Messages in this thread | | | Date | Tue, 15 Mar 2022 18:29:12 +0200 | Subject | Re: [PATCH bpf-next v2 03/28] HID: hook up with bpf | From | Tero Kristo <> |
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Hi Benjamin,
On 04/03/2022 19:28, Benjamin Tissoires wrote: > Now that BPF can be compatible with HID, add the capability into HID. > drivers/hid/hid-bpf.c takes care of the glue between bpf and HID, and > hid-core can then inject any incoming event from the device into a BPF > program to filter/analyze it. > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > --- > > changes in v2: > - split the series by bpf/libbpf/hid/selftests and samples > - addressed review comments from v1 > --- > drivers/hid/Makefile | 1 + > drivers/hid/hid-bpf.c | 157 +++++++++++++++++++++++++++++++++++++++++ > drivers/hid/hid-core.c | 21 +++++- > include/linux/hid.h | 11 +++ > 4 files changed, 187 insertions(+), 3 deletions(-) > create mode 100644 drivers/hid/hid-bpf.c > > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile > index 6d3e630e81af..08d2d7619937 100644 > --- a/drivers/hid/Makefile > +++ b/drivers/hid/Makefile > @@ -4,6 +4,7 @@ > # > hid-y := hid-core.o hid-input.o hid-quirks.o > hid-$(CONFIG_DEBUG_FS) += hid-debug.o > +hid-$(CONFIG_BPF) += hid-bpf.o > > obj-$(CONFIG_HID) += hid.o > obj-$(CONFIG_UHID) += uhid.o > diff --git a/drivers/hid/hid-bpf.c b/drivers/hid/hid-bpf.c > new file mode 100644 > index 000000000000..8120e598de9f > --- /dev/null > +++ b/drivers/hid/hid-bpf.c > @@ -0,0 +1,157 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * BPF in HID support for Linux > + * > + * Copyright (c) 2022 Benjamin Tissoires > + */ > + > +#include <linux/filter.h> > +#include <linux/mutex.h> > +#include <linux/slab.h> > + > +#include <uapi/linux/bpf_hid.h> > +#include <linux/hid.h> > + > +static int __hid_bpf_match_sysfs(struct device *dev, const void *data) > +{ > + struct kernfs_node *kn = dev->kobj.sd; > + struct kernfs_node *uevent_kn; > + > + uevent_kn = kernfs_find_and_get_ns(kn, "uevent", NULL); > + > + return uevent_kn == data; > +} > + > +static struct hid_device *hid_bpf_fd_to_hdev(int fd) > +{ > + struct device *dev; > + struct hid_device *hdev; > + struct fd f = fdget(fd); > + struct inode *inode; > + struct kernfs_node *node; > + > + if (!f.file) { > + hdev = ERR_PTR(-EBADF); > + goto out; > + } > + > + inode = file_inode(f.file); > + node = inode->i_private; > + > + dev = bus_find_device(&hid_bus_type, NULL, node, __hid_bpf_match_sysfs); > + > + if (dev) > + hdev = to_hid_device(dev); > + else > + hdev = ERR_PTR(-EINVAL); > + > + out: > + fdput(f); > + return hdev; > +} > + > +static int hid_bpf_link_attach(struct hid_device *hdev, enum bpf_hid_attach_type type) > +{ > + int err = 0; > + > + 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); > + if (IS_ERR(hdev->bpf.ctx)) { > + err = PTR_ERR(hdev->bpf.ctx); > + hdev->bpf.ctx = NULL; > + } > + } > + break; > + default: > + /* do nothing */
These cause following error:
CC drivers/hid/hid-bpf.o drivers/hid/hid-bpf.c: In function ‘hid_bpf_link_attach’: drivers/hid/hid-bpf.c:88:2: error: label at end of compound statement 88 | default: | ^~~~~~~ drivers/hid/hid-bpf.c: In function ‘hid_bpf_link_attached’: drivers/hid/hid-bpf.c:101:2: error: label at end of compound statement 101 | default: | ^~~~~~~ drivers/hid/hid-bpf.c: In function ‘hid_bpf_array_detached’: drivers/hid/hid-bpf.c:116:2: error: label at end of compound statement 116 | default: | ^~~~~~~ make[2]: *** [scripts/Makefile.build:288: drivers/hid/hid-bpf.o] Error 1 make[1]: *** [scripts/Makefile.build:550: drivers/hid] Error 2 make[1]: *** Waiting for unfinished jobs.... make: *** [Makefile:1831: drivers] Error 2
To fix that, you need to add a break statement at end:
default:
/* do nothing */
break;
Same for couple of other occurrences in the file.
-Tero
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