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| author | Sami Tolvanen <samitolvanen@google.com> | 2021-08-16 11:05:19 -0700 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-09-03 08:12:39 +0900 |
| commit | 850ded46c64299f04d15e39caaba21963fb966f8 (patch) | |
| tree | 782ee2114059886c099257096c2ede2623ad0b1e /scripts/gen_autoksyms.sh | |
| parent | 7d73c3e9c51400d3e0e755488050804e4d44737a (diff) | |
| download | linux-850ded46c64299f04d15e39caaba21963fb966f8.tar.gz linux-850ded46c64299f04d15e39caaba21963fb966f8.tar.xz | |
kbuild: Fix TRIM_UNUSED_KSYMS with LTO_CLANG
With CONFIG_LTO_CLANG, we currently link modules into native
code just before modpost, which means with TRIM_UNUSED_KSYMS
enabled, we still look at the LLVM bitcode in the .o files when
generating the list of used symbols. As the bitcode doesn't
yet have calls to compiler intrinsics and llvm-nm doesn't see
function references that only exist in function-level inline
assembly, we currently need a whitelist for TRIM_UNUSED_KSYMS to
work with LTO.
This change moves module LTO linking to happen earlier, and
thus avoids the issue with LLVM bitcode and TRIM_UNUSED_KSYMS
entirely, allowing us to also drop the whitelist from
gen_autoksyms.sh.
Link: https://github.com/ClangBuiltLinux/linux/issues/1369
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Tested-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'scripts/gen_autoksyms.sh')
| -rwxr-xr-x | scripts/gen_autoksyms.sh | 12 |
1 files changed, 0 insertions, 12 deletions
diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh index da320151e7c3..6ed0d225c8b1 100755 --- a/scripts/gen_autoksyms.sh +++ b/scripts/gen_autoksyms.sh @@ -26,18 +26,6 @@ if [ -n "$CONFIG_MODVERSIONS" ]; then needed_symbols="$needed_symbols module_layout" fi -# 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. -if [ -n "$CONFIG_LTO_CLANG" ]; then - # intrinsic functions - needed_symbols="$needed_symbols memcpy memmove memset" - # ftrace - needed_symbols="$needed_symbols _mcount" - # stack protector symbols - needed_symbols="$needed_symbols __stack_chk_fail __stack_chk_guard" -fi - ksym_wl= if [ -n "$CONFIG_UNUSED_KSYMS_WHITELIST" ]; then # Use 'eval' to expand the whitelist path and check if it is relative |