From: Douglas Anderson dianders@chromium.org
stable inclusion from linux-4.19.155 commit cbc03dedecb6e5366f2d3f0a328cfc3ef4762a25
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[ 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.I4aa062751ff5e281f5116655c976dff5... Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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 fbb1bfdd2fa5..8c76141c99c8 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -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) {