[PATCH 1/1] sandbox: support CTRL-C processing in U-Boot

[Heinrich Schuchardt]

Currently if SIGINT is received, it terminates U-Boot. This does not allow
testing the handling of CTRL-C in U-Boot and in UEFI applications.
It is especially annoying when working with the 'mm' command.

Let the serial console driver provide character 0x03 if SIGINT occurs. We
can still exit U-Boot using the reset or poweroff command.

Adjust the sandbox test_ctrl_c() Python test accordingly.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 arch/sandbox/cpu/os.c              | 15 ++++++++++++---
 drivers/serial/sandbox.c           | 11 ++++++++---
 include/os.h                       | 14 ++++++++++++++
 test/py/tests/test_sandbox_exit.py | 10 +++++++++-
 4 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index e7ec892bdf..b5cfa38a32 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -161,6 +161,7 @@ err:
 static struct termios orig_term;
 static bool term_setup;
 static bool term_nonblock;
+static bool pending_ctrlc;

 void os_fd_restore(void)
 {
@@ -176,11 +177,19 @@ void os_fd_restore(void)
 	}
 }

+void os_clear_ctrlc(void)
+{
+	pending_ctrlc = false;
+}
+
+bool os_get_ctrlc(void)
+{
+	return pending_ctrlc;
+}
+
 static void os_sigint_handler(int sig)
 {
-	os_fd_restore();
-	signal(SIGINT, SIG_DFL);
-	raise(SIGINT);
+	pending_ctrlc = true;
 }

 /* Put tty into raw mode so <tab> and <ctrl+c> work */
diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c
index f09d291e04..e510d51e27 100644
--- a/drivers/serial/sandbox.c
+++ b/drivers/serial/sandbox.c
@@ -72,9 +72,6 @@ static int sandbox_serial_probe(struct udevice *dev)
 		os_tty_raw(0, state->term_raw == STATE_TERM_RAW_WITH_SIGS);
 	priv->start_of_line = 0;

-	if (state->term_raw != STATE_TERM_RAW)
-		disable_ctrlc(1);
-
 	return 0;
 }

@@ -118,6 +115,9 @@ static int sandbox_serial_pending(struct udevice *dev, bool input)
 		increment_buffer_index(serial_buf_write);
 	ssize_t count;

+	if (os_get_ctrlc())
+		return true;
+
 	if (!input)
 		return 0;

@@ -139,6 +139,11 @@ static int sandbox_serial_getc(struct udevice *dev)
 {
 	int result;

+	if (os_get_ctrlc()) {
+		os_clear_ctrlc();
+		return 0x03;
+	}
+
 	if (!sandbox_serial_pending(dev, true))
 		return -EAGAIN;	/* buffer empty */

diff --git a/include/os.h b/include/os.h
index 1874ae674f..0cbf737d57 100644
--- a/include/os.h
+++ b/include/os.h
@@ -355,4 +355,18 @@ int os_read_file(const char *name, void **bufp, int *sizep);
  */
 void *os_find_text_base(void);

+/**
+ * os_get_ctrlc() - check if a CTRL+C has occurred
+ *
+ * Return:	true if CTRL+C has occurred
+ */
+bool os_get_ctrlc(void);
+
+/**
+ * os_clear_ctrlc() - clear CTRL+C
+ *
+ * Mark a previous CTRL+C event as handled.
+ */
+void os_clear_ctrlc(void);
+
 #endif
diff --git a/test/py/tests/test_sandbox_exit.py b/test/py/tests/test_sandbox_exit.py
index a301f4b559..4bc703ea56 100644
--- a/test/py/tests/test_sandbox_exit.py
+++ b/test/py/tests/test_sandbox_exit.py
@@ -15,7 +15,15 @@ def test_reset(u_boot_console):

 @pytest.mark.boardspec('sandbox')
 def test_ctrl_c(u_boot_console):
-    """Test that sending SIGINT to sandbox causes it to exit."""
+    """Test that SIGINT is handled as CTRL-C."""

     u_boot_console.kill(signal.SIGINT)
+    u_boot_console.wait_for('<INTERRUPT>')
+    u_boot_console.run_command('echo')
+
+    u_boot_console.run_command('\x03', wait_for_echo=False, wait_for_prompt=False)
+    u_boot_console.wait_for('<INTERRUPT>')
+    u_boot_console.run_command('echo')
+
+    u_boot_console.kill(signal.SIGKILL)
     assert(u_boot_console.validate_exited())
--
2.28.0