[PATCH 5.12 148/178] Makefile: lto: Pass -warn-stack-size only on LLD < 13.0.0

Greg Kroah-Hartman
2021-06-21T16:49:54Z

From: Tor Vic <torvic9@mailbox.org>

commit 0236526d76b87c1dc2cbe3eb31ae29be5b0ca151 upstream.

Since LLVM commit fc018eb, the '-warn-stack-size' flag has been dropped
[1], leading to the following error message when building with Clang-13
and LLD-13:

ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument
'-warn-stack-size=2048'. Try: 'ld.lld --help'
ld.lld: Did you mean '--asan-stack=2048'?

In the same way as with commit 2398ce80152a ("x86, lto: Pass
-stack-alignment only on LLD < 13.0.0") , make '-warn-stack-size'
conditional on LLD < 13.0.0.

[1] https://reviews.llvm.org/D103928

Fixes: 24845dcb170e ("Makefile: LTO: have linker check -Wframe-larger-than")
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1377
Signed-off-by: Tor Vic <torvic9@mailbox.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/7631bab7-a8ab-f884-ab54-f4198976125c@mailbox.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Makefile | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/Makefile
+++ b/Makefile
@@ -913,11 +913,14 @@ CC_FLAGS_LTO += -fvisibility=hidden
# Limit inlining across translation units to reduce binary size
KBUILD_LDFLAGS += -mllvm -import-instr-limit=5

-# Check for frame size exceeding threshold during prolog/epilog insertion.
+# Check for frame size exceeding threshold during prolog/epilog insertion
+# when using lld < 13.0.0.
ifneq ($(CONFIG_FRAME_WARN),0)
+ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
KBUILD_LDFLAGS += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
endif
endif
+endif

ifdef CONFIG_LTO
KBUILD_CFLAGS += -fno-lto $(CC_FLAGS_LTO)