On Tue, Jun 15, 2021 at 02:58:12PM -0700, Linus Torvalds wrote:
And I think our horrible "kernel threads return to user space when done" is absolutely horrifically nasty. Maybe of the clever sort, but mostly of the historical horror sort.
How would you prefer to handle that, then? Separate magical path from kernel_execve() to switch to userland? We used to have something of that sort, and that had been a real horror... As it is, it's "kernel thread is spawned at the point similar to ret_from_fork(), runs the payload (which almost never returns) and then proceeds out to userland, same way fork(2) would've done." That way kernel_execve() doesn't have to do anything magical. Al, digging through the old notes and current call graph...
