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GPL-2.0-only
has been chosen to replace the boilerplate/reference in 655 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In _scif_prog_signal(), a DMA pool is allocated if the MIC Coprocessor is
not X100, i.e., the boolean variable 'x100' is false. This DMA pool will be
freed eventually through the callback function scif_prog_signal_cb() with
the parameter of 'status', which actually points to the start of DMA pool.
Specifically, in scif_prog_signal_cb(), the 'ep' field and the
'src_dma_addr' field of 'status' are used to free the DMA pool by invoking
dma_pool_free(). Given that 'status' points to the start address of the DMA
pool, both 'status->ep' and 'status->src_dma_addr' are in the DMA pool. And
so, the device has the permission to access them. Even worse, a malicious
device can modify them. As a result, dma_pool_free() will not succeed.
To avoid the above issue, this patch introduces a new data structure, i.e.,
scif_cb_arg, to store the arguments required by the call back function. A
variable 'cb_arg' is allocated in _scif_prog_signal() to pass the
arguments. 'cb_arg' will be freed after dma_pool_free() in
scif_prog_signal_cb().
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In _scif_prog_signal(), the boolean variable 'x100' is used to indicate
whether the MIC Coprocessor is X100. If 'x100' is true, the status
descriptor will be used to write the value to the destination. Otherwise, a
DMA pool will be allocated for this purpose. Specifically, if the DMA pool
is allocated successfully, two memory addresses will be returned. One is
for the CPU and the other is for the device to access the DMA pool. The
former is stored to the variable 'status' and the latter is stored to the
variable 'src'. After the allocation, the address in 'src' is saved to
'status->src_dma_addr', which is actually in the DMA pool, and 'src' is
then modified.
Later on, if an error occurs, the execution flow will transfer to the label
'dma_fail', which will check 'x100' and free up the allocated DMA pool if
'x100' is false. The point here is that 'status->src_dma_addr' is used for
freeing up the DMA pool. As mentioned before, 'status->src_dma_addr' is in
the DMA pool. And thus, the device is able to modify this data. This can
potentially cause failures when freeing up the DMA pool because of the
modified device address.
This patch avoids the above issue by using the variable 'src' (with
necessary calculation) to free up the DMA pool.
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
My static checker complains that we still use "mark" even when the
_scif_fence_mark() call fails so it can be uninitialized.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch implements the fence APIs required to synchronize
DMAs. SCIF provides an interface to return a "mark" for all DMAs
programmed at the instant the API was called. Users can then "wait" on
the mark provided previously by blocking inside the kernel. Upon
receipt of a DMA completion interrupt the waiting thread is woken
up. There is also an interface to signal DMA completion by polling for
a location to be updated via a "signal" cookie to avoid the interrupt
overhead in the mark/wait interface. SCIF allows programming fences on
both the local and the remote node for both the mark/wait or the fence
signal APIs.
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Thomas Gleixner
Wenwen Wang
Dan Carpenter
Sudeep Dutt