[Bug 59281] unshare(2) applies to threads, not processes

https://bugzilla.kernel.org/show_bug.cgi?id=59281

Michael Kerrisk [off-list ref] changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
         Resolution|---                         |CODE_FIX

--- Comment #2 from Michael Kerrisk <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> ---

(In reply to Florian Weimer from comment #0)

quoted

My version starts with "unshare() allows a process to disassociate parts of
its execution context", but I've been told that this incorrect because it
applies to the calling thread only, not the entire process.

Florian, while I understand the motivation of this bug report, there's no
really good fix. As Stuart notes, the line between thread and process in this
context is fuzzy. Really, the reader needs to have a grasp on what clone(2)
does.

Anyway, to improve things a little, I applied the patch below.

Cheers,

Michael

--- a/man2/unshare.2
+++ b/man2/unshare.2

@@ -49,15 +49,15 @@ _BSD_SOURCE || _SVID_SOURCE
 .ad b
 .SH DESCRIPTION
 .BR unshare ()
-allows a process to disassociate parts of its execution
-context that are currently being shared with other processes.
+allows a process (or thread) to disassociate parts of its execution
+context that are currently being shared with other processesi or theads).

 Part of the execution context, such as the mount namespace, is shared
 implicitly when a new process is created using
 .BR fork (2)
 or
 .BR vfork (2),
 while other parts, such as virtual memory, may be
-shared by explicit request when creating a process using
+shared by explicit request when creating a process or thread using
 .BR clone (2).

 The main use of