[PATCH] sched/core: add taint on "BUG: sleeping function called from invalid context"

[Vegard Nossum]

Seeing this, it occurs to me that we should probably add a taint here:

    BUG: sleeping function called from invalid context at mm/slab.h:388
    in_atomic(): 0, irqs_disabled(): 0, pid: 32211, name: trinity-c3
    Preemption disabled at:[<ffffffff811aaa37>] console_unlock+0x2f7/0x930

    CPU: 3 PID: 32211 Comm: trinity-c3 Not tainted 4.7.0-rc7+ #19
                                       ^^^^^^^^^^^
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 
Ubuntu-1.8.2-1ubuntu1 04/01/2014
     0000000000000000 ffff8800b8a17160 ffffffff81971441 ffff88011a3c4c80
     ffff88011a3c4c80 ffff8800b8a17198 ffffffff81158067 0000000000000de6
     ffff88011a3c4c80 ffffffff8390e07c 0000000000000184 0000000000000000
    Call Trace:
    [...]

    BUG: sleeping function called from invalid context at 
arch/x86/mm/fault.c:1309
    in_atomic(): 0, irqs_disabled(): 0, pid: 32211, name: trinity-c3
    Preemption disabled at:[<ffffffff8119db33>] down_trylock+0x13/0x80

    CPU: 3 PID: 32211 Comm: trinity-c3 Not tainted 4.7.0-rc7+ #19
                                       ^^^^^^^^^^^
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 
Ubuntu-1.8.2-1ubuntu1 04/01/2014
     0000000000000000 ffff8800b8a17e08 ffffffff81971441 ffff88011a3c4c80
     ffff88011a3c4c80 ffff8800b8a17e40 ffffffff81158067 0000000000000000
     ffff88011a3c4c80 ffffffff83437b20 000000000000051d 0000000000000000
    Call Trace:
    [...]

Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Rusty Russel <ru...@rustcorp.com.au>
Signed-off-by: Vegard Nossum <vegard.nos...@oracle.com>
---
 kernel/sched/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 97ee9ac..7171cf9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7573,6 +7573,7 @@ void ___might_sleep(const char *file, int line, int 
preempt_offset)
        }
 #endif
        dump_stack();
+       add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 }
 EXPORT_SYMBOL(___might_sleep);
 #endif
-- 
1.9.1