Re: [crash, bisected] Re: [PATCH 3/4] x86_64: Fold pda into per cpuarea

From: H. Peter Anvin
Date: Tue Jul 01 2008 - 21:44:19 EST


Mike Travis wrote:

One interesting thing I've discovered is the gcc --version may make a
difference.

The kernel panic that occurred from Ingo's config, I was able to replicate
with GCC 4.2.0 (which is on our devel server). But this one complained
about not being able to handle the STACK-PROTECTOR option so I moved
everything to another machine that has 4.2.4, and now it seems that it
works fine. I'm still re-verifying that the source bits and config options are identical (it was a later git-remote update), and that in fact it is
the gcc --version, but that may be the conclusion. (My code also has some
patches submitted but not yet included in the tip/master tree. Curiously
just enabling some debug options changed the footprint of the panic.)

Are we allowed to insist on a specific level of GCC for compiling the
kernel?


Yes, but certainly not anything even close to that recent -- I think right now we're supposed to support back to 3.2-something overall; specific architectures might have more stringent requirements. There are a couple of gcc versions known to miscompile there kernel that we don't support; I don't know if 4.2.0 is one of them.

-hpa
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