Merge branch 'for-6.10/hid-bpf' into for-linus

- updates to HID-BPF infrastructure, with some of the specific
  fixes (e.g. rdesc fixups) abstracted into separate BPF programs
  for consumption by libevdev/udev-hid-bpf (Benjamin Tissoires)

Author: Jiri Kosina

Documentation/hid/hid-bpf.rst

@@ -179,7 +179,7 @@ Available API that can be used in syscall HID-BPF programs:
 -----------------------------------------------------------
 
 .. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c
-   :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_allocate_context hid_bpf_release_context
+   :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_input_report hid_bpf_allocate_context hid_bpf_release_context
 
 General overview of a HID-BPF program
 =====================================

drivers/hid/bpf/hid_bpf_dispatch.c

@@ -143,48 +143,6 @@ u8 *call_hid_bpf_rdesc_fixup(struct hid_device *hdev, u8 *rdesc, unsigned int *s
 }
 EXPORT_SYMBOL_GPL(call_hid_bpf_rdesc_fixup);
 
-/* Disables missing prototype warnings */
-__bpf_kfunc_start_defs();
-
-/**
- * hid_bpf_get_data - Get the kernel memory pointer associated with the context @ctx
- *
- * @ctx: The HID-BPF context
- * @offset: The offset within the memory
- * @rdwr_buf_size: the const size of the buffer
- *
- * @returns %NULL on error, an %__u8 memory pointer on success
- */
-__bpf_kfunc __u8 *
-hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr_buf_size)
-{
-	struct hid_bpf_ctx_kern *ctx_kern;
-
-	if (!ctx)
-		return NULL;
-
-	ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx);
-
-	if (rdwr_buf_size + offset > ctx->allocated_size)
-		return NULL;
-
-	return ctx_kern->data + offset;
-}
-__bpf_kfunc_end_defs();
-
-/*
- * The following set contains all functions we agree BPF programs
- * can use.
- */
-BTF_KFUNCS_START(hid_bpf_kfunc_ids)
-BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
-BTF_KFUNCS_END(hid_bpf_kfunc_ids)
-
-static const struct btf_kfunc_id_set hid_bpf_kfunc_set = {
-	.owner = THIS_MODULE,
-	.set   = &hid_bpf_kfunc_ids,
-};
-
 static int device_match_id(struct device *dev, const void *id)
 {
 	struct hid_device *hdev = to_hid_device(dev);
@@ -281,6 +239,31 @@ static int do_hid_bpf_attach_prog(struct hid_device *hdev, int prog_fd, struct b
 /* Disables missing prototype warnings */
 __bpf_kfunc_start_defs();
 
+/**
+ * hid_bpf_get_data - Get the kernel memory pointer associated with the context @ctx
+ *
+ * @ctx: The HID-BPF context
+ * @offset: The offset within the memory
+ * @rdwr_buf_size: the const size of the buffer
+ *
+ * @returns %NULL on error, an %__u8 memory pointer on success
+ */
+__bpf_kfunc __u8 *
+hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr_buf_size)
+{
+	struct hid_bpf_ctx_kern *ctx_kern;
+
+	if (!ctx)
+		return NULL;
+
+	ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx);
+
+	if (rdwr_buf_size + offset > ctx->allocated_size)
+		return NULL;
+
+	return ctx_kern->data + offset;
+}
+
 /**
  * hid_bpf_attach_prog - Attach the given @prog_fd to the given HID device
  *
@@ -393,6 +376,46 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
 	put_device(&hid->dev);
 }
 
+static int
+__hid_bpf_hw_check_params(struct hid_bpf_ctx *ctx, __u8 *buf, size_t *buf__sz,
+			  enum hid_report_type rtype)
+{
+	struct hid_report_enum *report_enum;
+	struct hid_report *report;
+	struct hid_device *hdev;
+	u32 report_len;
+
+	/* check arguments */
+	if (!ctx || !hid_bpf_ops || !buf)
+		return -EINVAL;
+
+	switch (rtype) {
+	case HID_INPUT_REPORT:
+	case HID_OUTPUT_REPORT:
+	case HID_FEATURE_REPORT:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (*buf__sz < 1)
+		return -EINVAL;
+
+	hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+	report_enum = hdev->report_enum + rtype;
+	report = hid_bpf_ops->hid_get_report(report_enum, buf);
+	if (!report)
+		return -EINVAL;
+
+	report_len = hid_report_len(report);
+
+	if (*buf__sz > report_len)
+		*buf__sz = report_len;
+
+	return 0;
+}
+
 /**
  * hid_bpf_hw_request - Communicate with a HID device
  *
@@ -409,24 +432,14 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
 		   enum hid_report_type rtype, enum hid_class_request reqtype)
 {
 	struct hid_device *hdev;
-	struct hid_report *report;
-	struct hid_report_enum *report_enum;
+	size_t size = buf__sz;
 	u8 *dma_data;
-	u32 report_len;
 	int ret;
 
 	/* check arguments */
-	if (!ctx || !hid_bpf_ops || !buf)
-		return -EINVAL;
-
-	switch (rtype) {
-	case HID_INPUT_REPORT:
-	case HID_OUTPUT_REPORT:
-	case HID_FEATURE_REPORT:
-		break;
-	default:
-		return -EINVAL;
-	}
+	ret = __hid_bpf_hw_check_params(ctx, buf, &size, rtype);
+	if (ret)
+		return ret;
 
 	switch (reqtype) {
 	case HID_REQ_GET_REPORT:
@@ -440,29 +453,16 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
 		return -EINVAL;
 	}
 
-	if (buf__sz < 1)
-		return -EINVAL;
-
 	hdev = (struct hid_device *)ctx->hid; /* discard const */
 
-	report_enum = hdev->report_enum + rtype;
-	report = hid_bpf_ops->hid_get_report(report_enum, buf);
-	if (!report)
-		return -EINVAL;
-
-	report_len = hid_report_len(report);
-
-	if (buf__sz > report_len)
-		buf__sz = report_len;
-
-	dma_data = kmemdup(buf, buf__sz, GFP_KERNEL);
+	dma_data = kmemdup(buf, size, GFP_KERNEL);
 	if (!dma_data)
 		return -ENOMEM;
 
 	ret = hid_bpf_ops->hid_hw_raw_request(hdev,
 					      dma_data[0],
 					      dma_data,
-					      buf__sz,
+					      size,
 					      rtype,
 					      reqtype);
 
@@ -472,8 +472,90 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
 	kfree(dma_data);
 	return ret;
 }
+
+/**
+ * hid_bpf_hw_output_report - Send an output report to a HID device
+ *
+ * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
+ * @buf: a %PTR_TO_MEM buffer
+ * @buf__sz: the size of the data to transfer
+ *
+ * Returns the number of bytes transferred on success, a negative error code otherwise.
+ */
+__bpf_kfunc int
+hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz)
+{
+	struct hid_device *hdev;
+	size_t size = buf__sz;
+	u8 *dma_data;
+	int ret;
+
+	/* check arguments */
+	ret = __hid_bpf_hw_check_params(ctx, buf, &size, HID_OUTPUT_REPORT);
+	if (ret)
+		return ret;
+
+	hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+	dma_data = kmemdup(buf, size, GFP_KERNEL);
+	if (!dma_data)
+		return -ENOMEM;
+
+	ret = hid_bpf_ops->hid_hw_output_report(hdev,
+						dma_data,
+						size);
+
+	kfree(dma_data);
+	return ret;
+}
+
+/**
+ * hid_bpf_input_report - Inject a HID report in the kernel from a HID device
+ *
+ * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
+ * @type: the type of the report (%HID_INPUT_REPORT, %HID_FEATURE_REPORT, %HID_OUTPUT_REPORT)
+ * @buf: a %PTR_TO_MEM buffer
+ * @buf__sz: the size of the data to transfer
+ *
+ * Returns %0 on success, a negative error code otherwise.
+ */
+__bpf_kfunc int
+hid_bpf_input_report(struct hid_bpf_ctx *ctx, enum hid_report_type type, u8 *buf,
+		     const size_t buf__sz)
+{
+	struct hid_device *hdev;
+	size_t size = buf__sz;
+	int ret;
+
+	/* check arguments */
+	ret = __hid_bpf_hw_check_params(ctx, buf, &size, type);
+	if (ret)
+		return ret;
+
+	hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+	return hid_bpf_ops->hid_input_report(hdev, type, buf, size, 0);
+}
 __bpf_kfunc_end_defs();
 
+/*
+ * The following set contains all functions we agree BPF programs
+ * can use.
+ */
+BTF_KFUNCS_START(hid_bpf_kfunc_ids)
+BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
+BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_hw_request, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_hw_output_report, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_input_report, KF_SLEEPABLE)
+BTF_KFUNCS_END(hid_bpf_kfunc_ids)
+
+static const struct btf_kfunc_id_set hid_bpf_kfunc_set = {
+	.owner = THIS_MODULE,
+	.set   = &hid_bpf_kfunc_ids,
+};
+
 /* our HID-BPF entrypoints */
 BTF_SET8_START(hid_bpf_fmodret_ids)
 BTF_ID_FLAGS(func, hid_bpf_device_event)
@@ -492,6 +574,8 @@ BTF_ID_FLAGS(func, hid_bpf_attach_prog)
 BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE)
 BTF_ID_FLAGS(func, hid_bpf_hw_request)
+BTF_ID_FLAGS(func, hid_bpf_hw_output_report)
+BTF_ID_FLAGS(func, hid_bpf_input_report)
 BTF_KFUNCS_END(hid_bpf_syscall_kfunc_ids)
 
 static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = {