panic: decrease oops_in_progress only after having done the panic

Impact: eliminate secondary warnings during panic()

We can panic() in a number of difficult, atomic contexts, hence
we use bust_spinlocks(1) in panic() to increase oops_in_progress,
which prevents various debug checks we have in place.

But in practice this protection only covers the first few printk's
done by panic() - it does not cover the later attempt to stop all
other CPUs and kexec(). If a secondary warning triggers in one of
those facilities that can make the panic message scroll off.

So do bust_spinlocks(0) only much later in panic(). (which code
is only reached if panic policy is relaxed that it can return
after a warning message)

Reported-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B91A7E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2009-03-13 10:54:24 +01:00
parent cd80a8142e
commit ffd71da4e3

View file

@ -77,7 +77,6 @@ NORET_TYPE void panic(const char * fmt, ...)
#ifdef CONFIG_DEBUG_BUGVERBOSE
dump_stack();
#endif
bust_spinlocks(0);
/*
* If we have crashed and we have a crash kernel loaded let it handle
@ -136,6 +135,7 @@ NORET_TYPE void panic(const char * fmt, ...)
mdelay(1);
i++;
}
bust_spinlocks(0);
}
EXPORT_SYMBOL(panic);