From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/scsi/arm/queue.c | 319 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) create mode 100644 drivers/scsi/arm/queue.c (limited to 'drivers/scsi/arm/queue.c') diff --git a/drivers/scsi/arm/queue.c b/drivers/scsi/arm/queue.c new file mode 100644 index 000000000..797cf4971 --- /dev/null +++ b/drivers/scsi/arm/queue.c @@ -0,0 +1,319 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/drivers/acorn/scsi/queue.c: queue handling primitives + * + * Copyright (C) 1997-2000 Russell King + * + * Changelog: + * 15-Sep-1997 RMK Created. + * 11-Oct-1997 RMK Corrected problem with queue_remove_exclude + * not updating internal linked list properly + * (was causing commands to go missing). + * 30-Aug-2000 RMK Use Linux list handling and spinlocks + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#define DEBUG + +typedef struct queue_entry { + struct list_head list; + struct scsi_cmnd *SCpnt; +#ifdef DEBUG + unsigned long magic; +#endif +} QE_t; + +#ifdef DEBUG +#define QUEUE_MAGIC_FREE 0xf7e1c9a3 +#define QUEUE_MAGIC_USED 0xf7e1cc33 + +#define SET_MAGIC(q,m) ((q)->magic = (m)) +#define BAD_MAGIC(q,m) ((q)->magic != (m)) +#else +#define SET_MAGIC(q,m) do { } while (0) +#define BAD_MAGIC(q,m) (0) +#endif + +#include "queue.h" + +#define NR_QE 32 + +/* + * Function: void queue_initialise (Queue_t *queue) + * Purpose : initialise a queue + * Params : queue - queue to initialise + */ +int queue_initialise (Queue_t *queue) +{ + unsigned int nqueues = NR_QE; + QE_t *q; + + spin_lock_init(&queue->queue_lock); + INIT_LIST_HEAD(&queue->head); + INIT_LIST_HEAD(&queue->free); + + /* + * If life was easier, then SCpnt would have a + * host-available list head, and we wouldn't + * need to keep free lists or allocate this + * memory. + */ + queue->alloc = q = kmalloc_objs(QE_t, nqueues); + if (q) { + for (; nqueues; q++, nqueues--) { + SET_MAGIC(q, QUEUE_MAGIC_FREE); + q->SCpnt = NULL; + list_add(&q->list, &queue->free); + } + } + + return queue->alloc != NULL; +} + +/* + * Function: void queue_free (Queue_t *queue) + * Purpose : free a queue + * Params : queue - queue to free + */ +void queue_free (Queue_t *queue) +{ + if (!list_empty(&queue->head)) + printk(KERN_WARNING "freeing non-empty queue %p\n", queue); + kfree(queue->alloc); +} + + +/* + * Function: int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head) + * Purpose : Add a new command onto a queue, adding REQUEST_SENSE to head. + * Params : queue - destination queue + * SCpnt - command to add + * head - add command to head of queue + * Returns : 0 on error, !0 on success + */ +int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head) +{ + unsigned long flags; + struct list_head *l; + QE_t *q; + int ret = 0; + + spin_lock_irqsave(&queue->queue_lock, flags); + if (list_empty(&queue->free)) + goto empty; + + l = queue->free.next; + list_del(l); + + q = list_entry(l, QE_t, list); + BUG_ON(BAD_MAGIC(q, QUEUE_MAGIC_FREE)); + + SET_MAGIC(q, QUEUE_MAGIC_USED); + q->SCpnt = SCpnt; + + if (head) + list_add(l, &queue->head); + else + list_add_tail(l, &queue->head); + + ret = 1; +empty: + spin_unlock_irqrestore(&queue->queue_lock, flags); + return ret; +} + +static struct scsi_cmnd *__queue_remove(Queue_t *queue, struct list_head *ent) +{ + QE_t *q; + + /* + * Move the entry from the "used" list onto the "free" list + */ + list_del(ent); + q = list_entry(ent, QE_t, list); + BUG_ON(BAD_MAGIC(q, QUEUE_MAGIC_USED)); + + SET_MAGIC(q, QUEUE_MAGIC_FREE); + list_add(ent, &queue->free); + + return q->SCpnt; +} + +/* + * Function: struct scsi_cmnd *queue_remove_exclude (queue, exclude) + * Purpose : remove a SCSI command from a queue + * Params : queue - queue to remove command from + * exclude - bit array of target&lun which is busy + * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available + */ +struct scsi_cmnd *queue_remove_exclude(Queue_t *queue, unsigned long *exclude) +{ + unsigned long flags; + struct list_head *l; + struct scsi_cmnd *SCpnt = NULL; + + spin_lock_irqsave(&queue->queue_lock, flags); + list_for_each(l, &queue->head) { + QE_t *q = list_entry(l, QE_t, list); + if (!test_bit(q->SCpnt->device->id * 8 + + (u8)(q->SCpnt->device->lun & 0x7), exclude)) { + SCpnt = __queue_remove(queue, l); + break; + } + } + spin_unlock_irqrestore(&queue->queue_lock, flags); + + return SCpnt; +} + +/* + * 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 + */ +struct scsi_cmnd *queue_remove(Queue_t *queue) +{ + unsigned long flags; + struct scsi_cmnd *SCpnt = NULL; + + spin_lock_irqsave(&queue->queue_lock, flags); + if (!list_empty(&queue->head)) + SCpnt = __queue_remove(queue, queue->head.next); + spin_unlock_irqrestore(&queue->queue_lock, flags); + + return SCpnt; +} + +/* + * 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 + */ +struct scsi_cmnd *queue_remove_tgtluntag(Queue_t *queue, int target, int lun, + int tag) +{ + unsigned long flags; + struct list_head *l; + struct scsi_cmnd *SCpnt = NULL; + + spin_lock_irqsave(&queue->queue_lock, flags); + list_for_each(l, &queue->head) { + QE_t *q = list_entry(l, QE_t, list); + if (q->SCpnt->device->id == target && q->SCpnt->device->lun == lun && + scsi_cmd_to_rq(q->SCpnt)->tag == tag) { + SCpnt = __queue_remove(queue, l); + break; + } + } + spin_unlock_irqrestore(&queue->queue_lock, flags); + + return SCpnt; +} + +/* + * 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 + */ +void queue_remove_all_target(Queue_t *queue, int target) +{ + unsigned long flags; + struct list_head *l; + + spin_lock_irqsave(&queue->queue_lock, flags); + list_for_each(l, &queue->head) { + QE_t *q = list_entry(l, QE_t, list); + if (q->SCpnt->device->id == target) + __queue_remove(queue, l); + } + spin_unlock_irqrestore(&queue->queue_lock, flags); +} + +/* + * 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 + */ +int queue_probetgtlun (Queue_t *queue, int target, int lun) +{ + unsigned long flags; + struct list_head *l; + int found = 0; + + spin_lock_irqsave(&queue->queue_lock, flags); + list_for_each(l, &queue->head) { + QE_t *q = list_entry(l, QE_t, list); + if (q->SCpnt->device->id == target && q->SCpnt->device->lun == lun) { + found = 1; + break; + } + } + spin_unlock_irqrestore(&queue->queue_lock, flags); + + return found; +} + +/* + * 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) +{ + unsigned long flags; + struct list_head *l; + int found = 0; + + spin_lock_irqsave(&queue->queue_lock, flags); + list_for_each(l, &queue->head) { + QE_t *q = list_entry(l, QE_t, list); + if (q->SCpnt == SCpnt) { + __queue_remove(queue, l); + found = 1; + break; + } + } + spin_unlock_irqrestore(&queue->queue_lock, flags); + + return found; +} + +EXPORT_SYMBOL(queue_initialise); +EXPORT_SYMBOL(queue_free); +EXPORT_SYMBOL(__queue_add); +EXPORT_SYMBOL(queue_remove); +EXPORT_SYMBOL(queue_remove_exclude); +EXPORT_SYMBOL(queue_remove_tgtluntag); +EXPORT_SYMBOL(queue_remove_cmd); +EXPORT_SYMBOL(queue_remove_all_target); +EXPORT_SYMBOL(queue_probetgtlun); + +MODULE_AUTHOR("Russell King"); +MODULE_DESCRIPTION("SCSI command queueing"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1