[PATCH AUTOSEL 5.10 29/36] kallsyms: fix nonconverging kallsyms table with lld

Sasha Levin
2021-02-08T18:04:34Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit efe6e3068067212b85c2d0474b5ee3b2d0c7adab ]

ARM randconfig builds with lld sometimes show a build failure
from kallsyms:

Inconsistent kallsyms data
Try make KALLSYMS_EXTRA_PASS=1 as a workaround

The problem is the veneers/thunks getting added by the linker extend
the symbol table, which in turn leads to more veneers being needed,
so it may take a few extra iterations to converge.

This bug has been fixed multiple times before, but comes back every time
a new symbol name is used. lld uses a different set of identifiers from
ld.bfd, so the additional ones need to be added as well.

I looked through the sources and found that arm64 and mips define similar
prefixes, so I'm adding those as well, aside from the ones I observed. I'm
not sure about powerpc64, which seems to already be handled through a
section match, but if it comes back, the "__long_branch_" and "__plt_"
prefixes would have to get added as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
scripts/kallsyms.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 7ecd2ccba531b..54ad86d137849 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -112,6 +112,12 @@ static bool is_ignored_symbol(const char *name, char type)
"__crc_", /* modversions */
"__efistub_", /* arm64 EFI stub namespace */
"__kvm_nvhe_", /* arm64 non-VHE KVM namespace */
+ "__AArch64ADRPThunk_", /* arm64 lld */
+ "__ARMV5PILongThunk_", /* arm lld */
+ "__ARMV7PILongThunk_",
+ "__ThumbV7PILongThunk_",
+ "__LA25Thunk_", /* mips lld */
+ "__microLA25Thunk_",
NULL
};

--
2.27.0