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Re: Constify host-side offload data`

On 10/21/15 13:33, Ilya Verbin wrote:

This happens because .gnu.offload_{funcs,vars} sections in
crtoffload{begin,end}.o now doesn't have WRITE flag, but the same sections
produced by omp_finish_file has it.  When linker joins writable + nonwritable
sections from several objects, it inserts some weird 2MB offset into the final
binary.  I.e. now there are 2 such offsets: one in the host binary and one in
the MIC target image, hence 4MB.  I haven't investigated how it happens, because
I thing it's bad idea to join sections with different flags.

That is a strange insertion of padding. Joining sections with different flags, is IIUC, perfectly fine.

But we can't make .gnu.offload_{funcs,vars} in omp_finish_file also readonly,
because in case of shared libraries there are R_X86_64_RELATIVE relocations,

Um, I thought they had absolute relocs, and thus were relro, but ICBW.

which make these sections writable.  So, I guess we need to remove all consts to
make these sections writable in all objects.

That seems like the prudent path.


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