CREDITS.in: use UTF-8 consistently

[strace] / ioctl.c

diff --git a/ioctl.c b/ioctl.c
index 264c7c02c71cafdd49d8b5baf189daf68d9b69ea..b61a5be5c464cd28a38e744dabce8235cb2c5a91 100644 (file)
--- a/ioctl.c
+++ b/ioctl.c
@@ -224,6 +224,33 @@ ioctl_decode_command_number(struct tcb *tcp)
        }
 }
 
+/**
+ * Decode arg parameter of the ioctl call.
+ *
+ * @return There are two flags of the return value important for the purposes of
+ *         processing by SYS_FUNC(ioctl):
+ *          - RVAL_IOCTL_DECODED: indicates that ioctl decoder code
+ *                                has printed arg parameter;
+ *          - RVAL_DECODED: indicates that decoding is done.
+ *         As a result, the following behaviour is expected:
+ *          - on entering:
+ *            - 0: decoding should be continued on exiting;
+ *            - RVAL_IOCTL_DECODED: decoding on exiting is not needed
+ *                                  and decoder has printed arg value;
+ *            - RVAL_DECODED: decoding on exiting is not needed
+ *                            and generic handler should print arg value.
+ *          - on exiting:
+ *            - 0: generic handler should print arg value;
+ *            - RVAL_IOCTL_DECODED: decoder has printed arg value.
+ *
+ *         Note that it makes no sense to return just RVAL_DECODED on exiting,
+ *         but, of course, it is not prohibited (for example, it may be useful
+ *         in cases where the return path is common on entering and on exiting
+ *         the syscall).
+ *
+ *         SYS_FUNC(ioctl) converts RVAL_IOCTL_DECODED flag to RVAL_DECODED,
+ *         and passes all other bits of ioctl_decode return value unchanged.
+ */
 static int
 ioctl_decode(struct tcb *tcp)
 {
@@ -319,16 +346,11 @@ SYS_FUNC(ioctl)
                ret = ioctl_decode(tcp) | RVAL_DECODED;
        }
 
-       if (ret & RVAL_DECODED) {
-               ret &= ~RVAL_DECODED;
-               if (ret)
-                       --ret;
-               else
-                       tprintf(", %#" PRI_klx, tcp->u_arg[2]);
+       if (ret & RVAL_IOCTL_DECODED) {
+               ret &= ~RVAL_IOCTL_DECODED;
                ret |= RVAL_DECODED;
-       } else {
-               if (ret)
-                       --ret;
+       } else if (ret & RVAL_DECODED) {
+               tprintf(", %#" PRI_klx, tcp->u_arg[2]);
        }
 
        return ret;