Re: PATCH: Small memory leak and doc fix

[Sven Wischnowsky <wischnow@informatik.hu-berlin.de>]

Felix Rosencrantz wrote:

> Here's another memory leak fix along with a small doc fix.
> 
> There seems to be some situations when the following code will see
> uninitialized memory reads from the following stack:
> 	pattern_match  [compmatch.c:1035]
>         match_str      [compmatch.c:577]
>         comp_match     [compmatch.c:941]
>         addmatches     [compcore.c:1954]
>         bin_compadd    [complete.c:595]
> I haven't looked into this, so if more details are needed let me know.

Haven't had the time to look at this, but knowing the match specs used
would help.

> --- Sven Wischnowsky <wischnow@informatik.hu-berlin.de> wrote:
> >Hmm. Maybe we get this because some parameter setfn() neither uses nor 
> >frees the string it gets.
> I took a look at some of the memory that wasn't freed, and found one of the
> strings had a value that only came out of the value of complist
> ("ambiguous packed rows").  So something that touches that value has a problem.
> Maybe a parameter operator.

I found that at the weekend already: it's $compstate[list]. And then
there was another one in $commands.

Does that fix the problems with addvars()?

> >I can't see where this comes from. mkautofn() creates the
> >autofn-program wich is then freed in loadautofn() (or
> >freeshfuncnode(), with ksh-autoloading).
> >
> >All these autofn-progs won't be freed at the end, though (together
> >with many other things).
> 
> I can see these errors even before the shell exits.  The memory checker
> will only list a memory leak if there are no pointers in memory to a memory
> block.  We are probably losing the pointer to the memory from buitlin.c:2162.

Ouch. Right. `pats' should point to the same memory as `prog' because
that's what's used for freeing.

Bye
 Sven

Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.20
diff -u -r1.20 builtin.c
--- Src/builtin.c	2000/05/27 08:31:32	1.20
+++ Src/builtin.c	2000/06/05 07:55:01
@@ -2162,7 +2162,7 @@
     p->strs = NULL;
     p->shf = shf;
     p->npats = 0;
-    p->pats = NULL;
+    p->pats = (Patprog *) p->prog;
     p->flags = EF_REAL;
     p->dump = NULL;
 
Index: Src/Modules/parameter.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Modules/parameter.c,v
retrieving revision 1.8
diff -u -r1.8 parameter.c
--- Src/Modules/parameter.c	2000/06/02 01:54:16	1.8
+++ Src/Modules/parameter.c	2000/06/05 07:55:01
@@ -192,9 +192,10 @@
 static void
 setpmcommand(Param pm, char *value)
 {
-    if (isset(RESTRICTED))
+    if (isset(RESTRICTED)) {
 	zwarn("restricted: %s", value, 0);
-    else {
+	zsfree(value);
+    } else {
 	Cmdnam cn = zcalloc(sizeof(*cn));
 
 	cn->flags = HASHED;
Index: Src/Zle/compresult.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/compresult.c,v
retrieving revision 1.18
diff -u -r1.18 compresult.c
--- Src/Zle/compresult.c	2000/05/31 09:56:12	1.18
+++ Src/Zle/compresult.c	2000/06/05 07:55:02
@@ -1168,7 +1168,7 @@
 comp_list(char *v)
 {
     zsfree(complist);
-    complist = ztrdup(v);
+    complist = v;
 
     onlyexpl = (v ? ((strstr(v, "expl") ? 1 : 0) |
 		     (strstr(v, "messages") ? 2 : 0)) : 0);

--
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de