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| author | Jason Wessel <jason.wessel@windriver.com> | 2009-09-23 18:13:13 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-24 13:01:13 +0200 |
| commit | 429a6e5e2c1fbe5d805aad123efbdb5f0c14769f (patch) | |
| tree | 5934bc0d2f6ea1ee6fdeb6cd072208c5d2de5955 | |
| parent | d2ff6de537c61a0f05731c6679f3e1abc2d95e68 (diff) | |
| download | lwn-429a6e5e2c1fbe5d805aad123efbdb5f0c14769f.tar.gz lwn-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>
| -rw-r--r-- | arch/x86/kernel/early_printk.c | 5 |
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; |