Abstract: An implementation of this disclosure provides a system comprising memory to store a plurality of layers and a processing device coupled to that memory to set up the layers and to mount them into an overlay. The layers comprise an upper and one or more lower layers. The overlay provides access to a plurality files stored in the overlay filesystem. A request from an application to access a file in the mounted overlay is received. An access policy for the mounter that mounted the layers is identified in view of the mounter's credentials. The processing device checks, in view of the access policy, whether a security context label for the file provides access to the application and to the mounter of the overlay in at least one lower layer comprising the file. An instruction to provide the application with access to the file is issued in view of the check.

Abstract: An implementation of this disclosure provides a system comprising memory to store a plurality of layers and a processing device coupled to that memory to set up the layers and to mount them into an overlay. The layers comprise an upper and one or more lower layers. The overlay provides access to a plurality files stored in the overlay filesystem. A request from an application to access a file in the mounted overlay is received. An access policy for the mounter that mounted the layers is identified in view of the mounter's credentials. The processing device checks, in view of the access policy, whether a security context label for the file provides access to the application and to the mounter of the overlay in at least one lower layer comprising the file. An instruction to provide the application with access to the file is issued in view of the check.

Abstract: According to one example, a method performed by a computing system includes determining that a size of key data to be stored within a kernel memory is greater than a threshold value. The threshold value is based on a size value associated with maintaining the key data outside of the kernel memory. The method further includes allocating a block of memory within a volatile memory store, the block of memory being outside the kernel memory, storing the key data within the block of memory, and storing, within the kernel memory, a pointer to the key data.

Abstract: According to one example, a method performed by a computing system includes determining that a size of key data to be stored within a kernel memory is greater than a threshold value. The threshold value is based on a size value associated with maintaining the key data outside of the kernel memory. The method further includes allocating a block of memory within a volatile memory store, the block of memory being outside the kernel memory, storing the key data within the block of memory, and storing, within the kernel memory, a pointer to the key data.

Abstract: A sonar imaging system for a watercraft is disclosed. The sonar imaging system comprises a transducer coupled to the watercraft and having at least one side scanning element and at least one bottom scanning element, an electronic control head unit coupled to the transducer and configured to display sonar images. The downward acoustic elements may be circular and the side scan acoustic elements may be rectangular. A software filter may be provided to remove noise generated by a spark plug or other operation of a motor for the watercraft.