From 900c00b2ae29aa10b5cf0b3b5c55aff7501fc382 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Wed, 12 Aug 2020 16:20:16 +1000
Subject: [PATCH 3/3] Data::Dumper (XS): use mortals to prevent leaks if magic
throws
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For example:
use Tie::Scalar;
use Data::Dumper;
sub T::TIESCALAR { bless {}, shift}
sub T::FETCH { die }
my $x;
tie $x, "T" or die;
while(1) {
eval { () = Dumper( [ \$x ] ) };
}
would leak various work SVs.
I start a new scope (ENTER/LEAVE) for most recursive DD_dump() calls
so that the work SVs don't accumulate on the temps stack, for example
if we're dumping a large array we'd end up with several SVs on the
temp stack for each member of the array.
The exceptions are where I don't expect a large number of unreleased
temps to accumulate, as with scalar or glob refs.
Petr Písař: Ported to Data-Dumper-2.173 from
815b4be4ab7ae210f796fc9d29754e55fc0d1f0e perl commit.
Signed-off-by: Petr Písař <ppisar@redhat.com>
---
Dumper.xs | 52 ++++++++++++++++++++++++++++------------------------
1 file changed, 28 insertions(+), 24 deletions(-)
diff --git a/Dumper.xs b/Dumper.xs
index d4b34ad..65639ae 100644
--- a/Dumper.xs
+++ b/Dumper.xs
@@ -808,12 +808,13 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
sv_catpvs(retval, "( ");
if (style->indent >= 2) {
blesspad = apad;
- apad = newSVsv(apad);
+ apad = sv_2mortal(newSVsv(apad));
sv_x(aTHX_ apad, " ", 1, blesslen+2);
}
}
ipad = sv_x(aTHX_ Nullsv, SvPVX_const(style->xpad), SvCUR(style->xpad), level+1);
+ sv_2mortal(ipad);
if (is_regex)
{
@@ -878,7 +879,7 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
realtype <= SVt_PVMG
#endif
) { /* scalar ref */
- SV * const namesv = newSVpvs("${");
+ SV * const namesv = sv_2mortal(newSVpvs("${"));
sv_catpvn(namesv, name, namelen);
sv_catpvs(namesv, "}");
if (realpack) { /* blessed */
@@ -892,7 +893,6 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
DD_dump(aTHX_ ival, SvPVX_const(namesv), SvCUR(namesv), retval, seenhv,
postav, level+1, apad, style);
}
- SvREFCNT_dec(namesv);
}
else if (realtype == SVt_PVGV) { /* glob ref */
SV * const namesv = newSVpvs("*{");
@@ -908,9 +908,10 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
SSize_t ix = 0;
const SSize_t ixmax = av_len((AV *)ival);
- SV * const ixsv = newSViv(0);
+ SV * const ixsv = sv_2mortal(newSViv(0));
/* allowing for a 24 char wide array index */
New(0, iname, namelen+28, char);
+ SAVEFREEPV(iname);
(void) strlcpy(iname, name, namelen+28);
inamelen = namelen;
if (name[0] == '@') {
@@ -940,7 +941,7 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
iname[inamelen++] = '-'; iname[inamelen++] = '>';
}
iname[inamelen++] = '['; iname[inamelen] = '\0';
- totpad = newSVsv(style->sep);
+ totpad = sv_2mortal(newSVsv(style->sep));
sv_catsv(totpad, style->pad);
sv_catsv(totpad, apad);
@@ -970,8 +971,12 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
}
sv_catsv(retval, totpad);
sv_catsv(retval, ipad);
+ ENTER;
+ SAVETMPS;
DD_dump(aTHX_ elem, iname, ilen, retval, seenhv, postav,
level+1, apad, style);
+ FREETMPS;
+ LEAVE;
if (ix < ixmax || (style->trailingcomma && style->indent >= 1))
sv_catpvs(retval, ",");
}
@@ -985,9 +990,6 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
sv_catpvs(retval, ")");
else
sv_catpvs(retval, "]");
- SvREFCNT_dec(ixsv);
- SvREFCNT_dec(totpad);
- Safefree(iname);
}
else if (realtype == SVt_PVHV) {
SV *totpad, *newapad;
@@ -997,7 +999,7 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
SV *hval;
AV *keys = NULL;
- SV * const iname = newSVpvn(name, namelen);
+ SV * const iname = newSVpvn_flags(name, namelen, SVs_TEMP);
if (name[0] == '%') {
sv_catpvs(retval, "(");
(SvPVX(iname))[0] = '$';
@@ -1021,7 +1023,7 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
sv_catpvs(iname, "->");
}
sv_catpvs(iname, "{");
- totpad = newSVsv(style->sep);
+ totpad = sv_2mortal(newSVsv(style->sep));
sv_catsv(totpad, style->pad);
sv_catsv(totpad, apad);
@@ -1117,6 +1119,10 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
sv_catsv(retval, totpad);
sv_catsv(retval, ipad);
+
+ ENTER;
+ SAVETMPS;
+
/* The (very)
old logic was first to check utf8 flag, and if utf8 always
call esc_q_utf8. This caused test to break under -Mutf8,
@@ -1143,6 +1149,7 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
else {
nticks = num_q(key, klen);
New(0, nkey_buffer, klen+nticks+3, char);
+ SAVEFREEPV(nkey_buffer);
nkey = nkey_buffer;
nkey[0] = '\'';
if (nticks)
@@ -1160,7 +1167,8 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
nlen = klen;
sv_catpvn(retval, nkey, klen);
}
- sname = newSVsv(iname);
+
+ sname = sv_2mortal(newSVsv(iname));
sv_catpvn(sname, nkey, nlen);
sv_catpvs(sname, "}");
@@ -1168,7 +1176,7 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
if (style->indent >= 2) {
char *extra;
STRLEN elen = 0;
- newapad = newSVsv(apad);
+ newapad = sv_2mortal(newSVsv(apad));
New(0, extra, klen+4+1, char);
while (elen < (klen+4))
extra[elen++] = ' ';
@@ -1181,10 +1189,9 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
DD_dump(aTHX_ hval, SvPVX_const(sname), SvCUR(sname), retval, seenhv,
postav, level+1, newapad, style);
- SvREFCNT_dec(sname);
- Safefree(nkey_buffer);
- if (style->indent >= 2)
- SvREFCNT_dec(newapad);
+
+ FREETMPS;
+ LEAVE;
}
if (i) {
SV *opad = sv_x(aTHX_ Nullsv, SvPVX_const(style->xpad),
@@ -1199,8 +1206,6 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
sv_catpvs(retval, ")");
else
sv_catpvs(retval, "}");
- SvREFCNT_dec(iname);
- SvREFCNT_dec(totpad);
}
else if (realtype == SVt_PVCV) {
if (style->deparse) {
@@ -1247,7 +1252,6 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
STRLEN plen, pticks;
if (style->indent >= 2) {
- SvREFCNT_dec(apad);
apad = blesspad;
}
sv_catpvs(retval, ", '");
@@ -1276,7 +1280,6 @@ DD_dump(pTHX_ SV *val, const char *name, STRLEN namelen, SV *retval, HV *seenhv,
sv_catpvs(retval, "()");
}
}
- SvREFCNT_dec(ipad);
}
else {
STRLEN i;
@@ -1671,20 +1674,21 @@ Data_Dumper_Dumpxs(href, ...)
if (style.indent >= 2 && !terse) {
SV * const tmpsv = sv_x(aTHX_ NULL, " ", 1, SvCUR(name)+3);
- newapad = newSVsv(apad);
+ newapad = sv_2mortal(newSVsv(apad));
sv_catsv(newapad, tmpsv);
SvREFCNT_dec(tmpsv);
}
else
newapad = apad;
+ ENTER;
+ SAVETMPS;
PUTBACK;
DD_dump(aTHX_ val, SvPVX_const(name), SvCUR(name), valstr, seenhv,
postav, 0, newapad, &style);
SPAGAIN;
-
- if (style.indent >= 2 && !terse)
- SvREFCNT_dec(newapad);
+ FREETMPS;
+ LEAVE;
postlen = av_len(postav);
if (postlen >= 0 || !terse) {
--
2.25.4