bsd-user: Implement link, linkat, unlink and unlinkat

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Jung-uk Kim <jkim@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

bsd-user/bsd-file.h

@@ -375,4 +375,58 @@ static abi_long do_bsd_renameat(abi_long arg1, abi_long arg2,
     return ret;
 }
 
+/* link(2) */
+static abi_long do_bsd_link(abi_long arg1, abi_long arg2)
+{
+    abi_long ret;
+    void *p1, *p2;
+
+    LOCK_PATH2(p1, arg1, p2, arg2);
+    ret = get_errno(link(p1, p2)); /* XXX path(p1), path(p2) */
+    UNLOCK_PATH2(p1, arg1, p2, arg2);
+
+    return ret;
+}
+
+/* linkat(2) */
+static abi_long do_bsd_linkat(abi_long arg1, abi_long arg2,
+        abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    abi_long ret;
+    void *p1, *p2;
+
+    LOCK_PATH2(p1, arg2, p2, arg4);
+    ret = get_errno(linkat(arg1, p1, arg3, p2, arg5));
+    UNLOCK_PATH2(p1, arg2, p2, arg4);
+
+    return ret;
+}
+
+/* unlink(2) */
+static abi_long do_bsd_unlink(abi_long arg1)
+{
+    abi_long ret;
+    void *p;
+
+    LOCK_PATH(p, arg1);
+    ret = get_errno(unlink(p)); /* XXX path(p) */
+    UNLOCK_PATH(p, arg1);
+
+    return ret;
+}
+
+/* unlinkat(2) */
+static abi_long do_bsd_unlinkat(abi_long arg1, abi_long arg2,
+        abi_long arg3)
+{
+    abi_long ret;
+    void *p;
+
+    LOCK_PATH(p, arg2);
+    ret = get_errno(unlinkat(arg1, p, arg3)); /* XXX path(p) */
+    UNLOCK_PATH(p, arg2);
+
+    return ret;
+}
+
 #endif /* BSD_FILE_H */

bsd-user/freebsd/os-syscall.c

@@ -317,6 +317,22 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
         ret = do_bsd_renameat(arg1, arg2, arg3, arg4);
         break;
 
+    case TARGET_FREEBSD_NR_link: /* link(2) */
+        ret = do_bsd_link(arg1, arg2);
+        break;
+
+    case TARGET_FREEBSD_NR_linkat: /* linkat(2) */
+        ret = do_bsd_linkat(arg1, arg2, arg3, arg4, arg5);
+        break;
+
+    case TARGET_FREEBSD_NR_unlink: /* unlink(2) */
+        ret = do_bsd_unlink(arg1);
+        break;
+
+    case TARGET_FREEBSD_NR_unlinkat: /* unlinkat(2) */
+        ret = do_bsd_unlinkat(arg1, arg2, arg3);
+        break;
+
     default:
         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
         ret = -TARGET_ENOSYS;