ec_openocd: handle sigint properly

Currently sigint is passed to everything here, openocd, gdb, the python
interpreter. This makes it impossible to interrupt the current execution
without a breakpoint.

Fix that by ignoring the signal for the python interpreter using signal,
and ignoring it for openocd using setsid.

BRANCH=none
BUG=b:276311425
TEST=./util/ec_openocd.py --board rex debug
TEST=./util/ec_openocd.py --board rex debug -x

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Change-Id: I4d73561985a19bcfe92bf1a85f8fda272ec36cb7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4386298
Reviewed-by: Robert Zieba <robertzieba@google.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/util/ec_openocd.py b/util/ec_openocd.py
index 76348c6329..325e1ab7c8 100755
--- a/util/ec_openocd.py
+++ b/util/ec_openocd.py
@@ -7,7 +7,9 @@
 import argparse
 import dataclasses
 import distutils.spawn
+import os
 import pathlib
+import signal
 import socket
 import subprocess
 import sys
@@ -111,6 +113,7 @@ def debug(interface, board, port, executable, attach):
         encoding="utf-8",
         stdout=subprocess.PIPE,
         stderr=subprocess.STDOUT,
+        preexec_fn=os.setsid,
     )
 
     # Wait for OpenOCD to start, it'll open a port for GDB connections
@@ -130,8 +133,10 @@ def debug(interface, board, port, executable, attach):
 
     sock.close()
 
-    gdb_args = create_gdb_args(board, port, executable, attach)
+    old_sigint = signal.signal(signal.SIGINT, signal.SIG_IGN)
+
     # Start GDB
+    gdb_args = create_gdb_args(board, port, executable, attach)
     gdb = subprocess.Popen(
         gdb_args, stdout=sys.stdout, stderr=subprocess.STDOUT, stdin=sys.stdin
     )
@@ -141,6 +146,8 @@ def debug(interface, board, port, executable, attach):
         (output, _) = openocd.communicate()
         openocd_out += output
 
+    signal.signal(signal.SIGINT, old_sigint)
+
     # Wait for OpenOCD to shutdown
     print("Waiting for OpenOCD to finish...")
     if openocd.poll() == None:
@@ -160,6 +167,9 @@ def debug(interface, board, port, executable, attach):
 def debug_external(board, port, executable, attach):
     """Run GDB against an external gdbserver."""
     gdb_args = create_gdb_args(board, port, executable, attach)
+
+    old_sigint = signal.signal(signal.SIGINT, signal.SIG_IGN)
+
     subprocess.run(
         gdb_args,
         stdout=sys.stdout,
@@ -168,6 +178,8 @@ def debug_external(board, port, executable, attach):
         check=True,
     )
 
+    signal.signal(signal.SIGINT, old_sigint)
+
 
 def get_flash_file(board):
     return (