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Merge branch 'bpf-libbpf-relo-fix-and-tests'
Jesper Dangaard Brouer says: ==================== While playing with using libbpf for the Suricata project, we had issues LLVM >= 4.0.1 generating ELF files that could not be loaded with libbpf (tools/lib/bpf/). During the troubleshooting phase, I wrote a test program and improved the debugging output in libbpf. I turned this into a selftests program, and it also serves as a code example for libbpf in itself. I discovered that there are at least three ELF load issues with libbpf. I left them as TODO comments in (tools/testing/selftests/bpf) test_libbpf.sh. I've only fixed the load issue with eh_frames, and other types of relo-section that does not have exec flags. We can work on the other issues later. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,49 @@ | ||
| #!/bin/sh | ||
| # SPDX-License-Identifier: GPL-2.0 | ||
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| export TESTNAME=test_libbpf | ||
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| # Determine selftest success via shell exit code | ||
| exit_handler() | ||
| { | ||
| if (( $? == 0 )); then | ||
| echo "selftests: $TESTNAME [PASS]"; | ||
| else | ||
| echo "$TESTNAME: failed at file $LAST_LOADED" 1>&2 | ||
| echo "selftests: $TESTNAME [FAILED]"; | ||
| fi | ||
| } | ||
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| libbpf_open_file() | ||
| { | ||
| LAST_LOADED=$1 | ||
| if [ -n "$VERBOSE" ]; then | ||
| ./test_libbpf_open $1 | ||
| else | ||
| ./test_libbpf_open --quiet $1 | ||
| fi | ||
| } | ||
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| # Exit script immediately (well catched by trap handler) if any | ||
| # program/thing exits with a non-zero status. | ||
| set -e | ||
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| # (Use 'trap -l' to list meaning of numbers) | ||
| trap exit_handler 0 2 3 6 9 | ||
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| libbpf_open_file test_l4lb.o | ||
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| # TODO: fix libbpf to load noinline functions | ||
| # [warning] libbpf: incorrect bpf_call opcode | ||
| #libbpf_open_file test_l4lb_noinline.o | ||
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| # TODO: fix test_xdp_meta.c to load with libbpf | ||
| # [warning] libbpf: test_xdp_meta.o doesn't provide kernel version | ||
| #libbpf_open_file test_xdp_meta.o | ||
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| # TODO: fix libbpf to handle .eh_frame | ||
| # [warning] libbpf: relocation failed: no section(10) | ||
| #libbpf_open_file ../../../../samples/bpf/tracex3_kern.o | ||
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| # Success | ||
| exit 0 |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,150 @@ | ||
| /* SPDX-License-Identifier: GPL-2.0 | ||
| * Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc. | ||
| */ | ||
| static const char *__doc__ = | ||
| "Libbpf test program for loading BPF ELF object files"; | ||
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| #include <stdlib.h> | ||
| #include <stdio.h> | ||
| #include <string.h> | ||
| #include <stdarg.h> | ||
| #include <bpf/libbpf.h> | ||
| #include <getopt.h> | ||
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| static const struct option long_options[] = { | ||
| {"help", no_argument, NULL, 'h' }, | ||
| {"debug", no_argument, NULL, 'D' }, | ||
| {"quiet", no_argument, NULL, 'q' }, | ||
| {0, 0, NULL, 0 } | ||
| }; | ||
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| static void usage(char *argv[]) | ||
| { | ||
| int i; | ||
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| printf("\nDOCUMENTATION:\n%s\n\n", __doc__); | ||
| printf(" Usage: %s (options-see-below) BPF_FILE\n", argv[0]); | ||
| printf(" Listing options:\n"); | ||
| for (i = 0; long_options[i].name != 0; i++) { | ||
| printf(" --%-12s", long_options[i].name); | ||
| printf(" short-option: -%c", | ||
| long_options[i].val); | ||
| printf("\n"); | ||
| } | ||
| printf("\n"); | ||
| } | ||
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| #define DEFINE_PRINT_FN(name, enabled) \ | ||
| static int libbpf_##name(const char *fmt, ...) \ | ||
| { \ | ||
| va_list args; \ | ||
| int ret; \ | ||
| \ | ||
| va_start(args, fmt); \ | ||
| if (enabled) { \ | ||
| fprintf(stderr, "[" #name "] "); \ | ||
| ret = vfprintf(stderr, fmt, args); \ | ||
| } \ | ||
| va_end(args); \ | ||
| return ret; \ | ||
| } | ||
| DEFINE_PRINT_FN(warning, 1) | ||
| DEFINE_PRINT_FN(info, 1) | ||
| DEFINE_PRINT_FN(debug, 1) | ||
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| #define EXIT_FAIL_LIBBPF EXIT_FAILURE | ||
| #define EXIT_FAIL_OPTION 2 | ||
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| int test_walk_progs(struct bpf_object *obj, bool verbose) | ||
| { | ||
| struct bpf_program *prog; | ||
| int cnt = 0; | ||
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| bpf_object__for_each_program(prog, obj) { | ||
| cnt++; | ||
| if (verbose) | ||
| printf("Prog (count:%d) section_name: %s\n", cnt, | ||
| bpf_program__title(prog, false)); | ||
| } | ||
| return 0; | ||
| } | ||
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| int test_walk_maps(struct bpf_object *obj, bool verbose) | ||
| { | ||
| struct bpf_map *map; | ||
| int cnt = 0; | ||
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| bpf_map__for_each(map, obj) { | ||
| cnt++; | ||
| if (verbose) | ||
| printf("Map (count:%d) name: %s\n", cnt, | ||
| bpf_map__name(map)); | ||
| } | ||
| return 0; | ||
| } | ||
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| int test_open_file(char *filename, bool verbose) | ||
| { | ||
| struct bpf_object *bpfobj = NULL; | ||
| long err; | ||
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| if (verbose) | ||
| printf("Open BPF ELF-file with libbpf: %s\n", filename); | ||
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| /* Load BPF ELF object file and check for errors */ | ||
| bpfobj = bpf_object__open(filename); | ||
| err = libbpf_get_error(bpfobj); | ||
| if (err) { | ||
| char err_buf[128]; | ||
| libbpf_strerror(err, err_buf, sizeof(err_buf)); | ||
| if (verbose) | ||
| printf("Unable to load eBPF objects in file '%s': %s\n", | ||
| filename, err_buf); | ||
| return EXIT_FAIL_LIBBPF; | ||
| } | ||
| test_walk_progs(bpfobj, verbose); | ||
| test_walk_maps(bpfobj, verbose); | ||
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| if (verbose) | ||
| printf("Close BPF ELF-file with libbpf: %s\n", | ||
| bpf_object__name(bpfobj)); | ||
| bpf_object__close(bpfobj); | ||
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| return 0; | ||
| } | ||
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| int main(int argc, char **argv) | ||
| { | ||
| char filename[1024] = { 0 }; | ||
| bool verbose = 1; | ||
| int longindex = 0; | ||
| int opt; | ||
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| libbpf_set_print(libbpf_warning, libbpf_info, NULL); | ||
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| /* Parse commands line args */ | ||
| while ((opt = getopt_long(argc, argv, "hDq", | ||
| long_options, &longindex)) != -1) { | ||
| switch (opt) { | ||
| case 'D': | ||
| libbpf_set_print(libbpf_warning, libbpf_info, | ||
| libbpf_debug); | ||
| break; | ||
| case 'q': /* Use in scripting mode */ | ||
| verbose = 0; | ||
| break; | ||
| case 'h': | ||
| default: | ||
| usage(argv); | ||
| return EXIT_FAIL_OPTION; | ||
| } | ||
| } | ||
| if (optind >= argc) { | ||
| usage(argv); | ||
| printf("ERROR: Expected BPF_FILE argument after options\n"); | ||
| return EXIT_FAIL_OPTION; | ||
| } | ||
| snprintf(filename, sizeof(filename), "%s", argv[optind]); | ||
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| return test_open_file(filename, verbose); | ||
| } |