Eliminate redundant checks of res variable

* syscall.c (trace_syscall_entering): Eliminate redundant checks of res variable.
(trace_syscall_exiting): Likewise.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/syscall.c b/syscall.c
index 1720058b617cdc21e996afa9375023bc5bb15804..ac0f76999443cfa628217d3168ad598868a58078 100644 (file)
--- a/syscall.c
+++ b/syscall.c
@@ -673,9 +673,9 @@ static long r3;
 #endif
 
 /* Returns:
- * 0: "ignore this ptrace stop", bail out of trace_syscall() silently.
- * 1: ok, continue in trace_syscall().
- * other: error, trace_syscall() should print error indicator
+ * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
+ * 1: ok, continue in trace_syscall_entering().
+ * other: error, trace_syscall_entering() should print error indicator
  *    ("????" etc) and bail out.
  */
 static int
@@ -1082,9 +1082,9 @@ get_scno(struct tcb *tcp)
 
 /* Called at each syscall entry.
  * Returns:
- * 0: "ignore this ptrace stop", bail out of trace_syscall() silently.
- * 1: ok, continue in trace_syscall().
- * other: error, trace_syscall() should print error indicator
+ * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
+ * 1: ok, continue in trace_syscall_entering().
+ * other: error, trace_syscall_entering() should print error indicator
  *    ("????" etc) and bail out.
  */
 static int
@@ -1459,12 +1459,13 @@ trace_syscall_entering(struct tcb *tcp)
        scno_good = res = get_scno(tcp);
        if (res == 0)
                return res;
-       if (res == 1)
+       if (res == 1) {
                res = syscall_fixup_on_sysenter(tcp);
-       if (res == 0)
-               return res;
-       if (res == 1)
-               res = get_syscall_args(tcp);
+               if (res == 0)
+                       return res;
+               if (res == 1)
+                       res = get_syscall_args(tcp);
+       }
 
        if (res != 1) {
                printleader(tcp);
@@ -1540,9 +1541,8 @@ trace_syscall_entering(struct tcb *tcp)
 }
 
 /* Returns:
- * 0: "ignore this ptrace stop", bail out of trace_syscall() silently.
- * 1: ok, continue in trace_syscall().
- * other: error, trace_syscall() should print error indicator
+ * 1: ok, continue in trace_syscall_exiting().
+ * -1: error, trace_syscall_exiting() should print error indicator
  *    ("????" etc) and bail out.
  */
 static int
@@ -1674,6 +1674,11 @@ is_negated_errno(unsigned long int val)
        return val > max;
 }
 
+/* Returns:
+ * 1: ok, continue in trace_syscall_exiting().
+ * -1: error, trace_syscall_exiting() should print error indicator
+ *    ("????" etc) and bail out.
+ */
 static int
 get_error(struct tcb *tcp)
 {
@@ -1902,26 +1907,22 @@ trace_syscall_exiting(struct tcb *tcp)
        update_personality(tcp, tcp->currpers);
 #endif
        res = get_syscall_result(tcp);
-       if (res == 0)
-               return res;
        if (res == 1) {
                syscall_fixup_on_sysexit(tcp); /* never fails */
-               res = get_error(tcp);
-       }
-       if (res == 0)
-               return res;
-       if (res == 1)
-               internal_syscall(tcp);
-
-       if (res == 1 && filtered(tcp)) {
-               goto ret;
+               res = get_error(tcp); /* returns 1 or -1 */
+               if (res == 1) {
+                       internal_syscall(tcp);
+                       if (filtered(tcp)) {
+                               goto ret;
+                       }
+               }
        }
 
        /* TODO: TCB_REPRINT is probably not necessary:
         * we can determine whether reprinting is needed
         * by examining printing_tcp. Something like:
         * if not in -ff mode, and printing_tcp != tcp,
-        * then the log is not currenlty ends with *our*
+        * then the log is not currently ends with *our*
         * syscall entry output, but with something else,
         * and we need to reprint.
         * If we'd implement this, printing_tcp = tcp