Revision d9abdee5fd5abffd0e763e52fbfa3116de167822 authored by Linus Torvalds on 19 October 2021, 15:41:36 UTC, committed by Linus Torvalds on 19 October 2021, 15:41:36 UTC
Merge misc fixes from Andrew Morton: "19 patches. Subsystems affected by this patch series: mm (userfaultfd, migration, memblock, mempolicy, slub, secretmem, and thp), ocfs2, binfmt, vfs, and misc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mailmap: add Andrej Shadura mm/thp: decrease nr_thps in file's mapping on THP split mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem() vfs: check fd has read access in kernel_read_file_from_fd() elfcore: correct reference to CONFIG_UML mm, slub: fix incorrect memcg slab count for bulk free mm, slub: fix potential use-after-free in slab_debugfs_fops mm, slub: fix potential memoryleak in kmem_cache_open() mm, slub: fix mismatch between reconstructed freelist depth and cnt mm, slub: fix two bugs in slab_debug_trace_open() mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind() memblock: check memory total_size ocfs2: mount fails with buffer overflow in strlen ocfs2: fix data corruption after conversion from inline format mm/migrate: fix CPUHP state to update node demotion order mm/migrate: add CPU hotplug to demotion #ifdef mm/migrate: optimize hotplug-time demotion order updates userfaultfd: fix a race between writeprotect and exit_mmap() mm/userfaultfd: selftests: fix memory corruption with thp enabled
user-return-notifier.c
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/user-return-notifier.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/export.h>
static DEFINE_PER_CPU(struct hlist_head, return_notifier_list);
/*
* Request a notification when the current cpu returns to userspace. Must be
* called in atomic context. The notifier will also be called in atomic
* context.
*/
void user_return_notifier_register(struct user_return_notifier *urn)
{
set_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
hlist_add_head(&urn->link, this_cpu_ptr(&return_notifier_list));
}
EXPORT_SYMBOL_GPL(user_return_notifier_register);
/*
* Removes a registered user return notifier. Must be called from atomic
* context, and from the same cpu registration occurred in.
*/
void user_return_notifier_unregister(struct user_return_notifier *urn)
{
hlist_del(&urn->link);
if (hlist_empty(this_cpu_ptr(&return_notifier_list)))
clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
}
EXPORT_SYMBOL_GPL(user_return_notifier_unregister);
/* Calls registered user return notifiers */
void fire_user_return_notifiers(void)
{
struct user_return_notifier *urn;
struct hlist_node *tmp2;
struct hlist_head *head;
head = &get_cpu_var(return_notifier_list);
hlist_for_each_entry_safe(urn, tmp2, head, link)
urn->on_user_return(urn);
put_cpu_var(return_notifier_list);
}
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