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2015f26cfa
For messages sent from the host to fw that solicit a reply from fw, the c4iw_wr_wait struct pointer is passed in the host->fw message, and included in the fw->host fw6_msg reply. This allows the sender to wait until the reply is received, and the code processing the ingress reply to wake up the sender. If c4iw_wait_for_reply() times out, however, we need to keep the c4iw_wr_wait object around in case the reply eventually does arrive. Otherwise we have touch-after-free bugs in the wake_up paths. This was hit due to a bad kernel driver that blocked ingress processing of cxgb4 for a long time, causing iw_cxgb4 timeouts, but eventually resuming ingress processing and thus hitting the touch-after-free bug. So I want to fix iw_cxgb4 such that we'll at least keep the wait object around until the reply comes. If it never comes we leak a small amount of memory, but if it does come late, we won't potentially crash the system. So add a kref struct in the c4iw_wr_wait struct, and take a reference before sending a message to FW that will generate a FW6 reply. And remove the reference (and potentially free the wait object) when the reply is processed. The ep code also uses the wr_wait for non FW6 CPL messages and doesn't embed the c4iw_wr_wait object in the message sent to firmware. So for those cases we add c4iw_wake_up_noref(). The mr/mw, cq, and qp object create/destroy paths do need this reference logic. For these paths, c4iw_ref_send_wait() is introduced to take the wr_wait reference, send the msg to fw, and then wait for the reply. So going forward, iw_cxgb4 either uses c4iw_ofld_send(), c4iw_wait_for_reply() and c4iw_wake_up_noref() like is done in the some of the endpoint logic, or c4iw_ref_send_wait() and c4iw_wake_up_deref() (formerly c4iw_wake_up()) when sending messages with the c4iw_wr_wait object pointer embedded in the message and resulting FW6 reply. Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Doug Ledford <dledford@redhat.com> |
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| .. | ||
| cm.c | ||
| cq.c | ||
| device.c | ||
| ev.c | ||
| id_table.c | ||
| iw_cxgb4.h | ||
| Kconfig | ||
| Makefile | ||
| mem.c | ||
| provider.c | ||
| qp.c | ||
| resource.c | ||
| t4.h | ||
| t4fw_ri_api.h | ||