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/media/mc/mc-request.c | 539 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 539 insertions(+) create mode 100644 drivers/media/mc/mc-request.c (limited to 'drivers/media/mc/mc-request.c') diff --git a/drivers/media/mc/mc-request.c b/drivers/media/mc/mc-request.c new file mode 100644 index 000000000..13e776488 --- /dev/null +++ b/drivers/media/mc/mc-request.c @@ -0,0 +1,539 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Media device request objects + * + * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + * Copyright (C) 2018 Intel Corporation + * Copyright (C) 2018 Google, Inc. + * + * Author: Hans Verkuil + * Author: Sakari Ailus + */ + +#include +#include +#include + +#include +#include + +static const char * const request_state[] = { + [MEDIA_REQUEST_STATE_IDLE] = "idle", + [MEDIA_REQUEST_STATE_VALIDATING] = "validating", + [MEDIA_REQUEST_STATE_QUEUED] = "queued", + [MEDIA_REQUEST_STATE_COMPLETE] = "complete", + [MEDIA_REQUEST_STATE_CLEANING] = "cleaning", + [MEDIA_REQUEST_STATE_UPDATING] = "updating", +}; + +static const char * +media_request_state_str(enum media_request_state state) +{ + BUILD_BUG_ON(ARRAY_SIZE(request_state) != NR_OF_MEDIA_REQUEST_STATE); + + if (WARN_ON(state >= ARRAY_SIZE(request_state))) + return "invalid"; + return request_state[state]; +} + +static void media_request_clean(struct media_request *req) +{ + struct media_request_object *obj, *obj_safe; + + /* Just a sanity check. No other code path is allowed to change this. */ + WARN_ON(req->state != MEDIA_REQUEST_STATE_CLEANING); + WARN_ON(req->updating_count); + WARN_ON(req->access_count); + + list_for_each_entry_safe(obj, obj_safe, &req->objects, list) { + media_request_object_unbind(obj); + media_request_object_put(obj); + } + + req->updating_count = 0; + req->access_count = 0; + WARN_ON(req->num_incomplete_objects); + req->num_incomplete_objects = 0; + req->manual_completion = false; + wake_up_interruptible_all(&req->poll_wait); +} + +static void media_request_release(struct kref *kref) +{ + struct media_request *req = + container_of(kref, struct media_request, kref); + struct media_device *mdev = req->mdev; + + dev_dbg(mdev->dev, "request: release %s\n", req->debug_str); + + /* No other users, no need for a spinlock */ + req->state = MEDIA_REQUEST_STATE_CLEANING; + + media_request_clean(req); + + if (mdev->ops->req_free) + mdev->ops->req_free(req); + else + kfree(req); + atomic_dec(&mdev->num_requests); +} + +void media_request_put(struct media_request *req) +{ + kref_put(&req->kref, media_request_release); +} +EXPORT_SYMBOL_GPL(media_request_put); + +static int media_request_close(struct inode *inode, struct file *filp) +{ + struct media_request *req = filp->private_data; + + media_request_put(req); + return 0; +} + +static __poll_t media_request_poll(struct file *filp, + struct poll_table_struct *wait) +{ + struct media_request *req = filp->private_data; + unsigned long flags; + __poll_t ret = 0; + + if (!(poll_requested_events(wait) & EPOLLPRI)) + return 0; + + poll_wait(filp, &req->poll_wait, wait); + spin_lock_irqsave(&req->lock, flags); + if (req->state == MEDIA_REQUEST_STATE_COMPLETE) { + ret = EPOLLPRI; + goto unlock; + } + if (req->state != MEDIA_REQUEST_STATE_QUEUED) { + ret = EPOLLERR; + goto unlock; + } + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + return ret; +} + +static long media_request_ioctl_queue(struct media_request *req) +{ + struct media_device *mdev = req->mdev; + enum media_request_state state; + unsigned long flags; + int ret; + + dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str); + + /* + * Ensure the request that is validated will be the one that gets queued + * next by serialising the queueing process. This mutex is also used + * to serialize with canceling a vb2 queue and with setting values such + * as controls in a request. + */ + mutex_lock(&mdev->req_queue_mutex); + + media_request_get(req); + + spin_lock_irqsave(&req->lock, flags); + if (req->state == MEDIA_REQUEST_STATE_IDLE) + req->state = MEDIA_REQUEST_STATE_VALIDATING; + state = req->state; + spin_unlock_irqrestore(&req->lock, flags); + if (state != MEDIA_REQUEST_STATE_VALIDATING) { + dev_dbg(mdev->dev, + "request: unable to queue %s, request in state %s\n", + req->debug_str, media_request_state_str(state)); + media_request_put(req); + mutex_unlock(&mdev->req_queue_mutex); + return -EBUSY; + } + + ret = mdev->ops->req_validate(req); + + /* + * If the req_validate was successful, then we mark the state as QUEUED + * and call req_queue. The reason we set the state first is that this + * allows req_queue to unbind or complete the queued objects in case + * they are immediately 'consumed'. State changes from QUEUED to another + * state can only happen if either the driver changes the state or if + * the user cancels the vb2 queue. The driver can only change the state + * after each object is queued through the req_queue op (and note that + * that op cannot fail), so setting the state to QUEUED up front is + * safe. + * + * The other reason for changing the state is if the vb2 queue is + * canceled, and that uses the req_queue_mutex which is still locked + * while req_queue is called, so that's safe as well. + */ + spin_lock_irqsave(&req->lock, flags); + req->state = ret ? MEDIA_REQUEST_STATE_IDLE + : MEDIA_REQUEST_STATE_QUEUED; + spin_unlock_irqrestore(&req->lock, flags); + + if (!ret) + mdev->ops->req_queue(req); + + mutex_unlock(&mdev->req_queue_mutex); + + if (ret) { + dev_dbg(mdev->dev, "request: can't queue %s (%d)\n", + req->debug_str, ret); + media_request_put(req); + } + + return ret; +} + +static long media_request_ioctl_reinit(struct media_request *req) +{ + struct media_device *mdev = req->mdev; + unsigned long flags; + + mutex_lock(&mdev->req_queue_mutex); + + spin_lock_irqsave(&req->lock, flags); + if (req->state != MEDIA_REQUEST_STATE_IDLE && + req->state != MEDIA_REQUEST_STATE_COMPLETE) { + dev_dbg(mdev->dev, + "request: %s not in idle or complete state, cannot reinit\n", + req->debug_str); + spin_unlock_irqrestore(&req->lock, flags); + mutex_unlock(&mdev->req_queue_mutex); + return -EBUSY; + } + if (req->access_count) { + dev_dbg(mdev->dev, + "request: %s is being accessed, cannot reinit\n", + req->debug_str); + spin_unlock_irqrestore(&req->lock, flags); + mutex_unlock(&mdev->req_queue_mutex); + return -EBUSY; + } + req->state = MEDIA_REQUEST_STATE_CLEANING; + spin_unlock_irqrestore(&req->lock, flags); + + media_request_clean(req); + + spin_lock_irqsave(&req->lock, flags); + req->state = MEDIA_REQUEST_STATE_IDLE; + spin_unlock_irqrestore(&req->lock, flags); + mutex_unlock(&mdev->req_queue_mutex); + + return 0; +} + +static long media_request_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct media_request *req = filp->private_data; + + switch (cmd) { + case MEDIA_REQUEST_IOC_QUEUE: + return media_request_ioctl_queue(req); + case MEDIA_REQUEST_IOC_REINIT: + return media_request_ioctl_reinit(req); + default: + return -ENOIOCTLCMD; + } +} + +static const struct file_operations request_fops = { + .owner = THIS_MODULE, + .poll = media_request_poll, + .unlocked_ioctl = media_request_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = media_request_ioctl, +#endif /* CONFIG_COMPAT */ + .release = media_request_close, +}; + +struct media_request * +media_request_get_by_fd(struct media_device *mdev, int request_fd) +{ + struct media_request *req; + + if (!mdev || !mdev->ops || + !mdev->ops->req_validate || !mdev->ops->req_queue) + return ERR_PTR(-EBADR); + + CLASS(fd, f)(request_fd); + if (fd_empty(f)) + goto err; + + if (fd_file(f)->f_op != &request_fops) + goto err; + req = fd_file(f)->private_data; + if (req->mdev != mdev) + goto err; + + /* + * Note: as long as someone has an open filehandle of the request, + * the request can never be released. The fdget() above ensures that + * even if userspace closes the request filehandle, the release() + * fop won't be called, so the media_request_get() always succeeds + * and there is no race condition where the request was released + * before media_request_get() is called. + */ + media_request_get(req); + return req; + +err: + dev_dbg(mdev->dev, "cannot find request_fd %d\n", request_fd); + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL_GPL(media_request_get_by_fd); + +int media_request_alloc(struct media_device *mdev, int *alloc_fd) +{ + struct media_request *req; + int ret; + + /* Either both are NULL or both are non-NULL */ + if (WARN_ON(!mdev->ops->req_alloc ^ !mdev->ops->req_free)) + return -ENOMEM; + + if (mdev->ops->req_alloc) + req = mdev->ops->req_alloc(mdev); + else + req = kzalloc_obj(*req); + if (!req) + return -ENOMEM; + + req->mdev = mdev; + req->state = MEDIA_REQUEST_STATE_IDLE; + req->num_incomplete_objects = 0; + req->manual_completion = false; + kref_init(&req->kref); + INIT_LIST_HEAD(&req->objects); + spin_lock_init(&req->lock); + init_waitqueue_head(&req->poll_wait); + req->updating_count = 0; + req->access_count = 0; + + FD_PREPARE(fdf, O_CLOEXEC, + anon_inode_getfile("request", &request_fops, NULL, + O_CLOEXEC)); + if (fdf.err) { + ret = fdf.err; + goto err_free_req; + } + + fd_prepare_file(fdf)->private_data = req; + + snprintf(req->debug_str, sizeof(req->debug_str), "%u:%d", + atomic_inc_return(&mdev->request_id), fd_prepare_fd(fdf)); + atomic_inc(&mdev->num_requests); + dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str); + + *alloc_fd = fd_publish(fdf); + + return 0; + +err_free_req: + if (mdev->ops->req_free) + mdev->ops->req_free(req); + else + kfree(req); + + return ret; +} + +static void media_request_object_release(struct kref *kref) +{ + struct media_request_object *obj = + container_of(kref, struct media_request_object, kref); + struct media_request *req = obj->req; + struct media_device *mdev = obj->mdev; + + if (WARN_ON(req)) + media_request_object_unbind(obj); + obj->ops->release(obj); + atomic_dec(&mdev->num_request_objects); +} + +struct media_request_object * +media_request_object_find(struct media_request *req, + const struct media_request_object_ops *ops, + void *priv) +{ + struct media_request_object *obj; + struct media_request_object *found = NULL; + unsigned long flags; + + if (WARN_ON(!ops || !priv)) + return NULL; + + spin_lock_irqsave(&req->lock, flags); + list_for_each_entry(obj, &req->objects, list) { + if (obj->ops == ops && obj->priv == priv) { + media_request_object_get(obj); + found = obj; + break; + } + } + spin_unlock_irqrestore(&req->lock, flags); + return found; +} +EXPORT_SYMBOL_GPL(media_request_object_find); + +void media_request_object_put(struct media_request_object *obj) +{ + kref_put(&obj->kref, media_request_object_release); +} +EXPORT_SYMBOL_GPL(media_request_object_put); + +void media_request_object_init(struct media_request_object *obj) +{ + obj->ops = NULL; + obj->req = NULL; + obj->priv = NULL; + obj->completed = false; + INIT_LIST_HEAD(&obj->list); + kref_init(&obj->kref); +} +EXPORT_SYMBOL_GPL(media_request_object_init); + +int media_request_object_bind(struct media_request *req, + const struct media_request_object_ops *ops, + void *priv, bool is_buffer, + struct media_request_object *obj) +{ + unsigned long flags; + int ret = -EBUSY; + + if (WARN_ON(!ops->release)) + return -EBADR; + + spin_lock_irqsave(&req->lock, flags); + + if (WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING && + req->state != MEDIA_REQUEST_STATE_QUEUED)) + goto unlock; + + obj->req = req; + obj->ops = ops; + obj->priv = priv; + obj->mdev = req->mdev; + + if (is_buffer) + list_add_tail(&obj->list, &req->objects); + else + list_add(&obj->list, &req->objects); + req->num_incomplete_objects++; + ret = 0; + atomic_inc(&obj->mdev->num_request_objects); + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(media_request_object_bind); + +void media_request_object_unbind(struct media_request_object *obj) +{ + struct media_request *req = obj->req; + unsigned long flags; + bool completed = false; + + if (WARN_ON(!req)) + return; + + spin_lock_irqsave(&req->lock, flags); + list_del(&obj->list); + obj->req = NULL; + + if (req->state == MEDIA_REQUEST_STATE_COMPLETE) + goto unlock; + + if (WARN_ON(req->state == MEDIA_REQUEST_STATE_VALIDATING)) + goto unlock; + + if (req->state == MEDIA_REQUEST_STATE_CLEANING) { + if (!obj->completed) + req->num_incomplete_objects--; + goto unlock; + } + + if (WARN_ON(!req->num_incomplete_objects)) + goto unlock; + + req->num_incomplete_objects--; + if (req->state == MEDIA_REQUEST_STATE_QUEUED && + !req->num_incomplete_objects && !req->manual_completion) { + req->state = MEDIA_REQUEST_STATE_COMPLETE; + completed = true; + wake_up_interruptible_all(&req->poll_wait); + } + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + if (obj->ops->unbind) + obj->ops->unbind(obj); + if (completed) + media_request_put(req); +} +EXPORT_SYMBOL_GPL(media_request_object_unbind); + +void media_request_object_complete(struct media_request_object *obj) +{ + struct media_request *req = obj->req; + unsigned long flags; + bool completed = false; + + spin_lock_irqsave(&req->lock, flags); + if (obj->completed) + goto unlock; + obj->completed = true; + if (WARN_ON(!req->num_incomplete_objects) || + WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED)) + goto unlock; + + if (!--req->num_incomplete_objects && !req->manual_completion) { + req->state = MEDIA_REQUEST_STATE_COMPLETE; + wake_up_interruptible_all(&req->poll_wait); + completed = true; + } +unlock: + spin_unlock_irqrestore(&req->lock, flags); + if (completed) + media_request_put(req); +} +EXPORT_SYMBOL_GPL(media_request_object_complete); + +void media_request_manual_complete(struct media_request *req) +{ + bool completed = false; + unsigned long flags; + + if (WARN_ON_ONCE(!req)) + return; + + spin_lock_irqsave(&req->lock, flags); + + if (WARN_ON_ONCE(!req->manual_completion)) + goto unlock; + + if (WARN_ON_ONCE(req->state != MEDIA_REQUEST_STATE_QUEUED)) + goto unlock; + + req->manual_completion = false; + /* + * It is expected that all other objects in this request are + * completed when this function is called. WARN if that is + * not the case. + */ + if (!WARN_ON(req->num_incomplete_objects)) { + req->state = MEDIA_REQUEST_STATE_COMPLETE; + wake_up_interruptible_all(&req->poll_wait); + completed = true; + } + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + if (completed) + media_request_put(req); +} +EXPORT_SYMBOL_GPL(media_request_manual_complete); -- cgit v1.3.1