The mmc core uses a PM notifier to temporarily during system suspend, turn
off the card detection mechanism for removal/insertion of (e)MMC/SD/SDIO
cards. Additionally, the notifier may be used to remove an SDIO card
entirely, if a corresponding SDIO functional driver don't have the system
suspend/resume callbacks assigned. This behaviour has been around for a
very long time.
However, a recent bug report tells us there are problems with this
approach. More precisely, when receiving the PM_SUSPEND_PREPARE
notification, we may end up hanging on I/O to be completed, thus also
preventing the system from getting suspended.
In the end what happens, is that the cancel_delayed_work_sync() in
mmc_pm_notify() ends up waiting for mmc_rescan() to complete - and since
mmc_rescan() wants to claim the host, it needs to wait for the I/O to be
completed first.
Typically, this problem is triggered in Android, if there is ongoing I/O
while the user decides to suspend, resume and then suspend the system
again. This due to that after the resume, an mmc_rescan() work gets punted
to the workqueue, which job is to verify that the card remains inserted
after the system has resumed.
To fix this problem, userspace needs to become frozen to suspend the I/O,
prior to turning off the card detection mechanism. Therefore, let's drop
the PM notifiers for mmc subsystem altogether and rely on the card
detection to be turned off/on as a part of the system_freezable_wq, that we
are already using.
Moreover, to allow and SDIO card to be removed during system suspend, let's
manage this from a ->prepare() callback, assigned at the mmc_host_class
level. In this way, we can use the parent device (the mmc_host_class
device), to remove the card device that is the child, in the
device_prepare() phase.
Reported-by: Kiwoong Kim <kwmad.kim@samsung.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210310152900.149380-1-ulf.hansson@linaro.org
Reviewed-by: Kiwoong Kim <kwmad.kim@samsung.com>
When the mmc_rescan work is enabled for execution (host->rescan_disable),
it's the only instance per mmc host that is allowed to set/clear the
host->bus_ops pointer.
Besides the mmc_rescan work, there are a couple of scenarios when the
host->bus_ops pointer may be accessed. Typically, those can be described as
as below:
*)
Upper mmc driver layers (like the mmc block device driver or an SDIO
functional driver) needs to execute a host->bus_ops callback. This can be
considered as safe without having to use some special locking mechanism,
because they operate on top of the struct mmc_card. As long as there is a
card to operate upon, the mmc core guarantees that there is a host->bus_ops
assigned as well. Note that, upper layer mmc drivers are of course
responsible to clean up from themselves from their ->remove() callbacks,
otherwise things would fall apart anyways.
**)
Via the mmc host instance, we may need to force a removal of an inserted
mmc card. This happens when a mmc host driver gets unbind, for example. In
this case, we protect the host->bus_ops pointer from concurrent accesses,
by disabling the mmc_rescan work upfront (host->rescan_disable). See
mmc_stop_host() for example.
This said, it seems like the reference counting of the host->bus_ops
pointer at some point have become superfluous. As this is an old mechanism
of the mmc core, it a bit difficult to digest the history of when that
could have happened. However, let's drop the reference counting to avoid
unnecessary code-paths and lockings.
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20210212131610.236843-1-ulf.hansson@linaro.org
Add three macro to simplify the readability of big bit timing numbers:
- CAN_KBPS: kilobits per second (one thousand)
- CAN_MBPS: megabits per second (one million)
- CAN_MHZ: megahertz per second (one million)
Example:
u32 bitrate_max = 8 * CAN_MBPS;
struct can_clock clock = {.freq = 80 * CAN_MHZ};
instead of:
u32 bitrate_max = 8000000;
struct can_clock clock = {.freq = 80000000};
Apply the new macro to driver/net/can/dev/bittiming.c.
Link: https://lore.kernel.org/r/20210306054040.76483-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The logic for the tdco calculation is to just reuse the normal sample
point: tdco = sp. Because the sample point is expressed in tenth of
percent and the tdco is expressed in time quanta, a conversion is
needed.
At the end,
ssp = tdcv + tdco
= tdcv + sp.
Another popular method is to set tdco to the middle of the bit:
tdc->tdco = can_bit_time(dbt) / 2
During benchmark tests, we could not find a clear advantages for one
of the two methods.
The tdco calculation is triggered each time the data_bittiming is
changed so that users relying on automated calculation can use the
netlink interface the exact same way without need of new parameters.
For example, a command such as:
ip link set canX type can bitrate 500000 dbitrate 4000000 fd on
would trigger the calculation.
The user using CONFIG_CAN_CALC_BITTIMING who does not want automated
calculation needs to manually set tdco to zero.
For example with:
ip link set canX type can tdco 0 bitrate 500000 dbitrate 4000000 fd on
(if the tdco parameter is provided in a previous command, it will be
overwritten).
If tdcv is set to zero (default), it is automatically calculated by
the transiver for each frame. As such, there is no code in the kernel
to calculate it.
tdcf has no automated calculation functions because we could not
figure out a formula for this parameter.
Link: https://lore.kernel.org/r/20210224002008.4158-6-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In order to implement byte queue limits (bql) in CAN drivers, the
length of the CAN frame needs to be passed into the networking stack
even if the transmission failed for some reason.
To avoid to calculate this length twice, extend can_free_echo_skb() to
return that value. Convert all users of this function, too.
This patch is the natural extension of commit:
| 9420e1d495 ("can: dev: can_get_echo_skb(): extend to return can
| frame length")
Link: https://lore.kernel.org/r/20210319142700.305648-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The command:
find ./include/linux/soc/qcom/ | xargs ./scripts/kernel-doc -none
reports:
./include/linux/soc/qcom/qmi.h:26: warning: cannot understand function prototype: 'struct qmi_header '
./include/linux/soc/qcom/qmi.h:101: warning: cannot understand function prototype: 'struct qmi_response_type_v01 '
./include/linux/soc/qcom/irq.h:19: warning: expecting prototype for QCOM specific IRQ domain flags that distinguishes the handling of wakeup(). Prototype was for IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP() instead
./include/linux/soc/qcom/apr.h:126: warning: Function parameter or member '__apr_driver' not described in 'module_apr_driver'
./include/linux/soc/qcom/apr.h:126: warning: Excess function parameter '__aprbus_driver' description in 'module_apr_driver'
./include/linux/soc/qcom/llcc-qcom.h:43: warning: cannot understand function prototype: 'struct llcc_slice_desc '
./include/linux/soc/qcom/llcc-qcom.h:60: warning: cannot understand function prototype: 'struct llcc_edac_reg_data '
./include/linux/soc/qcom/llcc-qcom.h:86: warning: cannot understand function prototype: 'struct llcc_drv_data '
Address all those warnings by:
- prefixing kernel-doc descriptions for structs with the keyword 'struct',
- turning a kernel-doc comment that does not follow the kernel-doc syntax
into a normal comment, and
- correcting a parameter name in a kernel-doc comment.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20210327065642.11969-3-lukas.bulwahn@gmail.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
A kernel panic was observed due to a timing issue between the sync thread
and the initiator processing a login response from the target. The session
reopen can be invoked both from the session sync thread when iscsid
restarts and from iscsid through the error handler. Before the initiator
receives the response to a login, another reopen request can be sent from
the error handler/sync session. When the initial login response is
subsequently processed, the connection has been closed and the socket has
been released.
To fix this a new connection state, ISCSI_CONN_BOUND, is added:
- Set the connection state value to ISCSI_CONN_DOWN upon
iscsi_if_ep_disconnect() and iscsi_if_stop_conn()
- Set the connection state to the newly created value ISCSI_CONN_BOUND
after bind connection (transport->bind_conn())
- In iscsi_set_param(), return -ENOTCONN if the connection state is not
either ISCSI_CONN_BOUND or ISCSI_CONN_UP
Link: https://lore.kernel.org/r/20210325093248.284678-1-gulam.mohamed@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Gulam Mohamed <gulam.mohamed@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
index 91074fd97f64..f4bf62b007a0 100644
The following problem has been reported by George Kennedy:
Since commit 7fef431be9 ("mm/page_alloc: place pages to tail
in __free_pages_core()") the following use after free occurs
intermittently when ACPI tables are accessed.
BUG: KASAN: use-after-free in ibft_init+0x134/0xc49
Read of size 4 at addr ffff8880be453004 by task swapper/0/1
CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1-7a7fd0d #1
Call Trace:
dump_stack+0xf6/0x158
print_address_description.constprop.9+0x41/0x60
kasan_report.cold.14+0x7b/0xd4
__asan_report_load_n_noabort+0xf/0x20
ibft_init+0x134/0xc49
do_one_initcall+0xc4/0x3e0
kernel_init_freeable+0x5af/0x66b
kernel_init+0x16/0x1d0
ret_from_fork+0x22/0x30
ACPI tables mapped via kmap() do not have their mapped pages
reserved and the pages can be "stolen" by the buddy allocator.
Apparently, on the affected system, the ACPI table in question is
not located in "reserved" memory, like ACPI NVS or ACPI Data, that
will not be used by the buddy allocator, so the memory occupied by
that table has to be explicitly reserved to prevent the buddy
allocator from using it.
In order to address this problem, rearrange the initialization of the
ACPI tables on x86 to locate the initial tables earlier and reserve
the memory occupied by them.
The other architectures using ACPI should not be affected by this
change.
Link: https://lore.kernel.org/linux-acpi/1614802160-29362-1-git-send-email-george.kennedy@oracle.com/
Reported-by: George Kennedy <george.kennedy@oracle.com>
Tested-by: George Kennedy <george.kennedy@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
The rtmutex specific deadlock detector predates lockdep coverage of rtmutex
and since commit f5694788ad ("rt_mutex: Add lockdep annotations") it
contains a lot of redundant functionality:
- lockdep will detect an potential deadlock before rtmutex-debug
has a chance to do so
- the deadlock debugging is restricted to rtmutexes which are not
associated to futexes and have an active waiter, which is covered by
lockdep already
Remove the redundant functionality and move actual deadlock WARN() into the
deadlock code path. The latter needs a seperate cleanup.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210326153943.320398604@linutronix.de
The following debug members of 'struct rtmutex' are unused:
- save_state: No users
- file,line: Printed if ::name is NULL. This is only used for non-futex
locks so ::name is never NULL
- magic: Assigned to NULL by rt_mutex_destroy(), no further usage
Remove them along with unused inline and macro leftovers related to
the long gone deadlock tester.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210326153943.195064296@linutronix.de
Extend common protocol registration routines and provide some new generic
protocols get/put helpers that can track protocols usage and automatically
perform the proper initialization and de-initialization on demand when
required.
Convert all standard protocols to use this new registration scheme while
keeping them all still using the usual initialization logic bound to SCMI
devices probing.
Link: https://lore.kernel.org/r/20210316124903.35011-2-cristian.marussi@arm.com
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
In commit ea7800565a ("can: add optional DLC element to Classical
CAN frame structure") the struct can_frame::can_dlc was put into an
anonymous union with another u8 variable.
For various reasons some members in struct can_frame and canfd_frame
including the first 8 byes of data are expected to have the same
memory layout. This is enforced by a BUILD_BUG_ON check in af_can.c.
Since the above mentioned commit this check fails on ARM kernels
compiled with the ARM OABI (which means CONFIG_AEABI not set). In this
case -mabi=apcs-gnu is passed to the compiler, which leads to a
structure size boundary of 32, instead of 8 compared to CONFIG_AEABI
enabled. This means the the union in struct can_frame takes 4 bytes
instead of the expected 1.
Rong Chen illustrates the problem with pahole in the ARM OABI case:
| struct can_frame {
| canid_t can_id; /* 0 4 */
| union {
| __u8 len; /* 4 1 */
| __u8 can_dlc; /* 4 1 */
| }; /* 4 4 */
| __u8 __pad; /* 8 1 */
| __u8 __res0; /* 9 1 */
| __u8 len8_dlc; /* 10 1 */
|
| /* XXX 5 bytes hole, try to pack */
|
| __u8 data[8]
| __attribute__((__aligned__(8))); /* 16 8 */
|
| /* size: 24, cachelines: 1, members: 6 */
| /* sum members: 19, holes: 1, sum holes: 5 */
| /* forced alignments: 1, forced holes: 1, sum forced holes: 5 */
| /* last cacheline: 24 bytes */
| } __attribute__((__aligned__(8)));
Marking the anonymous union as __attribute__((packed)) fixes the
BUILD_BUG_ON problem on these compilers.
Fixes: ea7800565a ("can: add optional DLC element to Classical CAN frame structure")
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Rong Chen <rong.a.chen@intel.com>
Link: https://lore.kernel.org/linux-can/2c82ec23-3551-61b5-1bd8-178c3407ee83@hartkopp.net/
Link: https://lore.kernel.org/r/20210325125850.1620-3-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
After resilient next-hop groups have been added recently, there are two
types of multipath next-hop groups: the legacy "mpath", and the new
"resilient". Calling the legacy next-hop group type "mpath" is unfortunate,
because that describes the fact that a packet could be forwarded in one of
several paths, which is also true for the resilient next-hop groups.
Therefore, to make the naming clearer, rename various artifacts to reflect
the assumptions made. Therefore as of this patch:
- The flag for multipath groups is nh_grp_entry::is_multipath. This
includes the legacy and resilient groups, as well as any future group
types that behave as multipath groups.
Functions that assume this have "mpath" in the name.
- The flag for legacy multipath groups is nh_grp_entry::hash_threshold.
Functions that assume this have "hthr" in the name.
- The flag for resilient groups is nh_grp_entry::resilient.
Functions that assume this have "res" in the name.
Besides the above, struct nh_grp_entry::mpath was renamed to ::hthr as
well.
UAPI artifacts were obviously left intact.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull locking fix from Ingo Molnar:
"Fix the non-debug mutex_lock_io_nested() method to map to
mutex_lock_io() instead of mutex_lock().
Right now nothing uses this API explicitly, but this is an
accident waiting to happen"
* tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/mutex: Fix non debug version of mutex_lock_io_nested()
Moritz writes:
FPGA Manager fixes for 5.12
Richard's fix addresses an errornously flipped flag.
All patches have been reviewed on the mailing list, and have been in the
last few linux-next releases (as part of my fixes branch) without issues.
Signed-off-by: Moritz Fischer <mdf@kernel.org>
* tag 'fpga-fixes-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga:
firmware: stratix10-svc: reset COMMAND_RECONFIG_FLAG_PARTIAL to 0
This patch adds a few kernel function bpf_kfunc_call_test*() for the
selftest's test_run purpose. They will be allowed for tc_cls prog.
The selftest calling the kernel function bpf_kfunc_call_test*()
is also added in this patch.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015252.1551395-1-kafai@fb.com
This patch adds support to BPF verifier to allow bpf program calling
kernel function directly.
The use case included in this set is to allow bpf-tcp-cc to directly
call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()"). Those
functions have already been used by some kernel tcp-cc implementations.
This set will also allow the bpf-tcp-cc program to directly call the
kernel tcp-cc implementation, For example, a bpf_dctcp may only want to
implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly
from the kernel tcp_dctcp.c instead of reimplementing (or
copy-and-pasting) them.
The tcp-cc kernel functions mentioned above will be white listed
for the struct_ops bpf-tcp-cc programs to use in a later patch.
The white listed functions are not bounded to a fixed ABI contract.
Those functions have already been used by the existing kernel tcp-cc.
If any of them has changed, both in-tree and out-of-tree kernel tcp-cc
implementations have to be changed. The same goes for the struct_ops
bpf-tcp-cc programs which have to be adjusted accordingly.
This patch is to make the required changes in the bpf verifier.
First change is in btf.c, it adds a case in "btf_check_func_arg_match()".
When the passed in "btf->kernel_btf == true", it means matching the
verifier regs' states with a kernel function. This will handle the
PTR_TO_BTF_ID reg. It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET,
and PTR_TO_TCP_SOCK to its kernel's btf_id.
In the later libbpf patch, the insn calling a kernel function will
look like:
insn->code == (BPF_JMP | BPF_CALL)
insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */
insn->imm == func_btf_id /* btf_id of the running kernel */
[ For the future calling function-in-kernel-module support, an array
of module btf_fds can be passed at the load time and insn->off
can be used to index into this array. ]
At the early stage of verifier, the verifier will collect all kernel
function calls into "struct bpf_kfunc_desc". Those
descriptors are stored in "prog->aux->kfunc_tab" and will
be available to the JIT. Since this "add" operation is similar
to the current "add_subprog()" and looking for the same insn->code,
they are done together in the new "add_subprog_and_kfunc()".
In the "do_check()" stage, the new "check_kfunc_call()" is added
to verify the kernel function call instruction:
1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE.
A new bpf_verifier_ops "check_kfunc_call" is added to do that.
The bpf-tcp-cc struct_ops program will implement this function in
a later patch.
2. Call "btf_check_kfunc_args_match()" to ensure the regs can be
used as the args of a kernel function.
3. Mark the regs' type, subreg_def, and zext_dst.
At the later do_misc_fixups() stage, the new fixup_kfunc_call()
will replace the insn->imm with the function address (relative
to __bpf_call_base). If needed, the jit can find the btf_func_model
by calling the new bpf_jit_find_kfunc_model(prog, insn).
With the imm set to the function address, "bpftool prog dump xlated"
will be able to display the kernel function calls the same way as
it displays other bpf helper calls.
gpl_compatible program is required to call kernel function.
This feature currently requires JIT.
The verifier selftests are adjusted because of the changes in
the verbose log in add_subprog_and_kfunc().
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
This patch moved the subprog specific logic from
btf_check_func_arg_match() to the new btf_check_subprog_arg_match().
The core logic is left in btf_check_func_arg_match() which
will be reused later to check the kernel function call.
The "if (!btf_type_is_ptr(t))" is checked first to improve the
indentation which will be useful for a later patch.
Some of the "btf_kind_str[]" usages is replaced with the shortcut
"btf_type_str(t)".
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015136.1544504-1-kafai@fb.com
This patch simplifies the linfo freeing logic by combining
"bpf_prog_free_jited_linfo()" and "bpf_prog_free_unused_jited_linfo()"
into the new "bpf_prog_jit_attempt_done()".
It is a prep work for the kernel function call support. In a later
patch, freeing the kernel function call descriptors will also
be done in the "bpf_prog_jit_attempt_done()".
"bpf_prog_free_linfo()" is removed since it is only called by
"__bpf_prog_put_noref()". The kvfree() are directly called
instead.
It also takes this chance to s/kcalloc/kvcalloc/ for the jited_linfo
allocation.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015130.1544323-1-kafai@fb.com
