seccomp (short for secure computing mode) is a computer security facility that provides an application sandboxing mechanism in the Linux kernel; it was merged into the Linux kernel mainline in kernel version 2.6.12, which was released on March 8, 2005. seccomp allows a process to make a one-way transition into a "secure" state where it cannot make any system calls except exit(), sigreturn(), read() and write() to already-open file descriptors.