Ok, I was wrong. The code really *does* compile to that insane
	a3 14 00 00 00          mov    %eax,0x14
by your compiler.
That's the
	asc_dvc_varp->overrun_buf = kzalloc(ASC_OVERRUN_BSIZE, GFP_KERNEL);
thing, and gcc seems to have decided that it can statically prove that

asc_dvc_varp is NULL.
Quite frankly, I don't see that being true. But you have some patches in

your tree that I haven't followed, so.. Are you sure the patches applied

to the right spot? The patch I saw added that kzalloc() to the _end_ of

the function (long after asc_dvc_varp was initialized), maybe that one got

mis-applied?
Or maybe your compiler version is simply totally broken.
			Linus

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I'll try applying the patch to a freshly downloaded git-tree.
Shall I try another compiler? I have at least these two:
gcc version 3.4.6 (Ubuntu 3.4.6-6ubuntu2)

gcc version 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)
in addition to the self-compiled 4.2.3 I used for the tests.

--

Hilsen Harald.

--

I would suggest a patch mis-application problem first (or possibly even

the patch itself being broken - I simply didn't look very closely at the

patch, but it *looked* ok).
If it's a compiler bug, it's a pretty big one, and quite frankly, I doubt

it. Compiler bugs do happen, but they are pretty rare, and they tend to

have more subtle effects than the one you see. 
4.2.3? Really? That's pretty damn recent, and so almost totally untested.

That does make a compiler bug at least more likely.
So yes, if you already have other compilers installed, you should try

them. If it really is a compiler bug, it's a really bad one, and you would

want to let the gcc people know.
Still, I'd double-check that the
	asc_dvc_varp->overrun_buf = kzalloc(ASC_OVERRUN_BSIZE, GFP_KERNEL);
line was added properly first. You should see it way after the point where

it did 
	asc_dvc_varp = &boardp->dvc_var.asc_dvc_var;
to initialize it (and both statements should be inside a
	if (ASC_NARROW_BOARD(boardp)) {
conditional - please check that the source code looks sane too).
			Linus

--

I just re-downloaded an re-patched and re-compiled (with gcc 4.2.3),

and now the kernel boots. I must have screwed up the previous

patching.
It now works, with Fujita's patch applied.

--

Hilsen Harald

--

On Thu, 7 Feb 2008 23:24:00 +0100
Thanks Harald and Linus,
The bug has been in the advansys driver. 2.6.23 and 2.6.24 works just

because the size of Scsi_Host structure was multiples of 8. After

2.6.24, some patches change Scsi_Host structure and now the size is

not multiples of 8. So we hit this bug.
I'll resend the patch with a proper description.

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