Date: Fri, 18 Sep 2015 19:48:45 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 201611] [patch] Add devfs_get_cdevpriv_from_file(9) Message-ID: <bug-201611-8-J0MPZV9vSB@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-201611-8@https.bugs.freebsd.org/bugzilla/> References: <bug-201611-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=201611 Konstantin Belousov <kib@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |kib@FreeBSD.org --- Comment #2 from Konstantin Belousov <kib@FreeBSD.org> --- (In reply to Andy Ritger from comment #0) I do not quite understand this. Lets clarify the notational system first. I propose to rename the file descriptor we talk about in the context of the process B as fdb. Also, we note that both fd (from the process A filedescriptors namespace) and fdb (from B) point to the same file F. In the process B, to retrieve the video memory associated with F, you perform some kernel call, most likely ioctl(fdb, OPcode, ...). Then, during the call to the ioctl handler for OPcode, you get the same pointer to the file private data F by devfs_get_cdevpriv(). It does not matter if it is in context of ioctl(fd, OP1code) in A or in context of ioctl(fdb, OPcode) in B. The underlying file is same, since it was passed by ancillary data, and cdevpriv is same. -- You are receiving this mail because: You are the assignee for the bug.
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