Motivated by contemporary security challenges, we reeval uate and refine capability-based addressing for the RISC era. We present CHERI, a hybrid capability model that extends the 64-bit MIPS ISA with byte-granularity memory protection. We demonstrate that CHERI enables language memory model enforcement and fault isolation in hardware rather than soft ware, and that the CHERI mechanisms are easily adopted by existing programs for efficient in-program memory safety.In contrast to past capability models, CHERI complements, rather than replaces, the ubiquitous page-based protection mechanism, providing a migration path towards deconflat ing data-structure protection and OS memory management. Furthermore. CHERI adheres to a strict RISC philosophy: it maintains a load-store architecture and requires only single cycle instructions, and supplies protection primitives to the compiler, language runtime, and operating system.We demonstrate a mature FPGA implementation that runs the FreeBSD operating system with a full range of software and an open-source application suite compiled with an ex tended LLVM to use CHERI memory protection. A limit study compares published memory safety mechanisms in terms of instruction count and memory overheads. The study illustrates that CHERI is peiformance-competitive even while providing assurance and greater flexibility with simpler hardware.

CHERI extends a conventional RISC Instruction-Set Architecture, compiler, and operating system to support fine-grained, capability-based memory protection to mitigate memory-related vulnerabilities in C-language TCBs. We describe how CHERI capabilities can also underpin a hardware-software object-capability model for application compartmentalization that can mitigate broader classes of attack. Prototyped as an extension to the open-source 64-bit BERI RISC FPGA softcore processor, FreeBSD operating system, and LLVM compiler, we demonstrate multiple orders-of-magnitude improvement in scalability, simplified programmability, and resulting tangible security benefits as compared to compartmentalization based on pure Memory-Management Unit (MMU) designs. We evaluate incrementally deployable CHERI-based compartmentalization using several real-world UNIX libraries and applications.

Wheat production will be impacted by increasing concentration of atmospheric CO 2

A rising global population and demand for protein-rich diets are increasing pressure to maximize agricultural productivity. Rising atmospheric [CO2] is altering global temperature and precipitation patterns, which challenges agricultural productivity. While rising [CO2] provides a unique opportunity to increase the productivity of C3 crops, average yield stimulation observed to date is well below potential gains. Thus, there is room for improving productivity. However, only a fraction of available germplasm of crops has been tested for CO2 responsiveness.Yield is a complex phenotypic trait determined by the interactions of a genotype with the environment. Selection of promising genotypes and characterization of response mechanisms will only be effective if crop improvement and systems biology approaches are closely linked to production environments, that is, on the farm within major growing regions. Free air CO2 enrichment (FACE) experiments can provide the platform upon which to conduct genetic screening and elucidate the inheritance and mechanisms that underlie genotypic differences in productivity under elevated [CO2]. We propose a new generation of large-scale, low-cost per unit area FACE experiments to identify the most CO2-responsive genotypes and provide starting lines for future breeding programmes. This is Correspondence: E. A.