Thomas B Wylegala

US Patent:

7596694, Sep 29, 2009

Filed:

Mar 8, 2004

Appl. No.:

10/796690

Inventors:

Alan Karp - Palo Alto CA, US
Arindam Banerji - Sunnyvale CA, US
Thomas Wylegala - Santa Clara CA, US
Rajiv Gupta - Los Altos CA, US
Peter Phaal - San Francisco CA, US

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

H04L 29/06

US Classification:

713164

Abstract:

Embodiments of the present invention include a system and method for making it safe to execute downloaded code. The method includes accessing an application, the application making a system call to a library of a computer system for a resource, establishing a requesting thread. The method further includes the library sending a request message to a local security filter; the local security filter validating the requesting thread and returning a digital signature, that uniquely identifies the requesting thread, to the application. The application making a system call to a kernel of the computer system wherein the kernel uses the digital signature from the security filter to validate the requesting thread before allowing access to the requested resource.

US Patent:

20020162050, Oct 31, 2002

Filed:

Apr 30, 2001

Appl. No.:

09/845469

Inventors:

Dejan Milojicic - Palo Alto CA, US
Thomas Wylegala - Santa Clara CA, US
Fong Pong - Mountain View CA, US
Stephen Hoyle - Mountain View CA, US
Lance Russell - Hollister CA, US
Lu Xu - San Jose CA, US
Alberto Munoz - Los Altos CA, US

International Classification:

H02H003/05

US Classification:

714/020000

Abstract:

The present invention is a system and method for recovering from memory failures in computer systems. The method of the present invention includes the steps of: identifying a predetermined instruction sequence; monitoring for memory access errors in response to the request; logging a memory access error in an error logging register; polling the register for any logged memory access error during execution of the instruction sequence; and raising exceptions, if the memory access error is logged. Within the system of the present invention, memory access errors are stored in an error logging register, machine check abort handles are masked, and memory controllers are under full control of the software so that memory access errors can be intercepted and responded to without necessitating a system reboot or application restart. The present invention is particularly applicable to O/S code which can not otherwise recover from memory errors except by rebooting.