c12a67fec8
Commitad61a4c7a9("iw_cxgb4: don't block in destroy_qp awaiting the last deref") introduced a bug where the RDMA QP EQ queue memory (and QIDs) are possibly freed before the underlying connection has been fully shutdown. The result being a possible DMA read issued by HW after the queue memory has been unmapped and freed. This results in possible WR corruption in the worst case, system bus errors if an IOMMU is in use, and SGE "bad WR" errors reported in the very least. The fix is to defer unmap/free of queue memory and QID resources until the QP struct has been fully dereferenced. To do this, the c4iw_ucontext must also be kept around until the last QP that references it is fully freed. In addition, since the last QP deref can happen in an IRQ disabled context, we need a new workqueue thread to do the final unmap/free of the EQ queue memory. Fixes:ad61a4c7a9("iw_cxgb4: don't block in destroy_qp awaiting the last deref") Cc: stable@vger.kernel.org Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.