Date: Fri, 24 Aug 2018 18:44:23 +0200 From: Johannes Lundberg <johalun0@gmail.com> To: Warner Losh <imp@bsdimp.com> Cc: freebsd-rwg@pdx.rh.cn85.dnsmgr.net, kevans@freebsd.org, Matthew Macy <mmacy@freebsd.org>, freebsd-current <freebsd-current@freebsd.org> Subject: Re: priority of paths to kernel modules? Message-ID: <CAECmPwtHchQpq5ccCeCqZtB9S4qis_9-8_b_-qk%2B39vUWhA4HA@mail.gmail.com> In-Reply-To: <CANCZdfryv44hD-oAB6cqJJAH2ZhX83ntswnO2K5ddhN5wP8mLQ@mail.gmail.com> References: <CACNAnaGMsifVntGHQ8T4-w6jL%2B2dx5e1Ciw3-CQ9W2MwF38mfg@mail.gmail.com> <201808241411.w7OEBXg8095140@pdx.rh.CN85.dnsmgr.net> <CANCZdfoNdFHM6Z8KVNrUCFzASjRLsd=dkw_fZGpJjsYmFzySUg@mail.gmail.com> <CAECmPwvouNd6J8Es4yC3Djr02ZeP=b88-aUFFA%2BHF-pYF3hb0w@mail.gmail.com> <CANCZdfryv44hD-oAB6cqJJAH2ZhX83ntswnO2K5ddhN5wP8mLQ@mail.gmail.com>
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On Fri, Aug 24, 2018 at 5:43 PM Warner Losh <imp@bsdimp.com> wrote: > > > On Fri, Aug 24, 2018 at 9:27 AM Johannes Lundberg <johalun0@gmail.com> > wrote: > >> There's some tricks we can do here. >>> >>> First, I talked to Kyle yesterday about augmenting the Lua loader to >>> have a X_loadflag option. Some background. We look at a lot of X_xxxx flags >>> for loading modules. X_load=yes being the most familiar. One way to avoid >>> POLA would be to have in boot/defaults/loader.conf a i915kms_loadflag=-K so >>> that by default, we'd run load -K i915kms instead of load i915kms. We'd >>> augment the built-in load command so it knew that -K means 'add the kernel >>> to the path last rather than first'. This would solve one of the POLA >>> violations in a very targeted way: people that put i915kms_load=YES in >>> their loader.conf wouldn't be surprised by this transition. It would be at >>> the cost of 2 entires in loader.conf, I believe, and it shuts down one >>> vector of hassle for our users. People do this, btw, to get more lines / >>> columns in the BIOS boot environment for their console, so it's not an >>> unreasonable path to attend to. >>> >>> We could also have a sysctl that we could set to override specific >>> modules locations. This would allow the graphics port to have a rc script >>> that sets this up so when X11 goes to automatically load the module, the >>> right one gets loaded. This would solve the issue for the people that 'do >>> nothing' except install the port. While it's a small bit of programming for >>> the kernel, it's a general mechanism that's laser-focused on exceptions to >>> the rule w/o wholesale changes. This would solve the other main vector and >>> motivator for the 'kill it with fire' calls that doesn't leave behind a >>> scorched earth. >>> >> >> >> Just a small note here. With the modesetting driver (which is replacing >> the deprecated xf86-video-intel and is built into Xorg), X will not load >> the drm driver for you. It has to be done by putting kld_list="i915kms" in >> your rc.conf (I don't think loading drm next modules from /boot/loader.conf >> works). >> > > I have done this in the past, but I had to jump through a number of hoops > to do it. I'll have to buy a laptop and see if I can do it with modern gear > and modern software. > > But if X isn't loading the module for you, that makes the problem much, > much easier. > Yes for Intel+modesetting. I forgot to mention that for amdgpu and radeon, X might still do it. Need to test to confirm. However, there's nothing stopping you from loading it in rc.conf before starting X (which is probably better anyway). > Warner >
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