4 files changed, 16 insertions, 10 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 1c859dae758f..3f84d5f15889 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1236,7 +1236,7 @@ compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec,
 
 asmlinkage ssize_t
 compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec,
-                  unsigned long vlen, u32 pos_high, u32 pos_low)
+                  unsigned long vlen, u32 pos_low, u32 pos_high)
 {
         loff_t pos = ((loff_t)pos_high << 32) | pos_low;
         struct file *file;
@@ -1293,7 +1293,7 @@ compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec,
 
 asmlinkage ssize_t
 compat_sys_pwritev(unsigned long fd, const struct compat_iovec __user *vec,
-                   unsigned long vlen, u32 pos_high, u32 pos_low)
+                   unsigned long vlen, u32 pos_low, u32 pos_high)
 {
         loff_t pos = ((loff_t)pos_high << 32) | pos_low;
         struct file *file;
diff --git a/fs/read_write.c b/fs/read_write.c
index 6d5d8ff238aa..9d1e76bb9ee1 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -731,10 +731,16 @@ SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
         return ret;
 }
 
+static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
+{
+#define HALF_LONG_BITS (BITS_PER_LONG / 2)
+        return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
+}
+
 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
-                unsigned long, vlen, u32, pos_high, u32, pos_low)
+                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
 {
-        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+        loff_t pos = pos_from_hilo(pos_h, pos_l);
         struct file *file;
         ssize_t ret = -EBADF;
         int fput_needed;
@@ -757,9 +763,9 @@ SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
 }
 
 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
-                unsigned long, vlen, u32, pos_high, u32, pos_low)
+                unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
 {
-        loff_t pos = ((loff_t)pos_high << 32) | pos_low;
+        loff_t pos = pos_from_hilo(pos_h, pos_l);
         struct file *file;
         ssize_t ret = -EBADF;
         int fput_needed;
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 9723edd6455c..f2ded21f9a3c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -193,10 +193,10 @@ asmlinkage ssize_t compat_sys_writev(unsigned long fd,
                 const struct compat_iovec __user *vec, unsigned long vlen);
 asmlinkage ssize_t compat_sys_preadv(unsigned long fd,
                 const struct compat_iovec __user *vec,
-                unsigned long vlen, u32 pos_high, u32 pos_low);
+                unsigned long vlen, u32 pos_low, u32 pos_high);
 asmlinkage ssize_t compat_sys_pwritev(unsigned long fd,
                 const struct compat_iovec __user *vec,
-                unsigned long vlen, u32 pos_high, u32 pos_low);
+                unsigned long vlen, u32 pos_low, u32 pos_high);
 
 int compat_do_execve(char * filename, compat_uptr_t __user *argv,
                 compat_uptr_t __user *envp, struct pt_regs * regs);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index b299a82a05e7..18771cac2f85 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -462,9 +462,9 @@ asmlinkage long sys_pread64(unsigned int fd, char __user *buf,
 asmlinkage long sys_pwrite64(unsigned int fd, const char __user *buf,
                              size_t count, loff_t pos);
 asmlinkage long sys_preadv(unsigned long fd, const struct iovec __user *vec,
-                           unsigned long vlen, u32 pos_high, u32 pos_low);
+                           unsigned long vlen, unsigned long pos_l, unsigned long pos_h);
 asmlinkage long sys_pwritev(unsigned long fd, const struct iovec __user *vec,
-                            unsigned long vlen, u32 pos_high, u32 pos_low);
+                            unsigned long vlen, unsigned long pos_l, unsigned long pos_h);
 asmlinkage long sys_getcwd(char __user *buf, unsigned long size);
 asmlinkage long sys_mkdir(const char __user *pathname, int mode);
 asmlinkage long sys_chdir(const char __user *filename);