On 9/30/2014 5:58 PM, Rob Landley wrote: > On 09/30/14 19:41, Frank Rowand wrote: >> The earliest mention I find of this on lkml is v4. Was there earlier >> discussion of this elsewhere? (Just so I have a clue as to the full >> context and don't repeat previous discussion.) The mention of names >> in the change logs tells me I should be able to find the discussion >> somewhere. > > The previous ones had a different topic sentence (add strictinit). So > they added code to do less.
Thanks! That gives me the context I was looking for. For posterity and anyone searching in the future, the previous threads were: [PATCH ...] init: Add strictinit to disable init= fallbacks > >> On 9/28/2014 7:40 PM, Andy Lutomirski wrote: >>> If a user puts init=/whatever on the command line and /whatever >>> can't be run, then the kernel will try a few default options before >>> giving up. If init=/whatever came from a bootloader prompt, then >>> this is unexpected but probably harmless. On the other hand, if it >>> comes from a script (e.g. a tool like virtme or perhaps a future >>> kselftest script), then the fallbacks are likely to exist, but >>> they'll do the wrong thing. For example, they might unexpectedly >>> invoke systemd. >>> >>> This makes a failure to run the specified init= process be fatal. >>> >>> As a temporary measure, users can set CONFIG_INIT_FALLBACK=y to >>> preserve the old behavior. If no one speaks up, we can remove that >>> option entirely after a release or two. >> >> I'm speaking up already, no need to wait two releases. I like the >> current behavior where I can fall back into a shell without >> recompiling the kernel and/or changing the boot command line to >> debug an init failure. >> >> I would suggest that the current behavior remain the >> default and the choice to make a failure of the specified >> init= process fatal should be an explicit choice. > > Oh please no. Having to switch kernel configuration entries _on_ in > order to switch behavior _off_ is how you get nonsense like > allnoconfig_y which breaks miniconfig, why is why I patch it back out > locally: > > http://landley.net/hg/aboriginal/file/1672/sources/patches/linux-deeplystupid.patch > > If you're going to argue that it should "default y", that's a defensible > choice. But please don't argue for kernel config symbols with a negative > meaning or we'll start having allyesconfig_n brain damage too... Yes, "default y" is a valid answer to my request. > >> Instead of using a config option, would adding another kernel >> command line option, such as 'init_fail_is_fatal', work for >> your needs? > > That was the previous series of patches you ignored, which added code so > you can provide _extra_ kernel commands to tell it _not_ to do stuff. > The patches did not generate noticeable enthusiasm. But there also was not a strong push back either. Just Chuck's suggestion of an alternate syntax, and your suggestion of instead using a config option (and possibly immediately deprecating the config option). You could as easily frame the argument that the added code was to tell the kernel to "_do_ stuff" (panic) instead of "_not_ do stuff". But that is just semantics on my part; whatever. I thought the general trend was to try to avoid adding config options. The strictinit method seems fine to me. >> I have a feeling this has already been proposed, >> as the 'strictinit' option mentioned in the changes from v3 >> below might be the same concept? > > That was it, yes. > > Having to get your kernel config right (and your kernel command line > right) in order for your system to boot is not really a new concept, is > it? You can still specify "init=/bin/sh" if you want that. (I do it all > the time when I need to edit a system I haven't bothered to look up the > root password to.) Yes, of course I can. So it falls back to personal preference (as I said, I like that some failed boots will drop into a shell without having to change the kernel command line). -Frank -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
