From: Benjamin Tissoires <bentiss@kernel.org>
To: Jiri Kosina <jikos@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>,
Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>
Cc: Benjamin Tissoires <bentiss@kernel.org>,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kselftest@vger.kernel.org
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 [thread overview]
Message-ID: <20240315-b4-hid-bpf-new-funcs-v4-0-079c282469d3@kernel.org> (raw)
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 <jikos@kernel.org>
To: Benjamin Tissoires <benjamin.tissoires@redhat.com>
To: Jonathan Corbet <corbet@lwn.net>
To: Shuah Khan <shuah@kernel.org>
Cc: Benjamin Tissoires <bentiss@kernel.org>
Cc: <linux-input@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: <bpf@vger.kernel.org>
Cc: <linux-doc@vger.kernel.org>
Cc: <linux-kselftest@vger.kernel.org>
---
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,
--
Benjamin Tissoires <bentiss@kernel.org>
next reply other threads:[~2024-03-15 14:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-15 14:44 Benjamin Tissoires [this message]
2024-03-15 14:44 ` [PATCH v4 1/7] HID: bpf/dispatch: regroup kfuncs definitions Benjamin Tissoires
2024-03-15 14:44 ` [PATCH v4 2/7] HID: bpf: export hid_hw_output_report as a BPF kfunc Benjamin Tissoires
2024-03-15 15:55 ` Randy Dunlap
2024-03-22 15:00 ` Benjamin Tissoires
2024-03-15 14:44 ` [PATCH v4 3/7] selftests/hid: add KASAN to the VM tests Benjamin Tissoires
2024-03-15 14:44 ` [PATCH v4 4/7] selftests/hid: Add test for hid_bpf_hw_output_report Benjamin Tissoires
2024-03-15 14:44 ` [PATCH v4 5/7] HID: bpf: allow to inject HID event from BPF Benjamin Tissoires
2024-03-15 15:55 ` Randy Dunlap
2024-03-15 14:44 ` [PATCH v4 6/7] selftests/hid: add tests for hid_bpf_input_report Benjamin Tissoires
2024-03-15 14:44 ` [PATCH v4 7/7] HID: bpf: allow to use bpf_timer_set_sleepable_cb() in tracing callbacks Benjamin Tissoires
2024-04-10 16:33 ` [PATCH v4 0/7] Extend HID-BPF kfuncs (was: allow HID-BPF to do device IOs) Benjamin Tissoires
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240315-b4-hid-bpf-new-funcs-v4-0-079c282469d3@kernel.org \
--to=bentiss@kernel.org \
--cc=benjamin.tissoires@redhat.com \
--cc=bpf@vger.kernel.org \
--cc=corbet@lwn.net \
--cc=jikos@kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=shuah@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).