linux/drivers/gpu/drm/i915/i915_query.c
Daniele Ceraolo Spurio eef4670ead drm/i915/query: fix subslice length
We dump the info as an array of u8, so we want to know the length
in number of bytes. Current code is still safe because the
variable we use BITS_PER_TYPE on is a u8.

Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181109004013.34394-1-daniele.ceraolospurio@intel.com
2018-11-09 11:42:00 -08:00

132 lines
3.4 KiB
C

/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2018 Intel Corporation
*/
#include <linux/nospec.h>
#include "i915_drv.h"
#include "i915_query.h"
#include <uapi/drm/i915_drm.h>
static int query_topology_info(struct drm_i915_private *dev_priv,
struct drm_i915_query_item *query_item)
{
const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
struct drm_i915_query_topology_info topo;
u32 slice_length, subslice_length, eu_length, total_length;
if (query_item->flags != 0)
return -EINVAL;
if (sseu->max_slices == 0)
return -ENODEV;
BUILD_BUG_ON(sizeof(u8) != sizeof(sseu->slice_mask));
slice_length = sizeof(sseu->slice_mask);
subslice_length = sseu->max_slices *
DIV_ROUND_UP(sseu->max_subslices, BITS_PER_BYTE);
eu_length = sseu->max_slices * sseu->max_subslices *
DIV_ROUND_UP(sseu->max_eus_per_subslice, BITS_PER_BYTE);
total_length = sizeof(topo) + slice_length + subslice_length + eu_length;
if (query_item->length == 0)
return total_length;
if (query_item->length < total_length)
return -EINVAL;
if (copy_from_user(&topo, u64_to_user_ptr(query_item->data_ptr),
sizeof(topo)))
return -EFAULT;
if (topo.flags != 0)
return -EINVAL;
if (!access_ok(VERIFY_WRITE, u64_to_user_ptr(query_item->data_ptr),
total_length))
return -EFAULT;
memset(&topo, 0, sizeof(topo));
topo.max_slices = sseu->max_slices;
topo.max_subslices = sseu->max_subslices;
topo.max_eus_per_subslice = sseu->max_eus_per_subslice;
topo.subslice_offset = slice_length;
topo.subslice_stride = DIV_ROUND_UP(sseu->max_subslices, BITS_PER_BYTE);
topo.eu_offset = slice_length + subslice_length;
topo.eu_stride =
DIV_ROUND_UP(sseu->max_eus_per_subslice, BITS_PER_BYTE);
if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr),
&topo, sizeof(topo)))
return -EFAULT;
if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr + sizeof(topo)),
&sseu->slice_mask, slice_length))
return -EFAULT;
if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
sizeof(topo) + slice_length),
sseu->subslice_mask, subslice_length))
return -EFAULT;
if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
sizeof(topo) +
slice_length + subslice_length),
sseu->eu_mask, eu_length))
return -EFAULT;
return total_length;
}
static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
struct drm_i915_query_item *query_item) = {
query_topology_info,
};
int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct drm_i915_query *args = data;
struct drm_i915_query_item __user *user_item_ptr =
u64_to_user_ptr(args->items_ptr);
u32 i;
if (args->flags != 0)
return -EINVAL;
for (i = 0; i < args->num_items; i++, user_item_ptr++) {
struct drm_i915_query_item item;
unsigned long func_idx;
int ret;
if (copy_from_user(&item, user_item_ptr, sizeof(item)))
return -EFAULT;
if (item.query_id == 0)
return -EINVAL;
if (overflows_type(item.query_id - 1, unsigned long))
return -EINVAL;
func_idx = item.query_id - 1;
ret = -EINVAL;
if (func_idx < ARRAY_SIZE(i915_query_funcs)) {
func_idx = array_index_nospec(func_idx,
ARRAY_SIZE(i915_query_funcs));
ret = i915_query_funcs[func_idx](dev_priv, &item);
}
/* Only write the length back to userspace if they differ. */
if (ret != item.length && put_user(ret, &user_item_ptr->length))
return -EFAULT;
}
return 0;
}