The ION begin_cpu_access and end_cpu_access functions use the
dma_sync_sg_for_cpu and dma_sync_sg_for_device APIs to perform cache
maintenance.
Currently it is possible to apply cache maintenance, via the
begin_cpu_access and end_cpu_access APIs, to ION buffers which are not
dma mapped.
The dma sync sg APIs should not be called on sg lists which have not been
dma mapped as this can result in cache maintenance being applied to the
wrong address. If an sg list has not been dma mapped then its dma_address
field has not been populated, some dma ops such as the swiotlb_dma_ops ops
use the dma_address field to calculate the address onto which to apply
cache maintenance.
Fix the ION begin_cpu_access and end_cpu_access functions to only apply
cache maintenance to buffers which have been dma mapped.
Fixes: 2a55e7b5e544 ("staging: android: ion: Call dma_map_sg for syncing and mapping")
Signed-off-by: Liam Mark <lmark(a)codeaurora.org>
---
drivers/staging/android/ion/ion.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index f480885e346b..e5df5272823d 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -214,6 +214,7 @@ struct ion_dma_buf_attachment {
struct device *dev;
struct sg_table *table;
struct list_head list;
+ bool dma_mapped;
};
static int ion_dma_buf_attach(struct dma_buf *dmabuf, struct device *dev,
@@ -235,6 +236,7 @@ static int ion_dma_buf_attach(struct dma_buf *dmabuf, struct device *dev,
a->table = table;
a->dev = dev;
+ a->dma_mapped = false;
INIT_LIST_HEAD(&a->list);
attachment->priv = a;
@@ -272,6 +274,7 @@ static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
direction))
return ERR_PTR(-ENOMEM);
+ a->dma_mapped = true;
return table;
}
@@ -279,7 +282,10 @@ static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment,
struct sg_table *table,
enum dma_data_direction direction)
{
+ struct ion_dma_buf_attachment *a = attachment->priv;
+
dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
+ a->dma_mapped = false;
}
static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
@@ -345,8 +351,9 @@ static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
mutex_lock(&buffer->lock);
list_for_each_entry(a, &buffer->attachments, list) {
- dma_sync_sg_for_cpu(a->dev, a->table->sgl, a->table->nents,
- direction);
+ if (a->dma_mapped)
+ dma_sync_sg_for_cpu(a->dev, a->table->sgl,
+ a->table->nents, direction);
}
mutex_unlock(&buffer->lock);
@@ -367,8 +374,9 @@ static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
mutex_lock(&buffer->lock);
list_for_each_entry(a, &buffer->attachments, list) {
- dma_sync_sg_for_device(a->dev, a->table->sgl, a->table->nents,
- direction);
+ if (a->dma_mapped)
+ dma_sync_sg_for_device(a->dev, a->table->sgl,
+ a->table->nents, direction);
}
mutex_unlock(&buffer->lock);
--
1.8.5.2
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
Since commit 204f672255c2 ("staging: android: ion: Use CMA APIs directly")
the CMA API is now used directly and therefore the allocated memory is no
longer automatically zeroed.
Explicitly zero CMA allocated memory to ensure that no data is exposed to
userspace.
Fixes: 204f672255c2 ("staging: android: ion: Use CMA APIs directly")
Signed-off-by: Liam Mark <lmark(a)codeaurora.org>
---
Changes in v2:
- Clean up the commit message.
- Add 'Fixes:'
Changes in v3:
- Add support for highmem pages
drivers/staging/android/ion/ion_cma_heap.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index 86196ffd2faf..fa3e4b7e0c9f 100644
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -21,6 +21,7 @@
#include <linux/err.h>
#include <linux/cma.h>
#include <linux/scatterlist.h>
+#include <linux/highmem.h>
#include "ion.h"
@@ -51,6 +52,22 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
if (!pages)
return -ENOMEM;
+ if (PageHighMem(pages)) {
+ unsigned long nr_clear_pages = nr_pages;
+ struct page *page = pages;
+
+ while (nr_clear_pages > 0) {
+ void *vaddr = kmap_atomic(page);
+
+ memset(vaddr, 0, PAGE_SIZE);
+ kunmap_atomic(vaddr);
+ page++;
+ nr_clear_pages--;
+ }
+ } else {
+ memset(page_address(pages), 0, size);
+ }
+
table = kmalloc(sizeof(*table), GFP_KERNEL);
if (!table)
goto err;
--
1.8.5.2
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
Since commit 204f672255c2 ("staging: android: ion: Use CMA APIs directly")
the CMA API is now used directly and therefore the allocated memory is no
longer automatically zeroed.
Explicitly zero CMA allocated memory to ensure that no data is exposed to
userspace.
Fixes: 204f672255c2 ("staging: android: ion: Use CMA APIs directly")
Signed-off-by: Liam Mark <lmark(a)codeaurora.org>
---
Changes in v2:
- Clean up the commit message.
- Add 'Fixes:'
drivers/staging/android/ion/ion_cma_heap.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index 86196ffd2faf..91a98785607a 100644
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -51,6 +51,8 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
if (!pages)
return -ENOMEM;
+ memset(page_address(pages), 0, size);
+
table = kmalloc(sizeof(*table), GFP_KERNEL);
if (!table)
goto err;
--
1.8.5.2
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
Since the CMA API is now used directly the allocated memory is no longer
automatically zeroed.
Explicitly zero CMA allocated memory to ensure that no data is exposed
to userspace.
Change-Id: I08e143707a0d31610821a7f16826c262bf3c1999
Signed-off-by: Liam Mark <lmark(a)codeaurora.org>
---
drivers/staging/android/ion/ion_cma_heap.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index 86196ff..91a9878 100644
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -51,6 +51,8 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
if (!pages)
return -ENOMEM;
+ memset(page_address(pages), 0, size);
+
table = kmalloc(sizeof(*table), GFP_KERNEL);
if (!table)
goto err;
--
1.8.5.2
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
Change reservation_object_get_fences_rcu to make the exclusive fence
pointer optional.
If not specified the exclusive fence is put into the fence array as
well.
This is helpful for a couple of cases where we need all fences in a
single array.
Signed-off-by: Christian König <christian.koenig(a)amd.com>
---
drivers/dma-buf/reservation.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index b759a569b7b8..461afa9febd4 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -374,8 +374,9 @@ EXPORT_SYMBOL(reservation_object_copy_fences);
* @pshared: the array of shared fence ptrs returned (array is krealloc'd to
* the required size, and must be freed by caller)
*
- * RETURNS
- * Zero or -errno
+ * Retrieve all fences from the reservation object. If the pointer for the
+ * exclusive fence is not specified the fence is put into the array of the
+ * shared fences as well. Returns either zero or -ENOMEM.
*/
int reservation_object_get_fences_rcu(struct reservation_object *obj,
struct dma_fence **pfence_excl,
@@ -389,8 +390,8 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
do {
struct reservation_object_list *fobj;
- unsigned seq;
- unsigned int i;
+ unsigned int i, seq;
+ size_t sz = 0;
shared_count = i = 0;
@@ -402,9 +403,14 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
goto unlock;
fobj = rcu_dereference(obj->fence);
- if (fobj) {
+ if (fobj)
+ sz += sizeof(*shared) * fobj->shared_max;
+
+ if (!pfence_excl && fence_excl)
+ sz += sizeof(*shared);
+
+ if (sz) {
struct dma_fence **nshared;
- size_t sz = sizeof(*shared) * fobj->shared_max;
nshared = krealloc(shared, sz,
GFP_NOWAIT | __GFP_NOWARN);
@@ -420,13 +426,19 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
break;
}
shared = nshared;
- shared_count = fobj->shared_count;
-
+ shared_count = fobj ? fobj->shared_count : 0;
for (i = 0; i < shared_count; ++i) {
shared[i] = rcu_dereference(fobj->shared[i]);
if (!dma_fence_get_rcu(shared[i]))
break;
}
+
+ if (!pfence_excl && fence_excl) {
+ shared[i] = fence_excl;
+ fence_excl = NULL;
+ ++i;
+ ++shared_count;
+ }
}
if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) {
@@ -448,7 +460,8 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
*pshared_count = shared_count;
*pshared = shared;
- *pfence_excl = fence_excl;
+ if (pfence_excl)
+ *pfence_excl = fence_excl;
return ret;
}
--
2.14.1
Change reservation_object_get_fences_rcu to make the exclusive fence
pointer optional.
If not specified the exclusive fence is put into the fence array as
well.
This is helpful for a couple of cases where we need all fences in a
single array.
Signed-off-by: Christian König <christian.koenig(a)amd.com>
---
drivers/dma-buf/reservation.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index b759a569b7b8..461afa9febd4 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -374,8 +374,9 @@ EXPORT_SYMBOL(reservation_object_copy_fences);
* @pshared: the array of shared fence ptrs returned (array is krealloc'd to
* the required size, and must be freed by caller)
*
- * RETURNS
- * Zero or -errno
+ * Retrieve all fences from the reservation object. If the pointer for the
+ * exclusive fence is not specified the fence is put into the array of the
+ * shared fences as well. Returns either zero or -ENOMEM.
*/
int reservation_object_get_fences_rcu(struct reservation_object *obj,
struct dma_fence **pfence_excl,
@@ -389,8 +390,8 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
do {
struct reservation_object_list *fobj;
- unsigned seq;
- unsigned int i;
+ unsigned int i, seq;
+ size_t sz = 0;
shared_count = i = 0;
@@ -402,9 +403,14 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
goto unlock;
fobj = rcu_dereference(obj->fence);
- if (fobj) {
+ if (fobj)
+ sz += sizeof(*shared) * fobj->shared_max;
+
+ if (!pfence_excl && fence_excl)
+ sz += sizeof(*shared);
+
+ if (sz) {
struct dma_fence **nshared;
- size_t sz = sizeof(*shared) * fobj->shared_max;
nshared = krealloc(shared, sz,
GFP_NOWAIT | __GFP_NOWARN);
@@ -420,13 +426,19 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
break;
}
shared = nshared;
- shared_count = fobj->shared_count;
-
+ shared_count = fobj ? fobj->shared_count : 0;
for (i = 0; i < shared_count; ++i) {
shared[i] = rcu_dereference(fobj->shared[i]);
if (!dma_fence_get_rcu(shared[i]))
break;
}
+
+ if (!pfence_excl && fence_excl) {
+ shared[i] = fence_excl;
+ fence_excl = NULL;
+ ++i;
+ ++shared_count;
+ }
}
if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) {
@@ -448,7 +460,8 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
*pshared_count = shared_count;
*pshared = shared;
- *pfence_excl = fence_excl;
+ if (pfence_excl)
+ *pfence_excl = fence_excl;
return ret;
}
--
2.14.1
Am 01.12.2017 um 01:23 schrieb Lyude Paul:
> I haven't gone to see where it started, but as of late a good number of
> pretty nasty deadlock issues have appeared with the kernel. Easy
> reproduction recipe on a laptop with i915/amdgpu prime with lockdep enabled:
>
> DRI_PRIME=1 glxinfo
Acked-by: Christian König <christian.koenig(a)amd.com>
Thanks for taking care of this,
Christian.
>
> Additionally, some more race conditions exist that I've managed to
> trigger with piglit and lockdep enabled after applying these patches:
>
> =============================
> WARNING: suspicious RCU usage
> 4.14.3Lyude-Test+ #2 Not tainted
> -----------------------------
> ./include/linux/reservation.h:216 suspicious rcu_dereference_protected() usage!
>
> other info that might help us debug this:
>
> rcu_scheduler_active = 2, debug_locks = 1
> 1 lock held by ext_image_dma_b/27451:
> #0: (reservation_ww_class_mutex){+.+.}, at: [<ffffffffa034f2ff>] ttm_bo_unref+0x9f/0x3c0 [ttm]
>
> stack backtrace:
> CPU: 0 PID: 27451 Comm: ext_image_dma_b Not tainted 4.14.3Lyude-Test+ #2
> Hardware name: HP HP ZBook 15 G4/8275, BIOS P70 Ver. 01.02 06/09/2017
> Call Trace:
> dump_stack+0x8e/0xce
> lockdep_rcu_suspicious+0xc5/0x100
> reservation_object_copy_fences+0x292/0x2b0
> ? ttm_bo_unref+0x9f/0x3c0 [ttm]
> ttm_bo_unref+0xbd/0x3c0 [ttm]
> amdgpu_bo_unref+0x2a/0x50 [amdgpu]
> amdgpu_gem_object_free+0x4b/0x50 [amdgpu]
> drm_gem_object_free+0x1f/0x40 [drm]
> drm_gem_object_put_unlocked+0x40/0xb0 [drm]
> drm_gem_object_handle_put_unlocked+0x6c/0xb0 [drm]
> drm_gem_object_release_handle+0x51/0x90 [drm]
> drm_gem_handle_delete+0x5e/0x90 [drm]
> ? drm_gem_handle_create+0x40/0x40 [drm]
> drm_gem_close_ioctl+0x20/0x30 [drm]
> drm_ioctl_kernel+0x5d/0xb0 [drm]
> drm_ioctl+0x2f7/0x3b0 [drm]
> ? drm_gem_handle_create+0x40/0x40 [drm]
> ? trace_hardirqs_on_caller+0xf4/0x190
> ? trace_hardirqs_on+0xd/0x10
> amdgpu_drm_ioctl+0x4f/0x90 [amdgpu]
> do_vfs_ioctl+0x93/0x670
> ? __fget+0x108/0x1f0
> SyS_ioctl+0x79/0x90
> entry_SYSCALL_64_fastpath+0x23/0xc2
>
> I've also added the relevant fixes for the issue mentioned above.
>
> Christian König (3):
> drm/ttm: fix ttm_bo_cleanup_refs_or_queue once more
> dma-buf: make reservation_object_copy_fences rcu save
> drm/amdgpu: reserve root PD while releasing it
>
> Michel Dänzer (1):
> drm/ttm: Always and only destroy bo->ttm_resv in ttm_bo_release_list
>
> drivers/dma-buf/reservation.c | 56 +++++++++++++++++++++++++---------
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 13 ++++++--
> drivers/gpu/drm/ttm/ttm_bo.c | 43 +++++++++++++-------------
> 3 files changed, 74 insertions(+), 38 deletions(-)
>
> --
> 2.14.3
>
> _______________________________________________
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> amd-gfx(a)lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx