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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-23 17:11:11 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-23 17:11:11 +0200 |
commit | e6764aa0e5530066dd969eccea2a1a7d177859a8 (patch) | |
tree | 5d29a474bd1e410c685e27b81bf11cf38b244c0b | |
parent | 4ef12f7198023c09ad6d25b652bd8748c965c7fa (diff) | |
download | lwn-e6764aa0e5530066dd969eccea2a1a7d177859a8.tar.gz lwn-e6764aa0e5530066dd969eccea2a1a7d177859a8.zip |
Revert "kobject: Make sure the parent does not get released before its children"
This reverts commit 4ef12f7198023c09ad6d25b652bd8748c965c7fa.
Guenter reports:
All my arm64be (arm64 big endian) boot tests crash with this
patch applied. Reverting it fixes the problem. Crash log and
bisect results (from pending-fixes branch) below.
And also:
arm64 images don't crash but report lots of "poison overwritten"
backtraces like the one below. On arm, I see "refcount_t:
underflow", also attached. I didn't bisect those, but given the
context I would suspect the same culprit.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200513151840.36400-1-heikki.krogerus@linux.intel.com
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: kernel test robot <rong.a.chen@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | lib/kobject.c | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/lib/kobject.c b/lib/kobject.c index 2bd631460e18..83198cb37d8d 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -599,7 +599,14 @@ out: } EXPORT_SYMBOL_GPL(kobject_move); -static void __kobject_del(struct kobject *kobj) +/** + * kobject_del() - Unlink kobject from hierarchy. + * @kobj: object. + * + * This is the function that should be called to delete an object + * successfully added via kobject_add(). + */ +void kobject_del(struct kobject *kobj) { struct kernfs_node *sd; const struct kobj_type *ktype; @@ -618,23 +625,9 @@ static void __kobject_del(struct kobject *kobj) kobj->state_in_sysfs = 0; kobj_kset_leave(kobj); + kobject_put(kobj->parent); kobj->parent = NULL; } - -/** - * kobject_del() - Unlink kobject from hierarchy. - * @kobj: object. - * - * This is the function that should be called to delete an object - * successfully added via kobject_add(). - */ -void kobject_del(struct kobject *kobj) -{ - struct kobject *parent = kobj->parent; - - __kobject_del(kobj); - kobject_put(parent); -} EXPORT_SYMBOL(kobject_del); /** @@ -670,7 +663,6 @@ EXPORT_SYMBOL(kobject_get_unless_zero); */ static void kobject_cleanup(struct kobject *kobj) { - struct kobject *parent = kobj->parent; struct kobj_type *t = get_ktype(kobj); const char *name = kobj->name; @@ -692,7 +684,7 @@ static void kobject_cleanup(struct kobject *kobj) if (kobj->state_in_sysfs) { pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", kobject_name(kobj), kobj); - __kobject_del(kobj); + kobject_del(kobj); } if (t && t->release) { @@ -706,8 +698,6 @@ static void kobject_cleanup(struct kobject *kobj) pr_debug("kobject: '%s': free name\n", name); kfree_const(name); } - - kobject_put(parent); } #ifdef CONFIG_DEBUG_KOBJECT_RELEASE |