While looking at `time' for other things, tb@ pointed out that the
following code is broken:
$ time for i in 1 2; do echo $i; done
ksh: : is read only
Note the missing variable name: time's pipeline fails since for's
identifier gets mangled to an empty string by get_command() at
sync.c:368 which in turn causes global() at var.c:177/194 to set it
RDONLY.
This regression was introduced by
https://marc.info/?l=openbsd-tech&m=121613951723808 and made it's way
into 4.4 as
revision 1.28
date: 2008/07/23 16:34:38; author: jaredy; state: Exp; lines: +6 -1;
fix stack abuse in the `time' commmand, using alloc()'d memory instead.
reported by Thorsten Glaser, thanks.
ok millert@, earlier version miod@
The following diff fixes `time for ...' by copying the identifier over
to the new stack if given.
regress/bin/ksh still passes on amd64, but I'll add a new one for this
once we have a final fix.
Feedback?
Index: syn.c
===================================================================
RCS file: /cvs/src/bin/ksh/syn.c,v
retrieving revision 1.38
diff -u -p -r1.38 syn.c
--- syn.c 30 Dec 2015 09:07:00 -0000 1.38
+++ syn.c 22 Apr 2018 02:17:33 -0000
@@ -365,9 +365,13 @@ get_command(int cf)
syniocf &= ~(KEYWORD|ALIAS);
t = pipeline(0);
if (t) {
- t->str = alloc(2, ATEMP);
- t->str[0] = '\0'; /* TF_* flags */
- t->str[1] = '\0';
+ if (t->str) {
+ t->str = str_save(t->str, ATEMP);
+ } else {
+ t->str = alloc(2, ATEMP);
+ t->str[0] = '\0'; /* TF_* flags */
+ t->str[1] = '\0';
+ }
}
t = block(TTIME, t, NULL, NULL);
break;
