From e24328974a88aa8541e94e8bb8dfa2ade1b3c45d Mon Sep 17 00:00:00 2001 From: Donggeun Yoo Date: Wed, 2 Sep 2026 00:21:26 +0900 Subject: iio: proximity: vl53l0x-i2c: claim direct mode for raw reads vl53l0x_read_raw() starts a single-shot ranging measurement and reads back the result. Once the triggered buffer is enabled the sensor runs in continuous mode and its data-ready interrupt is routed to the trigger, so a concurrent in_distance_raw read disturbs the streaming setup and never gets its completion, returning -ETIMEDOUT. The original submission claimed direct mode here, but it was dropped during review because the driver had no buffer support at the time [1]. Continuous (buffered) mode was later added without restoring the claim [2], reintroducing the conflict. Reject direct reads while buffered capture is active by claiming direct mode around the measurement, as the vl53l1x sibling already does. Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support") Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1] Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2] Signed-off-by: Donggeun Yoo Cc: stable@vger.kernel.org Signed-off-by: Jonathan Cameron --- samples/bpf/sock_example.c | 111 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) create mode 100644 samples/bpf/sock_example.c (limited to 'samples/bpf/sock_example.c') diff --git a/samples/bpf/sock_example.c b/samples/bpf/sock_example.c new file mode 100644 index 000000000..5b66f2401 --- /dev/null +++ b/samples/bpf/sock_example.c @@ -0,0 +1,111 @@ +/* eBPF example program: + * - creates arraymap in kernel with key 4 bytes and value 8 bytes + * + * - loads eBPF program: + * r0 = skb->data[ETH_HLEN + offsetof(struct iphdr, protocol)]; + * *(u32*)(fp - 4) = r0; + * // assuming packet is IPv4, lookup ip->proto in a map + * value = bpf_map_lookup_elem(map_fd, fp - 4); + * if (value) + * (*(u64*)value) += 1; + * + * - attaches this program to loopback interface "lo" raw socket + * + * - every second user space reads map[tcp], map[udp], map[icmp] to see + * how many packets of given protocol were seen on "lo" + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "bpf_insn.h" +#include "sock_example.h" +#include "bpf_util.h" + +char bpf_log_buf[BPF_LOG_BUF_SIZE]; + +static int test_sock(void) +{ + int sock = -1, map_fd, prog_fd, i, key; + long long value = 0, tcp_cnt, udp_cnt, icmp_cnt; + + map_fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(key), sizeof(value), + 256, NULL); + if (map_fd < 0) { + printf("failed to create map '%s'\n", strerror(errno)); + goto cleanup; + } + + struct bpf_insn prog[] = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_LD_ABS(BPF_B, ETH_HLEN + offsetof(struct iphdr, protocol) /* R0 = ip->proto */), + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */ + BPF_LD_MAP_FD(BPF_REG_1, map_fd), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */ + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), /* r0 = 0 */ + BPF_EXIT_INSN(), + }; + size_t insns_cnt = ARRAY_SIZE(prog); + LIBBPF_OPTS(bpf_prog_load_opts, opts, + .log_buf = bpf_log_buf, + .log_size = BPF_LOG_BUF_SIZE, + ); + + prog_fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", + prog, insns_cnt, &opts); + if (prog_fd < 0) { + printf("failed to load prog '%s'\n", strerror(errno)); + goto cleanup; + } + + sock = open_raw_sock("lo"); + + if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd, + sizeof(prog_fd)) < 0) { + printf("setsockopt %s\n", strerror(errno)); + goto cleanup; + } + + for (i = 0; i < 10; i++) { + key = IPPROTO_TCP; + assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0); + + key = IPPROTO_UDP; + assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0); + + key = IPPROTO_ICMP; + assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0); + + printf("TCP %lld UDP %lld ICMP %lld packets\n", + tcp_cnt, udp_cnt, icmp_cnt); + sleep(1); + } + +cleanup: + /* maps, programs, raw sockets will auto cleanup on process exit */ + return 0; +} + +int main(void) +{ + FILE *f; + + f = popen("ping -4 -c5 localhost", "r"); + (void)f; + + return test_sock(); +} -- cgit v1.3.1