On 24 July 2018 at 10:32, Matt Hart <matthew.hart@xxxxxxxxxx> wrote: > > > > On 24 July 2018 at 10:16, Will Deacon <will.deacon@xxxxxxx> wrote: >> >> On Mon, Jul 23, 2018 at 07:11:50PM +0100, Mark Brown wrote: >> > On Mon, Jul 23, 2018 at 05:59:12PM +0100, Build bot for Mark Brown wrote: >> > >> > Today's -next fails to build an arm64 allmodconfig with: >> > >> > > arm64-allmodconfig >> > > ERROR: "__sync_icache_dcache" [drivers/xen/xen-privcmd.ko] undefined! >> > >> > using >> > >> > aarch64-linux-gnu-gcc (Linaro GCC 5.3-2016.05) 5.3.1 20160412 >> > >> > however it builds perfectly fine with >> > >> > aarch64-linux-gnu-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016 >> > >> > which honestly seems like a sensible and worthwhile upgrade at this >> > point anyway given that it's a year and a half old so I'm going to do >> > that for my builder (perhaps even jump on a newer version) but it seemed >> > worth highlighting in case this is considered undesirable. A similar >> > issue is hitting on KernelCI, we should probably look at upgrading the >> > toolchain there too. >> >> Hmm, it looks to me like this comes about because xen/privcmd.c is being >> built as a module, but contains a call to set_pte_at() with a special pte: >> >> pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot)); >> >> set_pte_at(r->mm, addr, ptep, pte); >> >> which on arm64 contains: >> >> if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte)) >> __sync_icache_dcache(pte); >> >> so GCC 6 can optimise away the call to the non-exported symbol, but GCC 5 >> has trouble. >> >> What I don't understand is why this suddenly cropped up. Did GCC 5 build >> linux-next arm64 allmodconfig last week? > > > KernelCI uses GCC5 for ARM64 and xen-privcmd.ko has been broken in linux-next (and mainline) allmodconfig for a long time Bloody gmail and it's HTML mean't this didn't get delivered to linux-arm-kernel list. Resent. > >> >> >> Cheers, >> >> Will > > -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
