[PATCH 02/12] s390: don't build vdso32 with clang

Arnd Bergmann
2019-04-08T21:26:15Z

clang does not support 31 bit object files on s390, so skip
the 32-bit vdso here, and only build it when using gcc to compile
the kernel.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/s390/Kconfig | 3 +++
arch/s390/kernel/Makefile | 2 +-
arch/s390/kernel/vdso.c | 10 +++++-----
3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b6e3d0653002..8cd860cba4d1 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -388,6 +388,9 @@ config COMPAT
(and some other stuff like libraries and such) is needed for
executing 31 bit applications. It is safe to say "Y".

+config COMPAT_VDSO
+ def_bool COMPAT && !CC_IS_CLANG
+
config SYSVIPC_COMPAT
def_bool y if COMPAT && SYSVIPC

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 8a62c7f72e1b..1222db6d4ee9 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -86,7 +86,7 @@ obj-$(CONFIG_TRACEPOINTS) += trace.o

# vdso
obj-y += vdso64/
-obj-$(CONFIG_COMPAT) += vdso32/
+obj-$(CONFIG_COMPAT_VDSO) += vdso32/

chkbss := head64.o early_nobss.o
include $(srctree)/arch/s390/scripts/Makefile.chkbss
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index e7920a68a12e..243d8b1185bf 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -29,7 +29,7 @@
#include <asm/vdso.h>
#include <asm/facility.h>

-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_VDSO
extern char vdso32_start, vdso32_end;
static void *vdso32_kbase = &vdso32_start;
static unsigned int vdso32_pages;
@@ -55,7 +55,7 @@ static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,

vdso_pagelist = vdso64_pagelist;
vdso_pages = vdso64_pages;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_VDSO
if (vma->vm_mm->context.compat_mm) {
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
@@ -76,7 +76,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
unsigned long vdso_pages;

vdso_pages = vdso64_pages;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_VDSO
if (vma->vm_mm->context.compat_mm)
vdso_pages = vdso32_pages;
#endif
@@ -223,7 +223,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
return 0;

vdso_pages = vdso64_pages;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_VDSO
mm->context.compat_mm = is_compat_task();
if (mm->context.compat_mm)
vdso_pages = vdso32_pages;
@@ -280,7 +280,7 @@ static int __init vdso_init(void)
int i;

vdso_init_data(vdso_data);
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_VDSO
/* Calculate the size of the 32 bit vDSO */
vdso32_pages = ((&vdso32_end - &vdso32_start
+ PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
--
2.20.0