International Business Machines Corporation

Elizabeth Jean Murray

Venkat Venkatsubra

Vasu Vallabhaneni

Vinit Jain

Jorge Rafael Nogueras

Jeffrey Paul Messing

Patrick Tam Vo

Tommy Lucas McLane

Mallesh K Lepakshaiah

Marco A Cabrera Escandell

Marco Escandell Cabrera

Methods, systems, and products for computer processing. In one general embodiment, the method comprises running an inner process in the context of an executing thread wherein the thread has an original address space in memory and hiding at least a portion of the memory from the inner process. The inner process may run on the same credentials as the thread. Running the inner process may include creating a new address space for the inner process in the memory and assigning the new address space to the thread, so that the inner process comprises its own address space. The inner process may he allowed to access only the new address space. The kernel may maintain the thread's original address space along with the new address space, so that multiple address spaces exist for a particular thread. The kernel may pass selected data from the thread to the inner process.

Inner process

A method and apparatus are provided for use with a SEA or other bridge device, which is positioned between virtual and physical LANS and is adapted to monitor connection setup packets. If the SEA detects such a packet, it determines whether it can accommodate the MSS value listed in the packet. In one embodiment, a method is provided for implementation by a bridge device positioned to transfer data packets between a specified LPAR system arid a specified host. The method comprises the step of detecting a packet that is transmitted to the bridge device, in order to set up a connection between the LPAR system and the host. The method further comprises determining whether the detected packet indicates an initial MSS value for the connection that is greater than a prespecified MSS value. Upon determining that the detected packet indicates an initial MSS value that exceeds the prespecified MSS value, the packet is altered to establish the prespecified MSS value as the MSS value for the connection.

Adjusting MSS of packets sent to a bridge device positioned between virtual and physical LANS

The present invention provides a computer implemented method, data processing system, and computer program product for verifying a return address. A computer stores the return address into a stack based on a function call. The computer generates a first hash based on a first stack frame and a second stack frame. The computer stores the first hash in a first canary location, wherein the first canary location is in the first stack frame. The computer executes at least one instruction of a routine referenced by the function call. The computer reads the first canary location to form a first suspect hash. The computer calculates a first verification hash based on the first stack frame and the second stack frame. The computer determines that the first verification hash matches the first suspect hash to form a first positive determination. The computer responsive to the first positive determination, the computer reads a second canary location to form a second suspect hash. The computer calculates a second verification hash based on the second stack frame. The computer determines that the second verification hash matches the second suspect hash to form a second positive determination. The computer responsive to the first positive determination and the second positive determination, the computer pops the return address off the stack. The computer executes at least one instruction at a memory location pointed to by the return address.

Method and apparatus for verifying a suspect return pointer in a stack

Mechanisms are disclosed for adjusting a fast re-transmit threshold (FRT) value for transmitting data streams over a computer system. One embodiment includes receiving, by a sender, a current fast re-transmit threshold value for a packet from a receiver. Further, these mechanisms include decreasing the size of the congestion window of the sender, and re-transmitting the packet to the receiver in network communication with the sender. Further still, the mechanisms include counting, by the sender, a number of dupacks after re-transmitting the packet until arrival, at the sender, of an acknowledgement (ACK) for the packet. Yet further, the mechanisms include determining, based on the size of the congestion window and the counting, a value of the FRT value. If the sender receives the ACK for the packet in less than one round trip time, then this may be a re-ordering problem for re-setting the FRT value.

Adaptive fast retransmit threshold to make TCP robust to non-congestion events

A host enables any adapter of multiple adapters of the host to concurrently support any VIPA of the multiple VIPAs assigned to the host. Responsive to a failure of at least one particular adapter from among the multiple adapters, the host triggers the remaining, functioning adapters to broadcast a separate hardware address update for each VIPA over the network, such that for a failover in the host supporting the multiple VIPAs the host directs at least one other host accessible via the network to address any new packets for the multiple VIPAs to one of the separate hardware addresses of one of the remaining adapters.

Failover in a host concurrently supporting multiple virtual IP addresses across multiple adapters

Data processing systems, computer implemented methods, and computer program products are provided for updating an address resolution protocol table. Updates received for the address resolution protocol table are comprised of an internet protocol address, a media access control address, and a unique identifier.

Growing community of inventors

Austin, TX, United States of America

Elizabeth Jean Murray