RtlCaptureContext can throw an exception. As we need to push the flags on the stack, we need to create unwind info to make sure we can properly unwind. So instead of pushing the flags and then popping them back, push them on the stack at the beginning of the function, reference the location later, clean up the stack at the function end. Also add .cif_adjust_cfa_offset unwind op.

svn path=/branches/ros-amd64-bringup/; revision=37370

reactos/lib/rtl/amd64/except_asm.S

@@ -23,40 +23,45 @@
 _RtlCaptureContext:
     .cfi_startproc
 
-    /* Push eflags */
+    /* Push rflags */
     pushfq
+    .cfi_adjust_cfa_offset 8
 
     /* Save the basic register context */
     mov [rcx + CONTEXT_Rax], rax
     mov [rcx + CONTEXT_Rcx], rcx
     mov [rcx + CONTEXT_Rdx], rdx
+
+    /* Load rflags into rax */
+    mov rax, [rsp]
+
     mov [rcx + CONTEXT_Rbx], rbx
-
-    /* pop eflags */
-    pop [rcx + CONTEXT_EFlags]
-
     mov [rcx + CONTEXT_Rsi], rsi
     mov [rcx + CONTEXT_Rdi], rdi
+
+    /* Store rflags */
+    mov [rcx + CONTEXT_EFlags], rax
+
     mov [rcx + CONTEXT_Rbp], rbp
-
-    /* Load former stack pointer in rax */
-    lea rax, [rsp + 8]
-
     mov [rcx + CONTEXT_R8], r8
     mov [rcx + CONTEXT_R9], r9
+
+    /* Load former stack pointer in rax */
+    lea rax, [rsp + 0x10]
+
     mov [rcx + CONTEXT_R10], r10
     mov [rcx + CONTEXT_R11], r11
+    mov [rcx + CONTEXT_R12], r12
 
     /* Store stack pointer */
     mov [rcx + CONTEXT_Rsp], rax
 
-    mov [rcx + CONTEXT_R12], r12
     mov [rcx + CONTEXT_R13], r13
     mov [rcx + CONTEXT_R14], r14
     mov [rcx + CONTEXT_R15], r15
 
     /* Load return address in rax */
-    mov rax, [rsp]
+    mov rax, [rsp + 8]
 
     /* Safe segment selectors */
     mov [rcx + CONTEXT_SegCs], cs
@@ -87,6 +92,8 @@ _RtlCaptureContext:
     movdqa [rcx + CONTEXT_Xmm14], xmm14
     movdqa [rcx + CONTEXT_Xmm15], xmm15
 */
+    /* Cleanup stack and return */
+    add rsp, 8
     ret
     .cfi_endproc
 .endfunc