Characterization of Linux Kernel Behavior under Errors

This paper describes an experimental study of Linux kernel behavior in the presence of errors that impact the instruction stream of the kernel code. Extensive error injection experiments including over 35,000 errors are conducted targeting the most frequently used functions in the selected kernel subsystems. Three types of faults/errors injection campaigns are conducted: (1) random non-branch instruction, (2) random conditional branch, and (3) valid but incorrect branch. The analysis of the obtained data shows: (i) 95% of the crashes are due to four major causes, namely, unable to handle kernel NULL pointer, unable to handle kernel paging request, invalid opcode, and general protection fault, (ii) less than 10% of the crashes are associated with fault propagation and nearly 40% of crash latencies are within 10 cycles, (iii) errors in the kernel can result in crashes that require reformatting the file system to restore system operation; the process of bringing up the system can take nearly an hour.