https://github.com/torvalds/linux
Revision 9a5c107f0c42eb7db6d70d12c8852ef6a8838a1e authored by Mike Christie on 19 December 2017, 10:03:54 UTC, committed by Bryant G. Ly on 28 February 2018, 18:55:59 UTC
We will always have a page mapped for cmd data if it is
valid command. If the mapping does not exist then something
bad happened in userspace and it should not proceed. This
has us return VM_FAULT_SIGBUS when this happens instead of
returning a freshly allocated paged. The latter can cause
corruption because userspace might write the pages data
overwriting valid data or return it to the initiator.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
1 parent bab81c3
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Tip revision: 9a5c107f0c42eb7db6d70d12c8852ef6a8838a1e authored by Mike Christie on 19 December 2017, 10:03:54 UTC
tcmu: prevent corruption when invalid data page requested
Tip revision: 9a5c107
workqueue_internal.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * kernel/workqueue_internal.h
 *
 * Workqueue internal header file.  Only to be included by workqueue and
 * core kernel subsystems.
 */
#ifndef _KERNEL_WORKQUEUE_INTERNAL_H
#define _KERNEL_WORKQUEUE_INTERNAL_H

#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <linux/preempt.h>

struct worker_pool;

/*
 * The poor guys doing the actual heavy lifting.  All on-duty workers are
 * either serving the manager role, on idle list or on busy hash.  For
 * details on the locking annotation (L, I, X...), refer to workqueue.c.
 *
 * Only to be used in workqueue and async.
 */
struct worker {
	/* on idle list while idle, on busy hash table while busy */
	union {
		struct list_head	entry;	/* L: while idle */
		struct hlist_node	hentry;	/* L: while busy */
	};

	struct work_struct	*current_work;	/* L: work being processed */
	work_func_t		current_func;	/* L: current_work's fn */
	struct pool_workqueue	*current_pwq; /* L: current_work's pwq */
	bool			desc_valid;	/* ->desc is valid */
	struct list_head	scheduled;	/* L: scheduled works */

	/* 64 bytes boundary on 64bit, 32 on 32bit */

	struct task_struct	*task;		/* I: worker task */
	struct worker_pool	*pool;		/* I: the associated pool */
						/* L: for rescuers */
	struct list_head	node;		/* A: anchored at pool->workers */
						/* A: runs through worker->node */

	unsigned long		last_active;	/* L: last active timestamp */
	unsigned int		flags;		/* X: flags */
	int			id;		/* I: worker id */

	/*
	 * Opaque string set with work_set_desc().  Printed out with task
	 * dump for debugging - WARN, BUG, panic or sysrq.
	 */
	char			desc[WORKER_DESC_LEN];

	/* used only by rescuers to point to the target workqueue */
	struct workqueue_struct	*rescue_wq;	/* I: the workqueue to rescue */
};

/**
 * current_wq_worker - return struct worker if %current is a workqueue worker
 */
static inline struct worker *current_wq_worker(void)
{
	if (in_task() && (current->flags & PF_WQ_WORKER))
		return kthread_data(current);
	return NULL;
}

/*
 * Scheduler hooks for concurrency managed workqueue.  Only to be used from
 * sched/core.c and workqueue.c.
 */
void wq_worker_waking_up(struct task_struct *task, int cpu);
struct task_struct *wq_worker_sleeping(struct task_struct *task);

#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
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