binfmt_misc: add F option description to documentation

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/Documentation/binfmt_misc.txt b/Documentation/binfmt_misc.txt
index 6b1de70583715d7728a7a31b4612564b0178679b..ec83bbce547a5c3bdf1b4f7c35c9dc515c41c767 100644 (file)
--- a/Documentation/binfmt_misc.txt
+++ b/Documentation/binfmt_misc.txt
@@ -66,6 +66,13 @@ Here is what the fields mean:
             This feature should be used with care as the interpreter
             will run with root permissions when a setuid binary owned by root
             is run with binfmt_misc.
+      'F' - fix binary.  The usual behaviour of binfmt_misc is to spawn the
+           binary lazily when the misc format file is invoked.  However,
+           this doesn't work very well in the face of mount namespaces and
+           changeroots, so the F mode opens the binary as soon as the
+           emulation is installed and uses the opened image to spawn the
+           emulator, meaning it is always available once installed,
+           regardless of how the environment changes.
 
 
 There are some restrictions: