[PATCH] lockdep, bug: Exclude TAINT_OOT_MODULE from disabling lock debugging

[PATCH] lockdep, bug: Exclude TAINT_OOT_MODULE from disabling lock debugging

[Ben Hutchings]

We do want to allow lock debugging for GPL-compatible modules that are
not (yet) built in-tree.  This was disabled as a side-effect of commit
2449b8ba0745327c5fa49a8d9acffe03b2eded69 ('module,bug: Add
TAINT_OOT_MODULE flag for modules not built in-tree').  Lock debug
warnings now include taint flags, so kernel developers should still
be able to deflect warnings caused by out-of-tree modules.

The TAINT_PROPRIETARY_MODULE flag for non-GPL-compatible modules will
still disable lock debugging.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 kernel/panic.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/panic.c b/kernel/panic.c
index 1b83fd8..3458469 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -237,11 +237,12 @@ void add_taint(unsigned flag)
 	 * Can't trust the integrity of the kernel anymore.
 	 * We don't call directly debug_locks_off() because the issue
 	 * is not necessarily serious enough to set oops_in_progress to 1
-	 * Also we want to keep up lockdep for staging development and
-	 * post-warning case.
+	 * Also we want to keep up lockdep for staging/out-of-tree
+	 * development and post-warning case.
 	 */
 	switch (flag) {
 	case TAINT_CRAP:
+	case TAINT_OOT_MODULE:
 	case TAINT_WARN:
 	case TAINT_FIRMWARE_WORKAROUND:
 		break;
-- 
1.7.7.3

Re: [PATCH] lockdep, bug: Exclude TAINT_OOT_MODULE from disabling lock debugging

[Rusty Russell]

On Wed, 07 Dec 2011 14:30:58 +0000, Ben Hutchings <ben@decadent.org.uk> wrote:
> We do want to allow lock debugging for GPL-compatible modules that are
> not (yet) built in-tree.  This was disabled as a side-effect of commit
> 2449b8ba0745327c5fa49a8d9acffe03b2eded69 ('module,bug: Add
> TAINT_OOT_MODULE flag for modules not built in-tree').  Lock debug
> warnings now include taint flags, so kernel developers should still
> be able to deflect warnings caused by out-of-tree modules.
> 
> The TAINT_PROPRIETARY_MODULE flag for non-GPL-compatible modules will
> still disable lock debugging.
> 
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

Meh.  Disabling lock debugging was always a weird thing to do, IMHO.
Taint flags should be used for warnings to developers, not these strange
side-effects.

Cheers,
Rusty.

[tip:core/locking] lockdep, bug: Exclude TAINT_OOT_MODULE from disabling lock debugging

[tip-bot for Ben Hutchings]

Commit-ID:  9ec84acee1e221d99dc33237bff5e82839d10cc0
Gitweb:     http://git.kernel.org/tip/9ec84acee1e221d99dc33237bff5e82839d10cc0
Author:     Ben Hutchings <ben@decadent.org.uk>
AuthorDate: Wed, 7 Dec 2011 14:30:58 +0000
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 7 Dec 2011 23:32:10 +0100

lockdep, bug: Exclude TAINT_OOT_MODULE from disabling lock debugging

We do want to allow lock debugging for GPL-compatible modules
that are not (yet) built in-tree.  This was disabled as a
side-effect of commit 2449b8ba0745327c5fa49a8d9acffe03b2eded69
('module,bug: Add TAINT_OOT_MODULE flag for modules not built
in-tree').  Lock debug warnings now include taint flags, so
kernel developers should still be able to deflect warnings
caused by out-of-tree modules.

The TAINT_PROPRIETARY_MODULE flag for non-GPL-compatible modules
will still disable lock debugging.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Nick Bowler <nbowler@elliptictech.com>
Cc: Greg KH <greg@kroah.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Debian kernel maintainers <debian-kernel@lists.debian.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/1323268258.18450.11.camel@deadeye
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/panic.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/panic.c b/kernel/panic.c
index 1b83fd8..3458469 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -237,11 +237,12 @@ void add_taint(unsigned flag)
 	 * Can't trust the integrity of the kernel anymore.
 	 * We don't call directly debug_locks_off() because the issue
 	 * is not necessarily serious enough to set oops_in_progress to 1
-	 * Also we want to keep up lockdep for staging development and
-	 * post-warning case.
+	 * Also we want to keep up lockdep for staging/out-of-tree
+	 * development and post-warning case.
 	 */
 	switch (flag) {
 	case TAINT_CRAP:
+	case TAINT_OOT_MODULE:
 	case TAINT_WARN:
 	case TAINT_FIRMWARE_WORKAROUND:
 		break;