f4adc6430d
[ Upstream commit 63d4a4c145cca2e84dc6e62d2ef5cb990c9723c2 ]
The reset work is scheduled by the timer routine whenever it
detects that a device reset is required (e.g. when a keep_alive signal
is missing).
When releasing device resources in ena_destroy_device() the driver
cancels the scheduling of the timer routine without destroying the reset
work explicitly.
This creates the following bug:
The driver is suspended and the ena_suspend() function is called
-> This function calls ena_destroy_device() to free the net device
resources
-> The driver waits for the timer routine to finish
its execution and then cancels it, thus preventing from it
to be called again.
If, in its final execution, the timer routine schedules a reset,
the reset routine might be called afterwards,and a redundant call to
ena_restore_device() would be made.
By changing the reset routine we allow it to read the device's state
accurately.
This is achieved by checking whether ENA_FLAG_TRIGGER_RESET flag is set
before resetting the device and making both the destruction function and
the flag check are under rtnl lock.
The ENA_FLAG_TRIGGER_RESET is cleared at the end of the destruction
routine. Also surround the flag check with 'likely' because
we expect that the reset routine would be called only when
ENA_FLAG_TRIGGER_RESET flag is set.
The destruction of the timer and reset services in __ena_shutoff() have to
stay, even though the timer routine is destroyed in ena_destroy_device().
This is to avoid a case in which the reset routine is scheduled after
free_netdev() in __ena_shutoff(), which would create an access to freed
memory in adapter->flags.
Fixes: 8c5c7abdeb2d ("net: ena: add power management ops to the ENA driver")
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.