Re: [PATCH] lockdep: disable lock debugging when kernel state becomes untrusted

From: Ingo Molnar
Date: Tue Sep 05 2006 - 03:22:25 EST



* Andrew Morton <akpm@xxxxxxxx> wrote:

> That would appear to be a bug. debug_locks_off() is running
> console_verbose() waaaay after the locking selftest code has
> completed.

debug_locks_off() should only be used when a real bug is being displayed
- which isnt the case when we call add_taint(). The patch below should
fix this.

Ingo

---------------->
Subject: lockdep: do not touch console state when tainting the kernel
From: Ingo Molnar <mingo@xxxxxxx>

Remove an unintended console_verbose() side-effect from add_taint().

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/panic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/kernel/panic.c
===================================================================
--- linux.orig/kernel/panic.c
+++ linux/kernel/panic.c
@@ -173,7 +173,7 @@ const char *print_tainted(void)

void add_taint(unsigned flag)
{
- debug_locks_off(); /* can't trust the integrity of the kernel anymore */
+ debug_locks = 0; /* can't trust the integrity of the kernel anymore */
tainted |= flag;
}
EXPORT_SYMBOL(add_taint);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/