The (relatively) new KCFI feature in LLVM/Clang encodes type information
for C functions by generating symbols named __kcfi_typeid_<fname>, which
can then be referenced from assembly. However, some custom build rules
(e.g. EFI, nVHE, or early PIE on arm64) use objcopy to add a prefix to
all the symbols in their object files, making mksysmap's ignore filter
miss those KCFI symbols.
Therefore, explicitly list those twice-prefixed KCFI symbols as ignored.
Alternatively, this could also be achieved in a less verbose way by
ignoring any symbol containing the string "__kcfi_typeid_". However,
listing the combined prefixes explicitly saves us from running the small
risk of ignoring symbols that should be kept.
Signed-off-by: Pierre-Clément Tosi <ptosi@xxxxxxxxxx>
---
scripts/mksysmap | 3 +++
1 file changed, 3 insertions(+)
diff --git a/scripts/mksysmap b/scripts/mksysmap
index 26f39772f7a5..17cf4292e26b 100755
--- a/scripts/mksysmap
+++ b/scripts/mksysmap
@@ -61,7 +61,10 @@ ${NM} -n ${1} | sed >${2} -e "
/ __microLA25Thunk_/d
# CFI type identifiers
+/ __efistub___kcfi_typeid_/d
/ __kcfi_typeid_/d
+/ __kvm_nvhe___kcfi_typeid_/d
+/ __pi___kcfi_typeid_/d
# CRC from modversions
/ __crc_/d
--
2.41.0.162.gfafddb0af9-goog
--
Pierre
