Fix leaks of cloned coderefs that access lexicals

[perl/modules/Variable-Magic.git] / Magic.xs

diff --git a/Magic.xs b/Magic.xs
index d9bc4b4d9c46cc354ace577714baa7a762b5d468..ec49843183def6fa826c8f2edd5e5d5712f11a7c 100644 (file)
--- a/Magic.xs
+++ b/Magic.xs
@@ -12,10 +12,6 @@
 
 #define __PACKAGE__ "Variable::Magic"
 
-#define PERL_VERSION_GE(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
-
-#define PERL_VERSION_LE(R, V, S) (PERL_REVISION < (R) || (PERL_REVISION == (R) && (PERL_VERSION < (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION <= (S))))))
-
 #ifndef VMG_PERL_PATCHLEVEL
 # ifdef PERL_PATCHNUM
 #  define VMG_PERL_PATCHLEVEL PERL_PATCHNUM
@@ -24,9 +20,11 @@
 # endif
 #endif
 
-#define VMG_HAS_PERL_OR(P, R, V, S) ((VMG_PERL_PATCHLEVEL >= (P)) || (!VMG_PERL_PATCHLEVEL && PERL_VERSION_GE((R), (V), (S))))
+#define VMG_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
+
+#define VMG_HAS_PERL_BRANCH(R, V, S) (PERL_REVISION == (R) && PERL_VERSION == (V) && PERL_SUBVERSION >= (S))
 
-#define VMG_HAS_PERL_AND(P, R, V, S) (PERL_VERSION_GE((R), (V), (S)) && (!VMG_PERL_PATCHLEVEL || (VMG_PERL_PATCHLEVEL >= (P))))
+#define VMG_HAS_PERL_MAINT(R, V, S, P) (PERL_REVISION == (R) && PERL_VERSION == (V) && (VMG_PERL_PATCHLEVEL >= (P) || (!VMG_PERL_PATCHLEVEL && PERL_SUBVERSION >= (S))))
 
 /* --- Threads and multiplicity -------------------------------------------- */
 
@@ -38,16 +36,18 @@
 # define dNOOP
 #endif
 
-#if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
-# define VMG_MULTIPLICITY 1
-# ifndef tTHX
-#  define tTHX PerlInterpreter*
+#ifndef VMG_MULTIPLICITY
+# if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
+#  define VMG_MULTIPLICITY 1
+# else
+#  define VMG_MULTIPLICITY 0
 # endif
-#else
-# define VMG_MULTIPLICITY 0
+#endif
+#if VMG_MULTIPLICITY && !defined(tTHX)
+# define tTHX PerlInterpreter*
 #endif
 
-#if VMG_MULTIPLICITY && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
+#if VMG_MULTIPLICITY && defined(USE_ITHREADS) && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
 # define VMG_THREADSAFE 1
 # ifndef MY_CXT_CLONE
 #  define MY_CXT_CLONE \
@@ -70,7 +70,7 @@
 # define MY_CXT_CLONE NOOP
 #endif
 
-#if VMG_MULTIPLICITY
+#if VMG_THREADSAFE
 
 STATIC SV *vmg_clone(pTHX_ SV *sv, tTHX owner) {
 #define vmg_clone(P, O) vmg_clone(aTHX_ (P), (O))
@@ -81,7 +81,7 @@ STATIC SV *vmg_clone(pTHX_ SV *sv, tTHX owner) {
  return sv_dup(sv, &param);
 }
 
-#endif /* VMG_MULTIPLICITY */
+#endif /* VMG_THREADSAFE */
 
 /* --- Compatibility ------------------------------------------------------- */
 
@@ -113,27 +113,35 @@ STATIC SV *vmg_clone(pTHX_ SV *sv, tTHX owner) {
 # define MGf_LOCAL 0
 #endif
 
-/* uvar magic and Hash::Util::FieldHash were commited with p28419 */
-#if VMG_HAS_PERL_AND(28419, 5, 9, 4)
+/* uvar magic and Hash::Util::FieldHash were commited with 28419 */
+#if VMG_HAS_PERL_MAINT(5, 9, 4, 28419) || VMG_HAS_PERL(5, 10, 0)
 # define VMG_UVAR 1
 #else
 # define VMG_UVAR 0
 #endif
 
-#if !defined(VMG_COMPAT_ARRAY_PUSH_NOLEN) && VMG_HAS_PERL_OR(25854, 5, 9, 3)
+/* Applied to dev-5.9 as 25854, integrated to maint-5.8 as 28160 */
+#if !defined(VMG_COMPAT_ARRAY_PUSH_NOLEN) && (VMG_HAS_PERL_MAINT(5, 8, 9, 28160) || VMG_HAS_PERL_MAINT(5, 9, 3, 25854) || VMG_HAS_PERL(5, 10, 0))
 # define VMG_COMPAT_ARRAY_PUSH_NOLEN 1
 #else
 # define VMG_COMPAT_ARRAY_PUSH_NOLEN 0
 #endif
 
-/* since 5.9.5 - see #43357 */
-#if VMG_HAS_PERL_OR(31473, 5, 9, 5)
+/* Applied to dev-5.11 as 34908 */
+#if VMG_HAS_PERL_MAINT(5, 11, 0, 34908)
+# define VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID 1
+#else
+# define VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID 0
+#endif
+
+/* Applied to dev-5.9 as 31473 (see #43357), integrated to maint-5.8 as 32542 */
+#if VMG_HAS_PERL_MAINT(5, 8, 9, 32542) || VMG_HAS_PERL_MAINT(5, 9, 5, 31473) || VMG_HAS_PERL(5, 10, 0)
 # define VMG_COMPAT_ARRAY_UNDEF_CLEAR 1
 #else
 # define VMG_COMPAT_ARRAY_UNDEF_CLEAR 0
 #endif
 
-#if VMG_HAS_PERL_OR(32969, 5, 11, 0)
+#if VMG_HAS_PERL_MAINT(5, 11, 0, 32969)
 # define VMG_COMPAT_SCALAR_LENGTH_NOLEN 1
 #else
 # define VMG_COMPAT_SCALAR_LENGTH_NOLEN 0
@@ -248,10 +256,10 @@ STATIC SV *vmg_data_new(pTHX_ SV *ctor, SV *sv, AV *args) {
 
  if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
  nsv = POPs;
-#if PERL_VERSION_LE(5, 8, 2)
- nsv = sv_newref(nsv); /* Workaround some bug in SvREFCNT_inc() */
-#else
+#if VMG_HAS_PERL(5, 8, 3)
  SvREFCNT_inc(nsv);    /* Or it will be destroyed in FREETMPS */
+#else
+ nsv = sv_newref(nsv); /* Workaround some bug in SvREFCNT_inc() */
 #endif
 
  PUTBACK;
@@ -316,7 +324,7 @@ STATIC UV vmg_cast(pTHX_ SV *sv, SV *wiz, AV *args) {
  if (w->cb_copy)
   mg->mg_flags |= MGf_COPY;
 #endif /* MGf_COPY */
-#if MGf_DUP
+#if 0 /* MGf_DUP */
  if (w->cb_dup)
   mg->mg_flags |= MGf_DUP;
 #endif /* MGf_DUP */
@@ -548,6 +556,12 @@ STATIC int vmg_svt_clear(pTHX_ SV *sv, MAGIC *mg) {
 STATIC int vmg_svt_free(pTHX_ SV *sv, MAGIC *mg) {
  /* So that it can survive tmp cleanup in vmg_cb_call */
  SvREFCNT_inc(sv);
+#if !VMG_HAS_PERL_MAINT(5, 11, 0, 32686)
+ /* The previous magic tokens were freed but the magic chain wasn't updated, so
+  * if you access the sv from the callback the old deleted magics will trigger
+  * and cause memory misreads. Change 32686 solved it that way : */
+ SvMAGIC_set(sv, mg);
+#endif
  /* Perl_mg_free will get rid of the magic and decrement mg->mg_obj and
   * mg->mg_ptr reference count */
  return vmg_cb_call1(SV2MGWIZ(mg->mg_ptr)->cb_free, sv, mg->mg_obj);
@@ -555,7 +569,7 @@ STATIC int vmg_svt_free(pTHX_ SV *sv, MAGIC *mg) {
 
 #if MGf_COPY
 STATIC int vmg_svt_copy(pTHX_ SV *sv, MAGIC *mg, SV *nsv, const char *key,
-# if VMG_HAS_PERL_AND(33256, 5, 11, 0)
+# if VMG_HAS_PERL_MAINT(5, 11, 0, 33256)
   I32 keylen
 # else
   int keylen
@@ -669,7 +683,7 @@ STATIC int vmg_wizard_free(pTHX_ SV *wiz, MAGIC *mg) {
 #if MGf_COPY
  if (w->cb_copy  != NULL) { SvREFCNT_dec(SvRV(w->cb_copy)); }
 #endif /* MGf_COPY */
-#if MGf_DUP
+#if 0 /* MGf_DUP */
  if (w->cb_dup   != NULL) { SvREFCNT_dec(SvRV(w->cb_dup)); }
 #endif /* MGf_DUP */
 #if MGf_LOCAL
@@ -792,11 +806,11 @@ STATIC SV *vmg_wizard_wiz(pTHX_ SV *wiz) {
   w->cb_  ## N = NULL;                \
  }
 
-#if VMG_MULTIPLICITY
+#if VMG_THREADSAFE
 
 #define VMG_CLONE_CB(N) \
- z->cb_ ## N = (w->cb_ ## N) ? newRV_noinc(vmg_clone(SvRV(w->cb_ ## N), \
-                                           w->owner))                   \
+ z->cb_ ## N = (w->cb_ ## N) ? newRV_inc(vmg_clone(SvRV(w->cb_ ## N), \
+                                         w->owner))                   \
                              : NULL;
 
 STATIC MGWIZ *vmg_wizard_clone(pTHX_ const MGWIZ *w) {
@@ -837,7 +851,7 @@ STATIC MGWIZ *vmg_wizard_clone(pTHX_ const MGWIZ *w) {
  return z;
 }
 
-#endif /* VMG_MULTIPLICITY */
+#endif /* VMG_THREADSAFE */
 
 /* --- XS ------------------------------------------------------------------ */
 
@@ -861,6 +875,8 @@ BOOT:
  newCONSTSUB(stash, "VMG_UVAR",  newSVuv(VMG_UVAR));
  newCONSTSUB(stash, "VMG_COMPAT_ARRAY_PUSH_NOLEN",
                     newSVuv(VMG_COMPAT_ARRAY_PUSH_NOLEN));
+ newCONSTSUB(stash, "VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID",
+                    newSVuv(VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID));
  newCONSTSUB(stash, "VMG_COMPAT_ARRAY_UNDEF_CLEAR",
                     newSVuv(VMG_COMPAT_ARRAY_UNDEF_CLEAR));
  newCONSTSUB(stash, "VMG_COMPAT_SCALAR_LENGTH_NOLEN",