On Sun, Dec 01, 2024 at 08:54:41AM -0800, Linus Torvalds wrote: > On Sun, 1 Dec 2024 at 06:17, Christian Brauner <brauner@xxxxxxxxxx> wrote: > > > > /* > > * Hold rcu lock to keep the name from being freed behind our back. > > * Use cquire semantics to make sure the terminating NUL from > > * __d_alloc() is seen. > > * > > * Note, we're deliberately sloppy here. We don't need to care about > > * detecting a concurrent rename and just want a sensible name. > > */ > > Sure. Note that even "sensible" isn't truly guaranteed in theory, > since a concurrent rename could be doing a "memcpy()" into the > dentry->d_name.name area at the same time on another CPU. Yeah, I saw, if the dname.name assignment is reorded to happen before the memcpy() afaict. Anyway, it's not that important especially since PR_SET_MM_MAP puts comm, auxv etc. fully under user control anyway.
