Index: uspace/lib/c/arch/ia32/include/config.h
===================================================================
--- uspace/lib/c/arch/ia32/include/config.h	(revision d1617158721960329b52442af00925269a6224a3)
+++ uspace/lib/c/arch/ia32/include/config.h	(revision 7da90cd8fa7928635efe129eb2f8a9b8238e6a1a)
@@ -36,6 +36,9 @@
 #define LIBC_ia32_CONFIG_H_
 
-#define PAGE_WIDTH	12
-#define PAGE_SIZE	(1 << PAGE_WIDTH)
+#define PAGE_WIDTH  12
+#define PAGE_SIZE   (1 << PAGE_WIDTH)
+
+#define USER_ADDRESS_SPACE_START_ARCH  UINT32_C(0x00000000)
+#define USER_ADDRESS_SPACE_END_ARCH    UINT32_C(0x7fffffff)
 
 #endif
Index: uspace/lib/c/arch/ia32/src/stacktrace.c
===================================================================
--- uspace/lib/c/arch/ia32/src/stacktrace.c	(revision d1617158721960329b52442af00925269a6224a3)
+++ uspace/lib/c/arch/ia32/src/stacktrace.c	(revision 7da90cd8fa7928635efe129eb2f8a9b8238e6a1a)
@@ -35,16 +35,16 @@
  */
 
+#include <libarch/config.h>
 #include <sys/types.h>
 #include <bool.h>
-
 #include <stacktrace.h>
 
-#define FRAME_OFFSET_FP_PREV	0
-#define FRAME_OFFSET_RA		4
+#define FRAME_OFFSET_FP_PREV  0
+#define FRAME_OFFSET_RA       4
 
 bool stacktrace_fp_valid(stacktrace_t *st, uintptr_t fp)
 {
 	(void) st;
-	return fp != 0;
+	return (fp != 0) && (fp <= USER_ADDRESS_SPACE_END_ARCH);
 }