lockdep, bug: Exclude TAINT_FIRMWARE_WORKAROUND from disabling lockdep

BugLink: http://bugs.launchpad.net/bugs/931719

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@decadent.org.uk>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-xopopjjens57r0i13qnyh2yo@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index 69231670eb9..8e48cf6ab56 100644
--- 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);
 }