[PATCH 6.1 351/473] s390/vdso: filter out mno-pic-data-is-text-relative cflag

Greg Kroah-Hartman
2024-06-06T14:17:44Z

From: Sumanth Korikkar <sumanthk@linux.ibm.com>

[ Upstream commit d15e4314abec83e4f910659437bc809b0889e3a5 ]

cmd_vdso_check checks if there are any dynamic relocations in
vdso64.so.dbg. When kernel is compiled with
-mno-pic-data-is-text-relative, R_390_RELATIVE relocs are generated and
this results in kernel build error.

kpatch uses -mno-pic-data-is-text-relative option when building the
kernel to prevent relative addressing between code and data. The flag
avoids relocation error when klp text and data are too far apart

kpatch does not patch vdso code and hence the
mno-pic-data-is-text-relative flag is not essential.

Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Stable-dep-of: 10f705253651 ("s390/vdso: Generate unwind information for C modules")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/s390/kernel/vdso32/Makefile | 1 +
arch/s390/kernel/vdso64/Makefile | 1 +
2 files changed, 2 insertions(+)

diff --git a/arch/s390/kernel/vdso32/Makefile b/arch/s390/kernel/vdso32/Makefile
index cc513add48eb5..1783e4d335136 100644
--- a/arch/s390/kernel/vdso32/Makefile
+++ b/arch/s390/kernel/vdso32/Makefile
@@ -20,6 +20,7 @@ KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
KBUILD_AFLAGS_32 += -m31 -s

KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
+KBUILD_CFLAGS_32 := $(filter-out -mno-pic-data-is-text-relative,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 += -m31 -fPIC -shared -fno-common -fno-builtin

LDFLAGS_vdso32.so.dbg += -shared -soname=linux-vdso32.so.1 \
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index 42d918d50a1ff..08e87b083647c 100644
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -25,6 +25,7 @@ KBUILD_AFLAGS_64 := $(filter-out -m64,$(KBUILD_AFLAGS))
KBUILD_AFLAGS_64 += -m64 -s

KBUILD_CFLAGS_64 := $(filter-out -m64,$(KBUILD_CFLAGS))
+KBUILD_CFLAGS_64 := $(filter-out -mno-pic-data-is-text-relative,$(KBUILD_CFLAGS_64))
KBUILD_CFLAGS_64 += -m64 -fPIC -fno-common -fno-builtin
ldflags-y := -shared -soname=linux-vdso64.so.1 \
--hash-style=both --build-id=sha1 -T
--
2.43.0