NOFORK fixes

"rm -i FILE" and "yes" can now be interrupted by ^C in hush.
This also now works:

$ usleep 19999999
^C
$ echo $?
130

function                                             old     new   delta
run_pipe                                            1668    1711     +43
pseudo_exec_argv                                     312     321      +9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 52/0)               Total: 52 bytes

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

4 files changed, 15 insertions, 5 deletions

diff --git a/coreutils/rm.c b/coreutils/rm.c
index f91c94570..5e4acab8c 100644
--- a/coreutils/rm.c
+++ b/coreutils/rm.c
@@ -16,7 +16,8 @@
 //config:       help
 //config:       rm is used to remove files or directories.
 
-//applet:IF_RM(APPLET_NOFORK(rm, rm, BB_DIR_BIN, BB_SUID_DROP, rm))
+//applet:IF_RM(APPLET_NOEXEC(rm, rm, BB_DIR_BIN, BB_SUID_DROP, rm))
+/* was NOFORK, but then "rm -i FILE" can't be ^C'ed if run by hush */
 
 //kbuild:lib-$(CONFIG_RM) += rm.o
 
@@ -36,7 +37,7 @@
 
 #include "libbb.h"
 
-/* This is a NOFORK applet. Be very careful! */
+/* This is a NOEXEC applet. Be very careful! */
 
 int rm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int rm_main(int argc UNUSED_PARAM, char **argv)
diff --git a/coreutils/seq.c b/coreutils/seq.c
index f36dbb4ec..c26ff06b9 100644
--- a/coreutils/seq.c
+++ b/coreutils/seq.c
@@ -12,7 +12,8 @@
 //config:       help
 //config:       print a sequence of numbers
 
-//applet:IF_SEQ(APPLET_NOFORK(seq, seq, BB_DIR_USR_BIN, BB_SUID_DROP, seq))
+//applet:IF_SEQ(APPLET_NOEXEC(seq, seq, BB_DIR_USR_BIN, BB_SUID_DROP, seq))
+/* was NOFORK, but then "seq 1 999999999" can't be ^C'ed if run by hush */
 
 //kbuild:lib-$(CONFIG_SEQ) += seq.o
 
@@ -26,7 +27,7 @@
 
 #include "libbb.h"
 
-/* This is a NOFORK applet. Be very careful! */
+/* This is a NOEXEC applet. Be very careful! */
 
 int seq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int seq_main(int argc, char **argv)
diff --git a/coreutils/usleep.c b/coreutils/usleep.c
index 7c25aada1..684ab781b 100644
--- a/coreutils/usleep.c
+++ b/coreutils/usleep.c
@@ -38,6 +38,13 @@ int usleep_main(int argc UNUSED_PARAM, char **argv)
                 bb_show_usage();
         }
 
+        /* Safe wrt NOFORK? (noforks are not allowed to run for
+         * a long time). Try "usleep 99999999" + ^C + "echo $?"
+         * in hush with FEATURE_SH_NOFORK=y.
+         * At least on uclibc, usleep() thanslates to nanosleep()
+         * which returns early on any signal (even caught one),
+         * and uclibc does not loop back on EINTR.
+         */
         usleep(xatou(argv[1]));
 
         return EXIT_SUCCESS;
diff --git a/coreutils/yes.c b/coreutils/yes.c
index ea35d146c..c244bfe10 100644
--- a/coreutils/yes.c
+++ b/coreutils/yes.c
@@ -17,7 +17,8 @@
 //config:       yes is used to repeatedly output a specific string, or
 //config:       the default string 'y'.
 
-//applet:IF_YES(APPLET_NOFORK(yes, yes, BB_DIR_USR_BIN, BB_SUID_DROP, yes))
+//applet:IF_YES(APPLET_NOEXEC(yes, yes, BB_DIR_USR_BIN, BB_SUID_DROP, yes))
+/* was NOFORK, but then yes can't be ^C'ed if run by hush */
 
 //kbuild:lib-$(CONFIG_YES) += yes.o