[PATCH] x86: print out early faults via early_printk()

Lost a few hours debugging an early-bootup fault within printk itself,
which manifested itself as a hard to debug early hang.

This patch makes it much easier by printing out early faults via
early_printk(), which function is a lot simpler than a full printk, and
hence more likely to succeed in emergencies.  (We do not recover from early
faults anyway, so there's no loss from not having these messages in the
normal printk buffer.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S
index 5884469f6bfee904cd6e33fd444b08a14b2188e5..2bee6499edd98a9b658aaed95787fbd05cb690ac 100644 (file)
--- a/arch/i386/kernel/head.S
+++ b/arch/i386/kernel/head.S
@@ -398,7 +398,11 @@ ignore_int:
        pushl 32(%esp)
        pushl 40(%esp)
        pushl $int_msg
+#ifdef CONFIG_EARLY_PRINTK
+       call early_printk
+#else
        call printk
+#endif
        addl $(5*4),%esp
        popl %ds
        popl %es