add the setmalloctags I used to analyse
the libsec-plug-some-leaks and find who
should be responsible for cleanup of the
leaked memory.
also removed one now superflous ...=nil; in x509.c

Axel.

Notes:
Mon Sep 19 07:15:50 EDT 2005 rsc
    I edited this patch before applying it, to remove some of
    the calls to setmalloctag.  betomp illustrates the general
    philosophy.  It looks like this:
    
    mpint*
    betomp(int n)
    {
    	b = malloc(sizeof *b);
    	b->p = malloc(n);
    	return b;
    }
    
    In this case, b should get tagged with setmalloctag,
    because the responsibility for freeing (via mpfree)
    b is being passed to the caller.  b->p, on the other
    hand, has a fine malloc tag as it is.  The caller is
    not responsible for freeing b->p.  b->p is hidden from
    the caller and expected to be freed by the innards of
    mpfree.  
    

Reference: /n/sources/patch/applied/setmalloctag-libsec-libmp
Date: Sat Sep 17 22:47:44 CES 2005
Reviewed-by: rsc

--- /sys/src/libsec/port/x509.c	Sat Sep 17 22:21:39 2005
+++ /sys/src/libsec/port/x509.c	Mon Sep 19 13:15:09 2005
@@ -172,6 +172,7 @@
 		exits("out of memory");
 	}
 	memset(p, 0, n);
+	setmalloctag(p, getcallerpc(&n));
 	return p;
 }
 
@@ -259,9 +260,11 @@
 	if(err == ASN_OK) {
 		err = length_decode(pp, pend, &length);
 		if(err == ASN_OK) {
-			if(tag.class == Universal)
+			if(tag.class == Universal) {
 				err = value_decode(pp, pend, length, tag.num, isconstr, &val);
-			else
+				if(val.tag == VSeq || val.tag == VSet)
+					setmalloctag(val.u.seqval, getcallerpc(&pp));
+			}else
 				err = value_decode(pp, pend, length, OCTET_STRING, 0, &val);
 			if(err == ASN_OK) {
 				pelem->tag = tag;
@@ -498,6 +501,7 @@
 
 	case SEQUENCE:
 		err = seq_decode(&p, pend, length, isconstr, &vl);
+		setmalloctag(vl, getcallerpc(&pp));
 		if(err == ASN_OK) {
 			pval->tag = VSeq ;
 			pval->u.seqval = vl;
@@ -506,6 +510,7 @@
 
 	case SETOF:
 		err = seq_decode(&p, pend, length, isconstr, &vl);
+		setmalloctag(vl, getcallerpc(&pp));
 		if(err == ASN_OK) {
 			pval->tag = VSet;
 			pval->u.setval = vl;
@@ -742,6 +747,7 @@
 	}
 	*pp = p;
 	*pelist = ans;
+	setmalloctag(ans, getcallerpc(&pp));
 	return err;
 }
 
@@ -1402,6 +1408,7 @@
 	Elist* el;
 
 	el = (Elist*)emalloc(sizeof(Elist));
+	setmalloctag(el, getcallerpc(&e));
 	el->hd = e;
 	el->tl = tail;
 	return el;
@@ -2042,7 +2049,6 @@
 	/* see 9.2.1 of rfc2437 */
 	pkcs1 = betomp(signature->data, signature->len, nil);
 	mpexp(pkcs1, pk->ek, pk->n, pkcs1);
-	pkcs1buf = nil;
 	buflen = mptobe(pkcs1, nil, 0, &pkcs1buf);
 	buf = pkcs1buf;
 	if(buflen != nlen || buf[0] != 1) {
--- /sys/src/libmp/port/mptobe.c	Sat Sep 17 22:21:49 2005
+++ /sys/src/libmp/port/mptobe.c	Sat Sep 17 22:21:47 2005
@@ -15,6 +15,7 @@
 	if(p == nil){
 		n = (b->top+1)*Dbytes;
 		p = malloc(n);
+		setmalloctag(p, getcallerpc(&b));
 	}
 	if(p == nil)
 		return -1;
--- /sys/src/libmp/port/mpaux.c	Sat Sep 17 22:22:02 2005
+++ /sys/src/libmp/port/mpaux.c	Mon Sep 19 13:14:14 2005
@@ -58,6 +58,7 @@
 		sysfatal("mpsetminbits: n < 0");
 
 	b = mallocz(sizeof(mpint), 1);
+	setmalloctag(b, getcallerpc(&n));
 	if(b == nil)
 		sysfatal("mpnew: %r");
 	n = DIGITS(n);
--- /sys/src/libmp/port/betomp.c	Sat Sep 17 22:22:25 2005
+++ /sys/src/libmp/port/betomp.c	Mon Sep 19 13:14:42 2005
@@ -9,8 +9,10 @@
 	int m, s;
 	mpdigit x;
 
-	if(b == nil)
+	if(b == nil){
 		b = mpnew(0);
+		setmalloctag(b, getcallerpc(&p));
+	}
 
 	// dump leading zeros
 	while(*p == 0 && n > 1){