Fix [44b34c6152]: Fix crash on exit due to faulty asm code in DllMain

Author: jan.nijtmans

changes.md

@@ -39,6 +39,7 @@ to the userbase.
  - [tk print, canvas: raw smooth not implemented](https://core.tcl-lang.org/tk/info/e10819)
  - [Aqua: avoid use-after-free during RefocusGrabWindow()](https://core.tcl-lang.org/tk/info/6da885)
  - [Aqua: ttk::notebook tabs](https://core.tcl-lang.org/tk/info/cf296a)
+ - [Fix crash on exit due to faulty asm code in DllMain](https://core.tcl-lang.org/tk/info/44b34c)
 
 Release Tk 9.0.2 arises from the check-in with tag `core-9-0-2`.
 

win/tkWin32Dll.c

@@ -149,13 +149,21 @@ DllMain(
 
 	    "movq	%%rdx,		%%gs:0"		"\n\t"
 
-	    /*
-	     * Call TkFinalize
-	     */
+	    :
+	    /* No outputs */
+	    :
+	    [registration]	"m"	(registration),
+	    [error]		"i"	(TCL_ERROR)
+	    :
+	    "%rax", "%rdx", "memory"
+	);
 
-	    "movq	$0x0,		0x0(%%rsp)"		"\n\t"
-	    "call	TkFinalize"			"\n\t"
+        /* Just do a regular C call so we don't need to worry about following
+         * the calling convention, specially the registers the function may
+         * clobber: */
+        TkFinalize(NULL);
 
+	__asm__ __volatile__ (
 	    /*
 	     * Come here on a normal exit. Recover the TCLEXCEPTION_REGISTRATION
 	     * and store a TCL_OK status
@@ -189,11 +197,9 @@ DllMain(
 	    :
 	    /* No outputs */
 	    :
-	    [registration]	"m"	(registration),
-	    [ok]		"i"	(TCL_OK),
-	    [error]		"i"	(TCL_ERROR)
+	    [ok]		"i"	(TCL_OK)
 	    :
-	    "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi", "memory"
+	    "%rax", "%rdx", "memory"
 	);
 
 #   else
@@ -219,12 +225,18 @@ DllMain(
 
 	    "movl	%%edx,		%%fs:0"		"\n\t"
 
-	    /*
-	     * Call TkFinalize
-	     */
+	    :
+	    /* No outputs */
+	    :
+	    [registration]	"m"	(registration),
+	    [error]		"i"	(TCL_ERROR)
+	    :
+	    "%eax", "%ebx", "%edx", "memory"
+	);
+
+        TkFinalize(NULL);
 
-	    "movl	$0x0,		0x0(%%esp)"		"\n\t"
-	    "call	_TkFinalize"			"\n\t"
+	__asm__ __volatile__ (
 
 	    /*
 	     * Come here on a normal exit. Recover the TCLEXCEPTION_REGISTRATION
@@ -260,11 +272,9 @@ DllMain(
 	    :
 	    /* No outputs */
 	    :
-	    [registration]	"m"	(registration),
-	    [ok]		"i"	(TCL_OK),
-	    [error]		"i"	(TCL_ERROR)
+	    [ok]		"i"	(TCL_OK)
 	    :
-	    "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"
+	    "%eax", "%ebx", "%edx", "memory"
 	);
 
 #   endif