diff mbox series

[bpf-next,v2,23/28] HID: bpf: compute only the required buffer size for the device

Message ID 20220304172852.274126-24-benjamin.tissoires@redhat.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Introduce eBPF support for HID devices | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
bpf/vmtest-bpf-next fail VM_Test
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 38 this patch: 38
netdev/cc_maintainers success CCed 13 of 13 maintainers
netdev/build_clang fail Errors and warnings before: 11 this patch: 11
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 38 this patch: 38
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Benjamin Tissoires March 4, 2022, 5:28 p.m. UTC 
There is no point in using 16 kB of memory if the device needs less
for all of its reports (uwhich is usually the case).

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

new in v2
---
 drivers/hid/hid-bpf.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/hid/hid-bpf.c b/drivers/hid/hid-bpf.c
index b8c0060f3180..d56fbad990ed 100644
--- a/drivers/hid/hid-bpf.c
+++ b/drivers/hid/hid-bpf.c
@@ -61,11 +61,24 @@  static int hid_reconnect(struct hid_device *hdev)
 static int hid_bpf_link_attach(struct hid_device *hdev, enum bpf_hid_attach_type type)
 {
 	int err = 0;
+	unsigned int i, j, max_report_len = 0;
+
+	/* compute the maximum report length for this device */
+	for (i = 0; i < HID_REPORT_TYPES; i++) {
+		struct hid_report_enum *report_enum = hdev->report_enum + i;
+
+		for (j = 0; j < HID_MAX_IDS; j++) {
+			struct hid_report *report = report_enum->report_id_hash[j];
+
+			if (report)
+				max_report_len = max(max_report_len, hid_report_len(report));
+		}
+	}
 
 	switch (type) {
 	case BPF_HID_ATTACH_DEVICE_EVENT:
 		if (!hdev->bpf.ctx) {
-			hdev->bpf.ctx = bpf_hid_allocate_ctx(hdev, HID_BPF_MAX_BUFFER_SIZE);
+			hdev->bpf.ctx = bpf_hid_allocate_ctx(hdev, max_report_len);
 			if (IS_ERR(hdev->bpf.ctx)) {
 				err = PTR_ERR(hdev->bpf.ctx);
 				hdev->bpf.ctx = NULL;