From 9acbb7ba4589d4715141d4e14230a828ddc95f3d Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 26 Jun 2024 15:46:32 +0200 Subject: HID: bpf: allow hid_device_event hooks to inject input reports on self This is the same logic than hid_hw_raw_request or hid_hw_output_report: we can allow hid_bpf_try_input_report to be called from a hook on hid_input_report if we ensure that the call can not be made twice in a row. There is one extra subtlety in which there is a lock in hid_input_report. But given that we can detect if we are already in the hook, we can notify hid_input_report to not take the lock. This is done by checking if ctx_kern data is valid or null, and if it is equal to the dedicated incoming data buffer. In order to have more control on whether the lock needs to be taken or not we introduce a new kfunc for it: hid_bpf_try_input_report() Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-11-cfd60fb6c79f@kernel.org Acked-by: Jiri Kosina Signed-off-by: Benjamin Tissoires --- Documentation/hid/hid-bpf.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/hid') diff --git a/Documentation/hid/hid-bpf.rst b/Documentation/hid/hid-bpf.rst index 8ae8f49801cb..5939eeafb361 100644 --- a/Documentation/hid/hid-bpf.rst +++ b/Documentation/hid/hid-bpf.rst @@ -202,7 +202,7 @@ Available API that can be used in syscall HID-BPF programs or in sleepable HID-B ------------------------------------------------------------------------------------------------------- .. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c - :identifiers: hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_input_report hid_bpf_allocate_context hid_bpf_release_context + :identifiers: hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_input_report hid_bpf_try_input_report hid_bpf_allocate_context hid_bpf_release_context General overview of a HID-BPF program ===================================== -- cgit v1.2.3