This patch limits the size of total memory that can be requested in a
single allocation from the system heap. This would prevent a
buggy/malicious client from depleting system memory by requesting for an
extremely large allocation which might destabilize the system.
The limit is set to half the size of the device's total RAM which is the
same as what was set by the deprecated ION system heap.
Signed-off-by: Hridya Valsaraju <hridya(a)google.com>
---
drivers/dma-buf/heaps/system_heap.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index b7fbce66bcc0..099f5a8304b4 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -371,6 +371,12 @@ static struct dma_buf *system_heap_do_allocate(struct dma_heap *heap,
struct page *page, *tmp_page;
int i, ret = -ENOMEM;
+ if (len / PAGE_SIZE > totalram_pages() / 2) {
+ pr_err("pid %d requested too large an allocation(size %lu) from system heap\n",
+ current->pid, len);
+ return ERR_PTR(ret);
+ }
+
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (!buffer)
return ERR_PTR(-ENOMEM);
--
2.32.0.432.gabb21c7263-goog
On 8/9/21 5:22 AM, Gal Pressman wrote:
> Fix a few typos in the documentation:
> - Remove an extraneous 'or'
> - 'unpins' -> 'unpin'
> - 'braket' -> 'bracket'
> - 'mappinsg' -> 'mappings'
> - 'fullfills' -> 'fulfills'
>
> Signed-off-by: Gal Pressman <galpress(a)amazon.com>
Reviewed-by: Randy Dunlap <rdunlap(a)infradead.org>
Thanks.
> ---
> include/linux/dma-buf.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> index efdc56b9d95f..772403352767 100644
> --- a/include/linux/dma-buf.h
> +++ b/include/linux/dma-buf.h
> @@ -54,7 +54,7 @@ struct dma_buf_ops {
> * device), and otherwise need to fail the attach operation.
> *
> * The exporter should also in general check whether the current
> - * allocation fullfills the DMA constraints of the new device. If this
> + * allocation fulfills the DMA constraints of the new device. If this
> * is not the case, and the allocation cannot be moved, it should also
> * fail the attach operation.
> *
> @@ -146,7 +146,7 @@ struct dma_buf_ops {
> *
> * Returns:
> *
> - * A &sg_table scatter list of or the backing storage of the DMA buffer,
> + * A &sg_table scatter list of the backing storage of the DMA buffer,
> * already mapped into the device address space of the &device attached
> * with the provided &dma_buf_attachment. The addresses and lengths in
> * the scatter list are PAGE_SIZE aligned.
> @@ -168,7 +168,7 @@ struct dma_buf_ops {
> *
> * This is called by dma_buf_unmap_attachment() and should unmap and
> * release the &sg_table allocated in @map_dma_buf, and it is mandatory.
> - * For static dma_buf handling this might also unpins the backing
> + * For static dma_buf handling this might also unpin the backing
> * storage if this is the last mapping of the DMA buffer.
> */
> void (*unmap_dma_buf)(struct dma_buf_attachment *,
> @@ -237,7 +237,7 @@ struct dma_buf_ops {
> * This callback is used by the dma_buf_mmap() function
> *
> * Note that the mapping needs to be incoherent, userspace is expected
> - * to braket CPU access using the DMA_BUF_IOCTL_SYNC interface.
> + * to bracket CPU access using the DMA_BUF_IOCTL_SYNC interface.
> *
> * Because dma-buf buffers have invariant size over their lifetime, the
> * dma-buf core checks whether a vma is too large and rejects such
> @@ -464,7 +464,7 @@ static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf)
>
> /**
> * dma_buf_attachment_is_dynamic - check if a DMA-buf attachment uses dynamic
> - * mappinsg
> + * mappings
> * @attach: the DMA-buf attachment to check
> *
> * Returns true if a DMA-buf importer wants to call the map/unmap functions with
>
--
~Randy
On Mon, Aug 02, 2021 at 06:59:57PM +0800, Desmond Cheong Zhi Xi wrote:
> In drm_is_current_master_locked, accessing drm_file.master should be
> protected by either drm_file.master_lookup_lock or
> drm_device.master_mutex. This was previously awkward to assert with
> lockdep.
>
> Following patch ("locking/lockdep: Provide lockdep_assert{,_once}()
> helpers"), this assertion is now convenient. So we add in the
> assertion and explain this lock design in the kerneldoc.
>
> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx(a)gmail.com>
> Acked-by: Boqun Feng <boqun.feng(a)gmail.com>
> Acked-by: Waiman Long <longman(a)redhat.com>
> Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Both patches pushed to drm-misc-next, thanks.
-Daniel
> ---
> drivers/gpu/drm/drm_auth.c | 6 +++---
> include/drm/drm_file.h | 4 ++++
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
> index 9c24b8cc8e36..6f4d7ff23c80 100644
> --- a/drivers/gpu/drm/drm_auth.c
> +++ b/drivers/gpu/drm/drm_auth.c
> @@ -63,9 +63,9 @@
>
> static bool drm_is_current_master_locked(struct drm_file *fpriv)
> {
> - /* Either drm_device.master_mutex or drm_file.master_lookup_lock
> - * should be held here.
> - */
> + lockdep_assert_once(lockdep_is_held(&fpriv->master_lookup_lock) ||
> + lockdep_is_held(&fpriv->minor->dev->master_mutex));
> +
> return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master;
> }
>
> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> index 726cfe0ff5f5..a3acb7ac3550 100644
> --- a/include/drm/drm_file.h
> +++ b/include/drm/drm_file.h
> @@ -233,6 +233,10 @@ struct drm_file {
> * this only matches &drm_device.master if the master is the currently
> * active one.
> *
> + * To update @master, both &drm_device.master_mutex and
> + * @master_lookup_lock need to be held, therefore holding either of
> + * them is safe and enough for the read side.
> + *
> * When dereferencing this pointer, either hold struct
> * &drm_device.master_mutex for the duration of the pointer's use, or
> * use drm_file_get_master() if struct &drm_device.master_mutex is not
> --
> 2.25.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
Am 31.07.21 um 10:13 schrieb Tuo Li:
> The variable ttm is assigned to the variable gtt, and the variable gtt
> is checked in:
> if (gtt && gtt->userptr)
>
> This indicates that both ttm and gtt can be NULL.
> If so, a null-pointer dereference will occur:
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
>
> Also, some null-pointer dereferences will occur in the function
> ttm_pool_free() which is called in:
> return ttm_pool_free(&adev->mman.bdev.pool, ttm);
>
> To fix these possible null-pointer dereferences, the function returns
> when ttm is NULL.
NAK, same as with the other patch.
The ttm object is mandatory, asking the driver to destroy a ttm object
which doesn't exists makes no sense at all and is a bug in the upper layer.
The NULL check is just a leftover from when the gtt and ttm objects
where distinct. Please remove that one instead.
BTW: Bonus points for changing the (void *) cast into a much cleaner
container_of().
Thanks,
Christian.
>
> Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo(a)gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 3a55f08e00e1..0216ca085f11 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1146,7 +1146,10 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
> struct amdgpu_device *adev;
>
> - if (gtt && gtt->userptr) {
> + if (ttm == NULL)
> + return;
> +
> + if (gtt->userptr) {
> amdgpu_ttm_tt_set_user_pages(ttm, NULL);
> kfree(ttm->sg);
> ttm->sg = NULL;
Am 31.07.21 um 10:04 schrieb Tuo Li:
> The variable ttm is assigned to the variable gtt, and the variable gtt
> is checked in:
> if (gtt && gtt->userptr)
>
> This indicates that both ttm and gtt can be NULL.
> If so, a null-pointer dereference will occur:
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
>
> Also, some null-pointer dereferences will occur in the function
> ttm_pool_alloc() which is called in:
> return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
>
> To fix these possible null-pointer dereferences, the function returns
> -EINVAL when ttm is NULL.
NAK, the NULL test is just a leftover from when the objects where distinct.
Please remove the NULL test instead.
Regards,
Christian.
>
> Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo(a)gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 3a55f08e00e1..80440f799c09 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1120,8 +1120,11 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
> struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>
> + if (ttm == NULL)
> + return -EINVAL;
> +
> /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
> - if (gtt && gtt->userptr) {
> + if (gtt->userptr) {
> ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> if (!ttm->sg)
> return -ENOMEM;
Entirely unused.
Signed-off-by: Christian König <christian.koenig(a)amd.com>
---
drivers/dma-buf/Makefile | 2 +-
drivers/dma-buf/seqno-fence.c | 71 ----------------------
include/linux/seqno-fence.h | 109 ----------------------------------
3 files changed, 1 insertion(+), 181 deletions(-)
delete mode 100644 drivers/dma-buf/seqno-fence.c
delete mode 100644 include/linux/seqno-fence.h
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 40d81f23cacf..1ef021273a06 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
- dma-resv.o seqno-fence.o
+ dma-resv.o
obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o
obj-$(CONFIG_DMABUF_HEAPS) += heaps/
obj-$(CONFIG_SYNC_FILE) += sync_file.o
diff --git a/drivers/dma-buf/seqno-fence.c b/drivers/dma-buf/seqno-fence.c
deleted file mode 100644
index bfe14e94c488..000000000000
--- a/drivers/dma-buf/seqno-fence.c
+++ /dev/null
@@ -1,71 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012-2014 Canonical Ltd
- * Authors:
- * Rob Clark <robdclark(a)gmail.com>
- * Maarten Lankhorst <maarten.lankhorst(a)canonical.com>
- */
-
-#include <linux/slab.h>
-#include <linux/export.h>
-#include <linux/seqno-fence.h>
-
-static const char *seqno_fence_get_driver_name(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->get_driver_name(fence);
-}
-
-static const char *seqno_fence_get_timeline_name(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->get_timeline_name(fence);
-}
-
-static bool seqno_enable_signaling(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->enable_signaling(fence);
-}
-
-static bool seqno_signaled(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->signaled && seqno_fence->ops->signaled(fence);
-}
-
-static void seqno_release(struct dma_fence *fence)
-{
- struct seqno_fence *f = to_seqno_fence(fence);
-
- dma_buf_put(f->sync_buf);
- if (f->ops->release)
- f->ops->release(fence);
- else
- dma_fence_free(&f->base);
-}
-
-static signed long seqno_wait(struct dma_fence *fence, bool intr,
- signed long timeout)
-{
- struct seqno_fence *f = to_seqno_fence(fence);
-
- return f->ops->wait(fence, intr, timeout);
-}
-
-const struct dma_fence_ops seqno_fence_ops = {
- .get_driver_name = seqno_fence_get_driver_name,
- .get_timeline_name = seqno_fence_get_timeline_name,
- .enable_signaling = seqno_enable_signaling,
- .signaled = seqno_signaled,
- .wait = seqno_wait,
- .release = seqno_release,
-};
-EXPORT_SYMBOL(seqno_fence_ops);
diff --git a/include/linux/seqno-fence.h b/include/linux/seqno-fence.h
deleted file mode 100644
index 3cca2b8fac43..000000000000
--- a/include/linux/seqno-fence.h
+++ /dev/null
@@ -1,109 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012 Canonical Ltd
- * Authors:
- * Rob Clark <robdclark(a)gmail.com>
- * Maarten Lankhorst <maarten.lankhorst(a)canonical.com>
- */
-
-#ifndef __LINUX_SEQNO_FENCE_H
-#define __LINUX_SEQNO_FENCE_H
-
-#include <linux/dma-fence.h>
-#include <linux/dma-buf.h>
-
-enum seqno_fence_condition {
- SEQNO_FENCE_WAIT_GEQUAL,
- SEQNO_FENCE_WAIT_NONZERO
-};
-
-struct seqno_fence {
- struct dma_fence base;
-
- const struct dma_fence_ops *ops;
- struct dma_buf *sync_buf;
- uint32_t seqno_ofs;
- enum seqno_fence_condition condition;
-};
-
-extern const struct dma_fence_ops seqno_fence_ops;
-
-/**
- * to_seqno_fence - cast a fence to a seqno_fence
- * @fence: fence to cast to a seqno_fence
- *
- * Returns NULL if the fence is not a seqno_fence,
- * or the seqno_fence otherwise.
- */
-static inline struct seqno_fence *
-to_seqno_fence(struct dma_fence *fence)
-{
- if (fence->ops != &seqno_fence_ops)
- return NULL;
- return container_of(fence, struct seqno_fence, base);
-}
-
-/**
- * seqno_fence_init - initialize a seqno fence
- * @fence: seqno_fence to initialize
- * @lock: pointer to spinlock to use for fence
- * @sync_buf: buffer containing the memory location to signal on
- * @context: the execution context this fence is a part of
- * @seqno_ofs: the offset within @sync_buf
- * @seqno: the sequence # to signal on
- * @cond: fence wait condition
- * @ops: the fence_ops for operations on this seqno fence
- *
- * This function initializes a struct seqno_fence with passed parameters,
- * and takes a reference on sync_buf which is released on fence destruction.
- *
- * A seqno_fence is a dma_fence which can complete in software when
- * enable_signaling is called, but it also completes when
- * (s32)((sync_buf)[seqno_ofs] - seqno) >= 0 is true
- *
- * The seqno_fence will take a refcount on the sync_buf until it's
- * destroyed, but actual lifetime of sync_buf may be longer if one of the
- * callers take a reference to it.
- *
- * Certain hardware have instructions to insert this type of wait condition
- * in the command stream, so no intervention from software would be needed.
- * This type of fence can be destroyed before completed, however a reference
- * on the sync_buf dma-buf can be taken. It is encouraged to re-use the same
- * dma-buf for sync_buf, since mapping or unmapping the sync_buf to the
- * device's vm can be expensive.
- *
- * It is recommended for creators of seqno_fence to call dma_fence_signal()
- * before destruction. This will prevent possible issues from wraparound at
- * time of issue vs time of check, since users can check dma_fence_is_signaled()
- * before submitting instructions for the hardware to wait on the fence.
- * However, when ops.enable_signaling is not called, it doesn't have to be
- * done as soon as possible, just before there's any real danger of seqno
- * wraparound.
- */
-static inline void
-seqno_fence_init(struct seqno_fence *fence, spinlock_t *lock,
- struct dma_buf *sync_buf, uint32_t context,
- uint32_t seqno_ofs, uint32_t seqno,
- enum seqno_fence_condition cond,
- const struct dma_fence_ops *ops)
-{
- BUG_ON(!fence || !sync_buf || !ops);
- BUG_ON(!ops->wait || !ops->enable_signaling ||
- !ops->get_driver_name || !ops->get_timeline_name);
-
- /*
- * ops is used in dma_fence_init for get_driver_name, so needs to be
- * initialized first
- */
- fence->ops = ops;
- dma_fence_init(&fence->base, &seqno_fence_ops, lock, context, seqno);
- get_dma_buf(sync_buf);
- fence->sync_buf = sync_buf;
- fence->seqno_ofs = seqno_ofs;
- fence->condition = cond;
-}
-
-#endif /* __LINUX_SEQNO_FENCE_H */
--
2.25.1