit and exit or
the task state is reset to runnable such that it isn't scheduled out
indefinitely.
commit feb92d7d3813456c11dce21 "(ARC: perf: don't bail setup if pct irq
missing in device-tree)" introduced a silly brown-paper bag bug:
The assignment and comparison in an if statement were not bracketed
correctly leaving the order of evaluation undefined.
The problem is in the is_printable_array function that does not take the
zero byte into account and claim such string as not printable, so the
code will create byte array instead of string.
There is no need to dump authentication options while remounting,
because authentication initialization can only be doing once in
the first mount process. Dumping authentication mount options in
remount process may cause memory leak if UBIFS has already been
mounted with old authentication mount options.
When removing the last reference of an inode the size of an auth node
is already part of write_len. So we must not call ubifs_add_auth_dirt().
Call it only when needed.
Fix some potential memory leaks in error handling branches while
iterating xattr entries. For example, function ubifs_tnc_remove_ino()
forgets to free pxent if it exists. Similar problems also exist in
ubifs_purge_xattrs(), ubifs_add_orphan() and ubifs_jnl_write_inode().
Fix some potential memory leaks in error handling branches while
iterating dent entries. For example, function dbg_check_dir()
forgets to free pdent if it exists.
There's no protection in nfsd_dispatch() against a NULL .pc_func
helpers. A malicious NFS client can trigger a crash by invoking the
unused/unsupported NFSv2 ROOT or WRITECACHE procedures.
The current NFSD dispatcher does not support returning a void reply
to a non-NULL procedure, so the reply to both of these is wrong, for
the moment.
Cc: <stable@vger.kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 0e0cb35b417f ("NFSv4: Handle NFS4ERR_OLD_STATEID in
CLOSE/OPEN_DOWNGRADE") the following livelock may occur if a CLOSE races
with the update of the nfs_state:
Process 1 Process 2 Server
========= ========= ========
OPEN file
OPEN file
Reply OPEN (1)
Reply OPEN (2)
Update state (1)
CLOSE file (1)
Reply OLD_STATEID (1)
CLOSE file (2)
Reply CLOSE (-1)
Update state (2)
wait for state change
OPEN file
wake
CLOSE file
OPEN file
wake
CLOSE file
...
...
We can avoid this situation by not issuing an immediate retry with a bumped
seqid when CLOSE/OPEN_DOWNGRADE receives NFS4ERR_OLD_STATEID. Instead,
take the same approach used by OPEN and wait at least 5 seconds for
outstanding stateid updates to complete if we can detect that we're out of
sequence.
Note that after this change it is still possible (though unlikely) that
CLOSE waits a full 5 seconds, bumps the seqid, and retries -- and that
attempt races with another OPEN at the same time. In order to avoid this
race (which would result in the livelock), update
nfs_need_update_open_stateid() to handle the case where:
- the state is NFS_OPEN_STATE, and
- the stateid doesn't match the current open stateid
Finally, nfs_need_update_open_stateid() is modified to be idempotent and
renamed to better suit the purpose of signaling that the stateid passed
is the next stateid in sequence.
Fixes: 0e0cb35b417f ("NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Only initialize gl_delete for iopen glocks, but more importantly, only access
it for iopen glocks in flush_delete_work: flush_delete_work is called for
different types of glocks including rgrp glocks, and those use gl_vm which is
in a union with gl_delete. Without this fix, we'll end up clobbering gl_vm,
which results in general memory corruption.
Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit ca399c96e96e changes gfs2_log_flush to not withdraw the
filesystem while holding the log flush lock, but it fails to check if
the filesystem needs to be withdrawn once the log flush lock has been
released. Likewise, commit f05b86db314d depends on gfs2_log_flush to
trigger for delayed withdraws. Add that and clean up the code flow
somewhat.
In gfs2_put_super, add a check for delayed withdraws that have been
missed to prevent these kinds of bugs in the future.
Fixes: ca399c96e96e ("gfs2: flesh out delayed withdraw for gfs2_log_flush") Fixes: f05b86db314d ("gfs2: Prepare to withdraw as soon as an IO error occurs in log write") Cc: stable@vger.kernel.org # v5.7+: 462582b99b607: gfs2: add some much needed cleanup for log flushes that fail Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_poll_double_wake() is called for both request types - both pure poll
requests, and internal polls. This means that we should be using the
right handler based on the request type. Use the one that the original
caller already assigned for the waitqueue handling, that will always
match the correct type.
When the bio's size reaches max_append_sectors, bio_add_hw_page returns
0 then __bio_iov_append_get_pages returns -EINVAL. This is an expected
result of building a small enough bio not to be split in the IO path.
However, iov_iter is not advanced in this case, causing the same pages
are filled for the bio again and again.
Fix the case by properly advancing the iov_iter for already processed
pages.
We need r1 to be properly set before activating MMU, otherwise any new
exception taken while saving registers into the stack in exception
prologs will use the user stack, which is wrong and will even lockup
or crash when KUAP is selected.
Do that by switching the meaning of r11 and r1 until we have saved r1
to the stack: copy r1 into r11 and setup the new stack pointer in r1.
To avoid complicating and impacting all generic and specific prolog
code (and more), copy back r1 into r11 once r11 is save onto
the stack.
We could get rid of copying r1 back and forth at the cost of
rewriting everything to use r1 instead of r11 all the way when
CONFIG_VMAP_STACK is set, but the effort is probably not worth it.
We need r1 to be properly set before activating MMU, so
reading task_struct->stack must be done with MMU off.
This means we need an additional register to play with MSR
bits while r11 now points to the stack. For that, move r10
back to CR (As is already done for hash MMU) and use r10.
We still don't have r1 correct yet when we activate MMU.
It is done in following patch.
projects / linux-stable / log