Re: [PATCH v8 00/16] Add support for Clang LTO
From: Arnd Bergmann <arnd@kernel.org>
Date: 2020-12-09 12:37:01
Also in:
linux-arch, linux-kbuild, linux-pci, lkml
On Tue, Dec 8, 2020 at 1:15 PM Arnd Bergmann [off-list ref] wrote:
- one build seems to have dropped all symbols the string operations from vmlinux, so while the link goes through, modules cannot be loaded: ERROR: modpost: "memmove" [drivers/media/rc/rc-core.ko] undefined! ERROR: modpost: "memcpy" [net/wireless/cfg80211.ko] undefined! ERROR: modpost: "memcpy" [net/8021q/8021q.ko] undefined! ERROR: modpost: "memset" [net/8021q/8021q.ko] undefined! ERROR: modpost: "memcpy" [net/unix/unix.ko] undefined! ERROR: modpost: "memset" [net/sched/cls_u32.ko] undefined! ERROR: modpost: "memcpy" [net/sched/cls_u32.ko] undefined! ERROR: modpost: "memset" [net/sched/sch_skbprio.ko] undefined! ERROR: modpost: "memcpy" [net/802/garp.ko] undefined! I first thought this was related to a clang-12 bug I saw the other day, but this also happens with clang-11
It seems to happen because of CONFIG_TRIM_UNUSED_KSYMS,
which is a shame, since I think that is an option we'd always want to
have enabled with LTO, to allow more dead code to be eliminated.
Arnd
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel