spinlock_debug: print kallsyms name for lock

When a spinlock warning is printed we usually get

 BUG: spinlock bad magic on CPU#0, modprobe/111
  lock: 0xdff09f38, .magic: 00000000, .owner: /0, .owner_cpu: 0

but it's nicer to print the symbol for the lock if we have it so that we
can avoid 'grep dff09f38 /proc/kallsyms' to find out which lock it was.
Use kallsyms to print the symbol name so we get something a bit easier to
read

 BUG: spinlock bad magic on CPU#0, modprobe/112
  lock: test_lock, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0

If the lock is not in kallsyms %ps will fall back to printing the address
directly.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 525d160d44f05c112acca5b2866b566ded334e19..d0ec4f3d1593031b5498dcc120822b41c423a3c5 100644 (file)
--- a/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -58,7 +58,7 @@ static void spin_dump(raw_spinlock_t *lock, const char *msg)
        printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n",
                msg, raw_smp_processor_id(),
                current->comm, task_pid_nr(current));
-       printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, "
+       printk(KERN_EMERG " lock: %ps, .magic: %08x, .owner: %s/%d, "
                        ".owner_cpu: %d\n",
                lock, lock->magic,
                owner ? owner->comm : "<none>",