linux-user fchownat() syscall, by Thayne Harbaugh.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3220 c046a42c-6fe2-441c-8c8c-71466251a162

linux-user/syscall.c

@@ -139,6 +139,7 @@ type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5,type6 arg6)	\
 
 
 #define __NR_sys_uname __NR_uname
+#define __NR_sys_fchownat __NR_fchownat
 #define __NR_sys_getcwd1 __NR_getcwd
 #define __NR_sys_getdents __NR_getdents
 #define __NR_sys_getdents64 __NR_getdents64
@@ -162,6 +163,10 @@ static int gettid(void) {
 }
 #endif
 _syscall1(int,sys_uname,struct new_utsname *,buf)
+#if defined(TARGET_NR_fchownat) && defined(__NR_fchownat)
+_syscall5(int,sys_fchownat,int,dirfd,const char *,pathname,
+          uid_t,owner,gid_t,group,int,flags)
+#endif
 _syscall2(int,sys_getcwd1,char *,buf,size_t,size)
 _syscall3(int, sys_getdents, uint, fd, struct dirent *, dirp, uint, count);
 #if defined(TARGET_NR_getdents64) && defined(__NR_getdents64)
@@ -4293,6 +4298,21 @@ long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3,
     case TARGET_NR_fchown:
         ret = get_errno(fchown(arg1, low2highuid(arg2), low2highgid(arg3)));
         break;
+#if defined(TARGET_NR_fchownat) && defined(__NR_fchownat)
+    case TARGET_NR_fchownat:
+        if (!arg2) {
+            ret = -EFAULT;
+            goto fail;
+        }
+        p = lock_user_string(arg2);
+        if (!access_ok(VERIFY_READ, p, 1))
+            ret = -EFAULT;
+	else
+            ret = get_errno(sys_fchownat(arg1, p, low2highuid(arg3), low2highgid(arg4), arg5));
+        if (p)
+            unlock_user(p, arg2, 0);
+        break;
+#endif
 #ifdef TARGET_NR_setresuid
     case TARGET_NR_setresuid:
         ret = get_errno(setresuid(low2highuid(arg1),