Re: [PATCH 3/7] inflate pt1: clean up input logic

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Sat, Feb 25, 2006 at 03:47:04PM -0600, Matt Mackall wrote:
> On Sat, Feb 25, 2006 at 09:22:48PM +0000, Russell King wrote:
> > init/do_mounts_rd.c:#include "../lib/inflate.c"
> > init/initramfs.c:#include "../lib/inflate.c"
> > 
> > for these your arguments that halting is fine is _NOT_ correct nor is it
> > desirable.
> 
> If you have an argument for why we shouldn't halt on failed
> init{rd,ramfs} decompression, I look forward to hearing it.
> 
> > Did you read that post?
> 
> This? http://www.ussg.iu.edu/hypermail/linux/kernel/0312.2/1024.html

Yes, that.

> "The firmware then calls the kernel decompressor, which dutifully
> decompresses the image, and calls the kernel. This image ends up
> getting corrupted at some point."
> 
> Is your argument that we shouldn't halt after encountering a corrupt
> image?

You're getting very confused.

1. kernel is loaded.
2. firmware scans loaded kernel, finds gzip magic numbers (the compressed
   kernel.)
3. firmware sets initrd pointeres to point at the compressed kernel.
4. firmware calls kernel decompressor.
5. kernel decompresses and self-relocates.
6. compressed kernel image is thereby partly corrupted.
7. kernel boots.
8. kernel tries to decompress the compressed kernel image.
9. decompressor gets confused and tries to gobble more data than is
   available.
10. kernel sits there being a dumb fuck.

> In my mind, being unable to decompress init* is every bit as fatal as
> being unable to mount root.

It's very simple.  With fix, the kernel successfully boots on these
machines.  Without fix, the kernel hangs on these machines for _no_
good reason other than the firmware did something that was stupid.

I'm sorry, I just do not see why you're being soo bloody difficult
over this.

The buggest bloody thing about this is that _lots_ of time was wasted
on working out what the fuck was going on.  I have no intention of
allowing any supposed "cleanup" to return us to the days where we have
to go though such crap again - and I will keep bitching about it until
the message gets through.

As far as I'm concerned, we're better off keeping the existing code if
this is the extent to which folk have to go to in order to preserve
needed bug fixes.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core