[PATCH v2 0/4] Fix warnings in for-6.11/bpf

[PATCH v2 0/4] Fix warnings in for-6.11/bpf

[Benjamin Tissoires]

We had several complains in linux-next that there were warnings:

CKI was not happy: it was the same situation than in an early report
when HID-BPF was initially included: the automatically generated
vmlinux.h doesn't contain all of the required structs and the
compilation of the bpf program fails.

We have multiple pointer to int cast complains and some docs that were
not rendered properly.

Include everything here.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
Changes in v2:
- Also fix the pointer to int casts
- Also fix the docs complains
- Link to v1: https://lore.kernel.org/r/20240627-fix-cki-v1-1-2b47ceac116a@kernel.org

---
Benjamin Tissoires (4):
      selftests/hid: ensure CKI can compile our new tests on old kernels
      HID: bpf: fix gcc warning and unify __u64 into u64
      HID: bpf: doc fixes for hid_hw_request() hooks
      HID: bpf: doc fixes for hid_hw_request() hooks

 drivers/hid/bpf/hid_bpf_dispatch.c                 |  8 +++---
 drivers/hid/bpf/hid_bpf_struct_ops.c               |  2 +-
 drivers/hid/hid-core.c                             |  4 +--
 drivers/hid/hidraw.c                               |  6 ++---
 include/linux/hid_bpf.h                            | 31 +++++++++++++---------
 .../testing/selftests/hid/progs/hid_bpf_helpers.h  | 16 +++++++++++
 6 files changed, 44 insertions(+), 23 deletions(-)
---
base-commit: d3e15189bfd4d0a9d3a7ad8bd0e6ebb1c0419f93
change-id: 20240627-fix-cki-f372855cbf6f

Best regards,
-- 
Benjamin Tissoires <bentiss@kernel.org>

[PATCH v2 1/4] selftests/hid: ensure CKI can compile our new tests on old kernels

[Benjamin Tissoires]

In the same way than commit ae7487d112cf ("selftests/hid: ensure we can
compile the tests on kernels pre-6.3") we should expose struct hid_bpf_ops
when it's not available in vmlinux.h.

So unexpose an eventual struct hid_bpf_ops, include vmlinux.h, and
re-export struct hid_bpf_ops.

Fixes: d7696738d66b ("selftests/hid: convert the hid_bpf selftests with struct_ops")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202406270328.bscLN1IF-lkp@intel.com/
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
 tools/testing/selftests/hid/progs/hid_bpf_helpers.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
index c72e44321764..cfe37f491906 100644
--- a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
+++ b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
@@ -7,6 +7,7 @@
 
 /* "undefine" structs and enums in vmlinux.h, because we "override" them below */
 #define hid_bpf_ctx hid_bpf_ctx___not_used
+#define hid_bpf_ops hid_bpf_ops___not_used
 #define hid_report_type hid_report_type___not_used
 #define hid_class_request hid_class_request___not_used
 #define hid_bpf_attach_flags hid_bpf_attach_flags___not_used
@@ -24,6 +25,7 @@
 #include "vmlinux.h"
 
 #undef hid_bpf_ctx
+#undef hid_bpf_ops
 #undef hid_report_type
 #undef hid_class_request
 #undef hid_bpf_attach_flags
@@ -68,6 +70,20 @@ enum hid_class_request {
 	HID_REQ_SET_PROTOCOL		= 0x0B,
 };
 
+struct hid_bpf_ops {
+	int			hid_id;
+	u32			flags;
+	struct list_head	list;
+	int (*hid_device_event)(struct hid_bpf_ctx *ctx, enum hid_report_type report_type,
+				u64 source);
+	int (*hid_rdesc_fixup)(struct hid_bpf_ctx *ctx);
+	int (*hid_hw_request)(struct hid_bpf_ctx *ctx, unsigned char reportnum,
+			       enum hid_report_type rtype, enum hid_class_request reqtype,
+			       u64 source);
+	int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, u64 source);
+	struct hid_device *hdev;
+};
+
 #ifndef BPF_F_BEFORE
 #define BPF_F_BEFORE (1U << 3)
 #endif

-- 
2.44.0

[PATCH v2 2/4] HID: bpf: fix gcc warning and unify __u64 into u64

[Benjamin Tissoires]

I've got multiple reports of:
error: cast from pointer to integer of different size
[-Werror=pointer-to-int-cast].

Let's use the same trick than kernel/bpf/helpers.c to shut up that warning.

Even if we were on an architecture with addresses on more than 64 bits,
this isn't much of an issue as the address is not used as a pointer,
but as an hash and the caller is not supposed to go back to the kernel
address ever.

And while we change those, make sure we use u64 instead of __u64 for
consistency

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406280633.OPB5uIFj-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406282304.UydSVncq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406282242.Fk738zzy-lkp@intel.com/
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Fixes: 67eccf151d76 ("HID: add source argument to HID low level functions")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
 drivers/hid/bpf/hid_bpf_dispatch.c   | 6 +++---
 drivers/hid/bpf/hid_bpf_struct_ops.c | 2 +-
 drivers/hid/hid-core.c               | 4 ++--
 drivers/hid/hidraw.c                 | 6 +++---
 include/linux/hid_bpf.h              | 6 +++---
 5 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 23daf94510bb..a36e680399fe 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -440,7 +440,7 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
 					      size,
 					      rtype,
 					      reqtype,
-					      (__u64)ctx,
+					      (u64)(long)ctx,
 					      true); /* prevent infinite recursions */
 
 	if (ret > 0)
@@ -483,7 +483,7 @@ hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz)
 	if (!dma_data)
 		return -ENOMEM;
 
-	ret = hid_ops->hid_hw_output_report(hdev, dma_data, size, (__u64)ctx, true);
+	ret = hid_ops->hid_hw_output_report(hdev, dma_data, size, (u64)(long)ctx, true);
 
 	kfree(dma_data);
 	return ret;
@@ -505,7 +505,7 @@ __hid_bpf_input_report(struct hid_bpf_ctx *ctx, enum hid_report_type type, u8 *b
 	if (ret)
 		return ret;
 
-	return hid_ops->hid_input_report(ctx->hid, type, buf, size, 0, (__u64)ctx, true,
+	return hid_ops->hid_input_report(ctx->hid, type, buf, size, 0, (u64)(long)ctx, true,
 					 lock_already_taken);
 }
 
diff --git a/drivers/hid/bpf/hid_bpf_struct_ops.c b/drivers/hid/bpf/hid_bpf_struct_ops.c
index 37d2f8e2413a..b03b44ad3458 100644
--- a/drivers/hid/bpf/hid_bpf_struct_ops.c
+++ b/drivers/hid/bpf/hid_bpf_struct_ops.c
@@ -261,7 +261,7 @@ static void hid_bpf_unreg(void *kdata)
 	hid_put_device(hdev);
 }
 
-static int __hid_bpf_device_event(struct hid_bpf_ctx *ctx, enum hid_report_type type, __u64 source)
+static int __hid_bpf_device_event(struct hid_bpf_ctx *ctx, enum hid_report_type type, u64 source)
 {
 	return 0;
 }
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 52a75afe3e7d..0f797dab975b 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2412,7 +2412,7 @@ int __hid_hw_raw_request(struct hid_device *hdev,
 			 unsigned char reportnum, __u8 *buf,
 			 size_t len, enum hid_report_type rtype,
 			 enum hid_class_request reqtype,
-			 __u64 source, bool from_bpf)
+			 u64 source, bool from_bpf)
 {
 	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
 	int ret;
@@ -2454,7 +2454,7 @@ int hid_hw_raw_request(struct hid_device *hdev,
 }
 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
 
-int __hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len, __u64 source,
+int __hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len, u64 source,
 			   bool from_bpf)
 {
 	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index c2396916cdaa..716294e40e8a 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -140,7 +140,7 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
 
 	if ((report_type == HID_OUTPUT_REPORT) &&
 	    !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
-		ret = __hid_hw_output_report(dev, buf, count, (__u64)file, false);
+		ret = __hid_hw_output_report(dev, buf, count, (u64)(long)file, false);
 		/*
 		 * compatibility with old implementation of USB-HID and I2C-HID:
 		 * if the device does not support receiving output reports,
@@ -151,7 +151,7 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer,
 	}
 
 	ret = __hid_hw_raw_request(dev, buf[0], buf, count, report_type,
-				   HID_REQ_SET_REPORT, (__u64)file, false);
+				   HID_REQ_SET_REPORT, (u64)(long)file, false);
 
 out_free:
 	kfree(buf);
@@ -228,7 +228,7 @@ static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t
 	}
 
 	ret = __hid_hw_raw_request(dev, report_number, buf, count, report_type,
-				   HID_REQ_GET_REPORT, (__u64)file, false);
+				   HID_REQ_GET_REPORT, (u64)(long)file, false);
 
 	if (ret < 0)
 		goto out_free;
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index 93546ee7677a..3f6584014311 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -68,9 +68,9 @@ struct hid_ops {
 				  unsigned char reportnum, __u8 *buf,
 				  size_t len, enum hid_report_type rtype,
 				  enum hid_class_request reqtype,
-				  __u64 source, bool from_bpf);
+				  u64 source, bool from_bpf);
 	int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len,
-				    __u64 source, bool from_bpf);
+				    u64 source, bool from_bpf);
 	int (*hid_input_report)(struct hid_device *hid, enum hid_report_type type,
 				u8 *data, u32 size, int interrupt, u64 source, bool from_bpf,
 				bool lock_already_taken);
@@ -115,7 +115,7 @@ struct hid_bpf_ops {
 	 * Context: Interrupt context.
 	 */
 	int (*hid_device_event)(struct hid_bpf_ctx *ctx, enum hid_report_type report_type,
-				__u64 source);
+				u64 source);
 
 	/**
 	 * @hid_rdesc_fixup: called when the probe function parses the report descriptor

-- 
2.44.0

[PATCH v2 3/4] HID: bpf: doc fixes for hid_hw_request() hooks

[Benjamin Tissoires]

We had the following errors while doing make htmldocs:
Documentation/hid/hid-bpf:185: include/linux/hid_bpf.h:144:
	ERROR: Unexpected indentation.
Documentation/hid/hid-bpf:185: include/linux/hid_bpf.h:145:
	WARNING: Block quote ends without a blank line;
	unexpected unindent.
Documentation/hid/hid-bpf:185: include/linux/hid_bpf.h:147:
	ERROR: Unexpected indentation.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 8bd0488b5ea5 ("HID: bpf: add HID-BPF hooks for hid_hw_raw_requests")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
 include/linux/hid_bpf.h | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index 3f6584014311..c30c31b79419 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -139,12 +139,15 @@ struct hid_bpf_ops {
 	 *
 	 * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx
 	 * ``reportnum``: the report number, as in hid_hw_raw_request()
+	 *
 	 * ``rtype``: the report type (``HID_INPUT_REPORT``, ``HID_FEATURE_REPORT``,
-	 *            ``HID_OUTPUT_REPORT``)
+	 * ``HID_OUTPUT_REPORT``)
+	 *
 	 * ``reqtype``: the request
+	 *
 	 * ``source``: a u64 referring to a uniq but identifiable source. If %0, the
-	 *             kernel itself emitted that call. For hidraw, ``source`` is set
-	 *             to the associated ``struct file *``.
+	 * kernel itself emitted that call. For hidraw, ``source`` is set
+	 * to the associated ``struct file *``.
 	 *
 	 * Return: %0 to keep processing the request by hid-core; any other value
 	 * stops hid-core from processing that event. A positive value should be
@@ -153,7 +156,7 @@ struct hid_bpf_ops {
 	 */
 	int (*hid_hw_request)(struct hid_bpf_ctx *ctx, unsigned char reportnum,
 			       enum hid_report_type rtype, enum hid_class_request reqtype,
-			       __u64 source);
+			       u64 source);
 
 	/**
 	 * @hid_hw_output_report: called whenever a hid_hw_output_report() call is emitted

-- 
2.44.0

[PATCH v2 4/4] HID: bpf: doc fixes for hid_hw_request() hooks

[Benjamin Tissoires]

We had the following errors while doing make htmldocs:

Documentation/hid/hid-bpf:185: include/linux/hid_bpf.h:167:
	ERROR: Unexpected indentation.

Also ensure consistency with the rest of the __u64 vs u64.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 9286675a2aed ("HID: bpf: add HID-BPF hooks for hid_hw_output_report")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
 drivers/hid/bpf/hid_bpf_dispatch.c |  2 +-
 include/linux/hid_bpf.h            | 14 ++++++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index a36e680399fe..a272a086c950 100644
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -115,7 +115,7 @@ int dispatch_hid_bpf_raw_requests(struct hid_device *hdev,
 EXPORT_SYMBOL_GPL(dispatch_hid_bpf_raw_requests);
 
 int dispatch_hid_bpf_output_report(struct hid_device *hdev,
-				   __u8 *buf, u32 size, __u64 source,
+				   __u8 *buf, u32 size, u64 source,
 				   bool from_bpf)
 {
 	struct hid_bpf_ctx_kern ctx_kern = {
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index c30c31b79419..9ca96fc90449 100644
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -138,6 +138,7 @@ struct hid_bpf_ops {
 	 * It has the following arguments:
 	 *
 	 * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx
+	 *
 	 * ``reportnum``: the report number, as in hid_hw_raw_request()
 	 *
 	 * ``rtype``: the report type (``HID_INPUT_REPORT``, ``HID_FEATURE_REPORT``,
@@ -165,16 +166,17 @@ struct hid_bpf_ops {
 	 * It has the following arguments:
 	 *
 	 * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx
+	 *
 	 * ``source``: a u64 referring to a uniq but identifiable source. If %0, the
-	 *             kernel itself emitted that call. For hidraw, ``source`` is set
-	 *             to the associated ``struct file *``.
+	 * kernel itself emitted that call. For hidraw, ``source`` is set
+	 * to the associated ``struct file *``.
 	 *
 	 * Return: %0 to keep processing the request by hid-core; any other value
 	 * stops hid-core from processing that event. A positive value should be
 	 * returned with the number of bytes written to the device; a negative error
 	 * code interrupts the processing of this call.
 	 */
-	int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, __u64 source);
+	int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, u64 source);
 
 
 	/* private: do not show up in the docs */
@@ -203,9 +205,9 @@ int dispatch_hid_bpf_raw_requests(struct hid_device *hdev,
 				  unsigned char reportnum, __u8 *buf,
 				  u32 size, enum hid_report_type rtype,
 				  enum hid_class_request reqtype,
-				  __u64 source, bool from_bpf);
+				  u64 source, bool from_bpf);
 int dispatch_hid_bpf_output_report(struct hid_device *hdev, __u8 *buf, u32 size,
-				   __u64 source, bool from_bpf);
+				   u64 source, bool from_bpf);
 int hid_bpf_connect_device(struct hid_device *hdev);
 void hid_bpf_disconnect_device(struct hid_device *hdev);
 void hid_bpf_destroy_device(struct hid_device *hid);
@@ -221,7 +223,7 @@ static inline int dispatch_hid_bpf_raw_requests(struct hid_device *hdev,
 						enum hid_class_request reqtype,
 						u64 source, bool from_bpf) { return 0; }
 static inline int dispatch_hid_bpf_output_report(struct hid_device *hdev, __u8 *buf, u32 size,
-						 __u64 source, bool from_bpf) { return 0; }
+						 u64 source, bool from_bpf) { return 0; }
 static inline int hid_bpf_connect_device(struct hid_device *hdev) { return 0; }
 static inline void hid_bpf_disconnect_device(struct hid_device *hdev) {}
 static inline void hid_bpf_destroy_device(struct hid_device *hid) {}

-- 
2.44.0

Re: [PATCH v2 0/4] Fix warnings in for-6.11/bpf

[Benjamin Tissoires]

On Mon, 01 Jul 2024 14:39:48 +0200, Benjamin Tissoires wrote:
> We had several complains in linux-next that there were warnings:
> 
> CKI was not happy: it was the same situation than in an early report
> when HID-BPF was initially included: the automatically generated
> vmlinux.h doesn't contain all of the required structs and the
> compilation of the bpf program fails.
> 
> [...]

Applied to hid/hid.git (for-6.11/bpf), thanks!

[1/4] selftests/hid: ensure CKI can compile our new tests on old kernels
      https://git.kernel.org/hid/hid/c/fcdf830ea634
[2/4] HID: bpf: fix gcc warning and unify __u64 into u64
      https://git.kernel.org/hid/hid/c/762ced1630a9
[3/4] HID: bpf: doc fixes for hid_hw_request() hooks
      https://git.kernel.org/hid/hid/c/c79de517a226
[4/4] HID: bpf: doc fixes for hid_hw_request() hooks
      https://git.kernel.org/hid/hid/c/c79de517a226

Cheers,
-- 
Benjamin Tissoires <bentiss@kernel.org>