MFC r302856:

Fix up the order in which jail creation processes are run, to preserve
the config file's order in the non-parallel-start case.

PR: 209112

MFC r289677:

Fix a ton of speelling errors

MFC r285261, r285279:

- Fix offset calculation in variable substitution
in jail.conf. The following did not work correctly:

A="A_${B}_C_${D}"
B="BBBBB"
D="DDDD_${E}_FFFFF"
E="EEEEE"

- Implement PF_IMMUTABLE flag and apply it to "name" and "jid" in
jail.conf parameters. This flag disallows redefinition of the parameter.

"name" and/or "jid" are automatically defined in jail.conf by using
the jail names at the front of jail parameter definitions. However,
one could override them by using a variable with the same name like
$name = "foo". This confused the parser and could end up with SIGSEGV.

Note that this change also affects a case when all of parameters are
defined in the command line arguments, not in jail.conf. Specifically,
"jail -c name=j1 name=j2" no longer works. This should be harmless.

Approved by: re (gjb)

MFC r278323:

Add mount.procfs jail parameter, so procfs can be mounted when a prison's
root is in its fstab.

Also fix a typo while I'm at it.

PR: 197237 197066

MFC 256385:

- Add mount.fdescfs parameter to jail(8). This is similar to
mount.devfs but mounts fdescfs. The mount happens just after
mount.devfs.

- rc.d/jail now displays whole error message from jail(8) when a jail
fails to start.

Approved by: re (gjb)

MFC r285261, r285279:

- Fix offset calculation in variable substitution
in jail.conf. The following did not work correctly:

A="A_${B}_C_${D}"
B="BBBBB"
D="DDDD_${E}_FFFFF"
E="EEEEE"

- Implement PF_IMMUTABLE flag and apply it to "name" and "jid" in
jail.conf parameters. This flag disallows redefinition of the parameter.

"name" and/or "jid" are automatically defined in jail.conf by using
the jail names at the front of jail parameter definitions. However,
one could override them by using a variable with the same name like
$name = "foo". This confused the parser and could end up with SIGSEGV.

Note that this change also affects a case when all of parameters are
defined in the command line arguments, not in jail.conf. Specifically,
"jail -c name=j1 name=j2" no longer works. This should be harmless.

Approved by: re (gjb)

MFC r278323:

Add mount.procfs jail parameter, so procfs can be mounted when a prison's
root is in its fstab.

Also fix a typo while I'm at it.

PR: 197237 197066

MFC 256385:

- Add mount.fdescfs parameter to jail(8). This is similar to
mount.devfs but mounts fdescfs. The mount happens just after
mount.devfs.

- rc.d/jail now displays whole error message from jail(8) when a jail
fails to start.

Approved by: re (gjb)