+++ Masahiro Yamada [11/02/21 15:14 +0900]:
Stephen Rothwell reported a build error on ppc64 when CONFIG_TRIM_UNUSED_KSYMS is enabled.Jessica Yu pointed out the cause of the error with the reference to the ppc64 elf ABI: "Symbol names with a dot (.) prefix are reserved for holding entry point addresses. The value of a symbol named ".FN", if it exists, is the entry point of the function "FN". As it turned out, CONFIG_TRIM_UNUSED_KSYMS has never worked for ppc64, which has been unnoticed until recently because this option depends on !UNUSED_SYMBOLS hence is disabled by all{mod,yes}config. (Then, it was uncovered by another patch removing UNUSED_SYMBOLS.) Removing the dot prefix in scripts/gen_autoksyms.sh fixes the issue. Please note it must be done before 'sort -u', because modules have both ._mcount and _mcount undefined when CONFIG_FUNCTION_TRACER=y. Link: https://lore.kernel.org/lkml/20210209210843.3af66...@canb.auug.org.au/ Reported-by: Stephen Rothwell <s...@canb.auug.org.au> Signed-off-by: Masahiro Yamada <masahi...@kernel.org>
Thanks a lot for the quick fix. This fixes the ppc64 build issue on my end: Tested-by: Jessica Yu <j...@kernel.org> Do you plan to take this through the kbuild tree? If so, please let me know when you've applied it, then I can undo the temporary workaround I currently have in modules-next. Thank you! Jessica
