Re: [PATCH v4 3/3] bpf: add selftest for lirc_mode2 type program
From: Y Song
Date: Fri May 18 2018 - 15:22:14 EST
On Fri, May 18, 2018 at 7:07 AM, Sean Young <sean@xxxxxxxx> wrote:
> This is simple test over rc-loopback.
>
> Signed-off-by: Sean Young <sean@xxxxxxxx>
Acked-by: Yonghong Song <yhs@xxxxxx>
> ---
> tools/bpf/bpftool/prog.c | 1 +
> tools/include/uapi/linux/bpf.h | 53 ++++-
> tools/include/uapi/linux/lirc.h | 217 ++++++++++++++++++
> tools/lib/bpf/libbpf.c | 1 +
> tools/testing/selftests/bpf/Makefile | 8 +-
> tools/testing/selftests/bpf/bpf_helpers.h | 6 +
> .../testing/selftests/bpf/test_lirc_mode2.sh | 28 +++
> .../selftests/bpf/test_lirc_mode2_kern.c | 23 ++
> .../selftests/bpf/test_lirc_mode2_user.c | 154 +++++++++++++
> 9 files changed, 487 insertions(+), 4 deletions(-)
> create mode 100644 tools/include/uapi/linux/lirc.h
> create mode 100755 tools/testing/selftests/bpf/test_lirc_mode2.sh
> create mode 100644 tools/testing/selftests/bpf/test_lirc_mode2_kern.c
> create mode 100644 tools/testing/selftests/bpf/test_lirc_mode2_user.c
>
> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> index 9bdfdf2d3fbe..07f1ace39a46 100644
> --- a/tools/bpf/bpftool/prog.c
> +++ b/tools/bpf/bpftool/prog.c
> @@ -71,6 +71,7 @@ static const char * const prog_type_name[] = {
> [BPF_PROG_TYPE_SK_MSG] = "sk_msg",
> [BPF_PROG_TYPE_RAW_TRACEPOINT] = "raw_tracepoint",
> [BPF_PROG_TYPE_CGROUP_SOCK_ADDR] = "cgroup_sock_addr",
> + [BPF_PROG_TYPE_LIRC_MODE2] = "lirc_mode2",
> };
>
> static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index d94d333a8225..8227832b713e 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -141,6 +141,7 @@ enum bpf_prog_type {
> BPF_PROG_TYPE_SK_MSG,
> BPF_PROG_TYPE_RAW_TRACEPOINT,
> BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
> + BPF_PROG_TYPE_LIRC_MODE2,
> };
>
> enum bpf_attach_type {
> @@ -158,6 +159,7 @@ enum bpf_attach_type {
> BPF_CGROUP_INET6_CONNECT,
> BPF_CGROUP_INET4_POST_BIND,
> BPF_CGROUP_INET6_POST_BIND,
> + BPF_LIRC_MODE2,
> __MAX_BPF_ATTACH_TYPE
> };
>
> @@ -1902,6 +1904,53 @@ union bpf_attr {
> * egress otherwise). This is the only flag supported for now.
> * Return
> * **SK_PASS** on success, or **SK_DROP** on error.
> + *
> + * int bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
> + * Description
> + * This helper is used in programs implementing IR decoding, to
> + * report a successfully decoded key press with *scancode*,
> + * *toggle* value in the given *protocol*. The scancode will be
> + * translated to a keycode using the rc keymap, and reported as
> + * an input key down event. After a period a key up event is
> + * generated. This period can be extended by calling either
> + * **bpf_rc_keydown** () with the same values, or calling
> + * **bpf_rc_repeat** ().
> + *
> + * Some protocols include a toggle bit, in case the button
> + * was released and pressed again between consecutive scancodes
> + *
> + * The *ctx* should point to the lirc sample as passed into
> + * the program.
> + *
> + * The *protocol* is the decoded protocol number (see
> + * **enum rc_proto** for some predefined values).
> + *
> + * This helper is only available is the kernel was compiled with
> + * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
> + * "**y**".
> + *
> + * Return
> + * 0
> + *
> + * int bpf_rc_repeat(void *ctx)
> + * Description
> + * This helper is used in programs implementing IR decoding, to
> + * report a successfully decoded repeat key message. This delays
> + * the generation of a key up event for previously generated
> + * key down event.
> + *
> + * Some IR protocols like NEC have a special IR message for
> + * repeating last button, for when a button is held down.
> + *
> + * The *ctx* should point to the lirc sample as passed into
> + * the program.
> + *
> + * This helper is only available is the kernel was compiled with
> + * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
> + * "**y**".
> + *
> + * Return
> + * 0
> */
> #define __BPF_FUNC_MAPPER(FN) \
> FN(unspec), \
> @@ -1976,7 +2025,9 @@ union bpf_attr {
> FN(fib_lookup), \
> FN(sock_hash_update), \
> FN(msg_redirect_hash), \
> - FN(sk_redirect_hash),
> + FN(sk_redirect_hash), \
> + FN(rc_repeat), \
> + FN(rc_keydown),
>
> /* integer value in 'imm' field of BPF_CALL instruction selects which helper
> * function eBPF program intends to call
> diff --git a/tools/include/uapi/linux/lirc.h b/tools/include/uapi/linux/lirc.h
> new file mode 100644
> index 000000000000..f189931042a7
> --- /dev/null
> +++ b/tools/include/uapi/linux/lirc.h
> @@ -0,0 +1,217 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * lirc.h - linux infrared remote control header file
> + * last modified 2010/07/13 by Jarod Wilson
> + */
> +
> +#ifndef _LINUX_LIRC_H
> +#define _LINUX_LIRC_H
> +
> +#include <linux/types.h>
> +#include <linux/ioctl.h>
> +
> +#define PULSE_BIT 0x01000000
> +#define PULSE_MASK 0x00FFFFFF
> +
> +#define LIRC_MODE2_SPACE 0x00000000
> +#define LIRC_MODE2_PULSE 0x01000000
> +#define LIRC_MODE2_FREQUENCY 0x02000000
> +#define LIRC_MODE2_TIMEOUT 0x03000000
> +
> +#define LIRC_VALUE_MASK 0x00FFFFFF
> +#define LIRC_MODE2_MASK 0xFF000000
> +
> +#define LIRC_SPACE(val) (((val)&LIRC_VALUE_MASK) | LIRC_MODE2_SPACE)
> +#define LIRC_PULSE(val) (((val)&LIRC_VALUE_MASK) | LIRC_MODE2_PULSE)
> +#define LIRC_FREQUENCY(val) (((val)&LIRC_VALUE_MASK) | LIRC_MODE2_FREQUENCY)
> +#define LIRC_TIMEOUT(val) (((val)&LIRC_VALUE_MASK) | LIRC_MODE2_TIMEOUT)
> +
> +#define LIRC_VALUE(val) ((val)&LIRC_VALUE_MASK)
> +#define LIRC_MODE2(val) ((val)&LIRC_MODE2_MASK)
> +
> +#define LIRC_IS_SPACE(val) (LIRC_MODE2(val) == LIRC_MODE2_SPACE)
> +#define LIRC_IS_PULSE(val) (LIRC_MODE2(val) == LIRC_MODE2_PULSE)
> +#define LIRC_IS_FREQUENCY(val) (LIRC_MODE2(val) == LIRC_MODE2_FREQUENCY)
> +#define LIRC_IS_TIMEOUT(val) (LIRC_MODE2(val) == LIRC_MODE2_TIMEOUT)
> +
> +/* used heavily by lirc userspace */
> +#define lirc_t int
> +
> +/*** lirc compatible hardware features ***/
> +
> +#define LIRC_MODE2SEND(x) (x)
> +#define LIRC_SEND2MODE(x) (x)
> +#define LIRC_MODE2REC(x) ((x) << 16)
> +#define LIRC_REC2MODE(x) ((x) >> 16)
> +
> +#define LIRC_MODE_RAW 0x00000001
> +#define LIRC_MODE_PULSE 0x00000002
> +#define LIRC_MODE_MODE2 0x00000004
> +#define LIRC_MODE_SCANCODE 0x00000008
> +#define LIRC_MODE_LIRCCODE 0x00000010
> +
> +
> +#define LIRC_CAN_SEND_RAW LIRC_MODE2SEND(LIRC_MODE_RAW)
> +#define LIRC_CAN_SEND_PULSE LIRC_MODE2SEND(LIRC_MODE_PULSE)
> +#define LIRC_CAN_SEND_MODE2 LIRC_MODE2SEND(LIRC_MODE_MODE2)
> +#define LIRC_CAN_SEND_LIRCCODE LIRC_MODE2SEND(LIRC_MODE_LIRCCODE)
> +
> +#define LIRC_CAN_SEND_MASK 0x0000003f
> +
> +#define LIRC_CAN_SET_SEND_CARRIER 0x00000100
> +#define LIRC_CAN_SET_SEND_DUTY_CYCLE 0x00000200
> +#define LIRC_CAN_SET_TRANSMITTER_MASK 0x00000400
> +
> +#define LIRC_CAN_REC_RAW LIRC_MODE2REC(LIRC_MODE_RAW)
> +#define LIRC_CAN_REC_PULSE LIRC_MODE2REC(LIRC_MODE_PULSE)
> +#define LIRC_CAN_REC_MODE2 LIRC_MODE2REC(LIRC_MODE_MODE2)
> +#define LIRC_CAN_REC_SCANCODE LIRC_MODE2REC(LIRC_MODE_SCANCODE)
> +#define LIRC_CAN_REC_LIRCCODE LIRC_MODE2REC(LIRC_MODE_LIRCCODE)
> +
> +#define LIRC_CAN_REC_MASK LIRC_MODE2REC(LIRC_CAN_SEND_MASK)
> +
> +#define LIRC_CAN_SET_REC_CARRIER (LIRC_CAN_SET_SEND_CARRIER << 16)
> +#define LIRC_CAN_SET_REC_DUTY_CYCLE (LIRC_CAN_SET_SEND_DUTY_CYCLE << 16)
> +
> +#define LIRC_CAN_SET_REC_DUTY_CYCLE_RANGE 0x40000000
> +#define LIRC_CAN_SET_REC_CARRIER_RANGE 0x80000000
> +#define LIRC_CAN_GET_REC_RESOLUTION 0x20000000
> +#define LIRC_CAN_SET_REC_TIMEOUT 0x10000000
> +#define LIRC_CAN_SET_REC_FILTER 0x08000000
> +
> +#define LIRC_CAN_MEASURE_CARRIER 0x02000000
> +#define LIRC_CAN_USE_WIDEBAND_RECEIVER 0x04000000
> +
> +#define LIRC_CAN_SEND(x) ((x)&LIRC_CAN_SEND_MASK)
> +#define LIRC_CAN_REC(x) ((x)&LIRC_CAN_REC_MASK)
> +
> +#define LIRC_CAN_NOTIFY_DECODE 0x01000000
> +
> +/*** IOCTL commands for lirc driver ***/
> +
> +#define LIRC_GET_FEATURES _IOR('i', 0x00000000, __u32)
> +
> +#define LIRC_GET_SEND_MODE _IOR('i', 0x00000001, __u32)
> +#define LIRC_GET_REC_MODE _IOR('i', 0x00000002, __u32)
> +#define LIRC_GET_REC_RESOLUTION _IOR('i', 0x00000007, __u32)
> +
> +#define LIRC_GET_MIN_TIMEOUT _IOR('i', 0x00000008, __u32)
> +#define LIRC_GET_MAX_TIMEOUT _IOR('i', 0x00000009, __u32)
> +
> +/* code length in bits, currently only for LIRC_MODE_LIRCCODE */
> +#define LIRC_GET_LENGTH _IOR('i', 0x0000000f, __u32)
> +
> +#define LIRC_SET_SEND_MODE _IOW('i', 0x00000011, __u32)
> +#define LIRC_SET_REC_MODE _IOW('i', 0x00000012, __u32)
> +/* Note: these can reset the according pulse_width */
> +#define LIRC_SET_SEND_CARRIER _IOW('i', 0x00000013, __u32)
> +#define LIRC_SET_REC_CARRIER _IOW('i', 0x00000014, __u32)
> +#define LIRC_SET_SEND_DUTY_CYCLE _IOW('i', 0x00000015, __u32)
> +#define LIRC_SET_TRANSMITTER_MASK _IOW('i', 0x00000017, __u32)
> +
> +/*
> + * when a timeout != 0 is set the driver will send a
> + * LIRC_MODE2_TIMEOUT data packet, otherwise LIRC_MODE2_TIMEOUT is
> + * never sent, timeout is disabled by default
> + */
> +#define LIRC_SET_REC_TIMEOUT _IOW('i', 0x00000018, __u32)
> +
> +/* 1 enables, 0 disables timeout reports in MODE2 */
> +#define LIRC_SET_REC_TIMEOUT_REPORTS _IOW('i', 0x00000019, __u32)
> +
> +/*
> + * if enabled from the next key press on the driver will send
> + * LIRC_MODE2_FREQUENCY packets
> + */
> +#define LIRC_SET_MEASURE_CARRIER_MODE _IOW('i', 0x0000001d, __u32)
> +
> +/*
> + * to set a range use LIRC_SET_REC_CARRIER_RANGE with the
> + * lower bound first and later LIRC_SET_REC_CARRIER with the upper bound
> + */
> +#define LIRC_SET_REC_CARRIER_RANGE _IOW('i', 0x0000001f, __u32)
> +
> +#define LIRC_SET_WIDEBAND_RECEIVER _IOW('i', 0x00000023, __u32)
> +
> +/*
> + * struct lirc_scancode - decoded scancode with protocol for use with
> + * LIRC_MODE_SCANCODE
> + *
> + * @timestamp: Timestamp in nanoseconds using CLOCK_MONOTONIC when IR
> + * was decoded.
> + * @flags: should be 0 for transmit. When receiving scancodes,
> + * LIRC_SCANCODE_FLAG_TOGGLE or LIRC_SCANCODE_FLAG_REPEAT can be set
> + * depending on the protocol
> + * @rc_proto: see enum rc_proto
> + * @keycode: the translated keycode. Set to 0 for transmit.
> + * @scancode: the scancode received or to be sent
> + */
> +struct lirc_scancode {
> + __u64 timestamp;
> + __u16 flags;
> + __u16 rc_proto;
> + __u32 keycode;
> + __u64 scancode;
> +};
> +
> +/* Set if the toggle bit of rc-5 or rc-6 is enabled */
> +#define LIRC_SCANCODE_FLAG_TOGGLE 1
> +/* Set if this is a nec or sanyo repeat */
> +#define LIRC_SCANCODE_FLAG_REPEAT 2
> +
> +/**
> + * enum rc_proto - the Remote Controller protocol
> + *
> + * @RC_PROTO_UNKNOWN: Protocol not known
> + * @RC_PROTO_OTHER: Protocol known but proprietary
> + * @RC_PROTO_RC5: Philips RC5 protocol
> + * @RC_PROTO_RC5X_20: Philips RC5x 20 bit protocol
> + * @RC_PROTO_RC5_SZ: StreamZap variant of RC5
> + * @RC_PROTO_JVC: JVC protocol
> + * @RC_PROTO_SONY12: Sony 12 bit protocol
> + * @RC_PROTO_SONY15: Sony 15 bit protocol
> + * @RC_PROTO_SONY20: Sony 20 bit protocol
> + * @RC_PROTO_NEC: NEC protocol
> + * @RC_PROTO_NECX: Extended NEC protocol
> + * @RC_PROTO_NEC32: NEC 32 bit protocol
> + * @RC_PROTO_SANYO: Sanyo protocol
> + * @RC_PROTO_MCIR2_KBD: RC6-ish MCE keyboard
> + * @RC_PROTO_MCIR2_MSE: RC6-ish MCE mouse
> + * @RC_PROTO_RC6_0: Philips RC6-0-16 protocol
> + * @RC_PROTO_RC6_6A_20: Philips RC6-6A-20 protocol
> + * @RC_PROTO_RC6_6A_24: Philips RC6-6A-24 protocol
> + * @RC_PROTO_RC6_6A_32: Philips RC6-6A-32 protocol
> + * @RC_PROTO_RC6_MCE: MCE (Philips RC6-6A-32 subtype) protocol
> + * @RC_PROTO_SHARP: Sharp protocol
> + * @RC_PROTO_XMP: XMP protocol
> + * @RC_PROTO_CEC: CEC protocol
> + * @RC_PROTO_IMON: iMon Pad protocol
> + */
> +enum rc_proto {
> + RC_PROTO_UNKNOWN = 0,
> + RC_PROTO_OTHER = 1,
> + RC_PROTO_RC5 = 2,
> + RC_PROTO_RC5X_20 = 3,
> + RC_PROTO_RC5_SZ = 4,
> + RC_PROTO_JVC = 5,
> + RC_PROTO_SONY12 = 6,
> + RC_PROTO_SONY15 = 7,
> + RC_PROTO_SONY20 = 8,
> + RC_PROTO_NEC = 9,
> + RC_PROTO_NECX = 10,
> + RC_PROTO_NEC32 = 11,
> + RC_PROTO_SANYO = 12,
> + RC_PROTO_MCIR2_KBD = 13,
> + RC_PROTO_MCIR2_MSE = 14,
> + RC_PROTO_RC6_0 = 15,
> + RC_PROTO_RC6_6A_20 = 16,
> + RC_PROTO_RC6_6A_24 = 17,
> + RC_PROTO_RC6_6A_32 = 18,
> + RC_PROTO_RC6_MCE = 19,
> + RC_PROTO_SHARP = 20,
> + RC_PROTO_XMP = 21,
> + RC_PROTO_CEC = 22,
> + RC_PROTO_IMON = 23,
> +};
> +
> +#endif
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 3dbe217bf23e..01e514479f6b 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -1461,6 +1461,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
> case BPF_PROG_TYPE_CGROUP_DEVICE:
> case BPF_PROG_TYPE_SK_MSG:
> case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
> + case BPF_PROG_TYPE_LIRC_MODE2:
> return false;
> case BPF_PROG_TYPE_UNSPEC:
> case BPF_PROG_TYPE_KPROBE:
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index 1eb0fa2aba92..ee6d49f18be5 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -24,7 +24,7 @@ urandom_read: urandom_read.c
> # Order correspond to 'make run_tests' order
> TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
> test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
> - test_sock test_btf test_sockmap
> + test_sock test_btf test_sockmap test_lirc_mode2_user
>
> TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \
> test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
> @@ -33,7 +33,8 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
> sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
> sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
> test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \
> - test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o
> + test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \
> + test_lirc_mode2_kern.o
>
> # Order correspond to 'make run_tests' order
> TEST_PROGS := test_kmod.sh \
> @@ -42,7 +43,8 @@ TEST_PROGS := test_kmod.sh \
> test_xdp_meta.sh \
> test_offload.py \
> test_sock_addr.sh \
> - test_tunnel.sh
> + test_tunnel.sh \
> + test_lirc_mode2.sh
>
> # Compile but not part of 'make run_tests'
> TEST_GEN_PROGS_EXTENDED = test_libbpf_open test_sock_addr
> diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
> index 8f143dfb3700..a6864827ed34 100644
> --- a/tools/testing/selftests/bpf/bpf_helpers.h
> +++ b/tools/testing/selftests/bpf/bpf_helpers.h
> @@ -114,6 +114,12 @@ static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) =
> static int (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params,
> int plen, __u32 flags) =
> (void *) BPF_FUNC_fib_lookup;
> +static int (*bpf_rc_repeat)(void *ctx) =
> + (void *) BPF_FUNC_rc_repeat;
> +static int (*bpf_rc_keydown)(void *ctx, unsigned int protocol,
> + unsigned long long scancode, unsigned int toggle) =
> + (void *) BPF_FUNC_rc_keydown;
> +
>
> /* llvm builtin functions that eBPF C program may use to
> * emit BPF_LD_ABS and BPF_LD_IND instructions
> diff --git a/tools/testing/selftests/bpf/test_lirc_mode2.sh b/tools/testing/selftests/bpf/test_lirc_mode2.sh
> new file mode 100755
> index 000000000000..ce2e15e4f976
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/test_lirc_mode2.sh
> @@ -0,0 +1,28 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +
> +GREEN='\033[0;92m'
> +RED='\033[0;31m'
> +NC='\033[0m' # No Color
> +
> +modprobe rc-loopback
> +
> +for i in /sys/class/rc/rc*
> +do
> + if grep -q DRV_NAME=rc-loopback $i/uevent
> + then
> + LIRCDEV=$(grep DEVNAME= $i/lirc*/uevent | sed sQDEVNAME=Q/dev/Q)
> + fi
> +done
> +
> +if [ -n $LIRCDEV ];
> +then
> + TYPE=lirc_mode2
> + ./test_lirc_mode2_user $LIRCDEV
> + ret=$?
> + if [ $ret -ne 0 ]; then
> + echo -e ${RED}"FAIL: $TYPE"${NC}
> + else
> + echo -e ${GREEN}"PASS: $TYPE"${NC}
> + fi
> +fi
> diff --git a/tools/testing/selftests/bpf/test_lirc_mode2_kern.c b/tools/testing/selftests/bpf/test_lirc_mode2_kern.c
> new file mode 100644
> index 000000000000..ba26855563a5
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/test_lirc_mode2_kern.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// test ir decoder
> +//
> +// Copyright (C) 2018 Sean Young <sean@xxxxxxxx>
> +
> +#include <linux/bpf.h>
> +#include <linux/lirc.h>
> +#include "bpf_helpers.h"
> +
> +SEC("lirc_mode2")
> +int bpf_decoder(unsigned int *sample)
> +{
> + if (LIRC_IS_PULSE(*sample)) {
> + unsigned int duration = LIRC_VALUE(*sample);
> +
> + if (duration & 0x10000)
> + bpf_rc_keydown(sample, 0x40, duration & 0xffff, 0);
> + }
> +
> + return 0;
> +}
> +
> +char _license[] SEC("license") = "GPL";
> diff --git a/tools/testing/selftests/bpf/test_lirc_mode2_user.c b/tools/testing/selftests/bpf/test_lirc_mode2_user.c
> new file mode 100644
> index 000000000000..bd77688c8277
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/test_lirc_mode2_user.c
> @@ -0,0 +1,154 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// test ir decoder
> +//
> +// Copyright (C) 2018 Sean Young <sean@xxxxxxxx>
> +
> +// A lirc chardev is a device representing a consumer IR (cir) device which
> +// can receive infrared signals from remote control (and/or transmit IR)
> +//
> +// IR is sent as a series of pulses and space somewhat like morse code. The
> +// BPF program can decode this into scancodes so that rc-core can translate
> +// this into input key codes using the rc keymap
> +//
> +// This test works by sending IR over rc-loopback, so the IR is processed by
> +// BPF and then decoded into scancodes. The/ lirc chardev must be the one
> +// associated with rc-loopback, see the output of ir-keytable(1)".
> +//
> +// The following CONFIG options must be enabled for the test to succeed:
> +// CONFIG_RC_CORE=y
> +// CONFIG_BPF_RAWIR_EVENT=y
> +// CONFIG_RC_LOOPBACK=y
> +
> +// Steps:
> +// 1. Open the /dev/lircN device for rc-loopback (given on command line)
> +// 2. Attach bpf_lirc_mode2 program which decodes some IR.
> +// 3. Send some IR to the same IR device; since it is loopback, this will
> +// end up in the bpf program
> +// 4. bpf program should decode IR and report keycode
> +// 5. We can read keycode from same /dev/lirc device
> +
> +#include <linux/bpf.h>
> +#include <linux/lirc.h>
> +#include <assert.h>
> +#include <errno.h>
> +#include <signal.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <stdbool.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <poll.h>
> +#include <libgen.h>
> +#include <sys/resource.h>
> +#include <sys/types.h>
> +#include <sys/ioctl.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +
> +#include "bpf_util.h"
> +#include <bpf/bpf.h>
> +#include <bpf/libbpf.h>
> +
> +int main(int argc, char **argv)
> +{
> + struct bpf_object *obj;
> + int ret, lircfd, progfd, mode;
> + int testir = 0x1dead;
> + u32 prog_ids[10], prog_flags[10], prog_cnt;
> +
> + if (argc != 2) {
> + printf("Usage: %s /dev/lircN\n", argv[0]);
> + return 2;
> + }
> +
> + ret = bpf_prog_load("test_lirc_mode2_kern.o",
> + BPF_PROG_TYPE_LIRC_MODE2, &obj, &progfd);
> + if (ret) {
> + printf("Failed to load bpf program\n");
> + return 1;
> + }
> +
> + lircfd = open(argv[1], O_RDWR | O_NONBLOCK);
> + if (lircfd == -1) {
> + printf("failed to open lirc device %s: %m\n", argv[1]);
> + return 1;
> + }
> +
> + /* Let's try detach it before it was ever attached */
> + ret = bpf_prog_detach2(progfd, lircfd, BPF_LIRC_MODE2);
> + if (ret != -1 || errno != ENOENT) {
> + printf("bpf_prog_detach2 not attached should fail: %m\n");
> + return 1;
> + }
> +
> + mode = LIRC_MODE_SCANCODE;
> + if (ioctl(lircfd, LIRC_SET_REC_MODE, &mode)) {
> + printf("failed to set rec mode: %m\n");
> + return 1;
> + }
> +
> + prog_cnt = 10;
> + ret = bpf_prog_query(lircfd, BPF_LIRC_MODE2, 0, prog_flags, prog_ids,
> + &prog_cnt);
> + if (ret) {
> + printf("Failed to query bpf programs on lirc device: %m\n");
> + return 1;
> + }
> +
> + if (prog_cnt != 0) {
> + printf("Expected nothing to be attached\n");
> + return 1;
> + }
> +
> + ret = bpf_prog_attach(progfd, lircfd, BPF_LIRC_MODE2, 0);
> + if (ret) {
> + printf("Failed to attach bpf to lirc device: %m\n");
> + return 1;
> + }
> +
> + /* Write raw IR */
> + ret = write(lircfd, &testir, sizeof(testir));
> + if (ret != sizeof(testir)) {
> + printf("Failed to send test IR message: %m\n");
> + return 1;
> + }
> +
> + struct pollfd pfd = { .fd = lircfd, .events = POLLIN };
> + struct lirc_scancode lsc;
> +
> + poll(&pfd, 1, 100);
> +
> + /* Read decoded IR */
> + ret = read(lircfd, &lsc, sizeof(lsc));
> + if (ret != sizeof(lsc)) {
> + printf("Failed to read decoded IR: %m\n");
> + return 1;
> + }
> +
> + if (lsc.scancode != 0xdead || lsc.rc_proto != 64) {
> + printf("Incorrect scancode decoded\n");
> + return 1;
> + }
> +
> + prog_cnt = 10;
> + ret = bpf_prog_query(lircfd, BPF_LIRC_MODE2, 0, prog_flags, prog_ids,
> + &prog_cnt);
> + if (ret) {
> + printf("Failed to query bpf programs on lirc device: %m\n");
> + return 1;
> + }
> +
> + if (prog_cnt != 1) {
> + printf("Expected one program to be attached\n");
> + return 1;
> + }
> +
> + /* Let's try detaching it now it is actually attached */
> + ret = bpf_prog_detach2(progfd, lircfd, BPF_LIRC_MODE2);
> + if (ret) {
> + printf("bpf_prog_detach2: returned %m\n");
> + return 1;
> + }
> +
> + return 0;
> +}
> --
> 2.17.0
>