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Hi all, |
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|
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since the last time I asked Zac about this it came back to bite me[1] |
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this time I'm going to send the announce to the list first, and if |
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nobody can actually come up with a good reason not to, I'm going to ask |
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Zac tomorrow to re-enable the feature. |
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|
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What is this about? Portage already reports some of the overflow |
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warnings coming from the glibc fortified sources (-D_FORTIFY_SOURCE=2 |
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-O2 — enabled since gcc 4.3.3-r1 and even stronger with gcc 4.5 and |
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glibc 2.12+, afaict), but they really are divided into two categories: |
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|
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- might overflow (depends on combination of parameters and variables the |
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compiler can't completely untangle); |
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- _will_ overflow (whenever that code path is hit, an overflow will |
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happen). |
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|
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The former we should highlight but not die upon; the latter, though... |
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As Mike and me expressed on the linked bug, code that is built with that |
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warning is code that is going to crash as surely as |
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|
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char *foo = NULL; |
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foo[3] = 'a'; |
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which could result in nasty surprises for users (see [2] for the whole |
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reasoning). |
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Now, we've not seen "proper" false positives (in the Portage sense I |
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mean — because even if the C library hits a false positive, it _will_ |
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crash with an abort() from its own code!), but Kumba pointed me at a |
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case that wasn't entirely clear, and took a bit of detective work to |
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track down [3] so you could have users report issues you cannot easily |
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identify or reproduce. I cannot make promises, but if all else fail I'll |
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see to be around to help you with those cases. |
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|
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So if you want to have your say, gentoo-qa is there for that. |
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|
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Thank you, |
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|
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[1] https://bugs.gentoo.org/show_bug.cgi?id=337031 |
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[2] |
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http://blog.flameeyes.eu/2010/09/14/not-all-failures-are-caused-equal |
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[3] |
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http://blog.flameeyes.eu/2010/09/12/some-_fortify_source-far-fetched-warnings-are-funny |
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|
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-- |
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Diego Elio Pettenò — “Flameeyes” |
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http://blog.flameeyes.eu/ |
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|
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If you found a .asc file in this mail and know not what it is, |
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it's a GnuPG digital signature: http://www.gnupg.org/ |
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