From c584686fd1d1dc7d2059e619de90f35516598134 Mon Sep 17 00:00:00 2001 From: Brent Roman Date: Wed, 1 Feb 2017 20:49:18 -0800 Subject: [PATCH] server: Improve signal handling under Linux Commit 5087a955 added custom signal handlers for the openocd server process. Before this commit, when openocd is run as a background process having the same controlling terminal as gdb, Control-C would be handled by gdb to stop target execution and return to the gdb prompt. However, after commit 5087a955, the SIGINT caused by pressing Control-C also terminates openocd, effectively crashing the debugging session. The only way to avoid this is run openocd in a different controling terminal or to detach openocd from its controlling terminal, thus losing all job control for the openocd process. This patch improves the server's handling of POSIX signals: 1) Keyboard generated signals (INT and QUIT) are ignored when server process has is no controlling terminal. 2) SIGHUP and SIGPIPE are handled to ensure that .quit functions for each interface are called if user's logs out of X session or there is a network failure. SIG_INT & SIG_QUIT still stop openocd when it is running in the foreground. Change-Id: I03ad645e62408fdaf4edc49a3550b89b287eda10 Signed-off-by: Brent Roman Signed-off-by: Tomas Vanek Reviewed-on: http://openocd.zylin.com/3963 Tested-by: jenkins Reviewed-by: Antonio Borneo --- src/server/server.c | 40 ++++++++++++++++++++++++++++++---------- 1 file changed, 30 insertions(+), 10 deletions(-) diff --git a/src/server/server.c b/src/server/server.c index 4e806563..06a2f39d 100644 --- a/src/server/server.c +++ b/src/server/server.c @@ -505,7 +505,7 @@ int server_loop(struct command_context *command_context) for (service = services; service; service = service->next) { /* handle new connections on listeners */ if ((service->fd != -1) - && (FD_ISSET(service->fd, &read_fds))) { + && (FD_ISSET(service->fd, &read_fds))) { if (service->max_connections != 0) add_connection(service, command_context); else { @@ -563,21 +563,36 @@ int server_loop(struct command_context *command_context) return shutdown_openocd != 2 ? ERROR_OK : ERROR_FAIL; } +void sig_handler(int sig) +{ + /* store only first signal that hits us */ + if (!shutdown_openocd) { + last_signal = sig; + shutdown_openocd = 1; + LOG_DEBUG("Terminating on Signal %d", sig); + } else + LOG_DEBUG("Ignored extra Signal %d", sig); +} + + #ifdef _WIN32 BOOL WINAPI ControlHandler(DWORD dwCtrlType) { shutdown_openocd = 1; return TRUE; } -#endif - -void sig_handler(int sig) +#else +static void sigkey_handler(int sig) { - /* store only first signal that hits us */ - if (!last_signal) - last_signal = sig; - shutdown_openocd = 1; + /* ignore keystroke generated signals if not in foreground process group */ + + if (tcgetpgrp(STDIN_FILENO) > 0) + sig_handler(sig); + else + LOG_DEBUG("Ignored Signal %d", sig); } +#endif + int server_preinit(void) { @@ -600,8 +615,13 @@ int server_preinit(void) SetConsoleCtrlHandler(ControlHandler, TRUE); signal(SIGBREAK, sig_handler); -#endif signal(SIGINT, sig_handler); +#else + signal(SIGHUP, sig_handler); + signal(SIGPIPE, sig_handler); + signal(SIGQUIT, sigkey_handler); + signal(SIGINT, sigkey_handler); +#endif signal(SIGTERM, sig_handler); signal(SIGABRT, sig_handler); @@ -743,7 +763,7 @@ static const struct command_registration server_command_handlers[] = { .mode = COMMAND_ANY, .usage = "[name]", .help = "Specify address by name on which to listen for " - "incoming TCP/IP connections", + "incoming TCP/IP connections", }, COMMAND_REGISTRATION_DONE }; -- 2.39.5