From: Douglas Anderson <dianders@xxxxxxxxxxxx> [ 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@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200630151422.1.I4aa062751ff5e281f5116655c976dff545c09a46@changeid Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/debug/debug_core.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index b16dbc1bf0567..404d6d47a11da 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -94,14 +94,6 @@ 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); @@ -920,6 +912,20 @@ 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) { -- 2.25.1
