Hewlett-packard Development Company, L.P.

Eric Gouriou

Robert Hundt

Vinodha Ramasamy

Umesh Krishnaswamy

Sujoy Saraswati

Edward J Sharpe

David John Babcock

Thomas Lofgren

Sushanth Rai

Jose German Rivera

A monitoring interface, includes logic responsive to a pre-fork event, the pre-fork event responsive to a vfork system call. The pre-fork event includes indicia that identifies a child process to be created in accordance with the vfork system call. A method for controlling the execution of a child process created from a parent process, where the parent process is monitored by a software tool includes, receiving indicia that a vfork system call will be executed by the parent process, suspending execution of the parent process, extracting a process identifier from the indicia of the vfork system call, the process identifier corresponding to a child process to be generated by the parent process when the parent process executes the vfork system call, setting a process monitor thread to observe the child process, and resuming execution of the parent process to enable the parent process to execute past the vfork system call.

Method and apparatus for controlling execution of a child process generated by a modified parent process

A software tool includes logic configured to enable a child process that inherits the address space of a modified parent process to execute an unaltered version of the address space when the child process inherits the altered address space of the parent process. A method for processing breakpoint events in a child process created from a parent process, when the parent process is modified by a software tool includes, storing unmodified parent process code replaced by each occurrence of a breakpoint inserted into the address space during modification of the parent process, monitoring execution of a child process created by the parent process for an initial breakpoint in the address space, suspending execution of the child process in response to an initial breakpoint, replacing each occurrence of a breakpoint in the address space with the unmodified parent process code, and resuming execution of the child process.

System and method for processing breakpoint events in a child process generated by a parent process

A method and system for reverting a process in an in-line instrumented state to an uninstrumented state. In one embodiment, the present invention modifies selected text segment portions from the process to be uninstrumented. The present embodiment then unmaps instrumented code space such that the instrumented code space is inaccessible to the process. In this embodiment, the present invention also cleans a call stack of the process by unwinding the call stack and resetting the storage locations for return pointers from the instrumented code space to uninstrumented code space.

Uninstrumenting in-line code instrumentation via stack unwinding and cleanup

The present invention, in various embodiments, is directed to techniques for providing debugging capability for program code instrumentation. In one embodiment, an instrumentor inserts an instrumentation breakpoint at the beginning of a block of original code. When this breakpoint is reached during execution of the application program that includes the block of original code, the instrumenator, from the block of original code, generates a block of instrumented code. This block of instrumented code may include debugging breakpoints that are carried from the block of original code or are inserted into the block of instrumented code during debugging. After generating the instrumented code, the instrumentor executes the instrumented code until debugging breakpoints are reached that stop the program flow, thereby allowing a programmer to perform debugging functions at these debugging breakpoints.

Providing debugging capability for program instrumented code

Method and apparatus for dynamic instrumentation of an executable application program. The application program includes a plurality of functions, each function having an entry point and an endpoint. When the application is executed, a shared memory segment is created for an instrumentation program and the application program. Upon initial invocation of the original functions in the application program, corresponding substitute functions are created in the shared memory segment, the substitute versions including instrumentation code. Thereafter, the substitute functions are executed in lieu of the original functions in the application program.

Dynamic instrumentation of an executable program by means of causing a breakpoint at the entry point of a function and providing instrumentation code

Method and apparatus for handling calls from relocated instrumented functions to functions that expect a return pointer value in an original address space. In various embodiments of the invention, instrumented versions of selected functions of an executable program are generated and stored in a relocation address space. When a function is called by a function in the relocation address space, a return pointer register stores a first return-pointer value that is an address in the relocation address space. The address in the original address space that corresponds (logically) to the first return-pointer value is identified as an original return-pointer value. The first return-pointer value is associated with the original return-pointer value, references to the original return-pointer value are substituted for references to the first return-pointer value, and the instruction at the address indicated by the original return-pointer value is replaced with a breakpoint. When the breakpoint is encountered upon return of control at the original return-pointer value, the first return-pointer value that is associated with the original return-pointer value is obtained, and control is transferred to the instruction at the address referenced by the first return-pointer value.

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Sunnyvale, CA, United States of America

Eric Gouriou