System and method for executing applications in a non-native environment
The described system provides one or more processors and memory, coupled to the one or more processors, storing thereon a first OS kernel that receives a system call to access a second OS kernel function from a subsystem of the second OS retransmits the system call to one or more drivers of the first OS, support the subsystem. The system further comprises a subsystem of the second OS, comprising one or more user space components executing natively in a non-privileged mode of the one or more processors, a set of drivers associated with the second OS, the set of support components, and the one or more drivers of the first OS. The one or more drivers of the first OS receive the system call originating from the subsystem, wherein the system call is retransmitted by the first OS kernel and process the system call.
1. A system for executing, on a first operating system (OS), components native to a second operating system (OS), the system comprising:
one or more processors; and
memory, coupled to the one or more processors, storing thereon:
a first OS kernel that is executing on the one or more processors:
receives from a subsystem of the second OS a system call to access a second OS kernel function; and
retransmits the system call to one or more drivers native to the first OS; and
the subsystem of the second OS, comprising:
one or more user space components native to the second OS that are executing natively in a non-privileged mode of the one or more processors;
one or more drivers associated with the second OS that are executing in the non-privileged mode of the one or more processors;
one or more support components that:
are executing in the non-privileged mode of the one or more processors; and
comprise and provide, to the one or more drivers associated with the second OS and to the one or more drivers native to the first OS, high-level functionality of the second OS kernel, wherein the high-level functionality is defined as a functionality without direct access to hardware, privileged instructions and privileged system data, and wherein the high-level functionality includes high-level logic of at least one of: one or more second OS kernel subsystems and one or more second OS kernel exported functions; and
the one or more drivers native to the first OS that:
are executing in a privileged mode of the one or more processors;
receive the system call; and
process the system call using control transfer to the support components.
2. The system of claim 1 , wherein the one or more drivers associated with the second OS kernel and the one or more support components execute in a memory range that is protected from the one or more user space components.
3. The system of claim 2 , wherein the gap memory is the protected memory range and
wherein the first OS kernel assigns the gap memory to be accessible in non-privileged mode by modifying a memory map of the first OS, wherein the gap memory is a range of memory addresses that were previously accessible only in privileged mode.
4. The system of claim 3 , wherein the gap memory comprises several conjoint or non-conjoint memory address ranges.
5. The system of claim 3 , wherein the one or more drivers of the first OS, supporting the subsystem, performs at least one of the following actions, depending on the received system call:
(a) calling one of the components of the second OS subsystem, which are in a privileged mode of the one or more processors; or
(b) translating the system call to a call to an API of the first OS kernel; and calling the first OS kernel.
6. The system of claim 3 ,
wherein the one or more user space components of the second OS are executed in a first process, and the one or more drivers associated with the second OS and the one or more support components are executed in a second process, and
wherein a context switch between the one or more user space components of the second OS and the one or more drivers and the one or more support components associated with the second OS comprises switching between the first process and the second process.
7. The system of claim 1 , wherein the one or more drivers associated with the second OS execute in the non-privileged mode and the supporting components execute in the non-privileged mode.
8. The system of claim 7 , wherein the one or more drivers associated with the second OS call one or more second OS API functions from the one or more supporting components.
9. The system of claim 7 , wherein protection of the memory range from the one or more user space components further comprises that the memory range is inaccessible in a process, when the process is executing any of the one or more user space components.
10. The system of claim 1 , wherein a one or more drivers associated with the second OS are executing in the non-privileged mode by modifying a portion of the one or more drivers, and wherein the one or more drivers send system calls to kernel mode components.
11. The system of claim 1 , wherein the one or more user space components are applications native to the second OS.
12. The system of claim 1 , wherein the one or more drivers of the first OS, supporting the subsystem, process the system call by:
translating the system call to the API call of the first OS; and
invoking the API call.
13. A method for executing, on a first operating system (OS), components native to a second operating system (OS), the method comprising:
receiving, by a first OS kernel that is executing on one or more processors of the first OS, from a subsystem of the second OS a system call to access a second OS kernel function; and
retransmitting the system call to one or more drivers native to the first OS,
wherein the subsystem of the second OS, comprises:
one or more user space components native to the second OS that are executing natively in a non-privileged mode of the one or more processors,
one or more drivers associated with the second OS that are executing in the non-privileged mode of the one or more processors,
one or more support components that are executing in the non-privileged mode of the one or more processors, and
comprising and providing, to the one or more drivers associated with the second OS and to the one or more drivers native to the first OS, high-level functionality of the second OS kernel, wherein the high-level functionality is defined as a functionality without direct access to hardware, privileged instructions and privileged system data, and wherein the high-level functionality includes high-level logic of at least one of: one or more second OS kernel subsystems and one or more second OS kernel exported functions, and
wherein the one or more drivers native to the first OS that are executing in a privileged mode of the one or more processor, receive the system call, and process the system call using control transfer to the support components.
14. The method of claim 13 , wherein the one or more drivers associated with the second OS kernel and the one or more support components execute in a memory range that is protected from the one or more user space components.
15. The method of claim 13 , wherein the one or more drivers associated with the second OS execute in the non-privileged mode and the supporting components execute in the non-privileged mode.
16. The method of claim 15 , wherein the one or more drivers associated with the second OS call one or more second OS API functions from the one or more supporting components.
17. The method of claim 15 , wherein protection of the memory range from the one or more user space components further comprises that the memory range is inaccessible in a process, when the process is executing any of the one or more user space components.
18. The method of claim 13 , wherein a one or more drivers associated with the second OS are executing in the non-privileged mode by modifying a portion of the one or more drivers, and wherein the one or more drivers send system calls to kernel mode components.
19. The method of claim 13 , wherein the one or more user space components are applications native to the second OS.
20. A non-transitory computer-readable medium storing thereon instructions that when executed perform a method for executing, on a first OS, components native to a second OS, the method comprising:
receiving, by a first OS kernel that is executing on one or more processors of the first OS, from a subsystem of the second OS a system call to access a second OS kernel function; and
retransmitting the system call to one or more drivers native to the first OS,
wherein the subsystem of the second OS, comprises:
one or more user space components native to the second OS that are executing natively in a non-privileged mode of the one or more processors,
one or more drivers associated with the second OS that are executing in the non-privileged mode of the one or more processors,
one or more support components that are executing in the non-privileged mode of the one or more processors, and
comprising and providing, to the one or more drivers associated with the second OS and to the one or more drivers native to the first OS, high-level functionality of the second OS kernel, wherein the high-level functionality is defined as a functionality without direct access to hardware, privileged instructions and privileged system data, and wherein the high-level functionality includes high-level logic of at least one of: one or more second OS kernel subsystems and one or more second OS kernel exported functions, and
wherein the one or more drivers native to the first OS that are executing in a privileged mode of the one or more processor, receive the system call, and process the system call using control transfer to the support components.