Seccomp user-space notification and signals
Seccomp user-space notification and signals
The seccomp() mechanism allows the imposition of a filter program (expressed in "classic" BPF) that makes policy decisions on whether to allow each system call invoked by the target process. The user-space notification feature further allows those decisions to be deferred to another process. As this recent patch set from Sargun Dhillon shows, though, user-space notification still has some rough edges, especially when it comes to signals. This patch makes a simple change to try to address a rather complex problem brought to the fore by changes in the Go language's preemption model.