Messages in this thread Patch in this message | | | Date | Tue, 28 Jan 2014 21:49:06 +0100 | From | Borislav Petkov <> | Subject | Re: [GIT PULL] x86/kaslr for v3.14 |
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On Tue, Jan 28, 2014 at 12:25:15PM -0800, Linus Torvalds wrote: > Probably. And then we should make sure that allyesconfig/allmodconfig > don't pick it.
I'd need to think about that a bit longer as scripts/kconfig/conf.c goes and sets those. Unless someone has a better idea...
> There *are* reasonable uses for DEBUG_INFO: > > - if you very actively and extensively use kgdb, DEBUG_INFO is very useful.
Right, and at least KGDB depends on it. I was going to suggest to hide it and make only tools select it but...
> - distros might want to build distro kernels with DEBUG_INFO for the > kernel debug package
Yes. SUSE uses crash to analyze dumps and for that it needs -g symbols and other distros I'm sure too in some fashion.
> but for most kernel developers, DEBUG_INFO really just bloats things > and makes the build much *much* slower, for very little gain.
Right, your discussion kinda made me aware of this - I hadn't realized that KALLSYMS is enough.
> Sure, you get line numbers, but let's face it, it's not that hard > to just do "x/20i <address>" and trying to match it up with the > generated code instead. And since "just match it up" model works with > user-reported oopses of random kernels, you had better be able and > willing to do that *anyway*.
Hohumm.
> If most of the oopses you decode are on your own machine with your own > kernel, you might want to try to learn to be more careful when writing > code. And I'm not even kidding.
Haha.
Ok, here's the help text hunk:
--- diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index dbf94a7d25a8..73b36a1624ec 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -126,7 +126,11 @@ config DEBUG_INFO This adds debug symbols to the kernel and modules (gcc -g), and is needed if you intend to use kernel crashdump or binary object tools like crash, kgdb, LKCD, gdb, etc on the kernel. - Say Y here only if you plan to debug the kernel. + + If you only want to have symbols in kernel traces and are not + going to need support for those tools above, you don't need + to enable this as it is a huge bloat and build slowdown. + Enable CONFIG_KALLSYMS instead. If unsure, say N. -- Regards/Gruss, Boris.
Sent from a fat crate under my desk. Formatting is fine. --
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