AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64

Browse Source 
[ Upstream commit 29500f15b54b63ad0ea60b58e85144262bd24df2 ]

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,
but this issue 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/20210209210843.3af66662@canb.auug.org.au/
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Masahiro Yamada 2021-02-11 15:14:16 +09:00 committed by Greg Kroah-Hartman
parent b8b65310e4
commit 6ca89ac39e
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
scripts/gen_autoksyms.sh
View File

@ -43,6 +43,9 @@ EOT
sed 's/ko$/mod/' $modlist |
xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- |
cat - "$ksym_wl" |
# Remove the dot prefix for ppc64; symbol names with a dot (.) hold entry
# point addresses.
sed -e 's/^\.//' |
sort -u |
sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file"