From: Masahiro Yamada masahiroy@kernel.org
commit a494398bde273143c2352dd373cad8211f7d94b2 upstream.
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 nathan@kernel.org Signed-off-by: Masahiro Yamada masahiroy@kernel.org Link: https://lore.kernel.org/r/20230105031306.1455409-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/kernel/vmlinux.lds.S | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -15,6 +15,8 @@ /* Handle ro_after_init data on our own. */ #define RO_AFTER_INIT_DATA
+#define RUNTIME_DISCARD_EXIT + #define EMITS_PT_NOTE
#include <asm-generic/vmlinux.lds.h>