In the previous patch, it has a proper way to back-propagate the underlying driver error message to user space via the BPF syscall common attributes.
The tracepoint bpf_xdp_link_attach_failed seems redundant to report the error message. And, the tracepoint doesn't report the ifindex alongside the error message [1]. So, retire the tracepoint bpf_xdp_link_attach_failed and its selftest. According to the tracepoint change discussion [2], please revert this patch if users complain about the disappeared tracepoint bpf_xdp_link_attach_failed in the future. Links: [1] https://lore.kernel.org/bpf/CAFk-A4mE9Jweo2hfX7y_85xbPyt0FqpMT1EvqX1OcYZ=ltl...@mail.gmail.com/ [2] https://lore.kernel.org/linux-mm/cy8pr11mb7134346a3e4bb28eca28d6e989...@cy8pr11mb7134.namprd11.prod.outlook.com/ Signed-off-by: Leon Hwang <[email protected]> --- include/trace/events/xdp.h | 17 ----- net/core/dev.c | 1 - .../selftests/bpf/prog_tests/xdp_attach.c | 65 ------------------- .../bpf/progs/test_xdp_attach_fail.c | 54 --------------- 4 files changed, 137 deletions(-) delete mode 100644 tools/testing/selftests/bpf/progs/test_xdp_attach_fail.c diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h index 18c0ac514fcb..f1d4d0702884 100644 --- a/include/trace/events/xdp.h +++ b/include/trace/events/xdp.h @@ -362,23 +362,6 @@ TRACE_EVENT(mem_connect, ) ); -TRACE_EVENT(bpf_xdp_link_attach_failed, - - TP_PROTO(const char *msg), - - TP_ARGS(msg), - - TP_STRUCT__entry( - __string(msg, msg) - ), - - TP_fast_assign( - __assign_str(msg); - ), - - TP_printk("errmsg=%s", __get_str(msg)) -); - #endif /* _TRACE_XDP_H */ #include <trace/define_trace.h> diff --git a/net/core/dev.c b/net/core/dev.c index fdc1de21f358..266b510abd53 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10816,7 +10816,6 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog, link->dev = NULL; bpf_link_cleanup(&link_primer); bpf_log(log, extack._msg); - trace_bpf_xdp_link_attach_failed(extack._msg); goto out_put_dev; } diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_attach.c index e6bcb6051402..fa3cac5488f5 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_attach.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 #include <test_progs.h> -#include "test_xdp_attach_fail.skel.h" #define IFINDEX_LO 1 #define XDP_FLAGS_REPLACE (1U << 4) @@ -86,74 +85,10 @@ static void test_xdp_attach(const char *file) bpf_object__close(obj1); } -#define ERRMSG_LEN 64 - -struct xdp_errmsg { - char msg[ERRMSG_LEN]; -}; - -static void on_xdp_errmsg(void *ctx, int cpu, void *data, __u32 size) -{ - struct xdp_errmsg *ctx_errmg = ctx, *tp_errmsg = data; - - memcpy(&ctx_errmg->msg, &tp_errmsg->msg, ERRMSG_LEN); -} - -static const char tgt_errmsg[] = "Invalid XDP flags for BPF link attachment"; - -static void test_xdp_attach_fail(const char *file) -{ - struct test_xdp_attach_fail *skel = NULL; - struct xdp_errmsg errmsg = {}; - struct perf_buffer *pb = NULL; - struct bpf_object *obj = NULL; - int err, fd_xdp; - - LIBBPF_OPTS(bpf_link_create_opts, opts); - - skel = test_xdp_attach_fail__open_and_load(); - if (!ASSERT_OK_PTR(skel, "test_xdp_attach_fail__open_and_load")) - goto out_close; - - err = test_xdp_attach_fail__attach(skel); - if (!ASSERT_EQ(err, 0, "test_xdp_attach_fail__attach")) - goto out_close; - - /* set up perf buffer */ - pb = perf_buffer__new(bpf_map__fd(skel->maps.xdp_errmsg_pb), 1, - on_xdp_errmsg, NULL, &errmsg, NULL); - if (!ASSERT_OK_PTR(pb, "perf_buffer__new")) - goto out_close; - - err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj, &fd_xdp); - if (!ASSERT_EQ(err, 0, "bpf_prog_test_load")) - goto out_close; - - opts.flags = 0xFF; // invalid flags to fail to attach XDP prog - err = bpf_link_create(fd_xdp, IFINDEX_LO, BPF_XDP, &opts); - if (!ASSERT_EQ(err, -EINVAL, "bpf_link_create")) - goto out_close; - - /* read perf buffer */ - err = perf_buffer__poll(pb, 100); - if (!ASSERT_GT(err, -1, "perf_buffer__poll")) - goto out_close; - - ASSERT_STRNEQ((const char *) errmsg.msg, tgt_errmsg, - 42 /* strlen(tgt_errmsg) */, "check error message"); - -out_close: - perf_buffer__free(pb); - bpf_object__close(obj); - test_xdp_attach_fail__destroy(skel); -} - void serial_test_xdp_attach(void) { if (test__start_subtest("xdp_attach")) test_xdp_attach("./test_xdp.bpf.o"); if (test__start_subtest("xdp_attach_dynptr")) test_xdp_attach("./test_xdp_dynptr.bpf.o"); - if (test__start_subtest("xdp_attach_failed")) - test_xdp_attach_fail("./xdp_dummy.bpf.o"); } diff --git a/tools/testing/selftests/bpf/progs/test_xdp_attach_fail.c b/tools/testing/selftests/bpf/progs/test_xdp_attach_fail.c deleted file mode 100644 index 2ff1b596e87e..000000000000 --- a/tools/testing/selftests/bpf/progs/test_xdp_attach_fail.c +++ /dev/null @@ -1,54 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* Copyright Leon Hwang */ - -#include <linux/bpf.h> -#include <bpf/bpf_helpers.h> - -#define ERRMSG_LEN 64 - -struct xdp_errmsg { - char msg[ERRMSG_LEN]; -}; - -struct { - __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); - __type(key, int); - __type(value, int); -} xdp_errmsg_pb SEC(".maps"); - -struct xdp_attach_error_ctx { - unsigned long unused; - - /* - * bpf does not support tracepoint __data_loc directly. - * - * Actually, this field is a 32 bit integer whose value encodes - * information on where to find the actual data. The first 2 bytes is - * the size of the data. The last 2 bytes is the offset from the start - * of the tracepoint struct where the data begins. - * -- https://github.com/iovisor/bpftrace/pull/1542 - */ - __u32 msg; // __data_loc char[] msg; -}; - -/* - * Catch the error message at the tracepoint. - */ - -SEC("tp/xdp/bpf_xdp_link_attach_failed") -int tp__xdp__bpf_xdp_link_attach_failed(struct xdp_attach_error_ctx *ctx) -{ - char *msg = (void *)(__u64) ((void *) ctx + (__u16) ctx->msg); - struct xdp_errmsg errmsg = {}; - - bpf_probe_read_kernel_str(&errmsg.msg, ERRMSG_LEN, msg); - bpf_perf_event_output(ctx, &xdp_errmsg_pb, BPF_F_CURRENT_CPU, &errmsg, - ERRMSG_LEN); - return 0; -} - -/* - * Reuse the XDP program in xdp_dummy.c. - */ - -char LICENSE[] SEC("license") = "GPL"; -- 2.55.0
