Qiling.emu_stop() does not stop the emulator when gdb debugger is attached #1310
Description
Describe the bug
Thank you for your work on this useful framework.
When executing this sample code, Qiling waits for gdb to connect. I attached gdb using target remote 127.0.0.1:9999, then used the stepi command repeatedly until the executable reached the entry of foo. When I use stepi on the entry to foo, then my script's function print_asm calls ql.emu_stop(), which should stop the emulator, but the emulator does not stop - it remains on the same instruction. Because of this, if instead I use the step command to step to the next statement, then gdb hang in an infinite loop.
Sample Code
Qiling script:
from qiling import *
from qiling.const import QL_VERBOSE
def test_gdb(path, rootfs):
ql = Qiling(path, rootfs, verbose=QL_VERBOSE.OFF)
# Enable debugger to listen at localhost address, default port 9999
ql.debugger = True
ba = ql.loader.images[0].base
foo_addr = int("0000000000001135", 16) # start address of foo
foo_len = int("0000000000000024", 16) # length of foo
def print_asm(ql, address, size):
print("INSTRUCTION:", hex(address), size)
if address == ba + foo_addr:
print("REACHED TARGET INSTRUCTION", hex(ba+foo_addr), "END EMU")
ql.emu_stop()
ql.hook_code(print_asm, begin=ba + foo_addr, end=ba + foo_addr + foo_len)
ql.run()
if __name__ == "__main__":
test_gdb(["./test"], "/")Log of qiling script output: test_gdb.log
Expected behavior
When the ql.emu_stop() line is executed, emulation will quit and gdb will detach.
Additional context
I ran this test case on the official Docker container qilingframework/qiling:latest with the latest code from the dev branch.
It should be possible to reproduce the bug with any executable by calling Qiling.emu_stop() during execution.
Here is the target program I used:
#include <stdio.h>
void foo(int a) {
printf("Hello, world %d!\n", a);
}
int main(int argc, char **argv)
{
int a = 10;
foo(a);
return a;
}Compiled executable (unzip it first): test.zip