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/[email protected]/
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 <[email protected]>
To: Benjamin Tissoires <[email protected]>
To: Jonathan Corbet <[email protected]>
To: Shuah Khan <[email protected]>
Cc: Benjamin Tissoires <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
---
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/[email protected]
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/[email protected]
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/[email protected]
---
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 <[email protected]>
No code change, just move down the hid_bpf_get_data() kfunc definition
so we have only one block of __bpf_kfunc_start/end_defs()
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
no changes in v3
no changes in v2
---
drivers/hid/bpf/hid_bpf_dispatch.c | 80 ++++++++++++++++++--------------------
1 file changed, 38 insertions(+), 42 deletions(-)
diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index e630caf644e8..52abb27426f4 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -143,48 +143,6 @@ u8 *call_hid_bpf_rdesc_fixup(struct hid_device *hdev, u8 *rdesc, unsigned int *s
}
EXPORT_SYMBOL_GPL(call_hid_bpf_rdesc_fixup);
-/* Disables missing prototype warnings */
-__bpf_kfunc_start_defs();
-
-/**
- * hid_bpf_get_data - Get the kernel memory pointer associated with the context @ctx
- *
- * @ctx: The HID-BPF context
- * @offset: The offset within the memory
- * @rdwr_buf_size: the const size of the buffer
- *
- * @returns %NULL on error, an %__u8 memory pointer on success
- */
-__bpf_kfunc __u8 *
-hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr_buf_size)
-{
- struct hid_bpf_ctx_kern *ctx_kern;
-
- if (!ctx)
- return NULL;
-
- ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx);
-
- if (rdwr_buf_size + offset > ctx->allocated_size)
- return NULL;
-
- return ctx_kern->data + offset;
-}
-__bpf_kfunc_end_defs();
-
-/*
- * The following set contains all functions we agree BPF programs
- * can use.
- */
-BTF_KFUNCS_START(hid_bpf_kfunc_ids)
-BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
-BTF_KFUNCS_END(hid_bpf_kfunc_ids)
-
-static const struct btf_kfunc_id_set hid_bpf_kfunc_set = {
- .owner = THIS_MODULE,
- .set = &hid_bpf_kfunc_ids,
-};
-
static int device_match_id(struct device *dev, const void *id)
{
struct hid_device *hdev = to_hid_device(dev);
@@ -281,6 +239,31 @@ static int do_hid_bpf_attach_prog(struct hid_device *hdev, int prog_fd, struct b
/* Disables missing prototype warnings */
__bpf_kfunc_start_defs();
+/**
+ * hid_bpf_get_data - Get the kernel memory pointer associated with the context @ctx
+ *
+ * @ctx: The HID-BPF context
+ * @offset: The offset within the memory
+ * @rdwr_buf_size: the const size of the buffer
+ *
+ * @returns %NULL on error, an %__u8 memory pointer on success
+ */
+__bpf_kfunc __u8 *
+hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr_buf_size)
+{
+ struct hid_bpf_ctx_kern *ctx_kern;
+
+ if (!ctx)
+ return NULL;
+
+ ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx);
+
+ if (rdwr_buf_size + offset > ctx->allocated_size)
+ return NULL;
+
+ return ctx_kern->data + offset;
+}
+
/**
* hid_bpf_attach_prog - Attach the given @prog_fd to the given HID device
*
@@ -474,6 +457,19 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
}
__bpf_kfunc_end_defs();
+/*
+ * The following set contains all functions we agree BPF programs
+ * can use.
+ */
+BTF_KFUNCS_START(hid_bpf_kfunc_ids)
+BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
+BTF_KFUNCS_END(hid_bpf_kfunc_ids)
+
+static const struct btf_kfunc_id_set hid_bpf_kfunc_set = {
+ .owner = THIS_MODULE,
+ .set = &hid_bpf_kfunc_ids,
+};
+
/* our HID-BPF entrypoints */
BTF_SET8_START(hid_bpf_fmodret_ids)
BTF_ID_FLAGS(func, hid_bpf_device_event)
--
2.44.0
We currently only export hid_hw_raw_request() as a BPF kfunc.
However, some devices require an explicit write on the Output Report
instead of the use of the control channel.
So also export hid_hw_output_report to BPF
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
no changes in v3
no changes in v2
---
Documentation/hid/hid-bpf.rst | 2 +-
drivers/hid/bpf/hid_bpf_dispatch.c | 112 +++++++++++++++++++++++++++----------
drivers/hid/hid-core.c | 1 +
include/linux/hid_bpf.h | 1 +
4 files changed, 86 insertions(+), 30 deletions(-)
diff --git a/Documentation/hid/hid-bpf.rst b/Documentation/hid/hid-bpf.rst
index 4fad83a6ebc3..a575004d9025 100644
--- a/Documentation/hid/hid-bpf.rst
+++ b/Documentation/hid/hid-bpf.rst
@@ -179,7 +179,7 @@ Available API that can be used in syscall HID-BPF programs:
-----------------------------------------------------------
.. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c
- :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_allocate_context hid_bpf_release_context
+ :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_allocate_context hid_bpf_release_context
General overview of a HID-BPF program
=====================================
diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 52abb27426f4..a5b88b491b80 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -376,6 +376,46 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
put_device(&hid->dev);
}
+static int
+__hid_bpf_hw_check_params(struct hid_bpf_ctx *ctx, __u8 *buf, size_t *buf__sz,
+ enum hid_report_type rtype)
+{
+ struct hid_report_enum *report_enum;
+ struct hid_report *report;
+ struct hid_device *hdev;
+ u32 report_len;
+
+ /* check arguments */
+ if (!ctx || !hid_bpf_ops || !buf)
+ return -EINVAL;
+
+ switch (rtype) {
+ case HID_INPUT_REPORT:
+ case HID_OUTPUT_REPORT:
+ case HID_FEATURE_REPORT:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (*buf__sz < 1)
+ return -EINVAL;
+
+ hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+ report_enum = hdev->report_enum + rtype;
+ report = hid_bpf_ops->hid_get_report(report_enum, buf);
+ if (!report)
+ return -EINVAL;
+
+ report_len = hid_report_len(report);
+
+ if (*buf__sz > report_len)
+ *buf__sz = report_len;
+
+ return 0;
+}
+
/**
* hid_bpf_hw_request - Communicate with a HID device
*
@@ -392,24 +432,14 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
enum hid_report_type rtype, enum hid_class_request reqtype)
{
struct hid_device *hdev;
- struct hid_report *report;
- struct hid_report_enum *report_enum;
+ size_t size = buf__sz;
u8 *dma_data;
- u32 report_len;
int ret;
/* check arguments */
- if (!ctx || !hid_bpf_ops || !buf)
- return -EINVAL;
-
- switch (rtype) {
- case HID_INPUT_REPORT:
- case HID_OUTPUT_REPORT:
- case HID_FEATURE_REPORT:
- break;
- default:
- return -EINVAL;
- }
+ ret = __hid_bpf_hw_check_params(ctx, buf, &size, rtype);
+ if (ret)
+ return ret;
switch (reqtype) {
case HID_REQ_GET_REPORT:
@@ -423,29 +453,16 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
return -EINVAL;
}
- if (buf__sz < 1)
- return -EINVAL;
-
hdev = (struct hid_device *)ctx->hid; /* discard const */
- report_enum = hdev->report_enum + rtype;
- report = hid_bpf_ops->hid_get_report(report_enum, buf);
- if (!report)
- return -EINVAL;
-
- report_len = hid_report_len(report);
-
- if (buf__sz > report_len)
- buf__sz = report_len;
-
- dma_data = kmemdup(buf, buf__sz, GFP_KERNEL);
+ dma_data = kmemdup(buf, size, GFP_KERNEL);
if (!dma_data)
return -ENOMEM;
ret = hid_bpf_ops->hid_hw_raw_request(hdev,
dma_data[0],
dma_data,
- buf__sz,
+ size,
rtype,
reqtype);
@@ -455,6 +472,42 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
kfree(dma_data);
return ret;
}
+
+/**
+ * hid_bpf_hw_output_report - Send an output report to a HID device
+ *
+ * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
+ * @buf: a %PTR_TO_MEM buffer
+ * @buf__sz: the size of the data to transfer
+ *
+ * @returns the number of bytes transferred on success, a negative error code otherwise.
+ */
+__bpf_kfunc int
+hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz)
+{
+ struct hid_device *hdev;
+ size_t size = buf__sz;
+ u8 *dma_data;
+ int ret;
+
+ /* check arguments */
+ ret = __hid_bpf_hw_check_params(ctx, buf, &size, HID_OUTPUT_REPORT);
+ if (ret)
+ return ret;
+
+ hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+ dma_data = kmemdup(buf, size, GFP_KERNEL);
+ if (!dma_data)
+ return -ENOMEM;
+
+ ret = hid_bpf_ops->hid_hw_output_report(hdev,
+ dma_data,
+ size);
+
+ kfree(dma_data);
+ return ret;
+}
__bpf_kfunc_end_defs();
/*
@@ -488,6 +541,7 @@ BTF_ID_FLAGS(func, hid_bpf_attach_prog)
BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE)
BTF_ID_FLAGS(func, hid_bpf_hw_request)
+BTF_ID_FLAGS(func, hid_bpf_hw_output_report)
BTF_KFUNCS_END(hid_bpf_syscall_kfunc_ids)
static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = {
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index de7a477d6665..1243595890ba 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2974,6 +2974,7 @@ EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
static struct hid_bpf_ops hid_ops = {
.hid_get_report = hid_get_report,
.hid_hw_raw_request = hid_hw_raw_request,
+ .hid_hw_output_report = hid_hw_output_report,
.owner = THIS_MODULE,
.bus_type = &hid_bus_type,
};
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index 7118ac28d468..5c7ff93dc73e 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -103,6 +103,7 @@ struct hid_bpf_ops {
unsigned char reportnum, __u8 *buf,
size_t len, enum hid_report_type rtype,
enum hid_class_request reqtype);
+ int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len);
struct module *owner;
const struct bus_type *bus_type;
};
--
2.44.0
It can be interesting to inject events from BPF as if the event were
to come from the device.
For example, some multitouch devices do not all the time send a proximity
out event, and we might want to send it for the physical device.
Compared to uhid, we can now inject events on any physical device, not
just uhid virtual ones.
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
no changes in v3
no changes in v2
---
Documentation/hid/hid-bpf.rst | 2 +-
drivers/hid/bpf/hid_bpf_dispatch.c | 29 +++++++++++++++++++++++++++++
drivers/hid/hid-core.c | 1 +
include/linux/hid_bpf.h | 2 ++
4 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/Documentation/hid/hid-bpf.rst b/Documentation/hid/hid-bpf.rst
index a575004d9025..0765b3298ecf 100644
--- a/Documentation/hid/hid-bpf.rst
+++ b/Documentation/hid/hid-bpf.rst
@@ -179,7 +179,7 @@ Available API that can be used in syscall HID-BPF programs:
-----------------------------------------------------------
.. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c
- :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_allocate_context hid_bpf_release_context
+ :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_input_report hid_bpf_allocate_context hid_bpf_release_context
General overview of a HID-BPF program
=====================================
diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index a5b88b491b80..e1a650f4a626 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -508,6 +508,34 @@ hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz)
kfree(dma_data);
return ret;
}
+
+/**
+ * hid_bpf_input_report - Inject a HID report in the kernel from a HID device
+ *
+ * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
+ * @type: the type of the report (%HID_INPUT_REPORT, %HID_FEATURE_REPORT, %HID_OUTPUT_REPORT)
+ * @buf: a %PTR_TO_MEM buffer
+ * @buf__sz: the size of the data to transfer
+ *
+ * @returns %0 on success, a negative error code otherwise.
+ */
+__bpf_kfunc int
+hid_bpf_input_report(struct hid_bpf_ctx *ctx, enum hid_report_type type, u8 *buf,
+ const size_t buf__sz)
+{
+ struct hid_device *hdev;
+ size_t size = buf__sz;
+ int ret;
+
+ /* check arguments */
+ ret = __hid_bpf_hw_check_params(ctx, buf, &size, type);
+ if (ret)
+ return ret;
+
+ hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+ return hid_input_report(hdev, type, buf, size, 0);
+}
__bpf_kfunc_end_defs();
/*
@@ -542,6 +570,7 @@ BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE)
BTF_ID_FLAGS(func, hid_bpf_hw_request)
BTF_ID_FLAGS(func, hid_bpf_hw_output_report)
+BTF_ID_FLAGS(func, hid_bpf_input_report)
BTF_KFUNCS_END(hid_bpf_syscall_kfunc_ids)
static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = {
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 1243595890ba..b1fa0378e8f4 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2975,6 +2975,7 @@ static struct hid_bpf_ops hid_ops = {
.hid_get_report = hid_get_report,
.hid_hw_raw_request = hid_hw_raw_request,
.hid_hw_output_report = hid_hw_output_report,
+ .hid_input_report = hid_input_report,
.owner = THIS_MODULE,
.bus_type = &hid_bus_type,
};
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index 5c7ff93dc73e..17b08f500098 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -104,6 +104,8 @@ struct hid_bpf_ops {
size_t len, enum hid_report_type rtype,
enum hid_class_request reqtype);
int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len);
+ int (*hid_input_report)(struct hid_device *hid, enum hid_report_type type,
+ u8 *data, u32 size, int interrupt);
struct module *owner;
const struct bus_type *bus_type;
};
--
2.44.0
Usual way of testing, we call the function and ensures we receive
the event
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
no changes in v3
no changes in v2
---
tools/testing/selftests/hid/hid_bpf.c | 49 +++++++++++++++++++++-
tools/testing/selftests/hid/progs/hid.c | 22 ++++++++++
.../testing/selftests/hid/progs/hid_bpf_helpers.h | 4 ++
3 files changed, 73 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c
index 8332014838b0..f825623e3edc 100644
--- a/tools/testing/selftests/hid/hid_bpf.c
+++ b/tools/testing/selftests/hid/hid_bpf.c
@@ -749,6 +749,52 @@ TEST_F(hid_bpf, test_hid_change_report)
ASSERT_EQ(buf[2], 0) TH_LOG("leftovers_from_previous_test");
}
+/*
+ * Call hid_bpf_input_report against the given uhid device,
+ * check that the program is called and does the expected.
+ */
+TEST_F(hid_bpf, test_hid_user_input_report_call)
+{
+ struct hid_hw_request_syscall_args args = {
+ .retval = -1,
+ .size = 10,
+ };
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattrs,
+ .ctx_in = &args,
+ .ctx_size_in = sizeof(args),
+ );
+ __u8 buf[10] = {0};
+ int err, prog_fd;
+
+ LOAD_BPF;
+
+ args.hid = self->hid_id;
+ args.data[0] = 1; /* report ID */
+ args.data[1] = 2; /* report ID */
+ args.data[2] = 42; /* report ID */
+
+ prog_fd = bpf_program__fd(self->skel->progs.hid_user_input_report);
+
+ /* check that there is no data to read from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, -1) TH_LOG("read_hidraw");
+
+ err = bpf_prog_test_run_opts(prog_fd, &tattrs);
+
+ ASSERT_OK(err) TH_LOG("error while calling bpf_prog_test_run_opts");
+
+ ASSERT_EQ(args.retval, 0);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
+ ASSERT_EQ(buf[0], 1);
+ ASSERT_EQ(buf[1], 2);
+ ASSERT_EQ(buf[2], 42);
+}
+
/*
* Call hid_bpf_hw_output_report against the given uhid device,
* check that the program is called and does the expected.
@@ -797,8 +843,7 @@ TEST_F(hid_bpf, test_hid_user_output_report_call)
}
/*
- * Attach hid_user_raw_request to the given uhid device,
- * call the bpf program from userspace
+ * Call hid_hw_raw_request against the given uhid device,
* check that the program is called and does the expected.
*/
TEST_F(hid_bpf, test_hid_user_raw_request_call)
diff --git a/tools/testing/selftests/hid/progs/hid.c b/tools/testing/selftests/hid/progs/hid.c
index 2c2b679a83b1..f67d35def142 100644
--- a/tools/testing/selftests/hid/progs/hid.c
+++ b/tools/testing/selftests/hid/progs/hid.c
@@ -125,6 +125,28 @@ int hid_user_output_report(struct hid_hw_request_syscall_args *args)
return 0;
}
+SEC("syscall")
+int hid_user_input_report(struct hid_hw_request_syscall_args *args)
+{
+ struct hid_bpf_ctx *ctx;
+ const size_t size = args->size;
+ int i, ret = 0;
+
+ if (size > sizeof(args->data))
+ return -7; /* -E2BIG */
+
+ ctx = hid_bpf_allocate_context(args->hid);
+ if (!ctx)
+ return -1; /* EPERM check */
+
+ ret = hid_bpf_input_report(ctx, HID_INPUT_REPORT, args->data, size);
+ args->retval = ret;
+
+ hid_bpf_release_context(ctx);
+
+ return 0;
+}
+
static const __u8 rdesc[] = {
0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */
0x09, 0x32, /* USAGE (Z) */
diff --git a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
index 50c6a0d5765e..9cd56821d0f1 100644
--- a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
+++ b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
@@ -96,5 +96,9 @@ extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
enum hid_class_request reqtype) __ksym;
extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
__u8 *buf, size_t buf__sz) __ksym;
+extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
+ enum hid_report_type type,
+ __u8 *data,
+ size_t buf__sz) __ksym;
#endif /* __HID_BPF_HELPERS_H */
--
2.44.0
Export the sleepable kfuncs we have on HID-BPF in tracing bpf programs,
but with the condition of being used in a sleepable context.
This allows to use the bpf_timer when used in a sleepable context
through bpf_timer_set_sleepable_cb() and initiate work from a device event.
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
no changes in v3
new in v2
---
drivers/hid/bpf/hid_bpf_dispatch.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index e1a650f4a626..e27c2ffb4f60 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -544,6 +544,11 @@ __bpf_kfunc_end_defs();
*/
BTF_KFUNCS_START(hid_bpf_kfunc_ids)
BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
+BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_hw_request, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_hw_output_report, KF_SLEEPABLE)
+BTF_ID_FLAGS(func, hid_bpf_input_report, KF_SLEEPABLE)
BTF_KFUNCS_END(hid_bpf_kfunc_ids)
static const struct btf_kfunc_id_set hid_bpf_kfunc_set = {
--
2.44.0
It's always a good idea to have KASAN in tests.
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
new in v3
---
tools/testing/selftests/hid/config.common | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/testing/selftests/hid/config.common b/tools/testing/selftests/hid/config.common
index 0f456dbab62f..45b5570441ce 100644
--- a/tools/testing/selftests/hid/config.common
+++ b/tools/testing/selftests/hid/config.common
@@ -238,3 +238,4 @@ CONFIG_VLAN_8021Q=y
CONFIG_XFRM_SUB_POLICY=y
CONFIG_XFRM_USER=y
CONFIG_ZEROPLUS_FF=y
+CONFIG_KASAN=y
--
2.44.0
This time we need to ensure uhid receives it, thus the new mutex and
condition.
Signed-off-by: Benjamin Tissoires <[email protected]>
---
no changes in v4
no changes in v3
no changes in v2
---
tools/testing/selftests/hid/hid_bpf.c | 63 ++++++++++++++++++++++
tools/testing/selftests/hid/progs/hid.c | 24 +++++++++
.../testing/selftests/hid/progs/hid_bpf_helpers.h | 2 +
3 files changed, 89 insertions(+)
diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c
index 2cf96f818f25..8332014838b0 100644
--- a/tools/testing/selftests/hid/hid_bpf.c
+++ b/tools/testing/selftests/hid/hid_bpf.c
@@ -16,6 +16,11 @@
#define SHOW_UHID_DEBUG 0
+#define min(a, b) \
+ ({ __typeof__(a) _a = (a); \
+ __typeof__(b) _b = (b); \
+ _a < _b ? _a : _b; })
+
static unsigned char rdesc[] = {
0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */
0x09, 0x21, /* Usage (Vendor Usage 0x21) */
@@ -111,6 +116,10 @@ struct hid_hw_request_syscall_args {
static pthread_mutex_t uhid_started_mtx = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t uhid_started = PTHREAD_COND_INITIALIZER;
+static pthread_mutex_t uhid_output_mtx = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t uhid_output_cond = PTHREAD_COND_INITIALIZER;
+static unsigned char output_report[10];
+
/* no need to protect uhid_stopped, only one thread accesses it */
static bool uhid_stopped;
@@ -205,6 +214,13 @@ static int uhid_event(struct __test_metadata *_metadata, int fd)
break;
case UHID_OUTPUT:
UHID_LOG("UHID_OUTPUT from uhid-dev");
+
+ pthread_mutex_lock(&uhid_output_mtx);
+ memcpy(output_report,
+ ev.u.output.data,
+ min(ev.u.output.size, sizeof(output_report)));
+ pthread_cond_signal(&uhid_output_cond);
+ pthread_mutex_unlock(&uhid_output_mtx);
break;
case UHID_GET_REPORT:
UHID_LOG("UHID_GET_REPORT from uhid-dev");
@@ -733,6 +749,53 @@ TEST_F(hid_bpf, test_hid_change_report)
ASSERT_EQ(buf[2], 0) TH_LOG("leftovers_from_previous_test");
}
+/*
+ * Call hid_bpf_hw_output_report against the given uhid device,
+ * check that the program is called and does the expected.
+ */
+TEST_F(hid_bpf, test_hid_user_output_report_call)
+{
+ struct hid_hw_request_syscall_args args = {
+ .retval = -1,
+ .size = 10,
+ };
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattrs,
+ .ctx_in = &args,
+ .ctx_size_in = sizeof(args),
+ );
+ int err, cond_err, prog_fd;
+ struct timespec time_to_wait;
+
+ LOAD_BPF;
+
+ args.hid = self->hid_id;
+ args.data[0] = 1; /* report ID */
+ args.data[1] = 2; /* report ID */
+ args.data[2] = 42; /* report ID */
+
+ prog_fd = bpf_program__fd(self->skel->progs.hid_user_output_report);
+
+ pthread_mutex_lock(&uhid_output_mtx);
+
+ memset(output_report, 0, sizeof(output_report));
+ clock_gettime(CLOCK_REALTIME, &time_to_wait);
+ time_to_wait.tv_sec += 2;
+
+ err = bpf_prog_test_run_opts(prog_fd, &tattrs);
+ cond_err = pthread_cond_timedwait(&uhid_output_cond, &uhid_output_mtx, &time_to_wait);
+
+ ASSERT_OK(err) TH_LOG("error while calling bpf_prog_test_run_opts");
+ ASSERT_OK(cond_err) TH_LOG("error while calling waiting for the condition");
+
+ ASSERT_EQ(args.retval, 3);
+
+ ASSERT_EQ(output_report[0], 1);
+ ASSERT_EQ(output_report[1], 2);
+ ASSERT_EQ(output_report[2], 42);
+
+ pthread_mutex_unlock(&uhid_output_mtx);
+}
+
/*
* Attach hid_user_raw_request to the given uhid device,
* call the bpf program from userspace
diff --git a/tools/testing/selftests/hid/progs/hid.c b/tools/testing/selftests/hid/progs/hid.c
index 1e558826b809..2c2b679a83b1 100644
--- a/tools/testing/selftests/hid/progs/hid.c
+++ b/tools/testing/selftests/hid/progs/hid.c
@@ -101,6 +101,30 @@ int hid_user_raw_request(struct hid_hw_request_syscall_args *args)
return 0;
}
+SEC("syscall")
+int hid_user_output_report(struct hid_hw_request_syscall_args *args)
+{
+ struct hid_bpf_ctx *ctx;
+ const size_t size = args->size;
+ int i, ret = 0;
+
+ if (size > sizeof(args->data))
+ return -7; /* -E2BIG */
+
+ ctx = hid_bpf_allocate_context(args->hid);
+ if (!ctx)
+ return -1; /* EPERM check */
+
+ ret = hid_bpf_hw_output_report(ctx,
+ args->data,
+ size);
+ args->retval = ret;
+
+ hid_bpf_release_context(ctx);
+
+ return 0;
+}
+
static const __u8 rdesc[] = {
0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */
0x09, 0x32, /* USAGE (Z) */
diff --git a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
index 65e657ac1198..50c6a0d5765e 100644
--- a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
+++ b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
@@ -94,5 +94,7 @@ extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
size_t buf__sz,
enum hid_report_type type,
enum hid_class_request reqtype) __ksym;
+extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
+ __u8 *buf, size_t buf__sz) __ksym;
#endif /* __HID_BPF_HELPERS_H */
--
2.44.0
On 3/15/24 07:44, Benjamin Tissoires wrote:
> +/**
> + * hid_bpf_hw_output_report - Send an output report to a HID device
> + *
> + * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
> + * @buf: a %PTR_TO_MEM buffer
> + * @buf__sz: the size of the data to transfer
> + *
> + * @returns the number of bytes transferred on success, a negative error code otherwise.
> + */
Minimum change:
@returns:
Preferred change:
Returns:
"@returns" is not documented.
Thanks.
--
#Randy
On 3/15/24 07:44, Benjamin Tissoires wrote:
> It can be interesting to inject events from BPF as if the event were
> to come from the device.
> For example, some multitouch devices do not all the time send a proximity
> out event, and we might want to send it for the physical device.
>
> Compared to uhid, we can now inject events on any physical device, not
> just uhid virtual ones.
>
> Signed-off-by: Benjamin Tissoires <[email protected]>
>
> ---
>
> no changes in v4
>
> no changes in v3
>
> no changes in v2
> ---
> Documentation/hid/hid-bpf.rst | 2 +-
> drivers/hid/bpf/hid_bpf_dispatch.c | 29 +++++++++++++++++++++++++++++
> drivers/hid/hid-core.c | 1 +
> include/linux/hid_bpf.h | 2 ++
> 4 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/hid/hid-bpf.rst b/Documentation/hid/hid-bpf.rst
> index a575004d9025..0765b3298ecf 100644
> --- a/Documentation/hid/hid-bpf.rst
> +++ b/Documentation/hid/hid-bpf.rst
> @@ -179,7 +179,7 @@ Available API that can be used in syscall HID-BPF programs:
> -----------------------------------------------------------
>
> .. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c
> - :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_allocate_context hid_bpf_release_context
> + :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_input_report hid_bpf_allocate_context hid_bpf_release_context
>
> General overview of a HID-BPF program
> =====================================
> diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
> index a5b88b491b80..e1a650f4a626 100644
> --- a/drivers/hid/bpf/hid_bpf_dispatch.c
> +++ b/drivers/hid/bpf/hid_bpf_dispatch.c
> @@ -508,6 +508,34 @@ hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz)
> kfree(dma_data);
> return ret;
> }
> +
> +/**
> + * hid_bpf_input_report - Inject a HID report in the kernel from a HID device
> + *
> + * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
> + * @type: the type of the report (%HID_INPUT_REPORT, %HID_FEATURE_REPORT, %HID_OUTPUT_REPORT)
> + * @buf: a %PTR_TO_MEM buffer
> + * @buf__sz: the size of the data to transfer
> + *
> + * @returns %0 on success, a negative error code otherwise.
Minimum change:
@returns:
Preferred change:
Returns:
"@returns" is not documented.
> + */
> +__bpf_kfunc int
> +hid_bpf_input_report(struct hid_bpf_ctx *ctx, enum hid_report_type type, u8 *buf,
> + const size_t buf__sz)
> +{
--
#Randy
On Fri, Mar 15, 2024 at 5:06 PM Randy Dunlap <[email protected]> wrote:
>
>
>
> On 3/15/24 07:44, Benjamin Tissoires wrote:
> > +/**
> > + * hid_bpf_hw_output_report - Send an output report to a HID device
> > + *
> > + * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
> > + * @buf: a %PTR_TO_MEM buffer
> > + * @buf__sz: the size of the data to transfer
> > + *
> > + * @returns the number of bytes transferred on success, a negative error code otherwise.
> > + */
>
> Minimum change:
>
> @returns:
>
> Preferred change:
>
> Returns:
>
> "@returns" is not documented.
Thanks for the doc review (and in 5/7).
FWIW, I'm still waiting for other reviews if any, and if there are
none, I'll just amend the commit before pushing.
Cheers,
Benjamin
>
>
> Thanks.
> --
> #Randy
>
On Fri, 15 Mar 2024 15:44:37 +0100, Benjamin Tissoires wrote:
> 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/[email protected]/
>
> For reference, the use cases I have in mind:
>
> [...]
Applied to hid/hid.git (for-6.10/hid-bpf), thanks!
[1/7] HID: bpf/dispatch: regroup kfuncs definitions
https://git.kernel.org/hid/hid/c/4171954f56fb
[2/7] HID: bpf: export hid_hw_output_report as a BPF kfunc
https://git.kernel.org/hid/hid/c/5599f8019661
[3/7] selftests/hid: add KASAN to the VM tests
https://git.kernel.org/hid/hid/c/c8a1495947ff
[4/7] selftests/hid: Add test for hid_bpf_hw_output_report
https://git.kernel.org/hid/hid/c/db624e82c55f
[5/7] HID: bpf: allow to inject HID event from BPF
https://git.kernel.org/hid/hid/c/9be50ac30a83
[6/7] selftests/hid: add tests for hid_bpf_input_report
https://git.kernel.org/hid/hid/c/2c0e8ced7d4b
[7/7] HID: bpf: allow to use bpf_timer_set_sleepable_cb() in tracing callbacks.
https://git.kernel.org/hid/hid/c/685dadafbde2
Cheers,
--
Benjamin Tissoires <[email protected]>