tree 9c131cd6bf337a9da98f31703214385c07571c38
parent 9dec17eb577169f78d642c5424e4264186d27115
author David Howells <dhowells@redhat.com> 1152531892 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> 1152563061 -0700

[PATCH] NOMMU: Fix execution off of ramfs with mmap()

Fix execution through the FDPIC binfmt of programs stored on ramfs by
preventing the ramfs mmap() returning successfully on a private mapping of
a ramfs file.  This causes NOMMU mmap to make a copy of the mapped portion
of the file and map that instead.

This could be improved by granting direct mapping access to read-only
private mappings for which the data is stored on a contiguous run of pages.
 However, this is only likely to be the case if the file was extended with
truncate before being written.

ramfs is left to map the file directly for shared mappings so that SYSV IPC
and POSIX shared memory both still work.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>