From a76b858332a05c3c987d23dafa7218dba4775755 Mon Sep 17 00:00:00 2001
From: libumem <163767094+libumem@users.noreply.github.com>
Date: Fri, 14 Nov 2025 04:39:15 +0000
Subject: [PATCH] Tentative fix for epoll server test case

---
 qiling/os/posix/syscall/epoll.py | 2 +-
 tests/test_elf.py                | 9 +++------
 tests/test_onlinux.sh            | 2 +-
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/qiling/os/posix/syscall/epoll.py b/qiling/os/posix/syscall/epoll.py
index 46911678..9afb57f2 100644
--- a/qiling/os/posix/syscall/epoll.py
+++ b/qiling/os/posix/syscall/epoll.py
@@ -118,7 +118,7 @@ def ql_syscall_epoll_ctl(ql: Qiling, epfd: int, op: int, fd: int, event: int):
     if op not in (EPOLL_CTL_ADD, EPOLL_CTL_DEL, EPOLL_CTL_MOD):
         return -EINVAL
 
-    if epfd == fd:
+    if epfd == fd or fd == 0xffffffff: # latter condition was seen in testing, but should not happen in the real world
         return -EINVAL
 
     if epfd not in range(NR_OPEN):
diff --git a/tests/test_elf.py b/tests/test_elf.py
index 52db6719..afaca75c 100644
--- a/tests/test_elf.py
+++ b/tests/test_elf.py
@@ -217,13 +217,13 @@ class ELFTest(unittest.TestCase):
         ql = Qiling(["../examples/rootfs/x8664_linux/bin/x8664_hello_static"], "../examples/rootfs/x8664_linux", verbose=QL_VERBOSE.DEBUG)
         ql.run()
         del ql
-
+    #@unittest.skip('Experiment to avoid FD issue')
     def test_elf_linux_x86(self):
         filename = 'test.qlog'
 
         ql = Qiling(["../examples/rootfs/x86_linux/bin/x86_hello"], "../examples/rootfs/x86_linux", verbose=QL_VERBOSE.DEBUG, log_devices=[filename])
         ql.run()
-
+        ql._log_file_fd.handlers[0].close() # prevent FD leak that causes downstream issues
         os.remove(filename)
         del ql
 
@@ -789,8 +789,7 @@ class ELFTest(unittest.TestCase):
         ql.run()
 
         self.assertIn(b'echo\n', ql.os.stdout.read())
-        del ql
-    @unittest.skip("See comment in https://github.com/qilingframework/qiling/pull/1558")
+        del ql 
     def test_elf_linux_x8664_epoll_server(self):
         # This tests a simple server that uses epoll to wait for data, then prints it out. It has
         # been modified to exit after data has been received; instead of a typical server operation
@@ -810,7 +809,6 @@ class ELFTest(unittest.TestCase):
         def client():
             # give time for the server to listen
             time.sleep(3)
-
             s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             s.connect(("127.0.0.1", 8000))
             s.send(b"hello world")
@@ -826,7 +824,6 @@ class ELFTest(unittest.TestCase):
 
         client_thread = threading.Thread(target=client, daemon=True)
         client_thread.start()
-
         ql.run()
 
         self.assertIn(b'hello world', ql.os.stdout.read(200)) # 200 is arbitrary--"good enough" for this task
diff --git a/tests/test_onlinux.sh b/tests/test_onlinux.sh
index 557b2e77..9a333a68 100755
--- a/tests/test_onlinux.sh
+++ b/tests/test_onlinux.sh
@@ -4,7 +4,7 @@
 # Cross Platform and Multi Architecture Advanced Binary Emulation Framework
 #
 
-python3 ./test_posix.py && 
+python3 -m pdb ./test_posix.py && 
 python3 ./test_elf_multithread.py &&
 python3 ./test_elf_ko.py &&
 python3 ./test_debugger.py &&