Commit cbc03ded authored Jun 30, 2020 by Douglas Anderson Committed by Greg Kroah-Hartman Nov 05, 2020

kgdb: Make "kgdbcon" work properly with "kgdb_earlycon"



[ Upstream commit b18b099e04f450cdc77bec72acefcde7042bd1f3 ]

On my system the kernel processes the "kgdb_earlycon" parameter before
the "kgdbcon" parameter.  When we setup "kgdb_earlycon" we'll end up
in kgdb_register_callbacks() and "kgdb_use_con" won't have been set
yet so we'll never get around to starting "kgdbcon".  Let's remedy
this by detecting that the IO module was already registered when
setting "kgdb_use_con" and registering the console then.

As part of this, to avoid pre-declaring things, move the handling of
the "kgdbcon" further down in the file.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200630151422.1.I4aa062751ff5e281f5116655c976dff545c09a46@changeid


Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent d3380de4

kernel/debug/debug_core.c

+14 −8

Original line number	Diff line number	Diff line
		@@ -95,14 +95,6 @@ int dbg_switch_cpu;
		/* Use kdb or gdbserver mode */
		int dbg_kdb_mode = 1;

		static int __init opt_kgdb_con(char *str)
		{
		kgdb_use_con = 1;
		return 0;
		}

		early_param("kgdbcon", opt_kgdb_con);

		module_param(kgdb_use_con, int, 0644);
		module_param(kgdbreboot, int, 0644);

		@@ -820,6 +812,20 @@ static struct console kgdbcons = {
		.index = -1,
		};

		static int __init opt_kgdb_con(char *str)
		{
		kgdb_use_con = 1;

		if (kgdb_io_module_registered && !kgdb_con_registered) {
		register_console(&kgdbcons);
		kgdb_con_registered = 1;
		}

		return 0;
		}

		early_param("kgdbcon", opt_kgdb_con);

		#ifdef CONFIG_MAGIC_SYSRQ
		static void sysrq_handle_dbg(int key)
		{