3 files changed, 43 insertions, 8 deletions

diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index f4b5795..3f556c6 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -24,6 +24,8 @@
 #  include <asm/unistd_64_x32.h>
 #  define __ARCH_WANT_COMPAT_SYS_TIME
 #  define __ARCH_WANT_COMPAT_SYS_GETDENTS64
+#  define __ARCH_WANT_COMPAT_SYS_PREADV64
+#  define __ARCH_WANT_COMPAT_SYS_PWRITEV64
 
 # endif
 
diff --git a/fs/read_write.c b/fs/read_write.c
index edc5746..72c09b4 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -982,9 +982,9 @@ COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
-		const struct compat_iovec __user *,vec,
-		unsigned long, vlen, loff_t, pos)
+static long __compat_sys_preadv64(unsigned long fd,
+				  const struct compat_iovec __user *vec,
+				  unsigned long vlen, loff_t pos)
 {
 	struct fd f;
 	ssize_t ret;
@@ -1001,12 +1001,22 @@ COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
 	return ret;
 }
 
+#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
+COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
+		const struct compat_iovec __user *,vec,
+		unsigned long, vlen, loff_t, pos)
+{
+	return __compat_sys_preadv64(fd, vec, vlen, pos);
+}
+#endif
+
 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
 		const struct compat_iovec __user *,vec,
 		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
-	return compat_sys_preadv64(fd, vec, vlen, pos);
+
+	return __compat_sys_preadv64(fd, vec, vlen, pos);
 }
 
 static size_t compat_writev(struct file *file,
@@ -1049,9 +1059,9 @@ COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
-		const struct compat_iovec __user *,vec,
-		unsigned long, vlen, loff_t, pos)
+static long __compat_sys_pwritev64(unsigned long fd,
+				   const struct compat_iovec __user *vec,
+				   unsigned long vlen, loff_t pos)
 {
 	struct fd f;
 	ssize_t ret;
@@ -1068,12 +1078,22 @@ COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
 	return ret;
 }
 
+#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
+COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
+		const struct compat_iovec __user *,vec,
+		unsigned long, vlen, loff_t, pos)
+{
+	return __compat_sys_pwritev64(fd, vec, vlen, pos);
+}
+#endif
+
 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 		const struct compat_iovec __user *,vec,
 		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
-	return compat_sys_pwritev64(fd, vec, vlen, pos);
+
+	return __compat_sys_pwritev64(fd, vec, vlen, pos);
 }
 #endif
 
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 179b1da..1c45742 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -340,6 +340,19 @@ asmlinkage ssize_t compat_sys_preadv(compat_ulong_t fd,
 asmlinkage ssize_t compat_sys_pwritev(compat_ulong_t fd,
 		const struct compat_iovec __user *vec,
 		compat_ulong_t vlen, u32 pos_low, u32 pos_high);
+
+#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
+asmlinkage long compat_sys_preadv64(unsigned long fd,
+		const struct compat_iovec __user *vec,
+		unsigned long vlen, loff_t pos);
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
+asmlinkage long compat_sys_pwritev64(unsigned long fd,
+		const struct compat_iovec __user *vec,
+		unsigned long vlen, loff_t pos);
+#endif
+
 asmlinkage long compat_sys_lseek(unsigned int, compat_off_t, unsigned int);
 
 asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr_t __user *argv,