Re: O_EXEC and O_SEARCH

[Rich Felker <dalias at aerifal dot cx>]

On Fri, Feb 22, 2013 at 10:05:03PM -0500, KOSAKI Motohiro wrote:
> > I'd like to have a conversation with the glibc team about O_EXEC and
> > O_SEARCH in the interest of hopefully developing a unified plan for
> > supporting them on Linux. Presumably the reason glibc still does not
> > have them is that Linux O_PATH does not exactly match their semantics
> > in some cases, and O_PATH is sufficiently broken on many kernel
> > versions to make offering it problematic. In particular, current
> > coreutils break badly on most kernel versions around 2.6.39-3.6 or so
> > if O_SEARCH and O_EXEC are defined as O_PATH.
> 
> I'm curious why don't you implement them in kernel directly?

See this thread for Linus's opinion on why O_SEARCH was not added:

http://comments.gmane.org/gmane.linux.file-systems/33611

O_NODE seems to have been renamed to O_PATH, or perhaps O_PATH was a
later independent implementation of the same idea; it's not clear to
me which happened. But the idea is that the kernel folks did not want
to do O_SEARCH and O_EXEC properly in kernelspace but instead wanted
to provide a more general flag that could be used to implement both
O_SEARCH and O_EXEC.

Rich