The patch titled
Subject: kunit: make test->lock irq safe
has been added to the -mm tree. Its filename is
kunit-make-test-lock-irq-safe.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kunit-make-test-lock-irq-safe.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kunit-make-test-lock-irq-safe.patch
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------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: kunit: make test->lock irq safe
The upcoming SLUB kunit test will be calling kunit_find_named_resource()
from a context with disabled interrupts. That means kunit's test->lock
needs to be IRQ safe to avoid potential deadlocks and lockdep splats.
This patch therefore changes the test->lock usage to spin_lock_irqsave()
and spin_unlock_irqrestore().
Link: https://lkml.kernel.org/r/20210511150734.3492-1-glittao@xxxxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Oliver Glitta <glittao@xxxxxxxxx>
Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Daniel Latypov <dlatypov@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/kunit/test.h | 5 +++--
lib/kunit/test.c | 18 +++++++++++-------
2 files changed, 14 insertions(+), 9 deletions(-)
--- a/include/kunit/test.h~kunit-make-test-lock-irq-safe
+++ a/include/kunit/test.h
@@ -515,8 +515,9 @@ kunit_find_resource(struct kunit *test,
void *match_data)
{
struct kunit_resource *res, *found = NULL;
+ unsigned long flags;
- spin_lock(&test->lock);
+ spin_lock_irqsave(&test->lock, flags);
list_for_each_entry_reverse(res, &test->resources, node) {
if (match(test, res, (void *)match_data)) {
@@ -526,7 +527,7 @@ kunit_find_resource(struct kunit *test,
}
}
- spin_unlock(&test->lock);
+ spin_unlock_irqrestore(&test->lock, flags);
return found;
}
--- a/lib/kunit/test.c~kunit-make-test-lock-irq-safe
+++ a/lib/kunit/test.c
@@ -475,6 +475,7 @@ int kunit_add_resource(struct kunit *tes
void *data)
{
int ret = 0;
+ unsigned long flags;
res->free = free;
kref_init(&res->refcount);
@@ -487,10 +488,10 @@ int kunit_add_resource(struct kunit *tes
res->data = data;
}
- spin_lock(&test->lock);
+ spin_lock_irqsave(&test->lock, flags);
list_add_tail(&res->node, &test->resources);
/* refcount for list is established by kref_init() */
- spin_unlock(&test->lock);
+ spin_unlock_irqrestore(&test->lock, flags);
return ret;
}
@@ -548,9 +549,11 @@ EXPORT_SYMBOL_GPL(kunit_alloc_and_get_re
void kunit_remove_resource(struct kunit *test, struct kunit_resource *res)
{
- spin_lock(&test->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&test->lock, flags);
list_del(&res->node);
- spin_unlock(&test->lock);
+ spin_unlock_irqrestore(&test->lock, flags);
kunit_put_resource(res);
}
EXPORT_SYMBOL_GPL(kunit_remove_resource);
@@ -630,6 +633,7 @@ EXPORT_SYMBOL_GPL(kunit_kfree);
void kunit_cleanup(struct kunit *test)
{
struct kunit_resource *res;
+ unsigned long flags;
/*
* test->resources is a stack - each allocation must be freed in the
@@ -641,9 +645,9 @@ void kunit_cleanup(struct kunit *test)
* protect against the current node being deleted, not the next.
*/
while (true) {
- spin_lock(&test->lock);
+ spin_lock_irqsave(&test->lock, flags);
if (list_empty(&test->resources)) {
- spin_unlock(&test->lock);
+ spin_unlock_irqrestore(&test->lock, flags);
break;
}
res = list_last_entry(&test->resources,
@@ -654,7 +658,7 @@ void kunit_cleanup(struct kunit *test)
* resource, and this can't happen if the test->lock
* is held.
*/
- spin_unlock(&test->lock);
+ spin_unlock_irqrestore(&test->lock, flags);
kunit_remove_resource(test, res);
}
current->kunit_test = NULL;
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
mm-slub-move-slub_debug-static-key-enabling-outside-slab_mutex.patch
kunit-make-test-lock-irq-safe.patch
mm-memcg-slab-create-a-new-set-of-kmalloc-cg-n-caches-fix.patch
