| Message ID | 20220304172852.274126-20-benjamin.tissoires@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce eBPF support for HID devices | expand |
On Fri, Mar 4, 2022 at 9:35 AM Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote: > > When we are in a user_event context, we can talk to the device to fetch > or set features/outputs/inputs reports. > Add a bpf helper to do so. This helper is thus only available to > user_events, because calling this function while in IRQ context (any > other BPF type) is forbidden. > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > --- > > changes in v2: > - split the series by bpf/libbpf/hid/selftests and samples > --- > include/linux/bpf-hid.h | 2 ++ > include/uapi/linux/bpf.h | 8 ++++++++ > kernel/bpf/hid.c | 26 ++++++++++++++++++++++++++ > tools/include/uapi/linux/bpf.h | 8 ++++++++ > 4 files changed, 44 insertions(+) > > diff --git a/include/linux/bpf-hid.h b/include/linux/bpf-hid.h > index 4cf2e99109fe..bd548f6a4a26 100644 > --- a/include/linux/bpf-hid.h > +++ b/include/linux/bpf-hid.h > @@ -100,6 +100,8 @@ struct bpf_hid_hooks { > u64 offset, u32 n, u8 *data, u64 data_size); > int (*hid_set_data)(struct hid_device *hdev, u8 *buf, size_t buf_size, > u64 offset, u32 n, u8 *data, u64 data_size); > + int (*hid_raw_request)(struct hid_device *hdev, u8 *buf, size_t size, > + u8 rtype, u8 reqtype); > }; > > #ifdef CONFIG_BPF > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index b3063384d380..417cf1c31579 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -5121,6 +5121,13 @@ union bpf_attr { > * Return > * The length of data copied into ctx->event.data. On error, a negative > * value is returned. > + * > + * int bpf_hid_raw_request(void *ctx, void *buf, u64 size, u8 rtype, u8 reqtype) > + * Description > + * communicate with the HID device I think we need more description here, e.g. what are rtype and reqtype here? > + * Return > + * 0 on success. > + * negative value on error. > */ > #define __BPF_FUNC_MAPPER(FN) \ > FN(unspec), \ > @@ -5317,6 +5324,7 @@ union bpf_attr { > FN(copy_from_user_task), \ > FN(hid_get_data), \ > FN(hid_set_data), \ > + FN(hid_raw_request), \ > /* */ [...]
diff --git a/include/linux/bpf-hid.h b/include/linux/bpf-hid.h index 4cf2e99109fe..bd548f6a4a26 100644 --- a/include/linux/bpf-hid.h +++ b/include/linux/bpf-hid.h @@ -100,6 +100,8 @@ struct bpf_hid_hooks { u64 offset, u32 n, u8 *data, u64 data_size); int (*hid_set_data)(struct hid_device *hdev, u8 *buf, size_t buf_size, u64 offset, u32 n, u8 *data, u64 data_size); + int (*hid_raw_request)(struct hid_device *hdev, u8 *buf, size_t size, + u8 rtype, u8 reqtype); }; #ifdef CONFIG_BPF diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b3063384d380..417cf1c31579 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5121,6 +5121,13 @@ union bpf_attr { * Return * The length of data copied into ctx->event.data. On error, a negative * value is returned. + * + * int bpf_hid_raw_request(void *ctx, void *buf, u64 size, u8 rtype, u8 reqtype) + * Description + * communicate with the HID device + * Return + * 0 on success. + * negative value on error. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5317,6 +5324,7 @@ union bpf_attr { FN(copy_from_user_task), \ FN(hid_get_data), \ FN(hid_set_data), \ + FN(hid_raw_request), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/hid.c b/kernel/bpf/hid.c index de003dbd7d01..653d10c0f4e6 100644 --- a/kernel/bpf/hid.c +++ b/kernel/bpf/hid.c @@ -86,6 +86,28 @@ static const struct bpf_func_proto bpf_hid_set_data_proto = { .arg5_type = ARG_CONST_SIZE_OR_ZERO, }; +BPF_CALL_5(bpf_hid_raw_request, void*, ctx, void*, buf, u64, size, + u8, rtype, u8, reqtype) +{ + struct hid_bpf_ctx *bpf_ctx = ctx; + + if (!hid_hooks.hid_raw_request) + return -EOPNOTSUPP; + + return hid_hooks.hid_raw_request(bpf_ctx->hdev, buf, size, rtype, reqtype); +} + +static const struct bpf_func_proto bpf_hid_raw_request_proto = { + .func = bpf_hid_raw_request, + .gpl_only = true, /* hid_raw_request is EXPORT_SYMBOL_GPL */ + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * hid_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -94,6 +116,10 @@ hid_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_hid_get_data_proto; case BPF_FUNC_hid_set_data: return &bpf_hid_set_data_proto; + case BPF_FUNC_hid_raw_request: + if (prog->expected_attach_type != BPF_HID_DEVICE_EVENT) + return &bpf_hid_raw_request_proto; + return NULL; default: return bpf_base_func_proto(func_id); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index b3063384d380..417cf1c31579 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5121,6 +5121,13 @@ union bpf_attr { * Return * The length of data copied into ctx->event.data. On error, a negative * value is returned. + * + * int bpf_hid_raw_request(void *ctx, void *buf, u64 size, u8 rtype, u8 reqtype) + * Description + * communicate with the HID device + * Return + * 0 on success. + * negative value on error. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5317,6 +5324,7 @@ union bpf_attr { FN(copy_from_user_task), \ FN(hid_get_data), \ FN(hid_set_data), \ + FN(hid_raw_request), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
When we are in a user_event context, we can talk to the device to fetch or set features/outputs/inputs reports. Add a bpf helper to do so. This helper is thus only available to user_events, because calling this function while in IRQ context (any other BPF type) is forbidden. Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> --- changes in v2: - split the series by bpf/libbpf/hid/selftests and samples --- include/linux/bpf-hid.h | 2 ++ include/uapi/linux/bpf.h | 8 ++++++++ kernel/bpf/hid.c | 26 ++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 8 ++++++++ 4 files changed, 44 insertions(+)