From 6fba14e2ed9d159f76b23fa5c16f3ea99acbc003 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 5 Jan 2023 12:13:06 +0900 Subject: [PATCH] s390: define RUNTIME_DISCARD_EXIT to fix link error with GNU ld < 2.36 Nathan Chancellor reports that the s390 vmlinux fails to link with GNU ld < 2.36 since commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv"). It happens for defconfig, or more specifically for CONFIG_EXPOLINE=y. $ s390x-linux-gnu-ld --version | head -n1 GNU ld (GNU Binutils for Debian) 2.35.2 $ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- allnoconfig $ ./scripts/config -e CONFIG_EXPOLINE $ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- olddefconfig $ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- `.exit.text' referenced in section `.s390_return_reg' of drivers/base/dd.o: defined in discarded section `.exit.text' of drivers/base/dd.o make[1]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1 make: *** [Makefile:1252: vmlinux] Error 2 arch/s390/kernel/vmlinux.lds.S wants to keep EXIT_TEXT: .exit.text : { EXIT_TEXT } But, at the same time, EXIT_TEXT is thrown away by DISCARD because s390 does not define RUNTIME_DISCARD_EXIT. I still do not understand why the latter wins after 99cb0d917ffa, but defining RUNTIME_DISCARD_EXIT seems correct because the comment line in arch/s390/kernel/vmlinux.lds.S says: /* * .exit.text is discarded at runtime, not link time, * to deal with references from __bug_table */ Nathan also found that binutils commit 21401fc7bf67 ("Duplicate output sections in scripts") cured this issue, so we cannot reproduce it with binutils 2.36+, but it is better to not rely on it. Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") Link: https://lore.kernel.org/all/Y7Jal56f6UBh1abE@dev-arch.thelio-3990X/ Reported-by: Nathan Chancellor Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20230105031306.1455409-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens --- arch/s390/kernel/vmlinux.lds.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index 5ea3830af0cc..6e101e6f499d 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -17,6 +17,8 @@ /* Handle ro_after_init data on our own. */ #define RO_AFTER_INIT_DATA +#define RUNTIME_DISCARD_EXIT + #define EMITS_PT_NOTE #include -- 2.30.2