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On 01/09/2014 04:57 PM, Pacho Ramos wrote: |
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> El jue, 09-01-2014 a las 21:58 +0100, Magnus Granberg escribió: |
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>> Hi |
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>> |
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>> Some time ago we discussed that we should enable stack smashing |
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>> (-fstack-protector) by default. So we opened a bug to track this [1]. |
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>> The affected Gcc version will be 4.8.2 and newer. Only amd64, x86, mips, ppc, |
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>> ppc64 and arm will be affected by this change. |
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>> |
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>> You can turn off ssp by using the nossp USE flag or by adding |
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>> -fno-stack-protector to the CFLAGS and/or CXXFLAGS. We are using the same |
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>> patch as Debian/Ubuntu but with some Gentoo fixes. |
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>> |
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>> The patch will move the sed for the HARD_CFLAGS, ALLCFLAGS and |
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>> ALLCXXFLAGS from do_gcc_PIE_patches() to make_gcc_hard(). We will |
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>> make_gcc_hard() the default for all Gcc versions 4.8 and newer, and turn |
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>> it on or off with hardened_gcc_works() that will make some sanity checks. |
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>> |
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>> /Magnus |
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> What are the advantages of disabling SSP to deserve that "special" |
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> handling via USE flag or easily disabling it appending the flag? |
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> |
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> Thanks a lot for the info :) |
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> |
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> |
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There are some cases where ssp could break things. I know of once case |
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right now, but its somewhat exotic. Also, sometimes we *want* to break |
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things for testing. I'm thinking here of instance where we want to test |
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a pax hardened kernel to see if it catches abuses of memory which would |
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otherwise be caught by executables emitted from a hardened toolchain. |
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Take a look at the app-admin/paxtest suite. |
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-- |
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Anthony G. Basile, Ph.D. |
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Gentoo Linux Developer [Hardened] |
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E-Mail : blueness@g.o |
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GnuPG FP : 1FED FAD9 D82C 52A5 3BAB DC79 9384 FA6E F52D 4BBA |
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GnuPG ID : F52D4BBA |
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