Changeset 21427

Timestamp:

Aug 27, 2010, 2:20:14 AM (15 years ago)

Author:

dmik

Message:

SEH: Save EXCEPTION_RECORD and CONTEXT on heap when jumping back from the exception handler to execute the except() filter expression because they are stored on stack and may be overwritten during execution of the filter expression. This fixes garbage in structures pointed to by _exception_info()'s pointers.

Location:

trunk

Files:

• include/excpt.h (modified) (1 diff)
• src/kernel32/seh/makefile (modified) (1 diff)
• src/kernel32/seh/seh.c (added)
• src/kernel32/seh/sehutil.s (modified) (3 diffs)

trunk/include/excpt.h ¶

@@ -49 +49 @@
 #define __try \
     volatile __seh_PEXCEPTION_FRAME __seh_frame;                               \
+    __seh_frame.Pointers.ExceptionRecord = NULL;                               \
+    __seh_frame.Pointers.ContextRecord = NULL;                                 \
     __seh_frame.state = 0;                                                     \
     __asm__("\n0:\n"); /* pFilterCallback */                                   \

trunk/src/kernel32/seh/makefile ¶

@@ -29 +29 @@
 #
 OBJS = \
+$(OBJDIR)\seh.obj \
 $(OBJDIR)\sehutil.obj
 

trunk/src/kernel32/seh/sehutil.s ¶

@@ -64 +64 @@
     /* save the handler's stack on heap */
     movl %ecx, %eax /* size_t */
-    subl $16, %esp
+    subl $4, %esp
     movl %eax, 0(%esp)
     call odin_malloc /* _Optlink, rtl, EAX/EDX/ECX-in, caller cleans stack */
-    addl $16, %esp
+    addl $4, %esp
     testl %eax, %eax
     je ___seh_handler_Error /* No memory! */
@@ -77 +77 @@
 
     /* prepare a jump to the filter callback */
-    movl 12(%ebp), %eax
-
+    subl $12, %esp
+    movl 12(%ebp), %ebx
+    movl %ebx, 0(%esp)
     movl 8(%ebp), %ebx
-    movl %ebx, 48(%eax) /* pFrame->Pointers.ExceptionRecord */
+    movl %ebx, 4(%esp)
     movl 16(%ebp), %ebx
-    movl %ebx, 52(%eax) /* pFrame->Pointers.ContextRecord */
+    movl %ebx, 8(%esp)
+    call ___seh_makePointers  /* _cdecl, rtl, caller cleans stack */
+    addl $12, %esp
 
     /* restore __try/__catch context */
+    movl 12(%ebp), %eax
     movl 24(%eax), %ebx /* pFrame->pTryRegs */
     movl 28(%eax), %esi
@@ -109 +113 @@
     popl %ebp
 
-    /* free heap block */
-    movl 16(%ebx), %eax /* pFrame->pHandlerContext */
-    subl $16, %esp
+    /* free heap blocks */
+    movl 52(%ebx), %eax /* pFrame->Pointers.ContextRecord */
+    subl $4, %esp
     movl %eax, 0(%esp)
     call odin_free /* _Optlink, rtl, EAX/EDX/ECX-in, caller cleans stack */
-    addl $16, %esp
+    addl $4, %esp
+
+    movl 48(%ebx), %eax /* pFrame->Pointers.ExceptionRecord */
+    subl $4, %esp
+    movl %eax, 0(%esp)
+    call odin_free /* _Optlink, rtl, EAX/EDX/ECX-in, caller cleans stack */
+    addl $4, %esp
+
+    movl 16(%ebx), %eax /* pFrame->pHandlerContext */
+    subl $4, %esp
+    movl %eax, 0(%esp)
+    call odin_free /* _Optlink, rtl, EAX/EDX/ECX-in, caller cleans stack */
+    addl $4, %esp
 
     /* analyze filter result */