From f187f832b297045d85635ddbb1285ba0b83fb403 Mon Sep 17 00:00:00 2001 From: toni Date: Thu, 21 May 2015 13:02:04 +0200 Subject: simple 'inner function jmp' .. --- .gitignore | 1 + funcjmp_simple.c | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) create mode 100644 funcjmp_simple.c 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 +#include + + +#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; +} -- cgit v1.2.3