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| author | Sami Tolvanen <samitolvanen@google.com> | 2020-12-11 10:46:23 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-01-14 08:21:09 -0800 |
| commit | fbe078d397b4d59232f05fde977d3b1e7d0c2028 (patch) | |
| tree | 298965a7f44d326039861efb9a197839da21cc86 /init | |
| parent | dd2776222abb9893e5b5c237a2c8c880d8854cee (diff) | |
| download | linux-fbe078d397b4d59232f05fde977d3b1e7d0c2028.tar.bz2 | |
kbuild: lto: add a default list of used symbols
With CONFIG_LTO_CLANG, LLVM bitcode has not yet been compiled into a
binary when the .mod files are generated, which means they don't yet
contain references to certain symbols that will be present in the final
binaries. This includes intrinsic functions, such as memcpy, memmove,
and memset [1], and stack protector symbols [2]. This change adds a
default symbol list to use with CONFIG_TRIM_UNUSED_KSYMS when Clang's
LTO is used.
[1] https://llvm.org/docs/LangRef.html#standard-c-c-library-intrinsics
[2] https://llvm.org/docs/LangRef.html#llvm-stackprotector-intrinsic
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-7-samitolvanen@google.com
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963..5271138b8742 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2297,6 +2297,7 @@ config TRIM_UNUSED_KSYMS config UNUSED_KSYMS_WHITELIST string "Whitelist of symbols to keep in ksymtab" depends on TRIM_UNUSED_KSYMS + default "scripts/lto-used-symbollist.txt" if LTO_CLANG help By default, all unused exported symbols will be un-exported from the build when TRIM_UNUSED_KSYMS is selected. |