The macro was always used together with can_dlc2len() which sanitizes the
given dlc value on its own.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-4-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The get_can_dlc() macro is used to ensure the payload length information of
the Classical CAN frame to be max 8 bytes (the CAN_MAX_DLEN).
Rename the macro and use the correct constant in preparation of the len/dlc
cleanup for Classical CAN frames.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-3-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
ISO 11898-1 Chapter 8.4.2.3 defines a 4 bit data length code (DLC) table which
maps the DLC to the payload length of the CAN frame in bytes:
DLC -> payload length
0 .. 8 -> 0 .. 8
9 .. 15 -> 8
Although the DLC values 8 .. 15 in Classical CAN always result in a payload
length of 8 bytes these DLC values are transparently transmitted on the CAN
bus. As the struct can_frame only provides a 'len' element (formerly 'can_dlc')
which contains the plain payload length ( 0 .. 8 ) of the CAN frame, the raw
DLC is not visible to the application programmer, e.g. for testing use-cases.
To access the raw DLC values 9 .. 15 the len8_dlc element is introduced, which
is only valid when the payload length 'len' is 8 and the DLC is greater than 8.
The len8_dlc element is filled by the CAN interface driver and used for CAN
frame creation by the CAN driver when the CAN_CTRLMODE_CC_LEN8_DLC flag is
supported by the driver and enabled via netlink configuration interface.
Reported-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Use table markup to show the structure of the CAN identifier, PGN, PDU1, and
PDU2 formats. Also add introductory sentence.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Link: https://lore.kernel.org/r/20201104155730.25196-1-yegorslists@googlemail.com
[mkl: removed trailing whitespace]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The commit to introduce the num_altmodes attribute for partner had an
error where one of the parameters was named differently in the comment
and the function signature. Fix the version in the comment to align with
what is in the function signature.
This fixes the following htmldocs warning:
drivers/usb/typec/class.c:632: warning: Excess function parameter 'num_alt_modes' description in 'typec_partner_set_num_altmodes'
Fixes: a0ccdc4a77 ("usb: typec: Add number of altmodes partner attr")
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Link: https://lore.kernel.org/r/20201120063523.4159877-1-pmalani@chromium.org
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For DG1 we have a little of mix up wrt to DDI/port names and indexes.
Bspec refers to the ports as DDIA, DDIB, DDI USBC1 and DDI USBC2
(besides the DDIA, DDIB, DDIC, DDID), but the previous naming is the
most unambiguous one. This means that for any register on Display Engine
we should use the index of A, B, D and E. However in some places this is
not true:
- VBT: uses C and D and have to be mapped to D/E
- IO/Combo: uses C and D, but we already differentiate those when
we created the phy vs port distinction.
This additional mapping for VBT and phy are already covered in previous
patches, so now we can initialize all the DDIs as A, B, D and E.
v2: Squash previous patch enabling just ports A and B since most of the
pumbling code is already merged now
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Clinton Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201117084836.2318234-1-lucas.demarchi@intel.com
Reset MHI device channels when driver remove is called due to
module unload or any crash scenario. This will make sure that
MHI channels no longer remain enabled for transfers since the
MHI stack does not take care of this anymore after the auto-start
channels feature was removed.
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Claudiu Manoil says:
====================
enetc: Clean endianness warnings up
Cleanup patches to address the outstanding endianness issues
in the driver reported by sparse.
====================
Link: https://lore.kernel.org/r/20201119101215.19223-1-claudiu.manoil@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently the control buffer descriptor (cbd) fields have endianness
restrictions while the commands passed into the control buffers
don't (with one exception). This patch fixes offending code,
by adding endianness accessors for cbd fields and removing the
unnecessary ones in case of data buffer fields. Currently there's
no need to convert all commands to little endian format, the patch
only focuses on fixing current endianness issues reported by sparse.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
These particular fields are specified in the H/W reference
manual as having network byte order format, so enforce big
endian annotation for them and clear the related sparse
warnings in the process.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds an IPv6 routes encapsulation attribute
to the result of netlink RTM_GETROUTE requests
(i.e. ip route get 2001:db8::).
Signed-off-by: Oliver Herms <oliver.peter.herms@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20201118230651.GA8861@tws
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We must start the retransmission timer only there are
pending data in the rtx queue.
Otherwise we can hit a WARN_ON in mptcp_reset_timer(),
as syzbot demonstrated.
Reported-and-tested-by: syzbot+42aa53dafb66a07e5a24@syzkaller.appspotmail.com
Fixes: d9ca1de8c0 ("mptcp: move page frag allocation in mptcp_sendmsg()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/1a72039f112cae048c44d398ffa14e0a1432db3d.1605737083.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Fixes: c0c050c58d ("bnxt_en: New Broadcom ethernet driver.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Link: https://lore.kernel.org/r/1605792621-6268-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Fixes: c213eae8d3 ("bnxt_en: Improve VF/PF link change logic.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Link: https://lore.kernel.org/r/1605701851-20270-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jacob Keller says:
====================
devlink: move common flash_update calls to core
This series moves a couple common pieces done by all drivers of the
->flash_update interface into devlink.c flash update handler. Specifically,
the core code will now request_firmware and
devlink_flash_update_(begin|end)_notify.
This cleanup is intended to simplify driver implementations so that they
have less work to do and are less capable of doing the "wrong" thing.
For request_firmware, this simplification is done as it is not expected that
drivers would do anything else. It also standardizes all drivers so that
they use the same interface (request_firmware, as opposed to
request_firmware_direct), and allows reporting the netlink extended ack with
the file name attribute.
For status notification, this change prevents drivers from sending a status
message without properly sending the status end notification. The current
userspace implementation of devlink relies on this end notification to
properly close the flash update channel. Without this, the flash update
process may hang indefinitely. By moving the begin and end calls into the
core code, it is no longer possible for a driver author to get this wrong.
Changes since v3
* picked up acked-by and reviewed-by comments
* fixed the ionic driver to leave the print statement in place
For the original patch that moved request_firmware, see [1]. For the v2 see
[2]. For further discussion of the issues with devlink flash status see [3].
For v3 see [4].
[1] https://lore.kernel.org/netdev/20201113000142.3563690-1-jacob.e.keller@intel.com/
[2] https://lore.kernel.org/netdev/20201113224559.3910864-1-jacob.e.keller@intel.com/
[3] https://lore.kernel.org/netdev/6352e9d3-02af-721e-3a54-ef99a666be29@intel.com/
[4] https://lore.kernel.org/netdev/20201117200820.854115-1-jacob.e.keller@intel.com/
====================
Link: https://lore.kernel.org/r/20201118190636.1235045-1-jacob.e.keller@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When performing a flash update via devlink, device drivers may inform
user space of status updates via
devlink_flash_update_(begin|end|timeout|status)_notify functions.
It is expected that drivers do not send any status notifications unless
they send a begin and end message. If a driver sends a status
notification without sending the appropriate end notification upon
finishing (regardless of success or failure), the current implementation
of the devlink userspace program can get stuck endlessly waiting for the
end notification that will never come.
The current ice driver implementation may send such a status message
without the appropriate end notification in rare cases.
Fixing the ice driver is relatively simple: we just need to send the
begin_notify at the start of the function and always send an end_notify
no matter how the function exits.
Rather than assuming driver authors will always get this right in the
future, lets just fix the API so that it is not possible to get wrong.
Make devlink_flash_update_begin_notify and
devlink_flash_update_end_notify static, and call them in devlink.c core
code. Always send the begin_notify just before calling the driver's
flash_update routine. Always send the end_notify just after the routine
returns regardless of success or failure.
Doing this makes the status notification easier to use from the driver,
as it no longer needs to worry about catching failures and cleaning up
by calling devlink_flash_update_end_notify. It is now no longer possible
to do the wrong thing in this regard. We also save a couple of lines of
code in each driver.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All drivers which implement the devlink flash update support, with the
exception of netdevsim, use either request_firmware or
request_firmware_direct to locate the firmware file. Rather than having
each driver do this separately as part of its .flash_update
implementation, perform the request_firmware within net/core/devlink.c
Replace the file_name parameter in the struct devlink_flash_update_params
with a pointer to the fw object.
Use request_firmware rather than request_firmware_direct. Although most
Linux distributions today do not have the fallback mechanism
implemented, only about half the drivers used the _direct request, as
compared to the generic request_firmware. In the event that
a distribution does support the fallback mechanism, the devlink flash
update ought to be able to use it to provide the firmware contents. For
distributions which do not support the fallback userspace mechanism,
there should be essentially no difference between request_firmware and
request_firmware_direct.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Shannon Nelson <snelson@pensando.io>
Acked-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add the apps_smmu node for sm8250.
For UFS, now that the kernel initializes the iommu, the stream mappings
set by the bootloader are cleared. Adding the iommus property is required
so that new mappings are created for UFS.
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Link: https://lore.kernel.org/r/20200609194030.17756-5-jonathan@marek.ca
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Add the apps_smmu node for sm8150.
For UFS, now that the kernel initializes the iommu, the stream mappings
set by the bootloader are cleared. Adding the iommus property is required
so that new mappings are created for UFS.
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Link: https://lore.kernel.org/r/20200609194030.17756-4-jonathan@marek.ca
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Fixes the following W=1 kernel build warning(s):
drivers/input/mouse/vmmouse.c:99: warning: Function parameter or member 'cmd' not described in 'VMMOUSE_CMD'
drivers/input/mouse/vmmouse.c:99: warning: Function parameter or member 'in1' not described in 'VMMOUSE_CMD'
drivers/input/mouse/vmmouse.c:99: warning: Function parameter or member 'out1' not described in 'VMMOUSE_CMD'
drivers/input/mouse/vmmouse.c:99: warning: Function parameter or member 'out2' not described in 'VMMOUSE_CMD'
drivers/input/mouse/vmmouse.c:99: warning: Function parameter or member 'out3' not described in 'VMMOUSE_CMD'
drivers/input/mouse/vmmouse.c:99: warning: Function parameter or member 'out4' not described in 'VMMOUSE_CMD'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201112110204.2083435-16-lee.jones@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Fixes the following W=1 kernel build warning(s):
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'keyboard' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'touchpad' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'tp_info' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'tp_info_command' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'init_mt_command' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'capsl_command' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'bl_command' not described in 'message'
drivers/input/keyboard/applespi.c:306: warning: Function parameter or member 'data' not described in 'message'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201112110204.2083435-15-lee.jones@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Fixes the following W=1 kernel build warning(s):
drivers/input/touchscreen/goodix.c:1168: warning: Function parameter or member 'ctx' not described in 'goodix_config_cb'
drivers/input/touchscreen/goodix.c:1168: warning: Excess function parameter 'ts' description in 'goodix_config_cb'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201112110204.2083435-14-lee.jones@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This patch fixes the following smatch warnings:
drivers/crypto/allwinner/sun8i-ce/sun8i-ce-hash.c:412
sun8i_ce_hash_run() warn: possible memory leak of 'result'
Note: "buf" is leaked as well.
Furthermore, in case of ENOMEM, crypto_finalize_hash_request() was not
called which was an error.
Fixes: 56f6d5aee8 ("crypto: sun8i-ce - support hash algorithms")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
There are a couple of spelling mistakes in two crypto Kconfig files.
Fix these.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add support for QAT 4xxx devices.
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an hook to initialize the vector routing table with the default
values before MSIx is enabled.
The new function set_msix_rttable() is called only if present in the
struct adf_hw_device_data of the device. This is to allow for QAT
devices that do not support that functionality.
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Introduce support for devices that require multiple firmware images.
If a device requires more than a firmware image to operate, load the
image to the appropriate Acceleration Engine (AE).
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The pm_runtime_enable will increase power disable depth.
Thus a pairing decrement is needed on the error handling
path to keep it balanced according to context.
Fixes: f7b2b5dd6a ("crypto: omap-aes - add error check for pm_runtime_get_sync")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The patch 'irqchip/gic-v3-its: Balance initial LPI affinity across CPUs'
set the IRQ to an uncentain CPU. If an IRQ is bound to the CPU used by the
thread which is sending request, the throughput will be just half.
So allocate a 'work_queue' and set as 'WQ_UNBOUND' to do the back half work
on some different CPUS.
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Reviewed-by: Zaibo Xu <xuzaibo@huawei.com>
Reviewed-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch moves the curve25519_selftest into curve25519.h so
we don't get a warning from gcc complaining about a missing
prototype.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently <crypto/sha.h> contains declarations for both SHA-1 and SHA-2,
and <crypto/sha3.h> contains declarations for SHA-3.
This organization is inconsistent, but more importantly SHA-1 is no
longer considered to be cryptographically secure. So to the extent
possible, SHA-1 shouldn't be grouped together with any of the other SHA
versions, and usage of it should be phased out.
Therefore, split <crypto/sha.h> into two headers <crypto/sha1.h> and
<crypto/sha2.h>, and make everyone explicitly specify whether they want
the declarations for SHA-1, SHA-2, or both.
This avoids making the SHA-1 declarations visible to files that don't
want anything to do with SHA-1. It also prepares for potentially moving
sha1.h into a new insecure/ or dangerous/ directory.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Clang warns:
drivers/crypto/amcc/crypto4xx_core.c:921:60: warning: operator '?:' has
lower precedence than '|'; '|' will be evaluated first
[-Wbitwise-conditional-parentheses]
(crypto_tfm_alg_type(req->tfm) == CRYPTO_ALG_TYPE_AEAD) ?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
drivers/crypto/amcc/crypto4xx_core.c:921:60: note: place parentheses
around the '|' expression to silence this warning
(crypto_tfm_alg_type(req->tfm) == CRYPTO_ALG_TYPE_AEAD) ?
^
)
drivers/crypto/amcc/crypto4xx_core.c:921:60: note: place parentheses
around the '?:' expression to evaluate it first
(crypto_tfm_alg_type(req->tfm) == CRYPTO_ALG_TYPE_AEAD) ?
^
(
1 warning generated.
It looks like this should have been a logical OR so that
PD_CTL_HASH_FINAL gets added to the w bitmask if crypto_tfm_alg_type
is either CRYPTO_ALG_TYPE_AHASH or CRYPTO_ALG_TYPE_AEAD. Change the
operator so that everything works properly.
Fixes: 4b5b79998a ("crypto: crypto4xx - fix stalls under heavy load")
Link: https://github.com/ClangBuiltLinux/linux/issues/1198
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Wang Qing reports that IS_ERR_OR_NULL() should be matched with
PTR_ERR_OR_ZERO(), not PTR_ERR().
As it turns out, the error path always returns an error code,
i.e. NULL is never returned.
Update the code accordingly - s/IS_ERR_OR_NULL/IS_ERR.
Reported-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Instead of copying the calculated authentication tag to memory and
calling crypto_memneq() to verify it, use vector bytewise compare and
min across vector instructions to decide whether the tag is valid. This
is more efficient, and given that the tag is only transiently held in a
NEON register, it is also safer, given that calculated tags for failed
decryptions should be withheld.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix aead auth setting key process error. if use soft shash function, driver
need to use digest size replace of the user input key length.
Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The idea of the warning in ext4_update_dx_flag() is that we should warn
when we are clearing EXT4_INODE_INDEX on a filesystem with metadata
checksums enabled since after clearing the flag, checksums for internal
htree nodes will become invalid. So there's no need to warn (or actually
do anything) when EXT4_INODE_INDEX is not set.
Link: https://lore.kernel.org/r/20201118153032.17281-1-jack@suse.cz
Fixes: 48a3431195 ("ext4: fix checksum errors with indexed dirs")
Reported-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Kernel-doc markup should use this format:
identifier - description
They should not have any type before that, as otherwise
the parser won't do the right thing.
Also, some identifiers have different names between their
prototypes and the kernel-doc markup.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/72f5c6628f5f278d67625f60893ffbc2ca28d46e.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It turns out that init_srcu_struct() can be invoked from usermode tasks,
and that fatal signals received by these tasks can cause memory-allocation
failures. These failures are not handled well by init_srcu_struct(),
so much so that NULL pointer dereferences can result. This commit
therefore causes init_srcu_struct() to take an early exit upon detection
of memory-allocation failure.
Link: https://lore.kernel.org/lkml/20200908144306.33355-1-aik@ozlabs.ru/
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The current memmory-allocation interface causes the following difficulties
for kvfree_rcu():
a) If built with CONFIG_PROVE_RAW_LOCK_NESTING, the lockdep will
complain about violation of the nesting rules, as in "BUG: Invalid
wait context". This Kconfig option checks for proper raw_spinlock
vs. spinlock nesting, in particular, it is not legal to acquire a
spinlock_t while holding a raw_spinlock_t.
This is a problem because kfree_rcu() uses raw_spinlock_t whereas the
"page allocator" internally deals with spinlock_t to access to its
zones. The code also can be broken from higher level of view:
<snip>
raw_spin_lock(&some_lock);
kfree_rcu(some_pointer, some_field_offset);
<snip>
b) If built with CONFIG_PREEMPT_RT, spinlock_t is converted into
sleeplock. This means that invoking the page allocator from atomic
contexts results in "BUG: scheduling while atomic".
c) Please note that call_rcu() is already invoked from raw atomic context,
so it is only reasonable to expaect that kfree_rcu() and kvfree_rcu()
will also be called from atomic raw context.
This commit therefore defers page allocation to a clean context using the
combination of an hrtimer and a workqueue. The hrtimer stage is required
in order to avoid deadlocks with the scheduler. This deferred allocation
is required only when kvfree_rcu()'s per-CPU page cache is empty.
Link: https://lore.kernel.org/lkml/20200630164543.4mdcf6zb4zfclhln@linutronix.de/
Fixes: 3042f83f19 ("rcu: Support reclaim for head-less object")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
An outgoing CPU is marked offline in a stop-machine handler and most
of that CPU's services stop at that point, including IRQ work queues.
However, that CPU must take another pass through the scheduler and through
a number of CPU-hotplug notifiers, many of which contain RCU readers.
In the past, these readers were not a problem because the outgoing CPU
has interrupts disabled, so that rcu_read_unlock_special() would not
be invoked, and thus RCU would never attempt to queue IRQ work on the
outgoing CPU.
This changed with the advent of the CONFIG_RCU_STRICT_GRACE_PERIOD
Kconfig option, in which rcu_read_unlock_special() is invoked upon exit
from almost all RCU read-side critical sections. Worse yet, because
interrupts are disabled, rcu_read_unlock_special() cannot immediately
report a quiescent state and will therefore attempt to defer this
reporting, for example, by queueing IRQ work. Which fails with a splat
because the CPU is already marked as being offline.
But it turns out that there is no need to report this quiescent state
because rcu_report_dead() will do this job shortly after the outgoing
CPU makes its final dive into the idle loop. This commit therefore
makes rcu_read_unlock_special() refrain from queuing IRQ work onto
outgoing CPUs.
Fixes: 44bad5b3cc ("rcu: Do full report for .need_qs for strict GPs")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jann Horn <jannh@google.com>
This commit fixes a typo in the rcu_blocking_is_gp() function's header
comment.
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The rcu_cpu_starting() and rcu_report_dead() functions transition the
current CPU between online and offline state from an RCU perspective.
Unfortunately, this means that the rcu_cpu_starting() function's lock
acquisition and the rcu_report_dead() function's lock releases happen
while the CPU is offline from an RCU perspective, which can result
in lockdep-RCU splats about using RCU from an offline CPU. And this
situation can also result in too-short grace periods, especially in
guest OSes that are subject to vCPU preemption.
This commit therefore uses sequence-count-like synchronization to forgive
use of RCU while RCU thinks a CPU is offline across the full extent of
the rcu_cpu_starting() and rcu_report_dead() function's lock acquisitions
and releases.
One approach would have been to use the actual sequence-count primitives
provided by the Linux kernel. Unfortunately, the resulting code looks
completely broken and wrong, and is likely to result in patches that
break RCU in an attempt to address this appearance of broken wrongness.
Plus there is no net savings in lines of code, given the additional
explicit memory barriers required.
Therefore, this sequence count is instead implemented by a new ->ofl_seq
field in the rcu_node structure. If this counter's value is an odd
number, RCU forgives RCU read-side critical sections on other CPUs covered
by the same rcu_node structure, even if those CPUs are offline from
an RCU perspective. In addition, if a given leaf rcu_node structure's
->ofl_seq counter value is an odd number, rcu_gp_init() delays starting
the grace period until that counter value changes.
[ paulmck: Apply Peter Zijlstra feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Testing showed that rcu_pending() can return 1 when offloaded callbacks
are ready to execute. This invokes RCU core processing, for example,
by raising RCU_SOFTIRQ, eventually resulting in a call to rcu_core().
However, rcu_core() explicitly avoids in any way manipulating offloaded
callbacks, which are instead handled by the rcuog and rcuoc kthreads,
which work independently of rcu_core().
One exception to this independence is that rcu_core() invokes
do_nocb_deferred_wakeup(), however, rcu_pending() also checks
rcu_nocb_need_deferred_wakeup() in order to correctly handle this case,
invoking rcu_core() when needed.
This commit therefore avoids needlessly invoking RCU core processing
by checking rcu_segcblist_ready_cbs() only on non-offloaded CPUs.
This reduces overhead, for example, by reducing softirq activity.
This change passed 30 minute tests of TREE01 through TREE09 each.
On TREE08, there is at most 150us from the time that rcu_pending() chose
not to invoke RCU core processing to the time when the ready callbacks
were invoked by the rcuoc kthread. This provides further evidence that
there is no need to invoke rcu_core() for offloaded callbacks that are
ready to invoke.
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
