bpf_slow_path: sibling call to `skb_copy_bits' not allowed multiple TOCs (ppc)
paul.gortmaker at windriver.com
Thu Mar 29 11:54:56 EST 2012
Wondering if anyone has researched this, before I waste more time on it.
The linux-next build of powerpc-allyesconfig has for quite some time shown this:
powerpc-linux-ld: arch/powerpc/net/built-in.o: In function `bpf_slow_path_word':
(.text+0x90): sibling call optimization to `skb_copy_bits' does not
multiple TOCs; recompile with -mminimal-toc or -fno-optimize-sibling-calls, or
make `skb_copy_bits' extern
We get the same error for s/word/half/ and s/word/byte/ and s/word/msh/
Visually "bisecting" the linux-next builds shows the following:
good: Dec 7th, 2011: http://kisskb.ellerman.id.au/kisskb/buildresult/5059024/
bad: Dec 8th, 2011: http://kisskb.ellerman.id.au/kisskb/buildresult/5062069/
I wouldn't be surprised if this was some kind of size thing that doesn't matter
in the real world, as the powerpc-allyesconfig is really only of value for build
coverage. Even in the absence of the skb error, it still fails to link with:
"powerpc-linux-ld: TOC section size exceeds 64k"
i.e. it never links into anything a person could actually try and boot anyway.
So, just knowing "yes that is bogus because you've got a giant kernel
with multiple TOC" would be useful information here.
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