[PATCH HID v2 02/16] HID: bpf: add hid_get/put_device() helpers

Benjamin Tissoires
2024-06-07T15:28:36Z

no code change, but this way we reduce code duplication and we
can export it later.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

---

no changes in v2
---
drivers/hid/bpf/hid_bpf_dispatch.c | 47 ++++++++++++++++++++++----------------
1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 55c9f82fdef0..c8bb79ce2354 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -150,6 +150,25 @@ static int device_match_id(struct device *dev, const void *id)
return hdev->id == *(int *)id;
}

+static struct hid_device *hid_get_device(unsigned int hid_id)
+{
+ struct device *dev;
+
+ if (!hid_ops)
+ return ERR_PTR(-EINVAL);
+
+ dev = bus_find_device(hid_ops->bus_type, NULL, &hid_id, device_match_id);
+ if (!dev)
+ return ERR_PTR(-EINVAL);
+
+ return to_hid_device(dev);
+}
+
+static void hid_put_device(struct hid_device *hid)
+{
+ put_device(&hid->dev);
+}
+
static int __hid_bpf_allocate_data(struct hid_device *hdev, u8 **data, u32 *size)
{
u8 *alloc_data;
@@ -281,20 +300,14 @@ hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags)
{
struct hid_device *hdev;
struct bpf_prog *prog;
- struct device *dev;
int err, fd;

- if (!hid_ops)
- return -EINVAL;
-
if ((flags & ~HID_BPF_FLAG_MASK))
return -EINVAL;

- dev = bus_find_device(hid_ops->bus_type, NULL, &hid_id, device_match_id);
- if (!dev)
- return -EINVAL;
-
- hdev = to_hid_device(dev);
+ hdev = hid_get_device(hid_id);
+ if (IS_ERR(hdev))
+ return PTR_ERR(hdev);

/*
* take a ref on the prog itself, it will be released
@@ -317,7 +330,7 @@ hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags)
out_prog_put:
bpf_prog_put(prog);
out_dev_put:
- put_device(dev);
+ hid_put_device(hdev);
return err;
}

@@ -333,20 +346,14 @@ hid_bpf_allocate_context(unsigned int hid_id)
{
struct hid_device *hdev;
struct hid_bpf_ctx_kern *ctx_kern = NULL;
- struct device *dev;
-
- if (!hid_ops)
- return NULL;

- dev = bus_find_device(hid_ops->bus_type, NULL, &hid_id, device_match_id);
- if (!dev)
+ hdev = hid_get_device(hid_id);
+ if (IS_ERR(hdev))
return NULL;

- hdev = to_hid_device(dev);
-
ctx_kern = kzalloc(sizeof(*ctx_kern), GFP_KERNEL);
if (!ctx_kern) {
- put_device(dev);
+ hid_put_device(hdev);
return NULL;
}

@@ -373,7 +380,7 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
kfree(ctx_kern);

/* get_device() is called by bus_find_device() */
- put_device(&hid->dev);
+ hid_put_device(hid);
}

static int

--
2.44.0