On Wed, 2017-12-06 at 19:12:28 UTC, Desnes Augusto Nunes do Rosario wrote: > powerpc64 gcc can generate code that offsets an address, to access part of > an object in memory. If the address is a -mcmodel=medium toc pointer > relative address then code like the following is possible. > > addis r9,r2,var@toc@ha > ld r3,var@toc@l(r9) > ld r4,(var+8)@toc@l(r9) > > This works fine so long as var is naturally aligned, *and* r2 is > sufficiently aligned. If not, there is a possibility that the offset added > to access var+8 wraps over a n*64k+32k boundary. Modules don't have any > guarantee that r2 is sufficiently aligned. Moreover, code generated by > older compilers generates a .toc section with 2**0 alignment, which can > result in relocation failures at module load time even without the wrap > problem. > > Thus, this patch links modules with an aligned .toc section (Makefile and > module.lds changes), and forces alignment for out of tree modules or those > without a .toc section (module_64.c changes). > > Signed-off-by: Alan Modra <amo...@gmail.com> > [ desnesn: updated patch to apply to powerpc-next kernel v4.15 ] > Signed-off-by: Desnes A. Nunes do Rosario <desn...@linux.vnet.ibm.com>
Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/5c45b5280196a92c4437f5648209c5 cheers