[PATCH 3/3] dma-buf: nuke SW_SYNC debugfs files
Daniel Vetter
daniel at ffwll.ch
Thu Jul 29 12:31:28 UTC 2021
On Thu, Jul 29, 2021 at 2:25 PM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 29.07.21 um 13:59 schrieb Daniel Vetter:
> > On Thu, Jul 29, 2021 at 12:21 PM Christian König
> > <ckoenig.leichtzumerken at gmail.com> wrote:
> >> 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.
> > I think CrOS is using it to shovel buffers around between process, as
> > a convenient allocator for sw rendering dma-buf. But they don't use
> > the dma-fence part afaik.
> >
> > We can't taint in vgem fences though because our CI reboots on any
> > taint (or lockdep splat) and a few others, so that would make it
> > useless for testing. Maybe we should have the fence part of vgem
> > behind a separate Kconfig?
>
> And then making it depend on CONFIG_BROKEN? :)
>
> But more serious, that it probably makes sense.
>
> Can you take care of that? I'm not that familiar with the vgem code base.
Iirc CONFIG_BROKEN is stuff you can't even enable at all. So not an
option. Just a separate Kconfig for the fence ioctls.
> >> 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.
> > Hm right I forgot that you can't guarantee that it will complete, ever :-)
> >
> > Otoh I'm not sure the unconditional taint is very nice to the android
> > folks, they'll probably just patch it out and then it looses it
> > usefulness. taint on timeout otoh makes sure that normally it's not
> > hit, but anytime you die in userptr or shrinker there will be a taint
> > before anything else (since 10s is much shorter than the "stuck in
> > non-interruptible sleep" warning).
>
> And then you don't hit the timeout during test but only in production,
> e.g. not good enough either.
>
> And yes I know that this is not really nice. But since this depends on
> debugfs and Android usually disables debugfs AFAIK, they probably have
> that heavily patched already anyway.
>
> I just want to make sure that nobody else has the brilliant idea to
> enable this and build an userspace stack on top of a fundamentally
> broken approach.
>
> Alternative is to add a dependency to CONFIG_BROKEN.
Yeah CONFIG_BROKEN isn't a thing either that is useful. It's for code
that doesn't even compile (or soon will stop compiling) because build
testers never set that. And I think you have to patch the source to
even be able to get at it. So about equivalent to removal, except less
honest :-)
Tbh I'd just leave things as-is. Occasionally we have mildly terrible
stuff in-tree ...
-Daniel
> Christian.
>
> > -Daniel
> >
> >> 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
> >>>>>>
> >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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