Prevent Mono.Posix from using multiple C runtimes on Windows

Since libMonoPosixHelper.dll is linked against ucrtbase.dll the C runtime
wrapper functions in it will call into ucrtbase.dll. Some pinvokes in
Mono.Unix.Native.Stdlib, however, bind directly to C runtime functions in
msvcrt. This is problematic if a resource (heap memory, file pointer, etc) is
allocated using one C runtime and then operated upon using funcitons form the
other C runtime. E.g., Stdlib.malloc() calls into a wrapper in
libMonoPosixHelper so it will use the ucrtbase heap while Stdlib.free() calls
directly into msvcrt's free() which will abort the process since it's called
with a pointer in an unknown heap.

This commit adds libMonoPosixHelper wrappers for all memory and file related
functions in Stdlib to ensure that all such functions use the same C runtime.

Some of the Mono.Posix tests still fail but at least the test suite doesn't
crash after this change. The test failures will be addressed in a future PR.

3 files changed, 98 insertions, 0 deletions

diff --git a/support/map.h b/support/map.h
index ccd221b106a..8c6ef5000f2 100644
--- a/support/map.h
+++ b/support/map.h
@@ -2181,10 +2181,24 @@ int Mono_Posix_Stdlib_MB_CUR_MAX (void);
 int Mono_Posix_Stdlib_perror (const char* s, int err);
 int Mono_Posix_Stdlib_RAND_MAX (void);
 void* Mono_Posix_Stdlib_realloc (void* ptr, guint64 size);
+void Mono_Posix_Stdlib_free (void* p);
 int Mono_Posix_Stdlib_rewind (void* stream);
 int Mono_Posix_Stdlib_setbuf (void* stream, void* buf);
 void Mono_Posix_Stdlib_SetLastError (int error);
 int Mono_Posix_Stdlib_setvbuf (void* stream, void* buf, int mode, guint64 size);
+void* Mono_Posix_Stdlib_fopen (char* path, char* mode);
+void* Mono_Posix_Stdlib_freopen (char* path, char* mode, void *stream);
+gint32 Mono_Posix_Stdlib_fprintf (void* stream, char* format, char *message);
+gint32 Mono_Posix_Stdlib_fgetc (void* stream);
+char* Mono_Posix_Stdlib_fgets (char* str, gint32 size, void* stream);
+gint32 Mono_Posix_Stdlib_fputc (gint32 c, void* stream);
+gint32 Mono_Posix_Stdlib_fputs (char* s, void* stream);
+gint32 Mono_Posix_Stdlib_fclose (void* stream);
+gint32 Mono_Posix_Stdlib_fflush (void* stream);
+void* Mono_Posix_Stdlib_tmpfile (void);
+gint32 Mono_Posix_Stdlib_ungetc (gint32 c, void* stream);
+gint32 Mono_Posix_Stdlib_feof (void* stream);
+gint32 Mono_Posix_Stdlib_ferror (void* stream);
 void* Mono_Posix_Stdlib_SIG_DFL (void);
 void* Mono_Posix_Stdlib_SIG_ERR (void);
 void* Mono_Posix_Stdlib_SIG_IGN (void);
diff --git a/support/stdio.c b/support/stdio.c
index e5b54da47b9..b914dfdb1d0 100644
--- a/support/stdio.c
+++ b/support/stdio.c
@@ -142,6 +142,12 @@ Mono_Posix_Stdlib_TMP_MAX (void)
 	return TMP_MAX;
 }
 
+void*
+Mono_Posix_Stdlib_tmpfile (void)
+{
+	return tmpfile ();
+}
+
 gint32
 Mono_Posix_Stdlib_setvbuf (void* stream, void *buf, int mode, mph_size_t size)
 {
@@ -156,6 +162,60 @@ Mono_Posix_Stdlib_setbuf (void* stream, void* buf)
 	return 0;
 }
 
+void*
+Mono_Posix_Stdlib_fopen (char* path, char* mode)
+{
+	return fopen (path, mode);
+}
+
+void*
+Mono_Posix_Stdlib_freopen (char* path, char* mode, void *stream)
+{
+	return freopen (path, mode, stream);
+}
+
+gint32
+Mono_Posix_Stdlib_fprintf (void* stream, char* format, char *message)
+{
+	return fprintf (stream, format, message);
+}
+
+gint32
+Mono_Posix_Stdlib_fgetc (void* stream)
+{
+	return fgetc (stream);
+}
+
+char*
+Mono_Posix_Stdlib_fgets (char* str, gint32 size, void* stream)
+{
+	return fgets (str, size, stream);
+}
+
+gint32
+Mono_Posix_Stdlib_fputc (gint32 c, void* stream)
+{
+	return fputc (c, stream);
+}
+
+gint32
+Mono_Posix_Stdlib_fputs (char* s, void* stream)
+{
+	return fputs (s, stream);
+}
+
+gint32
+Mono_Posix_Stdlib_fclose (void* stream)
+{
+	return fclose (stream);
+}
+
+gint32
+Mono_Posix_Stdlib_fflush (void* stream)
+{
+	return fflush (stream);
+}
+
 gint32
 Mono_Posix_Stdlib_fseek (void* stream, gint64 offset, int origin)
 {
@@ -207,6 +267,24 @@ Mono_Posix_Stdlib_clearerr (void* stream)
 	return 0;
 }
 
+gint32
+Mono_Posix_Stdlib_ungetc (gint32 c, void* stream)
+{
+	return ungetc (c, stream);
+}
+
+gint32
+Mono_Posix_Stdlib_feof (void* stream)
+{
+	return feof (stream);
+}
+
+gint32
+Mono_Posix_Stdlib_ferror (void* stream)
+{
+	return ferror (stream);
+}
+
 int
 Mono_Posix_Stdlib_perror (const char* s, int err)
 {
diff --git a/support/stdlib.c b/support/stdlib.c
index 0c4358a5140..077a85e58f5 100644
--- a/support/stdlib.c
+++ b/support/stdlib.c
@@ -72,6 +72,12 @@ Mono_Posix_Stdlib_realloc (void* ptr, mph_size_t size)
 	return realloc (ptr, (size_t) size);
 }
 
+void
+Mono_Posix_Stdlib_free (void* p)
+{
+	free (p);
+}
+
 G_END_DECLS
 
 /*