Hi,
I've written this program to try a shellcode made by me:
char shell[] =
"\xeb\x25\x5e\xb8\x46\x00\x00\x00"
"\xbb\x00\x00\x00\x00\xb9\x00\x00"
"\x00\x00\xcd\x80\xb8\x0b\x00\x00"
"\x00\x89\xf3\x6a\x00\x56\x89\xe4"
"\xba\x00\x00\x00\x00\xcd\x80\xe8"
"\xd6\xff\xff\xff"
"/bin/sh";
main() {
printf ("%p\n",shell);
__asm__("call 0x08049600");
}
Where, of course, 0x08049600 is the address of my shellcode.
But when I compile and run the program I get a segmentation fault.
This is what I get disassembling the program with Gdb:
0x080483a4 <main+0>: push %ebp
0x080483a5 <main+1>: mov %esp,%ebp
0x080483a7 <main+3>: sub $0x8,%esp
0x080483aa <main+6>: and $0xfffffff0,%esp
0x080483ad <main+9>: mov $0x0,%eax
0x080483b2 <main+14>: add $0xf,%eax
0x080483b5 <main+17>: add $0xf,%eax
0x080483b8 <main+20>: shr $0x4,%eax
0x080483bb <main+23>: shl $0x4,%eax
0x080483be <main+26>: sub %eax,%esp
0x080483c0 <main+28>: sub $0x8,%esp
0x080483c3 <main+31>: push $0x8049600
0x080483c8 <main+36>: push $0x80484e4
0x080483cd <main+41>: call 0x80482b8 <[EMAIL PROTECTED]>
0x080483d2 <main+46>: add $0x10,%esp
0x080483d5 <main+49>: call 0x4
0x080483da <main+54>: leave
0x080483db <main+55>: ret
Why do I have a call 0x4 on main+49 instead of call 0x08049600?
--
Summary: Problem with call directive in inline ASM
Product: gcc
Version: 3.4.6
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: inline-asm
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: blacklight86 at gmail dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30002
