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authorJason Wessel <jason.wessel@windriver.com>2009-09-23 18:13:13 -0500
committerIngo Molnar <mingo@elte.hu>2009-09-24 13:01:13 +0200
commit429a6e5e2c1fbe5d805aad123efbdb5f0c14769f (patch)
tree5934bc0d2f6ea1ee6fdeb6cd072208c5d2de5955 /arch/x86/kernel/early_printk.c
parentMerge branch 'linus' into x86/urgent (diff)
downloadlinux-dev-429a6e5e2c1fbe5d805aad123efbdb5f0c14769f.tar.xz
linux-dev-429a6e5e2c1fbe5d805aad123efbdb5f0c14769f.zip
x86: early_printk: Protect against using the same device twice
If you use the kernel argument: earlyprintk=serial,ttyS0,115200 This will cause a recursive hang printing the same line again and again: BIOS-e820: 000000003fff3000 - 0000000040000000 (ACPI data) BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved) bootconsole [earlyser0] enabled Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Instead warn the end user that they specified the device a second time, and ignore that second console. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4ABAAB89.1080407@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/early_printk.c')
-rw-r--r--arch/x86/kernel/early_printk.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 2acfd3fdc0cc..41fd965c80c6 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -178,6 +178,11 @@ asmlinkage void early_printk(const char *fmt, ...)
static inline void early_console_register(struct console *con, int keep_early)
{
+ if (early_console->index != -1) {
+ printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
+ con->name);
+ return;
+ }
early_console = con;
if (keep_early)
early_console->flags &= ~CON_BOOT;