simple 'inner function jmp' ..

2 files changed, 40 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index 2815720..f691adf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ overflow_tcp
 overflow_tcp_x64
 sc-test
 sc-test_x64
+funcjmp_simple
diff --git a/funcjmp_simple.c b/funcjmp_simple.c
new file mode 100644
index 0000000..9e756cf
--- /dev/null
+++ b/funcjmp_simple.c
@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+
+#define INTEL_ASM(_asm_str) asm volatile(".intel_syntax noprefix"); \
+	asm volatile(_asm_str); \
+	asm volatile(".att_syntax prefix");
+#define JUMPABLE_FUNC(fname) __attribute__ ((__cdecl__)) int fname(void)
+#define JMP_FUNC_DECL(func) void *fptr = (void *)( &func );
+#define JMP_TO_FUNC \
+	INTEL_ASM(" \
+	        call getip; \
+	        jmp short donext; \
+	        cfunc: \
+	                mov eax,[fptr]; \
+	                add eax,0x0; \
+	                jmp eax; \
+	                ret; \
+	        getip: \
+	                nop; \
+	                jmp short cfunc; \
+	        donext: \
+	");
+
+JUMPABLE_FUNC(testfkt);
+JMP_FUNC_DECL(testfkt);
+
+JUMPABLE_FUNC(testfkt)
+{
+  int var0 = 0x1, var1 = 0x2, var2 = 0x3;
+  var0 += var1 + var2;
+  return 0;
+}
+
+int main(int argc, char **argv)
+{
+  JMP_TO_FUNC;
+  return 66;
+}