s390/vdso: filter out mno-pic-data-is-text-relative cflag

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>

diff --git a/arch/s390/kernel/vdso32/Makefile b/arch/s390/kernel/vdso32/Makefile
index f310e80..23e868b 100644 (file)
--- a/arch/s390/kernel/vdso32/Makefile
+++ b/arch/s390/kernel/vdso32/Makefile
@@ -19,6 +19,7 @@ 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 += -fPIC -shared -soname=linux-vdso32.so.1 \

diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index 279b3bd..fc1c6ff 100644 (file)
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -24,6 +24,7 @@ KBUILD_AFLAGS_64 := $(filter-out -m64,$(KBUILD_AFLAGS))
 KBUILD_AFLAGS_64 += -m64
 
 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 := -fPIC -shared -soname=linux-vdso64.so.1 \
             --hash-style=both --build-id=sha1 -T