On Aug 1 10:00, Corinna Vinschen wrote:
> On Jul 31 14:05, Jeremy Drake via Cygwin-patches wrote:
> > 3) running from dynamically loaded DLL's startup
> > newu would contain values from exe's startup, not zero, so would always
> > write the new pointers to cxx_malloc, memory corruption.
>
> Ah, ok, but then again, in this case a check against the actual version
> instead of checking just against != 0 should do it, shouldn't it?
>
> E.g.
>
> new_dll_with_additional_operators = newu->api_major != 0
> || newu->api_minor >= 359;
>
> That should be rewritten to a version check macro eventually, but
> it would disable wrapping the new functions depending on the
> executable being too old, even if the just loaded DLL is new enough.
> But that should be ok. Better than crashing methinks.
Like this:
diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index 69c233c24759..a272208139ab 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -724,6 +724,14 @@ dll_crt0_0 ()
lock_process::init ();
user_data->impure_ptr = _impure_ptr;
user_data->impure_ptr_ptr = &_impure_ptr;
+ /* DLL version info is used by newer _cygwin_crt0_common to handle
+ certain issues in a forward compatible way. _cygwin_crt0_common
+ overwrites these values with the application's version info at the
+ time of building the app, as usual. */
+ user_data->dll_major = cygwin_version.dll_major;
+ user_data->dll_minor = cygwin_version.dll_minor;
+ user_data->api_major = cygwin_version.api_major;
+ user_data->api_minor = cygwin_version.api_minor;
DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
GetCurrentProcess (), &hMainThread,
diff --git a/winsup/cygwin/include/cygwin/version.h
b/winsup/cygwin/include/cygwin/version.h
index f3321020f72e..00eedeb27ab4 100644
--- a/winsup/cygwin/include/cygwin/version.h
+++ b/winsup/cygwin/include/cygwin/version.h
@@ -36,6 +36,9 @@ details. */
#define CYGWIN_VERSION_CHECK_FOR_EXTRA_TM_MEMBERS \
(CYGWIN_VERSION_USER_API_VERSION_COMBINED >= 272)
+#define CYGWIN_VERSION_CHECK_FOR_CXX17_OVERLOADS(u) \
+ (CYGWIN_VERSION_PER_PROCESS_API_VERSION_COMBINED (u) >= 359)
+
/* API_MAJOR 0.0: Initial version. API_MINOR changes:
1: Export cygwin32_ calls as cygwin_ as well.
2: Export j1, jn, y1, yn.
diff --git a/winsup/cygwin/lib/_cygwin_crt0_common.cc
b/winsup/cygwin/lib/_cygwin_crt0_common.cc
index 5900e6315dbe..312cba5756c0 100644
--- a/winsup/cygwin/lib/_cygwin_crt0_common.cc
+++ b/winsup/cygwin/lib/_cygwin_crt0_common.cc
@@ -124,6 +124,9 @@ _cygwin_crt0_common (MainFunc f, per_process *u)
{
per_process *newu = (per_process *) cygwin_internal (CW_USER_DATA);
bool uwasnull;
+ bool new_dll_with_additional_operators =
+ newu ? CYGWIN_VERSION_CHECK_FOR_CXX17_OVERLOADS (newu)
+ : false;
/* u is non-NULL if we are in a DLL, and NULL in the main exe.
newu is the Cygwin DLL's internal per_process and never NULL. */
@@ -190,18 +193,21 @@ _cygwin_crt0_common (MainFunc f, per_process *u)
CONDITIONALLY_OVERRIDE(oper_new___nt);
CONDITIONALLY_OVERRIDE(oper_delete_nt);
CONDITIONALLY_OVERRIDE(oper_delete___nt);
- CONDITIONALLY_OVERRIDE(oper_delete_sz);
- CONDITIONALLY_OVERRIDE(oper_delete___sz);
- CONDITIONALLY_OVERRIDE(oper_new_al);
- CONDITIONALLY_OVERRIDE(oper_new___al);
- CONDITIONALLY_OVERRIDE(oper_delete_al);
- CONDITIONALLY_OVERRIDE(oper_delete___al);
- CONDITIONALLY_OVERRIDE(oper_delete_sz_al);
- CONDITIONALLY_OVERRIDE(oper_delete___sz_al);
- CONDITIONALLY_OVERRIDE(oper_new_al_nt);
- CONDITIONALLY_OVERRIDE(oper_new___al_nt);
- CONDITIONALLY_OVERRIDE(oper_delete_al_nt);
- CONDITIONALLY_OVERRIDE(oper_delete___al_nt);
+ if (new_dll_with_additional_operators)
+ {
+ CONDITIONALLY_OVERRIDE(oper_delete_sz);
+ CONDITIONALLY_OVERRIDE(oper_delete___sz);
+ CONDITIONALLY_OVERRIDE(oper_new_al);
+ CONDITIONALLY_OVERRIDE(oper_new___al);
+ CONDITIONALLY_OVERRIDE(oper_delete_al);
+ CONDITIONALLY_OVERRIDE(oper_delete___al);
+ CONDITIONALLY_OVERRIDE(oper_delete_sz_al);
+ CONDITIONALLY_OVERRIDE(oper_delete___sz_al);
+ CONDITIONALLY_OVERRIDE(oper_new_al_nt);
+ CONDITIONALLY_OVERRIDE(oper_new___al_nt);
+ CONDITIONALLY_OVERRIDE(oper_delete_al_nt);
+ CONDITIONALLY_OVERRIDE(oper_delete___al_nt);
+ }
/* Now update the resulting set into the global redirectors. */
*newu->cxx_malloc = __cygwin_cxx_malloc;
}
