[PATCH 09/15] clone.2: ERRORS: Add EACCESS with CLONE_INTO_CGROUP + clone3

[Andrew]:
I noticed that clone3 can send the EACCES errno after I wrote a
program that used clone3 with the CLONE_INTO_CGROUP flag.
To me, it's important to know what kind of failure occurred if the
clone3() fails, so I was glad that a unique errno is set for
this case, but it wasn't documented on the clone man page.

[Christian]:
In essence, any error that could occur during regular fs-based migration
at write-time can also occur during CLONE_INTO_CGROUP. The clone3()
manpage just has the inverse of that above statement:

"Note that all of the usual restrictions (described in cgroups(7)) on
placing a process into a version 2 cgroup apply."

Reported-by: Andrew Wock <redacted>
Acked-by: Christian Brauner <redacted>
Signed-off-by: Alejandro Colomar <redacted>
---
 man2/clone.2 | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/man2/clone.2 b/man2/clone.2
index e381da165..90db92ad6 100644
--- a/man2/clone.2
+++ b/man2/clone.2

@@ -1209,6 +1209,16 @@ in the caller's context, no child process is created, and
 is set to indicate the error.
 .SH ERRORS
 .TP
+.BR EACCES " (" clone3 "() only)"
+.B CLONE_INTO_CGROUP
+was specified in
+.IR cl_args.flags ,
+but the restrictions (described in
+.BR cgroups (7))
+on placing the child process into the version 2 cgroup referred to by
+.I cl_args.cgroup
+are not met.
+.TP
 .B EAGAIN
 Too many processes are already running; see
 .BR fork (2).

-- 
2.33.0