This prevents memory corruption if a newer app or dll is used with an
older cygwin dll. This is an unsupported scenario, but it's still a
good idea to avoid corrupting memory if possible.
Fixes: 7d5c55faa1 ("Cygwin: add wrappers for newer new/delete overloads")
Co-authored-by: Corinna Vinschen <[email protected]>
Signed-off-by: Jeremy Drake <[email protected]>
---
I left out initializing dll_major/dll_minor in dcrt0.cc as these fields
are initialized in globals.cc already. I also continue to update the
__cygwin_cxx_malloc struct even though I don't think anything should be
using it (rather the default_cygwin_cxx_malloc via the user_data pointer).
It's not static for some reason, so something *could* be accessing it I
guess.
winsup/cygwin/dcrt0.cc | 6 ++++
winsup/cygwin/include/cygwin/version.h | 3 ++
winsup/cygwin/lib/_cygwin_crt0_common.cc | 37 ++++++++++++++----------
3 files changed, 31 insertions(+), 15 deletions(-)
diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index 69c233c247..1a4ffc8925 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -724,6 +724,12 @@ dll_crt0_0 ()
lock_process::init ();
user_data->impure_ptr = _impure_ptr;
user_data->impure_ptr_ptr = &_impure_ptr;
+ /* API 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->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 f3321020f7..00eedeb27a 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 5900e6315d..87f3e8042b 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. */
@@ -180,8 +183,11 @@ _cygwin_crt0_common (MainFunc f, per_process *u)
{
/* Inherit what we don't override. */
#define CONDITIONALLY_OVERRIDE(MEMBER) \
- if (!__cygwin_cxx_malloc.MEMBER) \
+ if (__cygwin_cxx_malloc.MEMBER) \
+ newu->cxx_malloc->MEMBER = __cygwin_cxx_malloc.MEMBER; \
+ else \
__cygwin_cxx_malloc.MEMBER = newu->cxx_malloc->MEMBER;
+
CONDITIONALLY_OVERRIDE(oper_new);
CONDITIONALLY_OVERRIDE(oper_new__);
CONDITIONALLY_OVERRIDE(oper_delete);
@@ -190,20 +196,21 @@ _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);
- /* Now update the resulting set into the global redirectors. */
- *newu->cxx_malloc = __cygwin_cxx_malloc;
+ 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);
+ }
}
/* Setup the module handle so fork can get the path name. */
--
2.50.1.windows.1
