netdevsim: allow two netdevsim ports to be connected

Add two netdevsim bus attribute to sysfs:
/sys/bus/netdevsim/link_device
/sys/bus/netdevsim/unlink_device

Writing "A M B N" to link_device will

netdevsim: allow two netdevsim ports to be connected

Add two netdevsim bus attribute to sysfs:
/sys/bus/netdevsim/link_device
/sys/bus/netdevsim/unlink_device

Writing "A M B N" to link_device will link netdevsim M in netnsid A with
netdevsim N in netnsid B.

Writing "A M" to unlink_device will unlink netdevsim M in netnsid A from
its peer, if any.

rtnl_lock is taken to ensure nothing changes during the linking.

Signed-off-by: David Wei <[email protected]>
Reviewed-by: Maciek Machnikowski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

net: netdevsim: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
nsim_bu

net: netdevsim: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
nsim_bus_dev_type variable to be a constant structure as well, placing it
into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Ricardo B. Marliere <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: make nsim_bus const

Now that the driver core can properly handle constant struct bus_type,
move the nsim_bus variable to be a constant structure as well,
placing it into read-only memory

netdevsim: make nsim_bus const

Now that the driver core can properly handle constant struct bus_type,
move the nsim_bus variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <[email protected]>
Suggested-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Ricardo B. Marliere <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Block until all devices are released

Like other buses, devices on the netdevsim bus have a release callback
that is invoked when the reference count of the device drops to zero.
However,

netdevsim: Block until all devices are released

Like other buses, devices on the netdevsim bus have a release callback
that is invoked when the reference count of the device drops to zero.
However, unlike other buses such as PCI, the release callback is not
necessarily built into the kernel, as netdevsim can be built as a
module.

The above is problematic as nothing prevents the module from being
unloaded before the release callback has been invoked, which can happen
asynchronously. One such example can be found in commit a380687200e0
("devlink: take device reference for devlink object") where devlink
calls put_device() from an RCU callback.

The issue is not theoretical and the reproducer in [1] can reliably
crash the kernel. The conclusion of this discussion was that the issue
should be solved in netdevsim, which is what this patch is trying to do.

Add a reference count that is increased when a device is added to the
bus and decreased when a device is released. Signal a completion when
the reference count drops to zero and wait for the completion when
unloading the module so that the module will not be unloaded before all
the devices were released. The reference count is initialized to one so
that completion is only signaled when unloading the module.

With this patch, the reproducer in [1] no longer crashes the kernel.

[1] https://lore.kernel.org/netdev/[email protected]/

Fixes: a380687200e0 ("devlink: take device reference for devlink object")
Signed-off-by: Ido Schimmel <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

driver core: bus: mark the struct bus_type for sysfs callbacks as constant

struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, t

driver core: bus: mark the struct bus_type for sysfs callbacks as constant

struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
bus_type to be moved to read-only memory.

Cc: "David S. Miller" <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alexandre Bounine <[email protected]>
Cc: Alison Schofield <[email protected]>
Cc: Ben Widawsky <[email protected]>
Cc: Dexuan Cui <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Harald Freudenberger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hu Haowen <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Laurentiu Tudor <[email protected]>
Cc: Matt Porter <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Stuart Yoder <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Yanteng Si <[email protected]>
Acked-by: Ilya Dryomov <[email protected]> # rbd
Acked-by: Ira Weiny <[email protected]> # cxl
Reviewed-by: Alex Shi <[email protected]>
Acked-by: Iwona Winiarska <[email protected]>
Acked-by: Dan Williams <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]> # pci
Acked-by: Wei Liu <[email protected]>
Acked-by: Martin K. Petersen <[email protected]> # scsi
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

netdevsim: fix memory leak in nsim_bus_dev_new()

If device_register() failed in nsim_bus_dev_new(), the value of reference
in nsim_bus_dev->dev is 1. obj->name in nsim_bus_dev->dev will not be
relea

netdevsim: fix memory leak in nsim_bus_dev_new()

If device_register() failed in nsim_bus_dev_new(), the value of reference
in nsim_bus_dev->dev is 1. obj->name in nsim_bus_dev->dev will not be
released.

unreferenced object 0xffff88810352c480 (size 16):
comm "echo", pid 5691, jiffies 4294945921 (age 133.270s)
hex dump (first 16 bytes):
6e 65 74 64 65 76 73 69 6d 31 00 00 00 00 00 00 netdevsim1......
backtrace:
[<000000005e2e5e26>] __kmalloc_node_track_caller+0x3a/0xb0
[<0000000094ca4fc8>] kvasprintf+0xc3/0x160
[<00000000aad09bcc>] kvasprintf_const+0x55/0x180
[<000000009bac868d>] kobject_set_name_vargs+0x56/0x150
[<000000007c1a5d70>] dev_set_name+0xbb/0xf0
[<00000000ad0d126b>] device_add+0x1f8/0x1cb0
[<00000000c222ae24>] new_device_store+0x3b6/0x5e0
[<0000000043593421>] bus_attr_store+0x72/0xa0
[<00000000cbb1833a>] sysfs_kf_write+0x106/0x160
[<00000000d0dedb8a>] kernfs_fop_write_iter+0x3a8/0x5a0
[<00000000770b66e2>] vfs_write+0x8f0/0xc80
[<0000000078bb39be>] ksys_write+0x106/0x210
[<00000000005e55a4>] do_syscall_64+0x35/0x80
[<00000000eaa40bbc>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: 40e4fe4ce115 ("netdevsim: move device registration and related code to bus.c")
Signed-off-by: Zhengchao Shao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

netdevsim: convert driver to use unlocked devlink API during init/fini

Prepare for devlink reload being called with devlink->lock held and
convert the netdevsim driver to use unlocked devlink API du

netdevsim: convert driver to use unlocked devlink API during init/fini

Prepare for devlink reload being called with devlink->lock held and
convert the netdevsim driver to use unlocked devlink API during init and
fini flows. Take devl_lock() in reload_down() and reload_up() ops in the
meantime before reload cmd is converted to take the lock itself.

Signed-off-by: Jiri Pirko <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

netdevsim: rename 'driver' entry points

Rename functions serving as driver entry points
from nsim_dev_... to nsim_drv_... this makes the
API boundary between bus and dev clearer.

Signed-off-by: Jak

netdevsim: rename 'driver' entry points

Rename functions serving as driver entry points
from nsim_dev_... to nsim_drv_... this makes the
API boundary between bus and dev clearer.

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: move max vf config to dev

max_vfs is a strange little beast because the file
hangs off of nsim's debugfs, but it configures a field
in the bus device. Move it to dev.c, let's look at it
a

netdevsim: move max vf config to dev

max_vfs is a strange little beast because the file
hangs off of nsim's debugfs, but it configures a field
in the bus device. Move it to dev.c, let's look at it
as if the device driver was imposing VF limit based
on FW info (like pci_sriov_set_totalvfs()).

Again, when moving refactor the function not to hold
the vfs lock pointlessly while parsing the input.
Wrap the access from the read side in READ_ONCE()
to appease concurrency checkers. Do not check if
return value from snprintf() is negative...

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: move details of vf config to dev

Since "eswitch" configuration was added bus.c contains
a lot of device details which really belong to dev.c.

Restructure the code while moving it.

Signe

netdevsim: move details of vf config to dev

Since "eswitch" configuration was added bus.c contains
a lot of device details which really belong to dev.c.

Restructure the code while moving it.

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: move vfconfig to nsim_dev

When netdevsim got split into the faux bus vfconfig ended
up in the bus device (think pci_dev) which is strange because
it contains very networky not to say netd

netdevsim: move vfconfig to nsim_dev

When netdevsim got split into the faux bus vfconfig ended
up in the bus device (think pci_dev) which is strange because
it contains very networky not to say netdevy information.
Move it to nsim_dev, which is the driver "priv" structure
for the device.

To make sure we don't race with probe/remove take
the device lock (much like PCI).

While at it remove the NULL-checking of vfconfigs.
It appears to be pointless.

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: take rtnl_lock when assigning num_vfs

Legacy VF NDOs look at num_vfs and then based on that
index into vfconfig. If we don't rtnl_lock() num_vfs
may get set to 0 and vfconfig freed/replac

netdevsim: take rtnl_lock when assigning num_vfs

Legacy VF NDOs look at num_vfs and then based on that
index into vfconfig. If we don't rtnl_lock() num_vfs
may get set to 0 and vfconfig freed/replaced while
the NDO is running.

We don't need to protect replacing vfconfig since it's
only done when num_vfs is 0.

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Protect both reload_down and reload_up paths

Don't progress with adding and deleting ports as long as devlink
reload is running.

Fixes: 23809a726c0d ("netdevsim: Forbid devlink reload wh

netdevsim: Protect both reload_down and reload_up paths

Don't progress with adding and deleting ports as long as devlink
reload is running.

Fixes: 23809a726c0d ("netdevsim: Forbid devlink reload when adding or deleting ports")
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Forbid devlink reload when adding or deleting ports

In order to remove complexity in devlink core related to
devlink_reload_enable/disable, let's rewrite new_port/del_port
logic to rely o

netdevsim: Forbid devlink reload when adding or deleting ports

In order to remove complexity in devlink core related to
devlink_reload_enable/disable, let's rewrite new_port/del_port
logic to rely on internal to netdevsim lcok.

We should protect only reload_down flow because it destroys nsim_dev,
which is needed for nsim_dev_port_add/nsim_dev_port_del to hold
port_list_lock.

Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long last

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <[email protected]> (For fpga)
Reviewed-by: Mathieu Poirier <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <[email protected]> (For ARM, Amba and related parts)
Acked-by: Mark Brown <[email protected]>
Acked-by: Chen-Yu Tsai <[email protected]> (for sunxi-rsb)
Acked-by: Pali Rohár <[email protected]>
Acked-by: Mauro Carvalho Chehab <[email protected]> (for media)
Acked-by: Hans de Goede <[email protected]> (For drivers/platform)
Acked-by: Alexandre Belloni <[email protected]>
Acked-By: Vinod Koul <[email protected]>
Acked-by: Juergen Gross <[email protected]> (For xen)
Acked-by: Lee Jones <[email protected]> (For mfd)
Acked-by: Johannes Thumshirn <[email protected]> (For mcb)
Acked-by: Johan Hovold <[email protected]>
Acked-by: Srinivas Kandagatla <[email protected]> (For slimbus)
Acked-by: Kirti Wankhede <[email protected]> (For vfio)
Acked-by: Maximilian Luz <[email protected]>
Acked-by: Heikki Krogerus <[email protected]> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <[email protected]> (For ipack)
Acked-by: Geoff Levand <[email protected]> (For ps3)
Acked-by: Yehezkel Bernat <[email protected]> (For thunderbolt)
Acked-by: Alexander Shishkin <[email protected]> (For intel_th)
Acked-by: Dominik Brodowski <[email protected]> (For pcmcia)
Acked-by: Rafael J. Wysocki <[email protected]> (For ACPI)
Acked-by: Bjorn Andersson <[email protected]> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <[email protected]> (For intel-ish-hid)
Acked-by: Dan Williams <[email protected]> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <[email protected]> (For isa)
Acked-by: Stefan Richter <[email protected]> (For firewire)
Acked-by: Benjamin Tissoires <[email protected]> (For hid)
Acked-by: Thorsten Scherer <[email protected]> (For siox)
Acked-by: Sven Van Asbroeck <[email protected]> (For anybuss)
Acked-by: Ulf Hansson <[email protected]> (For MMC)
Acked-by: Wolfram Sang <[email protected]> # for I2C
Acked-by: Sudeep Holla <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Dmitry Torokhov <[email protected]>
Acked-by: Finn Thain <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

netdevsim: Add multi-queue support

Currently netdevsim only supports a single queue per port, which is
insufficient for testing multi-queue TC schedulers e.g. sch_mq. Extend
the current sysfs inter

netdevsim: Add multi-queue support

Currently netdevsim only supports a single queue per port, which is
insufficient for testing multi-queue TC schedulers e.g. sch_mq. Extend
the current sysfs interface so that users can create ports with multiple
queues:

$ echo "[ID] [PORT_COUNT] [NUM_QUEUES]" > /sys/bus/netdevsim/new_device

As an example, echoing "2 4 8" creates 4 ports, with 8 queues per port.
Note, this is compatible with the current interface, with default number
of queues set to 1. For example, echoing "2 4" creates 4 ports with 1
queue per port; echoing "2" simply creates 1 port with 1 queue.

Reviewed-by: Cong Wang <[email protected]>
Signed-off-by: Peilin Ye <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Fix unsigned being compared to less than zero

The comparison of len < 0 is always false because len is a size_t. Fix
this by making len a ssize_t instead.

Addresses-Coverity: ("Unsigned

netdevsim: Fix unsigned being compared to less than zero

The comparison of len < 0 is always false because len is a size_t. Fix
this by making len a ssize_t instead.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: d395381909a3 ("netdevsim: Add max_vfs to bus_dev")
Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Implement legacy/switchdev mode for VFs

Implement callbacks to set/get eswitch mode value. Add helpers to check
current mode.

Instantiate VFs' net devices and devlink ports on switchdev

netdevsim: Implement legacy/switchdev mode for VFs

Implement callbacks to set/get eswitch mode value. Add helpers to check
current mode.

Instantiate VFs' net devices and devlink ports on switchdev enabling and
remove them on legacy enabling. Changing number of VFs while in
switchdev mode triggers VFs creation/deletion.

Also disable NDO API callback to set VF rate, since it's legacy API.
Switchdev API to set VF rate will be implemented in one of the next
patches.

Signed-off-by: Dmytro Linkin <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Implement port types and indexing

Define type of ports, which netdevsim driver currently operates with as
PF. Define new port type - VF, which will be implemented in following
patches. Ad

netdevsim: Implement port types and indexing

Define type of ports, which netdevsim driver currently operates with as
PF. Define new port type - VF, which will be implemented in following
patches. Add helper functions to distinguish them. Add helper function
to get VF index from port index.

Add port indexing logic where PFs' indexes starts from 0, VFs' - from
NSIM_DEV_VF_PORT_INDEX_BASE.
All ports uses same index pool, which means that PF port may be created
with index from VFs' indexes range.
Maximum number of VFs, which the driver can allocate, is limited by
UINT_MAX - BASE.

Signed-off-by: Dmytro Linkin <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Disable VFs on nsim_dev_reload_destroy() call

Move VFs disabling from device release() to nsim_dev_reload_destroy() to
make VFs disabling and ports removal simultaneous.
This is a require

netdevsim: Disable VFs on nsim_dev_reload_destroy() call

Move VFs disabling from device release() to nsim_dev_reload_destroy() to
make VFs disabling and ports removal simultaneous.
This is a requirement for VFs ports implemented in next patches.

Signed-off-by: Dmytro Linkin <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

netdevsim: Add max_vfs to bus_dev

Currently there is no limit to the number of VFs netdevsim can enable.
In a real systems this value exist and used by the driver.
Fore example, some features might

netdevsim: Add max_vfs to bus_dev

Currently there is no limit to the number of VFs netdevsim can enable.
In a real systems this value exist and used by the driver.
Fore example, some features might need to consider this value when
allocating memory.

Expose max_vfs variable to debugfs as configurable resource. If are VFs
configured (num_vfs != 0) then changing of max_vfs not allowed.

Co-developed-by: Yuval Avnery <[email protected]>
Signed-off-by: Yuval Avnery <[email protected]>
Signed-off-by: Dmytro Linkin <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

show more ...

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through mar

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>

show more ...

netdevsim: use __GFP_NOWARN to avoid memalloc warning

vfnum buffer size and binary_len buffer size is received by user-space.
So, this buffer size could be too large. If so, kmalloc will internally

netdevsim: use __GFP_NOWARN to avoid memalloc warning

vfnum buffer size and binary_len buffer size is received by user-space.
So, this buffer size could be too large. If so, kmalloc will internally
print a warning message.
This warning message is actually not necessary for the netdevsim module.
So, this patch adds __GFP_NOWARN.

Test commands:
modprobe netdevsim
echo 1 > /sys/bus/netdevsim/new_device
echo 1000000000 > /sys/devices/netdevsim1/sriov_numvfs

Splat looks like:
[ 357.847266][ T1000] WARNING: CPU: 0 PID: 1000 at mm/page_alloc.c:4738 __alloc_pages_nodemask+0x2f3/0x740
[ 357.850273][ T1000] Modules linked in: netdevsim veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrx
[ 357.852989][ T1000] CPU: 0 PID: 1000 Comm: bash Tainted: G B 5.5.0-rc5+ #270
[ 357.854334][ T1000] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 357.855703][ T1000] RIP: 0010:__alloc_pages_nodemask+0x2f3/0x740
[ 357.856669][ T1000] Code: 64 fe ff ff 65 48 8b 04 25 c0 0f 02 00 48 05 f0 12 00 00 41 be 01 00 00 00 49 89 47 0
[ 357.860272][ T1000] RSP: 0018:ffff8880b7f47bd8 EFLAGS: 00010246
[ 357.861009][ T1000] RAX: ffffed1016fe8f80 RBX: 1ffff11016fe8fae RCX: 0000000000000000
[ 357.861843][ T1000] RDX: 0000000000000000 RSI: 0000000000000017 RDI: 0000000000000000
[ 357.862661][ T1000] RBP: 0000000000040dc0 R08: 1ffff11016fe8f67 R09: dffffc0000000000
[ 357.863509][ T1000] R10: ffff8880b7f47d68 R11: fffffbfff2798180 R12: 1ffff11016fe8f80
[ 357.864355][ T1000] R13: 0000000000000017 R14: 0000000000000017 R15: ffff8880c2038d68
[ 357.865178][ T1000] FS: 00007fd9a5b8c740(0000) GS:ffff8880d9c00000(0000) knlGS:0000000000000000
[ 357.866248][ T1000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 357.867531][ T1000] CR2: 000055ce01ba8100 CR3: 00000000b7dbe005 CR4: 00000000000606f0
[ 357.868972][ T1000] Call Trace:
[ 357.869423][ T1000] ? lock_contended+0xcd0/0xcd0
[ 357.870001][ T1000] ? __alloc_pages_slowpath+0x21d0/0x21d0
[ 357.870673][ T1000] ? _kstrtoull+0x76/0x160
[ 357.871148][ T1000] ? alloc_pages_current+0xc1/0x1a0
[ 357.871704][ T1000] kmalloc_order+0x22/0x80
[ 357.872184][ T1000] kmalloc_order_trace+0x1d/0x140
[ 357.872733][ T1000] __kmalloc+0x302/0x3a0
[ 357.873204][ T1000] nsim_bus_dev_numvfs_store+0x1ab/0x260 [netdevsim]
[ 357.873919][ T1000] ? kernfs_get_active+0x12c/0x180
[ 357.874459][ T1000] ? new_device_store+0x450/0x450 [netdevsim]
[ 357.875111][ T1000] ? kernfs_get_parent+0x70/0x70
[ 357.875632][ T1000] ? sysfs_file_ops+0x160/0x160
[ 357.876152][ T1000] kernfs_fop_write+0x276/0x410
[ 357.876680][ T1000] ? __sb_start_write+0x1ba/0x2e0
[ 357.877225][ T1000] vfs_write+0x197/0x4a0
[ 357.877671][ T1000] ksys_write+0x141/0x1d0
[ ... ]

Reviewed-by: Jakub Kicinski <[email protected]>
Fixes: 79579220566c ("netdevsim: add SR-IOV functionality")
Fixes: 82c93a87bf8b ("netdevsim: implement couple of testing devlink health reporters")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

netdevsim: disable devlink reload when resources are being used

devlink reload destroys resources and allocates resources again.
So, when devices and ports resources are being used, devlink reload
f

netdevsim: disable devlink reload when resources are being used

devlink reload destroys resources and allocates resources again.
So, when devices and ports resources are being used, devlink reload
function should not be executed. In order to avoid this race, a new
lock is added and new_port() and del_port() call devlink_reload_disable()
and devlink_reload_enable().

Thread0 Thread1
{new/del}_port() {new/del}_port()
devlink_reload_disable()
devlink_reload_disable()
devlink_reload_enable()
//here
devlink_reload_enable()

Before Thread1's devlink_reload_enable(), the devlink is already allowed
to execute reload because Thread0 allows it. devlink reload disable/enable
variable type is bool. So the above case would exist.
So, disable/enable should be executed atomically.
In order to do that, a new lock is used.

Test commands:
modprobe netdevsim
echo 1 > /sys/bus/netdevsim/new_device
while :
do
echo 1 > /sys/devices/netdevsim1/new_port &
echo 1 > /sys/devices/netdevsim1/del_port &
devlink dev reload netdevsim/netdevsim1 &
done

Splat looks like:
[ 23.342145][ T932] DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock))
[ 23.342159][ T932] WARNING: CPU: 0 PID: 932 at kernel/locking/mutex-debug.c:103 mutex_destroy+0xc7/0xf0
[ 23.344182][ T932] Modules linked in: netdevsim openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_dx
[ 23.346485][ T932] CPU: 0 PID: 932 Comm: devlink Not tainted 5.5.0+ #322
[ 23.347696][ T932] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 23.348893][ T932] RIP: 0010:mutex_destroy+0xc7/0xf0
[ 23.349505][ T932] Code: e0 07 83 c0 03 38 d0 7c 04 84 d2 75 2e 8b 05 00 ac b0 02 85 c0 75 8b 48 c7 c6 00 5e 07 96 40
[ 23.351887][ T932] RSP: 0018:ffff88806208f810 EFLAGS: 00010286
[ 23.353963][ T932] RAX: dffffc0000000008 RBX: ffff888067f6f2c0 RCX: ffffffff942c4bd4
[ 23.355222][ T932] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff96dac5b4
[ 23.356169][ T932] RBP: ffff888067f6f000 R08: fffffbfff2d235a5 R09: fffffbfff2d235a5
[ 23.357160][ T932] R10: 0000000000000001 R11: fffffbfff2d235a4 R12: ffff888067f6f208
[ 23.358288][ T932] R13: ffff88806208fa70 R14: ffff888067f6f000 R15: ffff888069ce3800
[ 23.359307][ T932] FS: 00007fe2a3876740(0000) GS:ffff88806c000000(0000) knlGS:0000000000000000
[ 23.360473][ T932] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 23.361319][ T932] CR2: 00005561357aa000 CR3: 000000005227a006 CR4: 00000000000606f0
[ 23.362323][ T932] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 23.363417][ T932] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 23.364414][ T932] Call Trace:
[ 23.364828][ T932] nsim_dev_reload_destroy+0x77/0xb0 [netdevsim]
[ 23.365655][ T932] nsim_dev_reload_down+0x84/0xb0 [netdevsim]
[ 23.366433][ T932] devlink_reload+0xb1/0x350
[ 23.367010][ T932] genl_rcv_msg+0x580/0xe90

[ ...]

[ 23.531729][ T1305] kernel BUG at lib/list_debug.c:53!
[ 23.532523][ T1305] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 23.533467][ T1305] CPU: 2 PID: 1305 Comm: bash Tainted: G W 5.5.0+ #322
[ 23.534962][ T1305] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 23.536503][ T1305] RIP: 0010:__list_del_entry_valid+0xe6/0x150
[ 23.538346][ T1305] Code: 89 ea 48 c7 c7 00 73 1e 96 e8 df f7 4c ff 0f 0b 48 c7 c7 60 73 1e 96 e8 d1 f7 4c ff 0f 0b 44
[ 23.541068][ T1305] RSP: 0018:ffff888047c27b58 EFLAGS: 00010282
[ 23.542001][ T1305] RAX: 0000000000000054 RBX: ffff888067f6f318 RCX: 0000000000000000
[ 23.543051][ T1305] RDX: 0000000000000054 RSI: 0000000000000008 RDI: ffffed1008f84f61
[ 23.544072][ T1305] RBP: ffff88804aa0fca0 R08: ffffed100d940539 R09: ffffed100d940539
[ 23.545085][ T1305] R10: 0000000000000001 R11: ffffed100d940538 R12: ffff888047c27cb0
[ 23.546422][ T1305] R13: ffff88806208b840 R14: ffffffff981976c0 R15: ffff888067f6f2c0
[ 23.547406][ T1305] FS: 00007f76c0431740(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000
[ 23.548527][ T1305] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 23.549389][ T1305] CR2: 00007f5048f1a2f8 CR3: 000000004b310006 CR4: 00000000000606e0
[ 23.550636][ T1305] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 23.551578][ T1305] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 23.552597][ T1305] Call Trace:
[ 23.553004][ T1305] mutex_remove_waiter+0x101/0x520
[ 23.553646][ T1305] __mutex_lock+0xac7/0x14b0
[ 23.554218][ T1305] ? nsim_dev_port_del+0x4e/0x140 [netdevsim]
[ 23.554908][ T1305] ? mutex_lock_io_nested+0x1380/0x1380
[ 23.555570][ T1305] ? _parse_integer+0xf0/0xf0
[ 23.556043][ T1305] ? kstrtouint+0x86/0x110
[ 23.556504][ T1305] ? nsim_dev_port_del+0x4e/0x140 [netdevsim]
[ 23.557133][ T1305] nsim_dev_port_del+0x4e/0x140 [netdevsim]
[ 23.558024][ T1305] del_port_store+0xcc/0xf0 [netdevsim]
[ ... ]

Fixes: 75ba029f3c07 ("netdevsim: implement proper devlink reload")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

netdevsim: fix using uninitialized resources

When module is being initialized, __init() calls bus_register() and
driver_register().
These functions internally create various resources and sysfs file

netdevsim: fix using uninitialized resources

When module is being initialized, __init() calls bus_register() and
driver_register().
These functions internally create various resources and sysfs files.
The sysfs files are used for basic operations(add/del device).
/sys/bus/netdevsim/new_device
/sys/bus/netdevsim/del_device

These sysfs files use netdevsim resources, they are mostly allocated
and initialized in ->probe() function, which is nsim_dev_probe().
But, sysfs files could be executed before ->probe() is finished.
So, accessing uninitialized data would occur.

Another problem is very similar.
/sys/bus/netdevsim/new_device internally creates sysfs files.
/sys/devices/netdevsim<id>/new_port
/sys/devices/netdevsim<id>/del_port

These sysfs files also use netdevsim resources, they are mostly allocated
and initialized in creating device routine, which is nsim_bus_dev_new().
But they also could be executed before nsim_bus_dev_new() is finished.
So, accessing uninitialized data would occur.

To fix these problems, this patch adds flags, which means whether the
operation is finished or not.
The flag variable 'nsim_bus_enable' means whether netdevsim bus was
initialized or not.
This is protected by nsim_bus_dev_list_lock.
The flag variable 'nsim_bus_dev->init' means whether nsim_bus_dev was
initialized or not.
This could be used in {new/del}_port_store() with no lock.

Test commands:
#SHELL1
modprobe netdevsim
while :
do
echo "1 1" > /sys/bus/netdevsim/new_device
echo "1 1" > /sys/bus/netdevsim/del_device
done

#SHELL2
while :
do
echo 1 > /sys/devices/netdevsim1/new_port
echo 1 > /sys/devices/netdevsim1/del_port
done

Splat looks like:
[ 47.508954][ T1008] general protection fault, probably for non-canonical address 0xdffffc0000000021: 0000 I
[ 47.510793][ T1008] KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
[ 47.511963][ T1008] CPU: 2 PID: 1008 Comm: bash Not tainted 5.5.0+ #322
[ 47.512823][ T1008] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 47.514041][ T1008] RIP: 0010:__mutex_lock+0x10a/0x14b0
[ 47.514699][ T1008] Code: 08 84 d2 0f 85 7f 12 00 00 44 8b 0d 10 23 65 02 45 85 c9 75 29 49 8d 7f 68 48 b8 00 00 00 0f
[ 47.517163][ T1008] RSP: 0018:ffff888059b4fbb0 EFLAGS: 00010206
[ 47.517802][ T1008] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 47.518941][ T1008] RDX: 0000000000000021 RSI: ffffffff85926440 RDI: 0000000000000108
[ 47.519732][ T1008] RBP: ffff888059b4fd30 R08: ffffffffc073fad0 R09: 0000000000000000
[ 47.520729][ T1008] R10: ffff888059b4fd50 R11: ffff88804bb38040 R12: 0000000000000000
[ 47.521702][ T1008] R13: dffffc0000000000 R14: ffffffff871976c0 R15: 00000000000000a0
[ 47.522760][ T1008] FS: 00007fd4be05a740(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000
[ 47.523877][ T1008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 47.524627][ T1008] CR2: 0000561c82b69cf0 CR3: 0000000065dd6004 CR4: 00000000000606e0
[ 47.527662][ T1008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 47.528604][ T1008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 47.529531][ T1008] Call Trace:
[ 47.529874][ T1008] ? nsim_dev_port_add+0x50/0x150 [netdevsim]
[ 47.530470][ T1008] ? mutex_lock_io_nested+0x1380/0x1380
[ 47.531018][ T1008] ? _kstrtoull+0x76/0x160
[ 47.531449][ T1008] ? _parse_integer+0xf0/0xf0
[ 47.531874][ T1008] ? kernfs_fop_write+0x1cf/0x410
[ 47.532330][ T1008] ? sysfs_file_ops+0x160/0x160
[ 47.532773][ T1008] ? kstrtouint+0x86/0x110
[ 47.533168][ T1008] ? nsim_dev_port_add+0x50/0x150 [netdevsim]
[ 47.533721][ T1008] nsim_dev_port_add+0x50/0x150 [netdevsim]
[ 47.534336][ T1008] ? sysfs_file_ops+0x160/0x160
[ 47.534858][ T1008] new_port_store+0x99/0xb0 [netdevsim]
[ 47.535439][ T1008] ? del_port_store+0xb0/0xb0 [netdevsim]
[ 47.536035][ T1008] ? sysfs_file_ops+0x112/0x160
[ 47.536544][ T1008] ? sysfs_kf_write+0x3b/0x180
[ 47.537029][ T1008] kernfs_fop_write+0x276/0x410
[ 47.537548][ T1008] ? __sb_start_write+0x215/0x2e0
[ 47.538110][ T1008] vfs_write+0x197/0x4a0
[ ... ]

Fixes: f9d9db47d3ba ("netdevsim: add bus attributes to add new and delete devices")
Fixes: 794b2c05ca1c ("netdevsim: extend device attrs to support port addition and deletion")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...