From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/scsi/arm/queue.h | 104 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 drivers/scsi/arm/queue.h (limited to 'drivers/scsi/arm/queue.h') diff --git a/drivers/scsi/arm/queue.h b/drivers/scsi/arm/queue.h new file mode 100644 index 000000000..cb51379dc --- /dev/null +++ b/drivers/scsi/arm/queue.h @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/drivers/acorn/scsi/queue.h: queue handling + * + * Copyright (C) 1997 Russell King + */ +#ifndef QUEUE_H +#define QUEUE_H + +typedef struct { + struct list_head head; + struct list_head free; + spinlock_t queue_lock; + void *alloc; /* start of allocated mem */ +} Queue_t; + +/* + * Function: void queue_initialise (Queue_t *queue) + * Purpose : initialise a queue + * Params : queue - queue to initialise + */ +extern int queue_initialise (Queue_t *queue); + +/* + * Function: void queue_free (Queue_t *queue) + * Purpose : free a queue + * Params : queue - queue to free + */ +extern void queue_free (Queue_t *queue); + +/* + * Function: struct scsi_cmnd *queue_remove (queue) + * Purpose : removes first SCSI command from a queue + * Params : queue - queue to remove command from + * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available + */ +extern struct scsi_cmnd *queue_remove (Queue_t *queue); + +/* + * Function: struct scsi_cmnd *queue_remove_exclude_ref (queue, exclude) + * Purpose : remove a SCSI command from a queue + * Params : queue - queue to remove command from + * exclude - array of busy LUNs + * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available + */ +extern struct scsi_cmnd *queue_remove_exclude(Queue_t *queue, + unsigned long *exclude); + +#define queue_add_cmd_ordered(queue,SCpnt) \ + __queue_add(queue,SCpnt,(SCpnt)->cmnd[0] == REQUEST_SENSE) +#define queue_add_cmd_tail(queue,SCpnt) \ + __queue_add(queue,SCpnt,0) +/* + * Function: int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head) + * Purpose : Add a new command onto a queue + * Params : queue - destination queue + * SCpnt - command to add + * head - add command to head of queue + * Returns : 0 on error, !0 on success + */ +extern int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head); + +/* + * Function: struct scsi_cmnd *queue_remove_tgtluntag (queue, target, lun, tag) + * Purpose : remove a SCSI command from the queue for a specified target/lun/tag + * Params : queue - queue to remove command from + * target - target that we want + * lun - lun on device + * tag - tag on device + * Returns : struct scsi_cmnd if successful, or NULL if no command satisfies requirements + */ +extern struct scsi_cmnd *queue_remove_tgtluntag(Queue_t *queue, int target, + int lun, int tag); + +/* + * Function: queue_remove_all_target(queue, target) + * Purpose : remove all SCSI commands from the queue for a specified target + * Params : queue - queue to remove command from + * target - target device id + * Returns : nothing + */ +extern void queue_remove_all_target(Queue_t *queue, int target); + +/* + * Function: int queue_probetgtlun (queue, target, lun) + * Purpose : check to see if we have a command in the queue for the specified + * target/lun. + * Params : queue - queue to look in + * target - target we want to probe + * lun - lun on target + * Returns : 0 if not found, != 0 if found + */ +extern int queue_probetgtlun (Queue_t *queue, int target, int lun); + +/* + * Function: int queue_remove_cmd (Queue_t *queue, struct scsi_cmnd *SCpnt) + * Purpose : remove a specific command from the queues + * Params : queue - queue to look in + * SCpnt - command to find + * Returns : 0 if not found + */ +int queue_remove_cmd(Queue_t *queue, struct scsi_cmnd *SCpnt); + +#endif /* QUEUE_H */ -- cgit v1.3.1