From patchwork Fri Mar 15 14:44:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 13593553 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73BD31B597; Fri, 15 Mar 2024 14:44:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710513888; cv=none; b=OAgtxraozI/QDuQyxLPcNEZiVOie2Vz2XtSM7hdL+KPaHEmrrr+DsLyKouX5e1fCr4UCdc5LiPJKTp0CslpREt1/M3XymmeWtm4NX/wexrxGcU6Jvczp/j7+Wqp49GPw50odvL4n0H8MlFgouPT1cUXMrBdHQXp1s6+gVXbI3pM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710513888; c=relaxed/simple; bh=K8NWyhLyI7nRKaKmhQDbTOy488CAWQLbY3vLJLDYOc0=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=GnSmJq/sIhcjeD2Js9Z5QwDnff0rAMMR5ExhlIEzzJaDcJI0Xxm3oBoYd112hUgd1oAMunElPYYnsOYoISyilHsgvWubKiFUow5oF0b65NHCd5//HGdXbKVnDp/RwwIPCH5WmvyA/MC36GzpaVHbN/cVNLoGuORUMdm4nEasEnM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HU2C5nCF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HU2C5nCF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE4F7C433F1; Fri, 15 Mar 2024 14:44:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710513888; bh=K8NWyhLyI7nRKaKmhQDbTOy488CAWQLbY3vLJLDYOc0=; h=From:Subject:Date:To:Cc:From; b=HU2C5nCF6c4nwBT0gMcjfhHmQiQDU29BSRJzYexzexgZ417Z0+EvBqdIFSrMjFEdy ue5hp1v651tQ4eed/8lAdpgcmkO3aQvHCla1RJ9Tq7iPDv/ORJkHlB4MFCZgUwSqjf JFsXFJsDkeKgFEQ6o/AoAHV9SUe85aUxy04zjOlx42KjTt4yQO8zIwZBlyQ5JSGLFu iZCqfPli146OqKTQl1ZCxTvfTTXbUPQfnO1FA1zy8Cnf3bVlspcYssn2VQ95/BFik1 tHFgevsH4OJ4F7vkjfTvTBkS00vM1B6izBPtgVy5tyr2dD/vdwhA8MYBTv2rkyPiXn JKxiG26ppkkcw== From: Benjamin Tissoires Subject: [PATCH v4 0/7] Extend HID-BPF kfuncs (was: allow HID-BPF to do device IOs) Date: Fri, 15 Mar 2024 15:44:37 +0100 Message-Id: <20240315-b4-hid-bpf-new-funcs-v4-0-079c282469d3@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIANVe9GUC/x3MPQqAMAxA4atIZgNRK4pXEQfbJpqlSos/IN7d4 vgN7z2QOConGIoHIp+adAsZpizArXNYGNVnQ021oaYyaA2u6tHugoEvlCO4hOyEWk8sfUeQ0z2 y6P1vx+l9P61PTHRmAAAA To: Jiri Kosina , Benjamin Tissoires , Jonathan Corbet , Shuah Khan Cc: Benjamin Tissoires , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=ed25519-sha256; t=1710513885; l=4344; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=K8NWyhLyI7nRKaKmhQDbTOy488CAWQLbY3vLJLDYOc0=; b=qkR2hKngdkomUDhM6rdvCvhO/34xBRaRLKunbKjNjkYVE7bjvSK0263RoYcUiMNopa/SxbqcZ fC6zXMSjT0QCTq3hRsnNF1Wjv7t7JLJZn9MYbrc2P5izarRhupCmvbq X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= New version of the sleepable bpf_timer code, without BPF changes, as they can now go through the HID tree independantly: https://lore.kernel.org/all/20240315-hid-bpf-sleepable-v4-0-5658f2540564@kernel.org/ For reference, the use cases I have in mind: --- Basically, I need to be able to defer a HID-BPF program for the following reasons (from the aforementioned patch): 1. defer an event: Sometimes we receive an out of proximity event, but the device can not be trusted enough, and we need to ensure that we won't receive another one in the following n milliseconds. So we need to wait those n milliseconds, and eventually re-inject that event in the stack. 2. inject new events in reaction to one given event: We might want to transform one given event into several. This is the case for macro keys where a single key press is supposed to send a sequence of key presses. But this could also be used to patch a faulty behavior, if a device forgets to send a release event. 3. communicate with the device in reaction to one event: We might want to communicate back to the device after a given event. For example a device might send us an event saying that it came back from sleeping state and needs to be re-initialized. Currently we can achieve that by keeping a userspace program around, raise a bpf event, and let that userspace program inject the events and commands. However, we are just keeping that program alive as a daemon for just scheduling commands. There is no logic in it, so it doesn't really justify an actual userspace wakeup. So a kernel workqueue seems simpler to handle. bpf_timers are currently running in a soft IRQ context, this patch series implements a sleppable context for them. Cheers, Benjamin To: Jiri Kosina To: Benjamin Tissoires To: Jonathan Corbet To: Shuah Khan Cc: Benjamin Tissoires Cc: Cc: Cc: Cc: Cc: --- Changes in v4: - dropped the BPF changes, they can go independently in bpf-core - dropped the HID-BPF integration tests with the sleppable timers, I'll re-add them once both series (this and sleepable timers) are merged - Link to v3: https://lore.kernel.org/r/20240221-hid-bpf-sleepable-v3-0-1fb378ca6301@kernel.org Changes in v3: - fixed the crash from v2 - changed the API to have only BPF_F_TIMER_SLEEPABLE for bpf_timer_start() - split the new kfuncs/verifier patch into several sub-patches, for easier reviews - Link to v2: https://lore.kernel.org/r/20240214-hid-bpf-sleepable-v2-0-5756b054724d@kernel.org Changes in v2: - make use of bpf_timer (and dropped the custom HID handling) - implemented bpf_timer_set_sleepable_cb as a kfunc - still not implemented global subprogs - no sleepable bpf_timer selftests yet - Link to v1: https://lore.kernel.org/r/20240209-hid-bpf-sleepable-v1-0-4cc895b5adbd@kernel.org --- Benjamin Tissoires (7): HID: bpf/dispatch: regroup kfuncs definitions HID: bpf: export hid_hw_output_report as a BPF kfunc selftests/hid: add KASAN to the VM tests selftests/hid: Add test for hid_bpf_hw_output_report HID: bpf: allow to inject HID event from BPF selftests/hid: add tests for hid_bpf_input_report HID: bpf: allow to use bpf_timer_set_sleepable_cb() in tracing callbacks. Documentation/hid/hid-bpf.rst | 2 +- drivers/hid/bpf/hid_bpf_dispatch.c | 226 ++++++++++++++------- drivers/hid/hid-core.c | 2 + include/linux/hid_bpf.h | 3 + tools/testing/selftests/hid/config.common | 1 + tools/testing/selftests/hid/hid_bpf.c | 112 +++++++++- tools/testing/selftests/hid/progs/hid.c | 46 +++++ .../testing/selftests/hid/progs/hid_bpf_helpers.h | 6 + 8 files changed, 324 insertions(+), 74 deletions(-) --- base-commit: 3e78a6c0d3e02e4cf881dc84c5127e9990f939d6 change-id: 20240314-b4-hid-bpf-new-funcs-ecf05d0ef870 Best regards,