Protection domains for a computer operating system
View Patent ↗A protection domain system is implemented to provide protection for applications executing in a computing environment. Protection domains are allocated system resources and may contain executing tasks. The protection domain system may allow tasks to access resources in other protection domains to which attachments have been made. Attachment is transparent to the software developer. The protection domain system provides flexibility in implementing operating system services and defining protection hierarchies.
1. A method for debugging a code module, comprising the step of:
creating a first protection domain having a first protection view, the first protection view preventing at least one unprotected link;
managing a linking permission between the first protection domain and at least one other protection domain, wherein the linking permission is restricted to protected links;
loading a developmental code module into the first protection domain; and
performing a debugging operation using the developmental code module, the debugging operation including at least one system call outside the protection view via the protected links, wherein the system call outside the protection view is routed via a linking table that includes an entry for each symbol of the developmental code requiring a link outside the first protection domain, each entry further including a corresponding link stub comprising a number of executable instructions used to access the external location,
wherein the step of performing the debugging operation is performed using a debugging tool having a facility to change the protection view of the protection domain.
2. The method of claim 1 , further comprising the step of:
loading the developmental code module into at least one other protection domain having a second protection view, the second protection view not preventing the at least one unprotected link.
3. The method of claim 1 , further comprising the step of:
upon completion of the debugging operation, managing the linking permission of the first protection domain to permit use of unprotected links between the first protection domain and the at least one other protection domain.
4. A method for debugging a code module, comprising the steps of:
loading a developmental code module into a protection domain in a computing environment, the protection domain having a protection view, the protection view being set to a first linkage permission restricting the protection domain to protected links between at least one other protection domain in the computing environment;
performing a debugging operation using the developmental code module, the debugging operation including at least one system call outside the protection view via the protected links, wherein the system call outside the protection view is routed via a linking table that includes an entry for each symbol of the developmental code requiring a link outside the first protection domain, each entry further including a corresponding link stub comprising a number of executable instructions used to access the external location; and
setting the protection view to a second linkage permission, that does not restrict the protection domain in the computing environment,
wherein the step of performing the debugging operation and setting the protection view to the second linkage permission are performed using a debugging tool having a facility to change the protection view of the protection domain.
5. The method of claim 4 , wherein the step of setting the protection view to a second linkage permission permits use of unprotected links between the first protection domain and the at least one other protection domain.