[patch 34/55] lockdep, bug: Exclude TAINT_FIRMWARE_WORKAROUND from disabling lockdep

From: Greg KH
Date: Fri Feb 10 2012 - 17:58:59 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>

commit df754e6af2f237a6c020c0daff55a1a609338e31 upstream.

It's unlikely that TAINT_FIRMWARE_WORKAROUND causes false
lockdep messages, so do not disable lockdep in that case.
We still want to keep lockdep disabled in the
TAINT_OOT_MODULE case:

- bin-only modules can cause various instabilities in
their and in unrelated kernel code

- they are impossible to debug for kernel developers

- they also typically do not have the copyright license
permission to link to the GPL-ed lockdep code.

Suggested-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-xopopjjens57r0i13qnyh2yo@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/panic.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -236,8 +236,16 @@ void add_taint(unsigned flag)
* Also we want to keep up lockdep for staging development and
* post-warning case.
*/
- if (flag != TAINT_CRAP && flag != TAINT_WARN && __debug_locks_off())
- printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
+ switch (flag) {
+ case TAINT_CRAP:
+ case TAINT_WARN:
+ case TAINT_FIRMWARE_WORKAROUND:
+ break;
+
+ default:
+ if (__debug_locks_off())
+ printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
+ }

set_bit(flag, &tainted_mask);
}


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