hostid: improve extremely unreadable parts

*: remove checks of sigaction and sigprocmask results
 in cases where they clearly can't fail:
 sigaction(known_good_sig)
 sigprocmask(known_good_how)

    text           data     bss     dec     hex filename
-    393              4       0     397     18d libc/pwd_grp/lckpwdf.o
+    382              4       0     386     182 libc/pwd_grp/lckpwdf.o
-     56              0       0      56      38 libc/signal/sigblock.o
+     44              0       0      44      2c libc/signal/sigblock.o
-    211              0       0     211      d3 libc/signal/sigset.o
+    202              0       0     202      ca libc/signal/sigset.o
-     56              0       0      56      38 libc/signal/sigsetmask.o
+     44              0       0      44      2c libc/signal/sigsetmask.o
-    309              0       0     309     135 libc/unistd/sleep.o
+    256              0       0     256     100 libc/unistd/sleep.o

1 files changed, 3 insertions, 33 deletions

diff --git a/libc/pwd_grp/lckpwdf.c b/libc/pwd_grp/lckpwdf.c
index 9b0b604e0..c0c8f0d90 100644
--- a/libc/pwd_grp/lckpwdf.c
+++ b/libc/pwd_grp/lckpwdf.c
@@ -80,25 +80,8 @@ lckpwdf (void)
 
   /* Make sure file gets correctly closed when process finished.  */
   flags = fcntl (lock_fd, F_GETFD);
-#if 0 /* never fails */
-  if (flags == -1) {
-    /* Cannot get file flags.  */
-    close(lock_fd);
-    lock_fd = -1;
-	goto DONE;
-  }
-#endif
   flags |= FD_CLOEXEC;
-#if 1
   fcntl (lock_fd, F_SETFD, flags);
-#else /* never fails */
-  if (fcntl (lock_fd, F_SETFD, flags) < 0) {
-    /* Cannot set new flags.  */
-    close(lock_fd);
-    lock_fd = -1;
-	goto DONE;
-  }
-#endif
   /* Now we have to get exclusive write access.  Since multiple
      process could try this we won't stop when it first fails.
      Instead we set a timeout for the system call.  Once the timer
@@ -112,27 +95,14 @@ lckpwdf (void)
   new_act.sa_handler = noop_handler;
   __sigfillset (&new_act.sa_mask);
 
-  /* Install new action handler for alarm and save old.  */
-  if (sigaction (SIGALRM, &new_act, &saved_act) < 0) {
-    /* Cannot install signal handler.  */
-    close(lock_fd);
-    lock_fd = -1;
-	goto DONE;
-  }
+  /* Install new action handler for alarm and save old.
+   * This never fails in Linux.  */
+  sigaction (SIGALRM, &new_act, &saved_act);
 
   /* Now make sure the alarm signal is not blocked.  */
   __sigemptyset (&new_set);
   __sigaddset (&new_set, SIGALRM);
-#if 1
   sigprocmask (SIG_UNBLOCK, &new_set, &saved_set);
-#else /* never fails */
-  if (sigprocmask (SIG_UNBLOCK, &new_set, &saved_set) < 0) {
-    sigaction (SIGALRM, &saved_act, NULL);
-    close(lock_fd);
-    lock_fd = -1;
-	goto DONE;
-  }
-#endif
 
   /* Start timer.  If we cannot get the lock in the specified time we
      get a signal.  */