libtf: fix stack frame creation and valgrind issues

debugging looks now better. there was also some valgrind issues
that needed attention.

1 files changed, 9 insertions, 11 deletions

diff --git a/src/uctx.h b/src/uctx.h
index e27a53c..5eca6be 100644
--- a/src/uctx.h
+++ b/src/uctx.h
@@ -37,15 +37,15 @@ struct tf_uctx {
 	do {						\
 		unsigned eax, ebx, ecx, edx, esi, edi;	\
 		__asm__ __volatile__ (			\
-		"push	%%ebp				\n" \
 		"call	1f				\n" \
 		"1:					\n" \
 		"addl	$2f-1b, (%%esp)			\n" \
+		"push	%%ebp				\n" \
 		"movl	%%esp, %[prev_sp]		\n" \
 		"movl	%[next_sp], %%esp		\n" \
+		"pop	%%ebp				\n" \
 		"ret					\n" \
 		"2:					\n" \
-		"pop	%%ebp				\n" \
 		: [prev_sp] "=m"(prev->current_sp),	\
 		  "=a"(eax), "=b"(ebx), "=c"(ecx),	\
 		  "=d"(edx), "=S"(esi), "=D"(edi)	\
@@ -101,8 +101,8 @@ tf_uctx_create_embedded(
 	size_t stack_size,
 	size_t private_size,
 	off_t uctx_offset,
-	void (*stack_frame_main)(void*), off_t main_argument_offset,
-	void (*stack_frame_return)(void))
+	void (*stack_frame_main)(void*, void*),
+	void *main_argument)
 {
 	size_t size = TF_STACK_SIZE;
 	void *user_data;
@@ -117,20 +117,18 @@ tf_uctx_create_embedded(
 	/* Create initial stack frame (cdecl convention) */
 	stack = stack_pointer(stack_base, size);
 	user_data = stack_push(&stack, TF_ALIGN(private_size, 64));
+	stack_push_ptr(&stack, main_argument);
+	stack_push_ptr(&stack, user_data);
 	stack_push_ptr(&stack, NULL);
-	stack_push_ptr(&stack, NULL);
-	stack_push_ptr(&stack, NULL);
-	stack_push_ptr(&stack, NULL);
-	stack_push_ptr(&stack, user_data + main_argument_offset);
-	stack_push_ptr(&stack, stack_frame_return);
-	stack_push_ptr(&stack, stack_frame_main);
+	stack_push_ptr(&stack, stack_frame_main);	/* eip */
+	stack_push_ptr(&stack, NULL);			/* ebp */
 
 	uctx = user_data + uctx_offset;
 	*uctx = (struct tf_uctx) {
 		.stack_guard = stack_guard(stack_base, size),
 		.alloc = stack_base,
 		.current_sp = stack,
-		.stack_id = VALGRIND_STACK_REGISTER(stack_base, size),
+		.stack_id = VALGRIND_STACK_REGISTER(stack_base, stack_base+size),
 	};
 	*uctx->stack_guard = STACK_GUARD;