Bash: sleep execution issue with bash loadable builtins

[Thiruvadi Rajaraman]

Hi,

Found a 'sleep' execution issue with bash loadable builtins and has
performed
the below sleep test on bash-4.4-rc1.

Bash version: 4.4-rc1
Web link: https://ftp.gnu.org/gnu/bash/bash-4.4-rc1.tar.gz

Reproducible test case and Console logs:
========================================

bash-4.4-rc1#./bash
bash-4.4-rc1# cd examples/loadables/
bash-4.4-rc1/examples/loadables# enable -f ./sleep sleep

bash-4.4-rc1/examples/loadables# date; sleep 1 & date; sleep 4; date
Mon Nov 27 17:00:01 IST 2017
[1] 5355
Mon Nov 27 17:00:01 IST 2017
Mon Nov 27 17:00:02 IST 2017    --------------> Took 1 Sec only instead of
4 Sec's.
[1]+  Done                    sleep 1


bash-4.4-rc1/examples/loadables#
bash-4.4-rc1/examples/loadables# date; sleep 4 & date; sleep 1; date
Mon Nov 27 17:00:16 IST 2017
[1] 5386
Mon Nov 27 17:00:16 IST 2017
Mon Nov 27 17:00:17 IST 2017


bash-4.4-rc1/examples/loadables#
bash-4.4-rc1/examples/loadables# date; sleep 1 & date; sleep 10; date
Mon Nov 27 17:00:29 IST 2017
[1]+  Done                    sleep 4
[1] 5390
Mon Nov 27 17:00:29 IST 2017
Mon Nov 27 17:00:30 IST 2017     -------------> Took 1 Sec only instead of
10 Sec's.
[1]+  Done                    sleep 1
root@cavium-Vostro-3446
:~/Desktop/bugzilla-CGX/77504/bash-4.4-rc1/examples/loadables#

Fix patch:
==========
# Attached the fix patch -
Fix_for_bash_loadable_builtin_sleep_execution_issue.patch


Please kindly review and suggest your comments.

Thanks,
Thiruvadi Rajaraman

Fix for bash loadable builtins 'sleep' execution failure issue

The rootcause of the failure was found with select() execution 
with time information in fsleep() function in lib/sh/ufunc.c file.

The fix patch content resolves the issue.

Test logs (After applying patch)
=========
 
# date; sleep 1 & date; sleep 10; date

Mon Nov 27 17:25:31 IST 2017
[1] 13173
Mon Nov 27 17:25:31 IST 2017
Mon Nov 27 17:25:41 IST 2017    -----> Took 10 Sec's sleep 
[1]+  Done                    sleep 1

#

Signed-off-by: Thiruvadi Rajaraman <trajara...@mvista.com> 

Index: bash-4.4-rc1/lib/sh/ufuncs.c
===================================================================
--- bash-4.4-rc1.orig/lib/sh/ufuncs.c	2017-11-27 13:57:18.172796871 +0530
+++ bash-4.4-rc1/lib/sh/ufuncs.c	2017-11-27 17:21:13.622624417 +0530
@@ -90,11 +90,16 @@
      unsigned int sec, usec;
 {
   struct timeval tv;
+  int ret = 0;
 
   tv.tv_sec = sec;
   tv.tv_usec = usec;
 
-  return select(0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &tv);
+  do {
+	ret = select(0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &tv);
+  } while ( (ret == -1));
+  
+  return ret;
 }
 #else /* !HAVE_TIMEVAL || !HAVE_SELECT */
 int