Merge branch 'uaccess.i915' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull i915 uaccess updates from Al Viro:
 "Low-hanging fruit in i915; there are several trickier followups, but
  that'll wait for the next cycle"

* 'uaccess.i915' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  i915:get_engines(): get rid of pointless access_ok()
  i915: alloc_oa_regs(): get rid of pointless access_ok()
  i915 compat ioctl(): just use drm_ioctl_kernel()
  i915: switch copy_perf_config_registers_or_number() to unsafe_put_user()
  i915: switch query_{topology,engine}_info() to copy_to_user()

Author: torvalds

drivers/gpu/drm/i915/gem/i915_gem_context.c

@@ -1921,11 +1921,6 @@ get_engines(struct i915_gem_context *ctx,
 	}
 
 	user = u64_to_user_ptr(args->value);
-	if (!access_ok(user, size)) {
-		err = -EFAULT;
-		goto err_free;
-	}
-
 	if (put_user(0, &user->extensions)) {
 		err = -EFAULT;
 		goto err_free;

drivers/gpu/drm/i915/i915_ioc32.c

@@ -47,20 +47,16 @@ static int compat_i915_getparam(struct file *file, unsigned int cmd,
 				unsigned long arg)
 {
 	struct drm_i915_getparam32 req32;
-	drm_i915_getparam_t __user *request;
+	struct drm_i915_getparam req;
 
 	if (copy_from_user(&req32, (void __user *)arg, sizeof(req32)))
 		return -EFAULT;
 
-	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(request, sizeof(*request)) ||
-	    __put_user(req32.param, &request->param) ||
-	    __put_user((void __user *)(unsigned long)req32.value,
-		       &request->value))
-		return -EFAULT;
+	req.param = req32.param;
+	req.value = compat_ptr(req32.value);
 
-	return drm_ioctl(file, DRM_IOCTL_I915_GETPARAM,
-			 (unsigned long)request);
+	return drm_ioctl_kernel(file, i915_getparam_ioctl, &req,
+				DRM_RENDER_ALLOW);
 }
 
 static drm_ioctl_compat_t *i915_compat_ioctls[] = {

drivers/gpu/drm/i915/i915_perf.c

@@ -3896,9 +3896,6 @@ static struct i915_oa_reg *alloc_oa_regs(struct i915_perf *perf,
 	if (!n_regs)
 		return NULL;
 
-	if (!access_ok(regs, n_regs * sizeof(u32) * 2))
-		return ERR_PTR(-EFAULT);
-
 	/* No is_valid function means we're not allowing any register to be programmed. */
 	GEM_BUG_ON(!is_valid);
 	if (!is_valid)

drivers/gpu/drm/i915/i915_query.c

@@ -25,10 +25,6 @@ static int copy_query_item(void *query_hdr, size_t query_sz,
 			   query_sz))
 		return -EFAULT;
 
-	if (!access_ok(u64_to_user_ptr(query_item->data_ptr),
-		       total_length))
-		return -EFAULT;
-
 	return 0;
 }
 
@@ -72,20 +68,20 @@ static int query_topology_info(struct drm_i915_private *dev_priv,
 	topo.eu_offset = slice_length + subslice_length;
 	topo.eu_stride = sseu->eu_stride;
 
-	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr),
+	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)),
+	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 +
+	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 +
+	if (copy_to_user(u64_to_user_ptr(query_item->data_ptr +
 					   sizeof(topo) +
 					   slice_length + subslice_length),
 			   sseu->eu_mask, eu_length))
@@ -131,14 +127,14 @@ query_engine_info(struct drm_i915_private *i915,
 		info.engine.engine_instance = engine->uabi_instance;
 		info.capabilities = engine->uabi_capabilities;
 
-		if (__copy_to_user(info_ptr, &info, sizeof(info)))
+		if (copy_to_user(info_ptr, &info, sizeof(info)))
 			return -EFAULT;
 
 		query.num_engines++;
 		info_ptr++;
 	}
 
-	if (__copy_to_user(query_ptr, &query, sizeof(query)))
+	if (copy_to_user(query_ptr, &query, sizeof(query)))
 		return -EFAULT;
 
 	return len;
@@ -158,10 +154,6 @@ static int can_copy_perf_config_registers_or_number(u32 user_n_regs,
 	if (user_n_regs < kernel_n_regs)
 		return -EINVAL;
 
-	if (!access_ok(u64_to_user_ptr(user_regs_ptr),
-		       2 * sizeof(u32) * kernel_n_regs))
-		return -EFAULT;
-
 	return 0;
 }
 
@@ -170,6 +162,7 @@ static int copy_perf_config_registers_or_number(const struct i915_oa_reg *kernel
 						u64 user_regs_ptr,
 						u32 *user_n_regs)
 {
+	u32 __user *p = u64_to_user_ptr(user_regs_ptr);
 	u32 r;
 
 	if (*user_n_regs == 0) {
@@ -179,25 +172,19 @@ static int copy_perf_config_registers_or_number(const struct i915_oa_reg *kernel
 
 	*user_n_regs = kernel_n_regs;
 
-	for (r = 0; r < kernel_n_regs; r++) {
-		u32 __user *user_reg_ptr =
-			u64_to_user_ptr(user_regs_ptr + sizeof(u32) * r * 2);
-		u32 __user *user_val_ptr =
-			u64_to_user_ptr(user_regs_ptr + sizeof(u32) * r * 2 +
-					sizeof(u32));
-		int ret;
-
-		ret = __put_user(i915_mmio_reg_offset(kernel_regs[r].addr),
-				 user_reg_ptr);
-		if (ret)
-			return -EFAULT;
+	if (!user_write_access_begin(p, 2 * sizeof(u32) * kernel_n_regs))
+		return -EFAULT;
 
-		ret = __put_user(kernel_regs[r].value, user_val_ptr);
-		if (ret)
-			return -EFAULT;
+	for (r = 0; r < kernel_n_regs; r++, p += 2) {
+		unsafe_put_user(i915_mmio_reg_offset(kernel_regs[r].addr),
+				p, Efault);
+		unsafe_put_user(kernel_regs[r].value, p + 1, Efault);
 	}
-
+	user_write_access_end();
 	return 0;
+Efault:
+	user_write_access_end();
+	return -EFAULT;
 }
 
 static int query_perf_config_data(struct drm_i915_private *i915,
@@ -233,10 +220,7 @@ static int query_perf_config_data(struct drm_i915_private *i915,
 		return -EINVAL;
 	}
 
-	if (!access_ok(user_query_config_ptr, total_size))
-		return -EFAULT;
-
-	if (__get_user(flags, &user_query_config_ptr->flags))
+	if (get_user(flags, &user_query_config_ptr->flags))
 		return -EFAULT;
 
 	if (flags != 0)
@@ -249,7 +233,7 @@ static int query_perf_config_data(struct drm_i915_private *i915,
 		BUILD_BUG_ON(sizeof(user_query_config_ptr->uuid) >= sizeof(uuid));
 
 		memset(&uuid, 0, sizeof(uuid));
-		if (__copy_from_user(uuid, user_query_config_ptr->uuid,
+		if (copy_from_user(uuid, user_query_config_ptr->uuid,
 				     sizeof(user_query_config_ptr->uuid)))
 			return -EFAULT;
 
@@ -263,16 +247,15 @@ static int query_perf_config_data(struct drm_i915_private *i915,
 		}
 		rcu_read_unlock();
 	} else {
-		if (__get_user(config_id, &user_query_config_ptr->config))
+		if (get_user(config_id, &user_query_config_ptr->config))
 			return -EFAULT;
 
 		oa_config = i915_perf_get_oa_config(perf, config_id);
 	}
 	if (!oa_config)
 		return -ENOENT;
 
-	if (__copy_from_user(&user_config, user_config_ptr,
-			     sizeof(user_config))) {
+	if (copy_from_user(&user_config, user_config_ptr, sizeof(user_config))) {
 		ret = -EFAULT;
 		goto out;
 	}
@@ -318,8 +301,7 @@ static int query_perf_config_data(struct drm_i915_private *i915,
 
 	memcpy(user_config.uuid, oa_config->uuid, sizeof(user_config.uuid));
 
-	if (__copy_to_user(user_config_ptr, &user_config,
-			   sizeof(user_config))) {
+	if (copy_to_user(user_config_ptr, &user_config, sizeof(user_config))) {
 		ret = -EFAULT;
 		goto out;
 	}

drivers/gpu/drm/i915/i915_reg.h

@@ -186,7 +186,7 @@ typedef struct {
 
 #define INVALID_MMIO_REG _MMIO(0)
 
-static inline u32 i915_mmio_reg_offset(i915_reg_t reg)
+static __always_inline u32 i915_mmio_reg_offset(i915_reg_t reg)
 {
 	return reg.reg;
 }