The patch titled
lockdep: debug_show_all_locks & debug_show_held_locks vs. debug_locks
has been added to the -mm tree. Its filename is
lockdep-debug_show_all_locks-debug_show_held_locks-vs-debug_locks.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: lockdep: debug_show_all_locks & debug_show_held_locks vs. debug_locks
From: Jarek Poplawski <jarkao2@xxxxx>
lockdep's data shouldn't be used when debug_locks == 0 because it's not
updated after this, so it's more misleading than helpful.
PS: probably lockdep's current-> fields should be reset after it turns
debug_locks off: so, after printing a bug report, but before return from
exported functions, but there are really a lot of these possibilities (e.g.
after DEBUG_LOCKS_WARN_ON), so, something could be missed. (Of course
direct use of this fields isn't recommended either.)
Reported-by: Folkert van Heusden <folkert@xxxxxxxxxxxxxx>
Inspired-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Jarek Poplawski <jarkao2@xxxxx>
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/lockdep.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff -puN kernel/lockdep.c~lockdep-debug_show_all_locks-debug_show_held_locks-vs-debug_locks kernel/lockdep.c
--- a/kernel/lockdep.c~lockdep-debug_show_all_locks-debug_show_held_locks-vs-debug_locks
+++ a/kernel/lockdep.c
@@ -2742,6 +2742,10 @@ void debug_show_all_locks(void)
int count = 10;
int unlock = 1;
+ if (unlikely(!debug_locks)) {
+ printk("INFO: lockdep is turned off.\n");
+ return;
+ }
printk("\nShowing all locks held in the system:\n");
/*
@@ -2785,6 +2789,10 @@ EXPORT_SYMBOL_GPL(debug_show_all_locks);
void debug_show_held_locks(struct task_struct *task)
{
+ if (unlikely(!debug_locks)) {
+ printk("INFO: lockdep is turned off.\n");
+ return;
+ }
lockdep_print_held_locks(task);
}
_
Patches currently in -mm which might be from jarkao2@xxxxx are
lockdep-lockdep_depth-vs-debug_locks-re-bug-workqueue-leaked-lock.patch
lockdep-debug_show_all_locks-debug_show_held_locks-vs-debug_locks.patch
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