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authorLinus Torvalds <torvalds@linux-foundation.org>2023-05-28 07:15:33 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2023-05-28 07:15:33 -0400
commitd8f14b84fefd8669cbcbe4fee3f61a44be904993 (patch)
treef3ad219bf4bedc28ed88a2ee6736a36f0bb80eff /kernel/locking
parent9bd5386c653f64755dc33f77793273ef0763fe63 (diff)
parenteb799279fb1f9c63c520fe8c1c41cb9154252db6 (diff)
Merge tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull debugobjects fixes from Thomas Gleixner: "Two fixes for debugobjects: - Prevent the allocation path from waking up kswapd. That's a long standing issue due to the GFP_ATOMIC allocation flag. As debug objects can be invoked from pretty much any context waking kswapd can end up in arbitrary lock chains versus the waitqueue lock - Correct the explicit lockdep wait-type violation in debug_object_fill_pool()" * tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: debugobjects: Don't wake up kswapd from fill_pool() debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/lockdep.c28
1 files changed, 21 insertions, 7 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index dcd1d5bfc1e0..4dfd2f3e09b2 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2263,6 +2263,9 @@ static inline bool usage_match(struct lock_list *entry, void *mask)
static inline bool usage_skip(struct lock_list *entry, void *mask)
{
+ if (entry->class->lock_type == LD_LOCK_NORMAL)
+ return false;
+
/*
* Skip local_lock() for irq inversion detection.
*
@@ -2289,14 +2292,16 @@ static inline bool usage_skip(struct lock_list *entry, void *mask)
* As a result, we will skip local_lock(), when we search for irq
* inversion bugs.
*/
- if (entry->class->lock_type == LD_LOCK_PERCPU) {
- if (DEBUG_LOCKS_WARN_ON(entry->class->wait_type_inner < LD_WAIT_CONFIG))
- return false;
+ if (entry->class->lock_type == LD_LOCK_PERCPU &&
+ DEBUG_LOCKS_WARN_ON(entry->class->wait_type_inner < LD_WAIT_CONFIG))
+ return false;
- return true;
- }
+ /*
+ * Skip WAIT_OVERRIDE for irq inversion detection -- it's not actually
+ * a lock and only used to override the wait_type.
+ */
- return false;
+ return true;
}
/*
@@ -4768,7 +4773,8 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
for (; depth < curr->lockdep_depth; depth++) {
struct held_lock *prev = curr->held_locks + depth;
- u8 prev_inner = hlock_class(prev)->wait_type_inner;
+ struct lock_class *class = hlock_class(prev);
+ u8 prev_inner = class->wait_type_inner;
if (prev_inner) {
/*
@@ -4778,6 +4784,14 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
* Also due to trylocks.
*/
curr_inner = min(curr_inner, prev_inner);
+
+ /*
+ * Allow override for annotations -- this is typically
+ * only valid/needed for code that only exists when
+ * CONFIG_PREEMPT_RT=n.
+ */
+ if (unlikely(class->lock_type == LD_LOCK_WAIT_OVERRIDE))
+ curr_inner = prev_inner;
}
}