[PATCH 3/3] dma-buf: nuke SW_SYNC debugfs files

Christian König ckoenig.leichtzumerken at gmail.com
Thu Jul 29 10:21:23 UTC 2021


Am 29.07.21 um 11:03 schrieb Daniel Vetter:
> On Thu, Jul 29, 2021 at 10:38 AM Christian König
> <ckoenig.leichtzumerken at gmail.com> wrote:
>> Am 29.07.21 um 09:23 schrieb Daniel Vetter:
>>> On Thu, Jul 29, 2021 at 09:03:30AM +0200, Christian König wrote:
>>>> As we now knew controlling dma_fence synchronization from userspace is
>>>> extremely dangerous and can not only deadlock drivers but trivially also the
>>>> whole kernel memory management.
>>>>
>>>> Entirely remove this option. We now have in kernel unit tests to exercise the
>>>> dma_fence framework and it's containers.
>>>>
>>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>>> There's also igts for this, and Android heavily uses this. So I'm not sure
>>> we can just nuke it.
>> I feared that you would say that.
>>
>>> I guess what we could do is maybe just taint the kernel if it's ever used?
>> What should we use then? TAINT_SOFTLOCKUP or TAINT_CRAP? :)
> I think the cleanest solution would be to install a 10s timer on each
> sw fence, and TAINT_SOFTLOOKUP if it fails to signal. That's similar
> to what we do with vgem, except vgem then just steps in with a
> dma_fence_signal() instead of tainting the kernel.

Well vgem is only for testing as far as I know.

When Android is using this for a production environment I think we 
should be a bit harder and explicitly note that this is not a good idea 
in sw_sync_debugfs_open().

> I think that should keep everyone happy, because if your Android has a
> fence stuck for more than 10s it's busted.

Well when they are using userptrs they are busted as soon as they have a 
fence stuck for much less time.

Regards,
Christian.

>
> Note that with hwc1 the indefinite fence was actually the model, when
> you did a page_flip you got an out-fence back which will only be
> signalled when the new buffer _stopped_ being used for scanout. Which
> generally depends upon the next page-flip happening (except for manual
> mode display, which only scan out once, if you ignore that the
> kernel's supposed to restore the display after suspend/resume, which
> android did). hwc2 fixed this, so a 10s timeout-to-taint should be
> fine with Android people.
>
> Also since we do have the igt/sw_sync.c test intel-gfx-ci should be
> able to check that code even.
> -Daniel
>
>> Regards,
>> Christian.
>>
>>> Also for testing we use vgem now, which enforces a timeout.
>>> -Daniel
>>>
>>>> ---
>>>>    drivers/dma-buf/Kconfig      |  13 --
>>>>    drivers/dma-buf/Makefile     |   1 -
>>>>    drivers/dma-buf/sw_sync.c    | 412 -----------------------------------
>>>>    drivers/dma-buf/sync_debug.c | 190 ----------------
>>>>    drivers/dma-buf/sync_debug.h |  72 ------
>>>>    5 files changed, 688 deletions(-)
>>>>    delete mode 100644 drivers/dma-buf/sw_sync.c
>>>>    delete mode 100644 drivers/dma-buf/sync_debug.c
>>>>    delete mode 100644 drivers/dma-buf/sync_debug.h
>>>>
>>>> diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
>>>> index 9561e3d2d428..26c53f45616a 100644
>>>> --- a/drivers/dma-buf/Kconfig
>>>> +++ b/drivers/dma-buf/Kconfig
>>>> @@ -17,19 +17,6 @@ config SYNC_FILE
>>>>         Files fds, to the DRM driver for example. More details at
>>>>         Documentation/driver-api/sync_file.rst.
>>>>
>>>> -config SW_SYNC
>>>> -    bool "Sync File Validation Framework"
>>>> -    default n
>>>> -    depends on SYNC_FILE
>>>> -    depends on DEBUG_FS
>>>> -    help
>>>> -      A sync object driver that uses a 32bit counter to coordinate
>>>> -      synchronization.  Useful when there is no hardware primitive backing
>>>> -      the synchronization.
>>>> -
>>>> -      WARNING: improper use of this can result in deadlocking kernel
>>>> -      drivers from userspace. Intended for test and debug only.
>>>> -
>>>>    config UDMABUF
>>>>       bool "userspace dmabuf misc driver"
>>>>       default n
>>>> diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
>>>> index 1ef021273a06..fa3af0953f87 100644
>>>> --- a/drivers/dma-buf/Makefile
>>>> +++ b/drivers/dma-buf/Makefile
>>>> @@ -4,7 +4,6 @@ obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
>>>>    obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o
>>>>    obj-$(CONFIG_DMABUF_HEAPS) += heaps/
>>>>    obj-$(CONFIG_SYNC_FILE)            += sync_file.o
>>>> -obj-$(CONFIG_SW_SYNC)               += sw_sync.o sync_debug.o
>>>>    obj-$(CONFIG_UDMABUF)              += udmabuf.o
>>>>    obj-$(CONFIG_DMABUF_SYSFS_STATS) += dma-buf-sysfs-stats.o
>>>>
>>>> diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
>>>> deleted file mode 100644
>>>> index 348b3a9170fa..000000000000
>>>> --- a/drivers/dma-buf/sw_sync.c
>>>> +++ /dev/null
>>>> @@ -1,412 +0,0 @@
>>>> -// SPDX-License-Identifier: GPL-2.0-only
>>>> -/*
>>>> - * Sync File validation framework
>>>> - *
>>>> - * Copyright (C) 2012 Google, Inc.
>>>> - */
>>>> -
>>>> -#include <linux/file.h>
>>>> -#include <linux/fs.h>
>>>> -#include <linux/uaccess.h>
>>>> -#include <linux/slab.h>
>>>> -#include <linux/sync_file.h>
>>>> -
>>>> -#include "sync_debug.h"
>>>> -
>>>> -#define CREATE_TRACE_POINTS
>>>> -#include "sync_trace.h"
>>>> -
>>>> -/*
>>>> - * SW SYNC validation framework
>>>> - *
>>>> - * A sync object driver that uses a 32bit counter to coordinate
>>>> - * synchronization.  Useful when there is no hardware primitive backing
>>>> - * the synchronization.
>>>> - *
>>>> - * To start the framework just open:
>>>> - *
>>>> - * <debugfs>/sync/sw_sync
>>>> - *
>>>> - * That will create a sync timeline, all fences created under this timeline
>>>> - * file descriptor will belong to the this timeline.
>>>> - *
>>>> - * The 'sw_sync' file can be opened many times as to create different
>>>> - * timelines.
>>>> - *
>>>> - * Fences can be created with SW_SYNC_IOC_CREATE_FENCE ioctl with struct
>>>> - * sw_sync_create_fence_data as parameter.
>>>> - *
>>>> - * To increment the timeline counter, SW_SYNC_IOC_INC ioctl should be used
>>>> - * with the increment as u32. This will update the last signaled value
>>>> - * from the timeline and signal any fence that has a seqno smaller or equal
>>>> - * to it.
>>>> - *
>>>> - * struct sw_sync_create_fence_data
>>>> - * @value:  the seqno to initialise the fence with
>>>> - * @name:   the name of the new sync point
>>>> - * @fence:  return the fd of the new sync_file with the created fence
>>>> - */
>>>> -struct sw_sync_create_fence_data {
>>>> -    __u32   value;
>>>> -    char    name[32];
>>>> -    __s32   fence; /* fd of new fence */
>>>> -};
>>>> -
>>>> -#define SW_SYNC_IOC_MAGIC   'W'
>>>> -
>>>> -#define SW_SYNC_IOC_CREATE_FENCE    _IOWR(SW_SYNC_IOC_MAGIC, 0,\
>>>> -            struct sw_sync_create_fence_data)
>>>> -
>>>> -#define SW_SYNC_IOC_INC                     _IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
>>>> -
>>>> -static const struct dma_fence_ops timeline_fence_ops;
>>>> -
>>>> -static inline struct sync_pt *dma_fence_to_sync_pt(struct dma_fence *fence)
>>>> -{
>>>> -    if (fence->ops != &timeline_fence_ops)
>>>> -            return NULL;
>>>> -    return container_of(fence, struct sync_pt, base);
>>>> -}
>>>> -
>>>> -/**
>>>> - * sync_timeline_create() - creates a sync object
>>>> - * @name:   sync_timeline name
>>>> - *
>>>> - * Creates a new sync_timeline. Returns the sync_timeline object or NULL in
>>>> - * case of error.
>>>> - */
>>>> -static struct sync_timeline *sync_timeline_create(const char *name)
>>>> -{
>>>> -    struct sync_timeline *obj;
>>>> -
>>>> -    obj = kzalloc(sizeof(*obj), GFP_KERNEL);
>>>> -    if (!obj)
>>>> -            return NULL;
>>>> -
>>>> -    kref_init(&obj->kref);
>>>> -    obj->context = dma_fence_context_alloc(1);
>>>> -    strlcpy(obj->name, name, sizeof(obj->name));
>>>> -
>>>> -    obj->pt_tree = RB_ROOT;
>>>> -    INIT_LIST_HEAD(&obj->pt_list);
>>>> -    spin_lock_init(&obj->lock);
>>>> -
>>>> -    sync_timeline_debug_add(obj);
>>>> -
>>>> -    return obj;
>>>> -}
>>>> -
>>>> -static void sync_timeline_free(struct kref *kref)
>>>> -{
>>>> -    struct sync_timeline *obj =
>>>> -            container_of(kref, struct sync_timeline, kref);
>>>> -
>>>> -    sync_timeline_debug_remove(obj);
>>>> -
>>>> -    kfree(obj);
>>>> -}
>>>> -
>>>> -static void sync_timeline_get(struct sync_timeline *obj)
>>>> -{
>>>> -    kref_get(&obj->kref);
>>>> -}
>>>> -
>>>> -static void sync_timeline_put(struct sync_timeline *obj)
>>>> -{
>>>> -    kref_put(&obj->kref, sync_timeline_free);
>>>> -}
>>>> -
>>>> -static const char *timeline_fence_get_driver_name(struct dma_fence *fence)
>>>> -{
>>>> -    return "sw_sync";
>>>> -}
>>>> -
>>>> -static const char *timeline_fence_get_timeline_name(struct dma_fence *fence)
>>>> -{
>>>> -    struct sync_timeline *parent = dma_fence_parent(fence);
>>>> -
>>>> -    return parent->name;
>>>> -}
>>>> -
>>>> -static void timeline_fence_release(struct dma_fence *fence)
>>>> -{
>>>> -    struct sync_pt *pt = dma_fence_to_sync_pt(fence);
>>>> -    struct sync_timeline *parent = dma_fence_parent(fence);
>>>> -    unsigned long flags;
>>>> -
>>>> -    spin_lock_irqsave(fence->lock, flags);
>>>> -    if (!list_empty(&pt->link)) {
>>>> -            list_del(&pt->link);
>>>> -            rb_erase(&pt->node, &parent->pt_tree);
>>>> -    }
>>>> -    spin_unlock_irqrestore(fence->lock, flags);
>>>> -
>>>> -    sync_timeline_put(parent);
>>>> -    dma_fence_free(fence);
>>>> -}
>>>> -
>>>> -static bool timeline_fence_signaled(struct dma_fence *fence)
>>>> -{
>>>> -    struct sync_timeline *parent = dma_fence_parent(fence);
>>>> -
>>>> -    return !__dma_fence_is_later(fence->seqno, parent->value, fence->ops);
>>>> -}
>>>> -
>>>> -static bool timeline_fence_enable_signaling(struct dma_fence *fence)
>>>> -{
>>>> -    return true;
>>>> -}
>>>> -
>>>> -static void timeline_fence_value_str(struct dma_fence *fence,
>>>> -                                char *str, int size)
>>>> -{
>>>> -    snprintf(str, size, "%lld", fence->seqno);
>>>> -}
>>>> -
>>>> -static void timeline_fence_timeline_value_str(struct dma_fence *fence,
>>>> -                                         char *str, int size)
>>>> -{
>>>> -    struct sync_timeline *parent = dma_fence_parent(fence);
>>>> -
>>>> -    snprintf(str, size, "%d", parent->value);
>>>> -}
>>>> -
>>>> -static const struct dma_fence_ops timeline_fence_ops = {
>>>> -    .get_driver_name = timeline_fence_get_driver_name,
>>>> -    .get_timeline_name = timeline_fence_get_timeline_name,
>>>> -    .enable_signaling = timeline_fence_enable_signaling,
>>>> -    .signaled = timeline_fence_signaled,
>>>> -    .release = timeline_fence_release,
>>>> -    .fence_value_str = timeline_fence_value_str,
>>>> -    .timeline_value_str = timeline_fence_timeline_value_str,
>>>> -};
>>>> -
>>>> -/**
>>>> - * sync_timeline_signal() - signal a status change on a sync_timeline
>>>> - * @obj:    sync_timeline to signal
>>>> - * @inc:    num to increment on timeline->value
>>>> - *
>>>> - * A sync implementation should call this any time one of it's fences
>>>> - * has signaled or has an error condition.
>>>> - */
>>>> -static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
>>>> -{
>>>> -    struct sync_pt *pt, *next;
>>>> -
>>>> -    trace_sync_timeline(obj);
>>>> -
>>>> -    spin_lock_irq(&obj->lock);
>>>> -
>>>> -    obj->value += inc;
>>>> -
>>>> -    list_for_each_entry_safe(pt, next, &obj->pt_list, link) {
>>>> -            if (!timeline_fence_signaled(&pt->base))
>>>> -                    break;
>>>> -
>>>> -            list_del_init(&pt->link);
>>>> -            rb_erase(&pt->node, &obj->pt_tree);
>>>> -
>>>> -            /*
>>>> -             * A signal callback may release the last reference to this
>>>> -             * fence, causing it to be freed. That operation has to be
>>>> -             * last to avoid a use after free inside this loop, and must
>>>> -             * be after we remove the fence from the timeline in order to
>>>> -             * prevent deadlocking on timeline->lock inside
>>>> -             * timeline_fence_release().
>>>> -             */
>>>> -            dma_fence_signal_locked(&pt->base);
>>>> -    }
>>>> -
>>>> -    spin_unlock_irq(&obj->lock);
>>>> -}
>>>> -
>>>> -/**
>>>> - * sync_pt_create() - creates a sync pt
>>>> - * @obj:    parent sync_timeline
>>>> - * @value:  value of the fence
>>>> - *
>>>> - * Creates a new sync_pt (fence) as a child of @parent.  @size bytes will be
>>>> - * allocated allowing for implementation specific data to be kept after
>>>> - * the generic sync_timeline struct. Returns the sync_pt object or
>>>> - * NULL in case of error.
>>>> - */
>>>> -static struct sync_pt *sync_pt_create(struct sync_timeline *obj,
>>>> -                                  unsigned int value)
>>>> -{
>>>> -    struct sync_pt *pt;
>>>> -
>>>> -    pt = kzalloc(sizeof(*pt), GFP_KERNEL);
>>>> -    if (!pt)
>>>> -            return NULL;
>>>> -
>>>> -    sync_timeline_get(obj);
>>>> -    dma_fence_init(&pt->base, &timeline_fence_ops, &obj->lock,
>>>> -                   obj->context, value);
>>>> -    INIT_LIST_HEAD(&pt->link);
>>>> -
>>>> -    spin_lock_irq(&obj->lock);
>>>> -    if (!dma_fence_is_signaled_locked(&pt->base)) {
>>>> -            struct rb_node **p = &obj->pt_tree.rb_node;
>>>> -            struct rb_node *parent = NULL;
>>>> -
>>>> -            while (*p) {
>>>> -                    struct sync_pt *other;
>>>> -                    int cmp;
>>>> -
>>>> -                    parent = *p;
>>>> -                    other = rb_entry(parent, typeof(*pt), node);
>>>> -                    cmp = value - other->base.seqno;
>>>> -                    if (cmp > 0) {
>>>> -                            p = &parent->rb_right;
>>>> -                    } else if (cmp < 0) {
>>>> -                            p = &parent->rb_left;
>>>> -                    } else {
>>>> -                            if (dma_fence_get_rcu(&other->base)) {
>>>> -                                    sync_timeline_put(obj);
>>>> -                                    kfree(pt);
>>>> -                                    pt = other;
>>>> -                                    goto unlock;
>>>> -                            }
>>>> -                            p = &parent->rb_left;
>>>> -                    }
>>>> -            }
>>>> -            rb_link_node(&pt->node, parent, p);
>>>> -            rb_insert_color(&pt->node, &obj->pt_tree);
>>>> -
>>>> -            parent = rb_next(&pt->node);
>>>> -            list_add_tail(&pt->link,
>>>> -                          parent ? &rb_entry(parent, typeof(*pt), node)->link : &obj->pt_list);
>>>> -    }
>>>> -unlock:
>>>> -    spin_unlock_irq(&obj->lock);
>>>> -
>>>> -    return pt;
>>>> -}
>>>> -
>>>> -/*
>>>> - * *WARNING*
>>>> - *
>>>> - * improper use of this can result in deadlocking kernel drivers from userspace.
>>>> - */
>>>> -
>>>> -/* opening sw_sync create a new sync obj */
>>>> -static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
>>>> -{
>>>> -    struct sync_timeline *obj;
>>>> -    char task_comm[TASK_COMM_LEN];
>>>> -
>>>> -    get_task_comm(task_comm, current);
>>>> -
>>>> -    obj = sync_timeline_create(task_comm);
>>>> -    if (!obj)
>>>> -            return -ENOMEM;
>>>> -
>>>> -    file->private_data = obj;
>>>> -
>>>> -    return 0;
>>>> -}
>>>> -
>>>> -static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
>>>> -{
>>>> -    struct sync_timeline *obj = file->private_data;
>>>> -    struct sync_pt *pt, *next;
>>>> -
>>>> -    spin_lock_irq(&obj->lock);
>>>> -
>>>> -    list_for_each_entry_safe(pt, next, &obj->pt_list, link) {
>>>> -            dma_fence_set_error(&pt->base, -ENOENT);
>>>> -            dma_fence_signal_locked(&pt->base);
>>>> -    }
>>>> -
>>>> -    spin_unlock_irq(&obj->lock);
>>>> -
>>>> -    sync_timeline_put(obj);
>>>> -    return 0;
>>>> -}
>>>> -
>>>> -static long sw_sync_ioctl_create_fence(struct sync_timeline *obj,
>>>> -                                   unsigned long arg)
>>>> -{
>>>> -    int fd = get_unused_fd_flags(O_CLOEXEC);
>>>> -    int err;
>>>> -    struct sync_pt *pt;
>>>> -    struct sync_file *sync_file;
>>>> -    struct sw_sync_create_fence_data data;
>>>> -
>>>> -    if (fd < 0)
>>>> -            return fd;
>>>> -
>>>> -    if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
>>>> -            err = -EFAULT;
>>>> -            goto err;
>>>> -    }
>>>> -
>>>> -    pt = sync_pt_create(obj, data.value);
>>>> -    if (!pt) {
>>>> -            err = -ENOMEM;
>>>> -            goto err;
>>>> -    }
>>>> -
>>>> -    sync_file = sync_file_create(&pt->base);
>>>> -    dma_fence_put(&pt->base);
>>>> -    if (!sync_file) {
>>>> -            err = -ENOMEM;
>>>> -            goto err;
>>>> -    }
>>>> -
>>>> -    data.fence = fd;
>>>> -    if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
>>>> -            fput(sync_file->file);
>>>> -            err = -EFAULT;
>>>> -            goto err;
>>>> -    }
>>>> -
>>>> -    fd_install(fd, sync_file->file);
>>>> -
>>>> -    return 0;
>>>> -
>>>> -err:
>>>> -    put_unused_fd(fd);
>>>> -    return err;
>>>> -}
>>>> -
>>>> -static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg)
>>>> -{
>>>> -    u32 value;
>>>> -
>>>> -    if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
>>>> -            return -EFAULT;
>>>> -
>>>> -    while (value > INT_MAX)  {
>>>> -            sync_timeline_signal(obj, INT_MAX);
>>>> -            value -= INT_MAX;
>>>> -    }
>>>> -
>>>> -    sync_timeline_signal(obj, value);
>>>> -
>>>> -    return 0;
>>>> -}
>>>> -
>>>> -static long sw_sync_ioctl(struct file *file, unsigned int cmd,
>>>> -                      unsigned long arg)
>>>> -{
>>>> -    struct sync_timeline *obj = file->private_data;
>>>> -
>>>> -    switch (cmd) {
>>>> -    case SW_SYNC_IOC_CREATE_FENCE:
>>>> -            return sw_sync_ioctl_create_fence(obj, arg);
>>>> -
>>>> -    case SW_SYNC_IOC_INC:
>>>> -            return sw_sync_ioctl_inc(obj, arg);
>>>> -
>>>> -    default:
>>>> -            return -ENOTTY;
>>>> -    }
>>>> -}
>>>> -
>>>> -const struct file_operations sw_sync_debugfs_fops = {
>>>> -    .open           = sw_sync_debugfs_open,
>>>> -    .release        = sw_sync_debugfs_release,
>>>> -    .unlocked_ioctl = sw_sync_ioctl,
>>>> -    .compat_ioctl   = compat_ptr_ioctl,
>>>> -};
>>>> diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
>>>> deleted file mode 100644
>>>> index 101394f16930..000000000000
>>>> --- a/drivers/dma-buf/sync_debug.c
>>>> +++ /dev/null
>>>> @@ -1,190 +0,0 @@
>>>> -// SPDX-License-Identifier: GPL-2.0-only
>>>> -/*
>>>> - * Sync File validation framework and debug information
>>>> - *
>>>> - * Copyright (C) 2012 Google, Inc.
>>>> - */
>>>> -
>>>> -#include <linux/debugfs.h>
>>>> -#include "sync_debug.h"
>>>> -
>>>> -static struct dentry *dbgfs;
>>>> -
>>>> -static LIST_HEAD(sync_timeline_list_head);
>>>> -static DEFINE_SPINLOCK(sync_timeline_list_lock);
>>>> -static LIST_HEAD(sync_file_list_head);
>>>> -static DEFINE_SPINLOCK(sync_file_list_lock);
>>>> -
>>>> -void sync_timeline_debug_add(struct sync_timeline *obj)
>>>> -{
>>>> -    unsigned long flags;
>>>> -
>>>> -    spin_lock_irqsave(&sync_timeline_list_lock, flags);
>>>> -    list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
>>>> -    spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
>>>> -}
>>>> -
>>>> -void sync_timeline_debug_remove(struct sync_timeline *obj)
>>>> -{
>>>> -    unsigned long flags;
>>>> -
>>>> -    spin_lock_irqsave(&sync_timeline_list_lock, flags);
>>>> -    list_del(&obj->sync_timeline_list);
>>>> -    spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
>>>> -}
>>>> -
>>>> -void sync_file_debug_add(struct sync_file *sync_file)
>>>> -{
>>>> -    unsigned long flags;
>>>> -
>>>> -    spin_lock_irqsave(&sync_file_list_lock, flags);
>>>> -    list_add_tail(&sync_file->sync_file_list, &sync_file_list_head);
>>>> -    spin_unlock_irqrestore(&sync_file_list_lock, flags);
>>>> -}
>>>> -
>>>> -void sync_file_debug_remove(struct sync_file *sync_file)
>>>> -{
>>>> -    unsigned long flags;
>>>> -
>>>> -    spin_lock_irqsave(&sync_file_list_lock, flags);
>>>> -    list_del(&sync_file->sync_file_list);
>>>> -    spin_unlock_irqrestore(&sync_file_list_lock, flags);
>>>> -}
>>>> -
>>>> -static const char *sync_status_str(int status)
>>>> -{
>>>> -    if (status < 0)
>>>> -            return "error";
>>>> -
>>>> -    if (status > 0)
>>>> -            return "signaled";
>>>> -
>>>> -    return "active";
>>>> -}
>>>> -
>>>> -static void sync_print_fence(struct seq_file *s,
>>>> -                         struct dma_fence *fence, bool show)
>>>> -{
>>>> -    struct sync_timeline *parent = dma_fence_parent(fence);
>>>> -    int status;
>>>> -
>>>> -    status = dma_fence_get_status_locked(fence);
>>>> -
>>>> -    seq_printf(s, "  %s%sfence %s",
>>>> -               show ? parent->name : "",
>>>> -               show ? "_" : "",
>>>> -               sync_status_str(status));
>>>> -
>>>> -    if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags)) {
>>>> -            struct timespec64 ts64 =
>>>> -                    ktime_to_timespec64(fence->timestamp);
>>>> -
>>>> -            seq_printf(s, "@%lld.%09ld", (s64)ts64.tv_sec, ts64.tv_nsec);
>>>> -    }
>>>> -
>>>> -    if (fence->ops->timeline_value_str &&
>>>> -            fence->ops->fence_value_str) {
>>>> -            char value[64];
>>>> -            bool success;
>>>> -
>>>> -            fence->ops->fence_value_str(fence, value, sizeof(value));
>>>> -            success = strlen(value);
>>>> -
>>>> -            if (success) {
>>>> -                    seq_printf(s, ": %s", value);
>>>> -
>>>> -                    fence->ops->timeline_value_str(fence, value,
>>>> -                                                   sizeof(value));
>>>> -
>>>> -                    if (strlen(value))
>>>> -                            seq_printf(s, " / %s", value);
>>>> -            }
>>>> -    }
>>>> -
>>>> -    seq_putc(s, '\n');
>>>> -}
>>>> -
>>>> -static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
>>>> -{
>>>> -    struct list_head *pos;
>>>> -
>>>> -    seq_printf(s, "%s: %d\n", obj->name, obj->value);
>>>> -
>>>> -    spin_lock_irq(&obj->lock);
>>>> -    list_for_each(pos, &obj->pt_list) {
>>>> -            struct sync_pt *pt = container_of(pos, struct sync_pt, link);
>>>> -            sync_print_fence(s, &pt->base, false);
>>>> -    }
>>>> -    spin_unlock_irq(&obj->lock);
>>>> -}
>>>> -
>>>> -static void sync_print_sync_file(struct seq_file *s,
>>>> -                              struct sync_file *sync_file)
>>>> -{
>>>> -    char buf[128];
>>>> -    int i;
>>>> -
>>>> -    seq_printf(s, "[%p] %s: %s\n", sync_file,
>>>> -               sync_file_get_name(sync_file, buf, sizeof(buf)),
>>>> -               sync_status_str(dma_fence_get_status(sync_file->fence)));
>>>> -
>>>> -    if (dma_fence_is_array(sync_file->fence)) {
>>>> -            struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);
>>>> -
>>>> -            for (i = 0; i < array->num_fences; ++i)
>>>> -                    sync_print_fence(s, array->fences[i], true);
>>>> -    } else {
>>>> -            sync_print_fence(s, sync_file->fence, true);
>>>> -    }
>>>> -}
>>>> -
>>>> -static int sync_info_debugfs_show(struct seq_file *s, void *unused)
>>>> -{
>>>> -    struct list_head *pos;
>>>> -
>>>> -    seq_puts(s, "objs:\n--------------\n");
>>>> -
>>>> -    spin_lock_irq(&sync_timeline_list_lock);
>>>> -    list_for_each(pos, &sync_timeline_list_head) {
>>>> -            struct sync_timeline *obj =
>>>> -                    container_of(pos, struct sync_timeline,
>>>> -                                 sync_timeline_list);
>>>> -
>>>> -            sync_print_obj(s, obj);
>>>> -            seq_putc(s, '\n');
>>>> -    }
>>>> -    spin_unlock_irq(&sync_timeline_list_lock);
>>>> -
>>>> -    seq_puts(s, "fences:\n--------------\n");
>>>> -
>>>> -    spin_lock_irq(&sync_file_list_lock);
>>>> -    list_for_each(pos, &sync_file_list_head) {
>>>> -            struct sync_file *sync_file =
>>>> -                    container_of(pos, struct sync_file, sync_file_list);
>>>> -
>>>> -            sync_print_sync_file(s, sync_file);
>>>> -            seq_putc(s, '\n');
>>>> -    }
>>>> -    spin_unlock_irq(&sync_file_list_lock);
>>>> -    return 0;
>>>> -}
>>>> -
>>>> -DEFINE_SHOW_ATTRIBUTE(sync_info_debugfs);
>>>> -
>>>> -static __init int sync_debugfs_init(void)
>>>> -{
>>>> -    dbgfs = debugfs_create_dir("sync", NULL);
>>>> -
>>>> -    /*
>>>> -     * The debugfs files won't ever get removed and thus, there is
>>>> -     * no need to protect it against removal races. The use of
>>>> -     * debugfs_create_file_unsafe() is actually safe here.
>>>> -     */
>>>> -    debugfs_create_file_unsafe("info", 0444, dbgfs, NULL,
>>>> -                               &sync_info_debugfs_fops);
>>>> -    debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL,
>>>> -                               &sw_sync_debugfs_fops);
>>>> -
>>>> -    return 0;
>>>> -}
>>>> -late_initcall(sync_debugfs_init);
>>>> diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
>>>> deleted file mode 100644
>>>> index 6176e52ba2d7..000000000000
>>>> --- a/drivers/dma-buf/sync_debug.h
>>>> +++ /dev/null
>>>> @@ -1,72 +0,0 @@
>>>> -/*
>>>> - * Sync File validation framework and debug infomation
>>>> - *
>>>> - * Copyright (C) 2012 Google, Inc.
>>>> - *
>>>> - * This program is distributed in the hope that it will be useful,
>>>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>> - * GNU General Public License for more details.
>>>> - *
>>>> - */
>>>> -
>>>> -#ifndef _LINUX_SYNC_H
>>>> -#define _LINUX_SYNC_H
>>>> -
>>>> -#include <linux/list.h>
>>>> -#include <linux/rbtree.h>
>>>> -#include <linux/spinlock.h>
>>>> -#include <linux/dma-fence.h>
>>>> -
>>>> -#include <linux/sync_file.h>
>>>> -#include <uapi/linux/sync_file.h>
>>>> -
>>>> -/**
>>>> - * struct sync_timeline - sync object
>>>> - * @kref:           reference count on fence.
>>>> - * @name:           name of the sync_timeline. Useful for debugging
>>>> - * @lock:           lock protecting @pt_list and @value
>>>> - * @pt_tree:                rbtree of active (unsignaled/errored) sync_pts
>>>> - * @pt_list:                list of active (unsignaled/errored) sync_pts
>>>> - * @sync_timeline_list:     membership in global sync_timeline_list
>>>> - */
>>>> -struct sync_timeline {
>>>> -    struct kref             kref;
>>>> -    char                    name[32];
>>>> -
>>>> -    /* protected by lock */
>>>> -    u64                     context;
>>>> -    int                     value;
>>>> -
>>>> -    struct rb_root          pt_tree;
>>>> -    struct list_head        pt_list;
>>>> -    spinlock_t              lock;
>>>> -
>>>> -    struct list_head        sync_timeline_list;
>>>> -};
>>>> -
>>>> -static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence)
>>>> -{
>>>> -    return container_of(fence->lock, struct sync_timeline, lock);
>>>> -}
>>>> -
>>>> -/**
>>>> - * struct sync_pt - sync_pt object
>>>> - * @base: base fence object
>>>> - * @link: link on the sync timeline's list
>>>> - * @node: node in the sync timeline's tree
>>>> - */
>>>> -struct sync_pt {
>>>> -    struct dma_fence base;
>>>> -    struct list_head link;
>>>> -    struct rb_node node;
>>>> -};
>>>> -
>>>> -extern const struct file_operations sw_sync_debugfs_fops;
>>>> -
>>>> -void sync_timeline_debug_add(struct sync_timeline *obj);
>>>> -void sync_timeline_debug_remove(struct sync_timeline *obj);
>>>> -void sync_file_debug_add(struct sync_file *fence);
>>>> -void sync_file_debug_remove(struct sync_file *fence);
>>>> -
>>>> -#endif /* _LINUX_SYNC_H */
>>>> --
>>>> 2.25.1
>>>>
>



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