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| author | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-11 15:14:16 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-12 03:02:21 +0900 |
| commit | 29500f15b54b63ad0ea60b58e85144262bd24df2 (patch) | |
| tree | 07fa6b1a005b09e3c66b1fbbbbc72246907ed33e /scripts | |
| parent | 92bf22614b21a2706f4993b278017e437f7785b3 (diff) | |
| download | lwn-29500f15b54b63ad0ea60b58e85144262bd24df2.tar.gz lwn-29500f15b54b63ad0ea60b58e85144262bd24df2.zip | |
kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64
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>
Diffstat (limited to 'scripts')
| -rwxr-xr-x | scripts/gen_autoksyms.sh | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh index 16c0b2ddaa4c..d54dfba15bf2 100755 --- a/scripts/gen_autoksyms.sh +++ b/scripts/gen_autoksyms.sh @@ -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" |