If on the kernel command line the parameter "earlyprintk" is written
twice, then setup_early_printk is called twice. This can happen for
example with the option CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND is
selected, and the "earlyprintk" is passed from the ATAG_CMDLINE and
from the dtb.
This lead to an infinite loop on the message "Booting Linux on
physical CPU 0" displayed from smp_setup_processor_id() in
arch/arm/kernel/setup.c. This behavior as been reproduced on ARMv7
architecture (Armada XP and Armada 370), and on a ARMv5 one
(AT91SAMG35 thanks to Richard Genoud), with and with CONFIG_SMP
selected.
This patch simply doesn't allow to call twice register_console() with
the early_console.
Signed-off-by: Gregory CLEMENT <gregory.clem...@free-electrons.com>
---
arch/arm/kernel/early_printk.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/early_printk.c b/arch/arm/kernel/early_printk.c
index 85aa2b2..435577a 100644
--- a/arch/arm/kernel/early_printk.c
+++ b/arch/arm/kernel/early_printk.c
@@ -50,7 +50,11 @@ asmlinkage void early_printk(const char *fmt, ...)
static int __init setup_early_printk(char *buf)
{
- register_console(&early_console);
+ static int done;
+ if (!done) {
+ register_console(&early_console);
+ done = 1;
+ }
return 0;
}
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
