From 2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Mon, 24 Aug 2026 01:18:14 +0900 Subject: coccinelle: alloc_cast: drop removed allocators - pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon Signed-off-by: Julia Lawall --- lib/is_single_threaded.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 lib/is_single_threaded.c (limited to 'lib/is_single_threaded.c') diff --git a/lib/is_single_threaded.c b/lib/is_single_threaded.c new file mode 100644 index 000000000..8c98b20bf --- /dev/null +++ b/lib/is_single_threaded.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Function to determine if a thread group is single threaded or not + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * - Derived from security/selinux/hooks.c + */ +#include +#include +#include + +/* + * Returns true if the task does not share ->mm with another thread/process. + */ +bool current_is_single_threaded(void) +{ + struct task_struct *task = current; + struct mm_struct *mm = task->mm; + struct task_struct *p, *t; + bool ret; + + if (atomic_read(&task->signal->live) != 1) + return false; + + if (atomic_read(&mm->mm_users) == 1) + return true; + + ret = false; + rcu_read_lock(); + for_each_process(p) { + if (unlikely(p->flags & PF_KTHREAD)) + continue; + if (unlikely(p == task->group_leader)) + continue; + + for_each_thread(p, t) { + if (unlikely(t->mm == mm)) + goto found; + if (likely(t->mm)) + break; + /* + * t->mm == NULL. Make sure next_thread/next_task + * will see other CLONE_VM tasks which might be + * forked before exiting. + */ + smp_rmb(); + } + } + ret = true; +found: + rcu_read_unlock(); + + return ret; +} -- cgit v1.3.1