On 16/06/2016 12:36, Chris Metcalf wrote: > Adhemerval Zanella is cleaning up the preadv/pwritev implementation in glibc > and came across an issue with the tilepro/tilegx32 implementation of argument > passing for 64-bit arguments in split register pairs. > > The glibc code base uses __LONG_LONG_PAIR to split 64-bit arguments, > passing "hi, lo" for BE systems and "lo, hi" for LE systems. Tile is almost > uniformly > LE, but we do support BE for specific customers. The 32-bit compat mode on > tilegx was getting passed "hi, lo" arguments by glibc but looking for them to > be "lo, hi" arguments on the kernel side. I fixed this here: > > https://lkml.kernel.org/g/1466019219-10462-1-git-send-email-cmetc...@mellanox.com > > Reviewing what other platforms do, it seems like powerpc compat mode may > have the opposite problem in little-endian mode, since arguments are passed > in "hi, lo" order unconditionally in arch/powerpc/kernel/sys_ppc32.c. You may > want to adopt the solution in the patch cited above, or similar solutions > elsewhere, eg regs_to_64 in arch/arm64/include/asm/assembler.h, or > merge_64 in arch/mips/kernel/linux32.c. > > Here's the email thread from libc-alpha: > > https://sourceware.org/ml/libc-alpha/2016-06/msg00638.html >
I am not fully familiar with kernel policy regarding ABI so is this considered an ABI breakage or a real defect? _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
