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Let's follow a consistent and documented coding style. Everything may not be to our liking but it is better than tacit knowledge. Moreover, this will help maintain style consistency between different developers. This contains only whitespace changes. Automatically formatted with: clang-format-14 -i security/landlock/*.[ch] include/uapi/linux/landlock.h Link: https://lore.kernel.org/r/20220506160513.523257-3-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net>
68 lines
1.7 KiB
C
68 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Landlock LSM - Object management
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*
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* Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net>
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* Copyright © 2018-2020 ANSSI
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*/
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#include <linux/bug.h>
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#include <linux/compiler_types.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/rcupdate.h>
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#include <linux/refcount.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include "object.h"
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struct landlock_object *
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landlock_create_object(const struct landlock_object_underops *const underops,
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void *const underobj)
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{
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struct landlock_object *new_object;
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if (WARN_ON_ONCE(!underops || !underobj))
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return ERR_PTR(-ENOENT);
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new_object = kzalloc(sizeof(*new_object), GFP_KERNEL_ACCOUNT);
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if (!new_object)
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return ERR_PTR(-ENOMEM);
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refcount_set(&new_object->usage, 1);
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spin_lock_init(&new_object->lock);
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new_object->underops = underops;
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new_object->underobj = underobj;
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return new_object;
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}
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/*
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* The caller must own the object (i.e. thanks to object->usage) to safely put
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* it.
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*/
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void landlock_put_object(struct landlock_object *const object)
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{
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/*
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* The call to @object->underops->release(object) might sleep, e.g.
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* because of iput().
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*/
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might_sleep();
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if (!object)
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return;
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/*
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* If the @object's refcount cannot drop to zero, we can just decrement
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* the refcount without holding a lock. Otherwise, the decrement must
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* happen under @object->lock for synchronization with things like
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* get_inode_object().
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*/
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if (refcount_dec_and_lock(&object->usage, &object->lock)) {
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__acquire(&object->lock);
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/*
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* With @object->lock initially held, remove the reference from
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* @object->underobj to @object (if it still exists).
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*/
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object->underops->release(object);
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kfree_rcu(object, rcu_free);
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}
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}
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