https://svn.boost.org/trac10/ticket/7369 <p> I need to create shared memory with unrestricted permissions (0666). This works fine. When I attempt to grow the shared memory, using the grow() function, the permissions get reset to 0644. </p> <p> I followed the code a bit and saw that it was using ftruncate. Checking the man page for ftruncate reveals, "the set-user-ID and set-group-ID permission bits may be cleared." Not sure what affects the "may" clause, but it did it every time for me. Umask was set to 0000. </p> <p> Obviously this only effects systems using ftruncate. Windows works correctly. </p> <p> Not sure on what versions may be needed, but: libc6 - 2.11.1 libglib2.0 - 2.24.1 gcc - 4.4.3 </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/7369 Trac 1.4.3