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-rw-r--r--tools/testing/selftests/bpf/veristat.c1322
1 files changed, 1322 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
new file mode 100644
index 000000000000..b0d83a28e348
--- /dev/null
+++ b/tools/testing/selftests/bpf/veristat.c
@@ -0,0 +1,1322 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+#define _GNU_SOURCE
+#include <argp.h>
+#include <string.h>
+#include <stdlib.h>
+#include <linux/compiler.h>
+#include <sched.h>
+#include <pthread.h>
+#include <dirent.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/sysinfo.h>
+#include <sys/stat.h>
+#include <bpf/libbpf.h>
+#include <libelf.h>
+#include <gelf.h>
+
+enum stat_id {
+	VERDICT,
+	DURATION,
+	TOTAL_INSNS,
+	TOTAL_STATES,
+	PEAK_STATES,
+	MAX_STATES_PER_INSN,
+	MARK_READ_MAX_LEN,
+
+	FILE_NAME,
+	PROG_NAME,
+
+	ALL_STATS_CNT,
+	NUM_STATS_CNT = FILE_NAME - VERDICT,
+};
+
+struct verif_stats {
+	char *file_name;
+	char *prog_name;
+
+	long stats[NUM_STATS_CNT];
+};
+
+struct stat_specs {
+	int spec_cnt;
+	enum stat_id ids[ALL_STATS_CNT];
+	bool asc[ALL_STATS_CNT];
+	int lens[ALL_STATS_CNT * 3]; /* 3x for comparison mode */
+};
+
+enum resfmt {
+	RESFMT_TABLE,
+	RESFMT_TABLE_CALCLEN, /* fake format to pre-calculate table's column widths */
+	RESFMT_CSV,
+};
+
+struct filter {
+	char *file_glob;
+	char *prog_glob;
+};
+
+static struct env {
+	char **filenames;
+	int filename_cnt;
+	bool verbose;
+	bool quiet;
+	int log_level;
+	enum resfmt out_fmt;
+	bool comparison_mode;
+
+	struct verif_stats *prog_stats;
+	int prog_stat_cnt;
+
+	/* baseline_stats is allocated and used only in comparsion mode */
+	struct verif_stats *baseline_stats;
+	int baseline_stat_cnt;
+
+	struct stat_specs output_spec;
+	struct stat_specs sort_spec;
+
+	struct filter *allow_filters;
+	struct filter *deny_filters;
+	int allow_filter_cnt;
+	int deny_filter_cnt;
+
+	int files_processed;
+	int files_skipped;
+	int progs_processed;
+	int progs_skipped;
+} env;
+
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+	if (!env.verbose)
+		return 0;
+	if (level == LIBBPF_DEBUG /* && !env.verbose */)
+		return 0;
+	return vfprintf(stderr, format, args);
+}
+
+const char *argp_program_version = "veristat";
+const char *argp_program_bug_address = "<bpf@vger.kernel.org>";
+const char argp_program_doc[] =
+"veristat    BPF verifier stats collection and comparison tool.\n"
+"\n"
+"USAGE: veristat <obj-file> [<obj-file>...]\n"
+"   OR: veristat -C <baseline.csv> <comparison.csv>\n";
+
+static const struct argp_option opts[] = {
+	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
+	{ "verbose", 'v', NULL, 0, "Verbose mode" },
+	{ "log-level", 'l', "LEVEL", 0, "Verifier log level (default 0 for normal mode, 1 for verbose mode)" },
+	{ "quiet", 'q', NULL, 0, "Quiet mode" },
+	{ "emit", 'e', "SPEC", 0, "Specify stats to be emitted" },
+	{ "sort", 's', "SPEC", 0, "Specify sort order" },
+	{ "output-format", 'o', "FMT", 0, "Result output format (table, csv), default is table." },
+	{ "compare", 'C', NULL, 0, "Comparison mode" },
+	{ "filter", 'f', "FILTER", 0, "Filter expressions (or @filename for file with expressions)." },
+	{},
+};
+
+static int parse_stats(const char *stats_str, struct stat_specs *specs);
+static int append_filter(struct filter **filters, int *cnt, const char *str);
+static int append_filter_file(const char *path);
+
+static error_t parse_arg(int key, char *arg, struct argp_state *state)
+{
+	void *tmp;
+	int err;
+
+	switch (key) {
+	case 'h':
+		argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
+		break;
+	case 'v':
+		env.verbose = true;
+		break;
+	case 'q':
+		env.quiet = true;
+		break;
+	case 'e':
+		err = parse_stats(arg, &env.output_spec);
+		if (err)
+			return err;
+		break;
+	case 's':
+		err = parse_stats(arg, &env.sort_spec);
+		if (err)
+			return err;
+		break;
+	case 'o':
+		if (strcmp(arg, "table") == 0) {
+			env.out_fmt = RESFMT_TABLE;
+		} else if (strcmp(arg, "csv") == 0) {
+			env.out_fmt = RESFMT_CSV;
+		} else {
+			fprintf(stderr, "Unrecognized output format '%s'\n", arg);
+			return -EINVAL;
+		}
+		break;
+	case 'l':
+		errno = 0;
+		env.log_level = strtol(arg, NULL, 10);
+		if (errno) {
+			fprintf(stderr, "invalid log level: %s\n", arg);
+			argp_usage(state);
+		}
+		break;
+	case 'C':
+		env.comparison_mode = true;
+		break;
+	case 'f':
+		if (arg[0] == '@')
+			err = append_filter_file(arg + 1);
+		else if (arg[0] == '!')
+			err = append_filter(&env.deny_filters, &env.deny_filter_cnt, arg + 1);
+		else
+			err = append_filter(&env.allow_filters, &env.allow_filter_cnt, arg);
+		if (err) {
+			fprintf(stderr, "Failed to collect program filter expressions: %d\n", err);
+			return err;
+		}
+		break;
+	case ARGP_KEY_ARG:
+		tmp = realloc(env.filenames, (env.filename_cnt + 1) * sizeof(*env.filenames));
+		if (!tmp)
+			return -ENOMEM;
+		env.filenames = tmp;
+		env.filenames[env.filename_cnt] = strdup(arg);
+		if (!env.filenames[env.filename_cnt])
+			return -ENOMEM;
+		env.filename_cnt++;
+		break;
+	default:
+		return ARGP_ERR_UNKNOWN;
+	}
+	return 0;
+}
+
+static const struct argp argp = {
+	.options = opts,
+	.parser = parse_arg,
+	.doc = argp_program_doc,
+};
+
+
+/* Adapted from perf/util/string.c */
+static bool glob_matches(const char *str, const char *pat)
+{
+	while (*str && *pat && *pat != '*') {
+		if (*str != *pat)
+			return false;
+		str++;
+		pat++;
+	}
+	/* Check wild card */
+	if (*pat == '*') {
+		while (*pat == '*')
+			pat++;
+		if (!*pat) /* Tail wild card matches all */
+			return true;
+		while (*str)
+			if (glob_matches(str++, pat))
+				return true;
+	}
+	return !*str && !*pat;
+}
+
+static bool should_process_file(const char *filename)
+{
+	int i;
+
+	if (env.deny_filter_cnt > 0) {
+		for (i = 0; i < env.deny_filter_cnt; i++) {
+			if (glob_matches(filename, env.deny_filters[i].file_glob))
+				return false;
+		}
+	}
+
+	if (env.allow_filter_cnt == 0)
+		return true;
+
+	for (i = 0; i < env.allow_filter_cnt; i++) {
+		if (glob_matches(filename, env.allow_filters[i].file_glob))
+			return true;
+	}
+
+	return false;
+}
+
+static bool is_bpf_obj_file(const char *path) {
+	Elf64_Ehdr *ehdr;
+	int fd, err = -EINVAL;
+	Elf *elf = NULL;
+
+	fd = open(path, O_RDONLY | O_CLOEXEC);
+	if (fd < 0)
+		return true; /* we'll fail later and propagate error */
+
+	/* ensure libelf is initialized */
+	(void)elf_version(EV_CURRENT);
+
+	elf = elf_begin(fd, ELF_C_READ, NULL);
+	if (!elf)
+		goto cleanup;
+
+	if (elf_kind(elf) != ELF_K_ELF || gelf_getclass(elf) != ELFCLASS64)
+		goto cleanup;
+
+	ehdr = elf64_getehdr(elf);
+	/* Old LLVM set e_machine to EM_NONE */
+	if (!ehdr || ehdr->e_type != ET_REL || (ehdr->e_machine && ehdr->e_machine != EM_BPF))
+		goto cleanup;
+
+	err = 0;
+cleanup:
+	if (elf)
+		elf_end(elf);
+	close(fd);
+	return err == 0;
+}
+
+static bool should_process_prog(const char *path, const char *prog_name)
+{
+	const char *filename = basename(path);
+	int i;
+
+	if (env.deny_filter_cnt > 0) {
+		for (i = 0; i < env.deny_filter_cnt; i++) {
+			if (glob_matches(filename, env.deny_filters[i].file_glob))
+				return false;
+			if (!env.deny_filters[i].prog_glob)
+				continue;
+			if (glob_matches(prog_name, env.deny_filters[i].prog_glob))
+				return false;
+		}
+	}
+
+	if (env.allow_filter_cnt == 0)
+		return true;
+
+	for (i = 0; i < env.allow_filter_cnt; i++) {
+		if (!glob_matches(filename, env.allow_filters[i].file_glob))
+			continue;
+		/* if filter specifies only filename glob part, it implicitly
+		 * allows all progs within that file
+		 */
+		if (!env.allow_filters[i].prog_glob)
+			return true;
+		if (glob_matches(prog_name, env.allow_filters[i].prog_glob))
+			return true;
+	}
+
+	return false;
+}
+
+static int append_filter(struct filter **filters, int *cnt, const char *str)
+{
+	struct filter *f;
+	void *tmp;
+	const char *p;
+
+	tmp = realloc(*filters, (*cnt + 1) * sizeof(**filters));
+	if (!tmp)
+		return -ENOMEM;
+	*filters = tmp;
+
+	f = &(*filters)[*cnt];
+	f->file_glob = f->prog_glob = NULL;
+
+	/* filter can be specified either as "<obj-glob>" or "<obj-glob>/<prog-glob>" */
+	p = strchr(str, '/');
+	if (!p) {
+		f->file_glob = strdup(str);
+		if (!f->file_glob)
+			return -ENOMEM;
+	} else {
+		f->file_glob = strndup(str, p - str);
+		f->prog_glob = strdup(p + 1);
+		if (!f->file_glob || !f->prog_glob) {
+			free(f->file_glob);
+			free(f->prog_glob);
+			f->file_glob = f->prog_glob = NULL;
+			return -ENOMEM;
+		}
+	}
+
+	*cnt = *cnt + 1;
+	return 0;
+}
+
+static int append_filter_file(const char *path)
+{
+	char buf[1024];
+	FILE *f;
+	int err = 0;
+
+	f = fopen(path, "r");
+	if (!f) {
+		err = -errno;
+		fprintf(stderr, "Failed to open filters in '%s': %d\n", path, err);
+		return err;
+	}
+
+	while (fscanf(f, " %1023[^\n]\n", buf) == 1) {
+		/* lines starting with # are comments, skip them */
+		if (buf[0] == '\0' || buf[0] == '#')
+			continue;
+		/* lines starting with ! are negative match filters */
+		if (buf[0] == '!')
+			err = append_filter(&env.deny_filters, &env.deny_filter_cnt, buf + 1);
+		else
+			err = append_filter(&env.allow_filters, &env.allow_filter_cnt, buf);
+		if (err)
+			goto cleanup;
+	}
+
+cleanup:
+	fclose(f);
+	return err;
+}
+
+static const struct stat_specs default_output_spec = {
+	.spec_cnt = 7,
+	.ids = {
+		FILE_NAME, PROG_NAME, VERDICT, DURATION,
+		TOTAL_INSNS, TOTAL_STATES, PEAK_STATES,
+	},
+};
+
+static const struct stat_specs default_sort_spec = {
+	.spec_cnt = 2,
+	.ids = {
+		FILE_NAME, PROG_NAME,
+	},
+	.asc = { true, true, },
+};
+
+static struct stat_def {
+	const char *header;
+	const char *names[4];
+	bool asc_by_default;
+} stat_defs[] = {
+	[FILE_NAME] = { "File", {"file_name", "filename", "file"}, true /* asc */ },
+	[PROG_NAME] = { "Program", {"prog_name", "progname", "prog"}, true /* asc */ },
+	[VERDICT] = { "Verdict", {"verdict"}, true /* asc: failure, success */ },
+	[DURATION] = { "Duration (us)", {"duration", "dur"}, },
+	[TOTAL_INSNS] = { "Total insns", {"total_insns", "insns"}, },
+	[TOTAL_STATES] = { "Total states", {"total_states", "states"}, },
+	[PEAK_STATES] = { "Peak states", {"peak_states"}, },
+	[MAX_STATES_PER_INSN] = { "Max states per insn", {"max_states_per_insn"}, },
+	[MARK_READ_MAX_LEN] = { "Max mark read length", {"max_mark_read_len", "mark_read"}, },
+};
+
+static int parse_stat(const char *stat_name, struct stat_specs *specs)
+{
+	int id, i;
+
+	if (specs->spec_cnt >= ARRAY_SIZE(specs->ids)) {
+		fprintf(stderr, "Can't specify more than %zd stats\n", ARRAY_SIZE(specs->ids));
+		return -E2BIG;
+	}
+
+	for (id = 0; id < ARRAY_SIZE(stat_defs); id++) {
+		struct stat_def *def = &stat_defs[id];
+
+		for (i = 0; i < ARRAY_SIZE(stat_defs[id].names); i++) {
+			if (!def->names[i] || strcmp(def->names[i], stat_name) != 0)
+				continue;
+
+			specs->ids[specs->spec_cnt] = id;
+			specs->asc[specs->spec_cnt] = def->asc_by_default;
+			specs->spec_cnt++;
+
+			return 0;
+		}
+	}
+
+	fprintf(stderr, "Unrecognized stat name '%s'\n", stat_name);
+	return -ESRCH;
+}
+
+static int parse_stats(const char *stats_str, struct stat_specs *specs)
+{
+	char *input, *state = NULL, *next;
+	int err;
+
+	input = strdup(stats_str);
+	if (!input)
+		return -ENOMEM;
+
+	while ((next = strtok_r(state ? NULL : input, ",", &state))) {
+		err = parse_stat(next, specs);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static void free_verif_stats(struct verif_stats *stats, size_t stat_cnt)
+{
+	int i;
+
+	if (!stats)
+		return;
+
+	for (i = 0; i < stat_cnt; i++) {
+		free(stats[i].file_name);
+		free(stats[i].prog_name);
+	}
+	free(stats);
+}
+
+static char verif_log_buf[64 * 1024];
+
+#define MAX_PARSED_LOG_LINES 100
+
+static int parse_verif_log(char * const buf, size_t buf_sz, struct verif_stats *s)
+{
+	const char *cur;
+	int pos, lines;
+
+	buf[buf_sz - 1] = '\0';
+
+	for (pos = strlen(buf) - 1, lines = 0; pos >= 0 && lines < MAX_PARSED_LOG_LINES; lines++) {
+		/* find previous endline or otherwise take the start of log buf */
+		for (cur = &buf[pos]; cur > buf && cur[0] != '\n'; cur--, pos--) {
+		}
+		/* next time start from end of previous line (or pos goes to <0) */
+		pos--;
+		/* if we found endline, point right after endline symbol;
+		 * otherwise, stay at the beginning of log buf
+		 */
+		if (cur[0] == '\n')
+			cur++;
+
+		if (1 == sscanf(cur, "verification time %ld usec\n", &s->stats[DURATION]))
+			continue;
+		if (6 == sscanf(cur, "processed %ld insns (limit %*d) max_states_per_insn %ld total_states %ld peak_states %ld mark_read %ld",
+				&s->stats[TOTAL_INSNS],
+				&s->stats[MAX_STATES_PER_INSN],
+				&s->stats[TOTAL_STATES],
+				&s->stats[PEAK_STATES],
+				&s->stats[MARK_READ_MAX_LEN]))
+			continue;
+	}
+
+	return 0;
+}
+
+static int process_prog(const char *filename, struct bpf_object *obj, struct bpf_program *prog)
+{
+	const char *prog_name = bpf_program__name(prog);
+	size_t buf_sz = sizeof(verif_log_buf);
+	char *buf = verif_log_buf;
+	struct verif_stats *stats;
+	int err = 0;
+	void *tmp;
+
+	if (!should_process_prog(filename, bpf_program__name(prog))) {
+		env.progs_skipped++;
+		return 0;
+	}
+
+	tmp = realloc(env.prog_stats, (env.prog_stat_cnt + 1) * sizeof(*env.prog_stats));
+	if (!tmp)
+		return -ENOMEM;
+	env.prog_stats = tmp;
+	stats = &env.prog_stats[env.prog_stat_cnt++];
+	memset(stats, 0, sizeof(*stats));
+
+	if (env.verbose) {
+		buf_sz = 16 * 1024 * 1024;
+		buf = malloc(buf_sz);
+		if (!buf)
+			return -ENOMEM;
+		bpf_program__set_log_buf(prog, buf, buf_sz);
+		bpf_program__set_log_level(prog, env.log_level | 4); /* stats + log */
+	} else {
+		bpf_program__set_log_buf(prog, buf, buf_sz);
+		bpf_program__set_log_level(prog, 4); /* only verifier stats */
+	}
+	verif_log_buf[0] = '\0';
+
+	err = bpf_object__load(obj);
+	env.progs_processed++;
+
+	stats->file_name = strdup(basename(filename));
+	stats->prog_name = strdup(bpf_program__name(prog));
+	stats->stats[VERDICT] = err == 0; /* 1 - success, 0 - failure */
+	parse_verif_log(buf, buf_sz, stats);
+
+	if (env.verbose) {
+		printf("PROCESSING %s/%s, DURATION US: %ld, VERDICT: %s, VERIFIER LOG:\n%s\n",
+		       filename, prog_name, stats->stats[DURATION],
+		       err ? "failure" : "success", buf);
+	}
+
+	if (verif_log_buf != buf)
+		free(buf);
+
+	return 0;
+};
+
+static int process_obj(const char *filename)
+{
+	struct bpf_object *obj = NULL, *tobj;
+	struct bpf_program *prog, *tprog, *lprog;
+	libbpf_print_fn_t old_libbpf_print_fn;
+	LIBBPF_OPTS(bpf_object_open_opts, opts);
+	int err = 0, prog_cnt = 0;
+
+	if (!should_process_file(basename(filename))) {
+		if (env.verbose)
+			printf("Skipping '%s' due to filters...\n", filename);
+		env.files_skipped++;
+		return 0;
+	}
+	if (!is_bpf_obj_file(filename)) {
+		if (env.verbose)
+			printf("Skipping '%s' as it's not a BPF object file...\n", filename);
+		env.files_skipped++;
+		return 0;
+	}
+
+	if (!env.quiet && env.out_fmt == RESFMT_TABLE)
+		printf("Processing '%s'...\n", basename(filename));
+
+	old_libbpf_print_fn = libbpf_set_print(libbpf_print_fn);
+	obj = bpf_object__open_file(filename, &opts);
+	if (!obj) {
+		/* if libbpf can't open BPF object file, it could be because
+		 * that BPF object file is incomplete and has to be statically
+		 * linked into a final BPF object file; instead of bailing
+		 * out, report it into stderr, mark it as skipped, and
+		 * proceeed
+		 */
+		fprintf(stderr, "Failed to open '%s': %d\n", filename, -errno);
+		env.files_skipped++;
+		err = 0;
+		goto cleanup;
+	}
+
+	env.files_processed++;
+
+	bpf_object__for_each_program(prog, obj) {
+		prog_cnt++;
+	}
+
+	if (prog_cnt == 1) {
+		prog = bpf_object__next_program(obj, NULL);
+		bpf_program__set_autoload(prog, true);
+		process_prog(filename, obj, prog);
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		const char *prog_name = bpf_program__name(prog);
+
+		tobj = bpf_object__open_file(filename, &opts);
+		if (!tobj) {
+			err = -errno;
+			fprintf(stderr, "Failed to open '%s': %d\n", filename, err);
+			goto cleanup;
+		}
+
+		bpf_object__for_each_program(tprog, tobj) {
+			const char *tprog_name = bpf_program__name(tprog);
+
+			if (strcmp(prog_name, tprog_name) == 0) {
+				bpf_program__set_autoload(tprog, true);
+				lprog = tprog;
+			} else {
+				bpf_program__set_autoload(tprog, false);
+			}
+		}
+
+		process_prog(filename, tobj, lprog);
+		bpf_object__close(tobj);
+	}
+
+cleanup:
+	bpf_object__close(obj);
+	libbpf_set_print(old_libbpf_print_fn);
+	return err;
+}
+
+static int cmp_stat(const struct verif_stats *s1, const struct verif_stats *s2,
+		    enum stat_id id, bool asc)
+{
+	int cmp = 0;
+
+	switch (id) {
+	case FILE_NAME:
+		cmp = strcmp(s1->file_name, s2->file_name);
+		break;
+	case PROG_NAME:
+		cmp = strcmp(s1->prog_name, s2->prog_name);
+		break;
+	case VERDICT:
+	case DURATION:
+	case TOTAL_INSNS:
+	case TOTAL_STATES:
+	case PEAK_STATES:
+	case MAX_STATES_PER_INSN:
+	case MARK_READ_MAX_LEN: {
+		long v1 = s1->stats[id];
+		long v2 = s2->stats[id];
+
+		if (v1 != v2)
+			cmp = v1 < v2 ? -1 : 1;
+		break;
+	}
+	default:
+		fprintf(stderr, "Unrecognized stat #%d\n", id);
+		exit(1);
+	}
+
+	return asc ? cmp : -cmp;
+}
+
+static int cmp_prog_stats(const void *v1, const void *v2)
+{
+	const struct verif_stats *s1 = v1, *s2 = v2;
+	int i, cmp;
+
+	for (i = 0; i < env.sort_spec.spec_cnt; i++) {
+		cmp = cmp_stat(s1, s2, env.sort_spec.ids[i], env.sort_spec.asc[i]);
+		if (cmp != 0)
+			return cmp;
+	}
+
+	return 0;
+}
+
+#define HEADER_CHAR '-'
+#define COLUMN_SEP "  "
+
+static void output_header_underlines(void)
+{
+	int i, j, len;
+
+	for (i = 0; i < env.output_spec.spec_cnt; i++) {
+		len = env.output_spec.lens[i];
+
+		printf("%s", i == 0 ? "" : COLUMN_SEP);
+		for (j = 0; j < len; j++)
+			printf("%c", HEADER_CHAR);
+	}
+	printf("\n");
+}
+
+static void output_headers(enum resfmt fmt)
+{
+	int i, len;
+
+	for (i = 0; i < env.output_spec.spec_cnt; i++) {
+		int id = env.output_spec.ids[i];
+		int *max_len = &env.output_spec.lens[i];
+
+		switch (fmt) {
+		case RESFMT_TABLE_CALCLEN:
+			len = snprintf(NULL, 0, "%s", stat_defs[id].header);
+			if (len > *max_len)
+				*max_len = len;
+			break;
+		case RESFMT_TABLE:
+			printf("%s%-*s", i == 0 ? "" : COLUMN_SEP,  *max_len, stat_defs[id].header);
+			if (i == env.output_spec.spec_cnt - 1)
+				printf("\n");
+			break;
+		case RESFMT_CSV:
+			printf("%s%s", i == 0 ? "" : ",", stat_defs[id].names[0]);
+			if (i == env.output_spec.spec_cnt - 1)
+				printf("\n");
+			break;
+		}
+	}
+
+	if (fmt == RESFMT_TABLE)
+		output_header_underlines();
+}
+
+static void prepare_value(const struct verif_stats *s, enum stat_id id,
+			  const char **str, long *val)
+{
+	switch (id) {
+	case FILE_NAME:
+		*str = s->file_name;
+		break;
+	case PROG_NAME:
+		*str = s->prog_name;
+		break;
+	case VERDICT:
+		*str = s->stats[VERDICT] ? "success" : "failure";
+		break;
+	case DURATION:
+	case TOTAL_INSNS:
+	case TOTAL_STATES:
+	case PEAK_STATES:
+	case MAX_STATES_PER_INSN:
+	case MARK_READ_MAX_LEN:
+		*val = s->stats[id];
+		break;
+	default:
+		fprintf(stderr, "Unrecognized stat #%d\n", id);
+		exit(1);
+	}
+}
+
+static void output_stats(const struct verif_stats *s, enum resfmt fmt, bool last)
+{
+	int i;
+
+	for (i = 0; i < env.output_spec.spec_cnt; i++) {
+		int id = env.output_spec.ids[i];
+		int *max_len = &env.output_spec.lens[i], len;
+		const char *str = NULL;
+		long val = 0;
+
+		prepare_value(s, id, &str, &val);
+
+		switch (fmt) {
+		case RESFMT_TABLE_CALCLEN:
+			if (str)
+				len = snprintf(NULL, 0, "%s", str);
+			else
+				len = snprintf(NULL, 0, "%ld", val);
+			if (len > *max_len)
+				*max_len = len;
+			break;
+		case RESFMT_TABLE:
+			if (str)
+				printf("%s%-*s", i == 0 ? "" : COLUMN_SEP, *max_len, str);
+			else
+				printf("%s%*ld", i == 0 ? "" : COLUMN_SEP,  *max_len, val);
+			if (i == env.output_spec.spec_cnt - 1)
+				printf("\n");
+			break;
+		case RESFMT_CSV:
+			if (str)
+				printf("%s%s", i == 0 ? "" : ",", str);
+			else
+				printf("%s%ld", i == 0 ? "" : ",", val);
+			if (i == env.output_spec.spec_cnt - 1)
+				printf("\n");
+			break;
+		}
+	}
+
+	if (last && fmt == RESFMT_TABLE) {
+		output_header_underlines();
+		printf("Done. Processed %d files, %d programs. Skipped %d files, %d programs.\n",
+		       env.files_processed, env.files_skipped, env.progs_processed, env.progs_skipped);
+	}
+}
+
+static int handle_verif_mode(void)
+{
+	int i, err;
+
+	if (env.filename_cnt == 0) {
+		fprintf(stderr, "Please provide path to BPF object file!\n");
+		argp_help(&argp, stderr, ARGP_HELP_USAGE, "veristat");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < env.filename_cnt; i++) {
+		err = process_obj(env.filenames[i]);
+		if (err) {
+			fprintf(stderr, "Failed to process '%s': %d\n", env.filenames[i], err);
+			return err;
+		}
+	}
+
+	qsort(env.prog_stats, env.prog_stat_cnt, sizeof(*env.prog_stats), cmp_prog_stats);
+
+	if (env.out_fmt == RESFMT_TABLE) {
+		/* calculate column widths */
+		output_headers(RESFMT_TABLE_CALCLEN);
+		for (i = 0; i < env.prog_stat_cnt; i++)
+			output_stats(&env.prog_stats[i], RESFMT_TABLE_CALCLEN, false);
+	}
+
+	/* actually output the table */
+	output_headers(env.out_fmt);
+	for (i = 0; i < env.prog_stat_cnt; i++) {
+		output_stats(&env.prog_stats[i], env.out_fmt, i == env.prog_stat_cnt - 1);
+	}
+
+	return 0;
+}
+
+static int parse_stat_value(const char *str, enum stat_id id, struct verif_stats *st)
+{
+	switch (id) {
+	case FILE_NAME:
+		st->file_name = strdup(str);
+		if (!st->file_name)
+			return -ENOMEM;
+		break;
+	case PROG_NAME:
+		st->prog_name = strdup(str);
+		if (!st->prog_name)
+			return -ENOMEM;
+		break;
+	case VERDICT:
+		if (strcmp(str, "success") == 0) {
+			st->stats[VERDICT] = true;
+		} else if (strcmp(str, "failure") == 0) {
+			st->stats[VERDICT] = false;
+		} else {
+			fprintf(stderr, "Unrecognized verification verdict '%s'\n", str);
+			return -EINVAL;
+		}
+		break;
+	case DURATION:
+	case TOTAL_INSNS:
+	case TOTAL_STATES:
+	case PEAK_STATES:
+	case MAX_STATES_PER_INSN:
+	case MARK_READ_MAX_LEN: {
+		long val;
+		int err, n;
+
+		if (sscanf(str, "%ld %n", &val, &n) != 1 || n != strlen(str)) {
+			err = -errno;
+			fprintf(stderr, "Failed to parse '%s' as integer\n", str);
+			return err;
+		}
+
+		st->stats[id] = val;
+		break;
+	}
+	default:
+		fprintf(stderr, "Unrecognized stat #%d\n", id);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int parse_stats_csv(const char *filename, struct stat_specs *specs,
+			   struct verif_stats **statsp, int *stat_cntp)
+{
+	char line[4096];
+	FILE *f;
+	int err = 0;
+	bool header = true;
+
+	f = fopen(filename, "r");
+	if (!f) {
+		err = -errno;
+		fprintf(stderr, "Failed to open '%s': %d\n", filename, err);
+		return err;
+	}
+
+	*stat_cntp = 0;
+
+	while (fgets(line, sizeof(line), f)) {
+		char *input = line, *state = NULL, *next;
+		struct verif_stats *st = NULL;
+		int col = 0;
+
+		if (!header) {
+			void *tmp;
+
+			tmp = realloc(*statsp, (*stat_cntp + 1) * sizeof(**statsp));
+			if (!tmp) {
+				err = -ENOMEM;
+				goto cleanup;
+			}
+			*statsp = tmp;
+
+			st = &(*statsp)[*stat_cntp];
+			memset(st, 0, sizeof(*st));
+
+			*stat_cntp += 1;
+		}
+
+		while ((next = strtok_r(state ? NULL : input, ",\n", &state))) {
+			if (header) {
+				/* for the first line, set up spec stats */
+				err = parse_stat(next, specs);
+				if (err)
+					goto cleanup;
+				continue;
+			}
+
+			/* for all other lines, parse values based on spec */
+			if (col >= specs->spec_cnt) {
+				fprintf(stderr, "Found extraneous column #%d in row #%d of '%s'\n",
+					col, *stat_cntp, filename);
+				err = -EINVAL;
+				goto cleanup;
+			}
+			err = parse_stat_value(next, specs->ids[col], st);
+			if (err)
+				goto cleanup;
+			col++;
+		}
+
+		if (header) {
+			header = false;
+			continue;
+		}
+
+		if (col < specs->spec_cnt) {
+			fprintf(stderr, "Not enough columns in row #%d in '%s'\n",
+				*stat_cntp, filename);
+			err = -EINVAL;
+			goto cleanup;
+		}
+
+		if (!st->file_name || !st->prog_name) {
+			fprintf(stderr, "Row #%d in '%s' is missing file and/or program name\n",
+				*stat_cntp, filename);
+			err = -EINVAL;
+			goto cleanup;
+		}
+
+		/* in comparison mode we can only check filters after we
+		 * parsed entire line; if row should be ignored we pretend we
+		 * never parsed it
+		 */
+		if (!should_process_prog(st->file_name, st->prog_name)) {
+			free(st->file_name);
+			free(st->prog_name);
+			*stat_cntp -= 1;
+		}
+	}
+
+	if (!feof(f)) {
+		err = -errno;
+		fprintf(stderr, "Failed I/O for '%s': %d\n", filename, err);
+	}
+
+cleanup:
+	fclose(f);
+	return err;
+}
+
+/* empty/zero stats for mismatched rows */
+static const struct verif_stats fallback_stats = { .file_name = "", .prog_name = "" };
+
+static bool is_key_stat(enum stat_id id)
+{
+	return id == FILE_NAME || id == PROG_NAME;
+}
+
+static void output_comp_header_underlines(void)
+{
+	int i, j, k;
+
+	for (i = 0; i < env.output_spec.spec_cnt; i++) {
+		int id = env.output_spec.ids[i];
+		int max_j = is_key_stat(id) ? 1 : 3;
+
+		for (j = 0; j < max_j; j++) {
+			int len = env.output_spec.lens[3 * i + j];
+
+			printf("%s", i + j == 0 ? "" : COLUMN_SEP);
+
+			for (k = 0; k < len; k++)
+				printf("%c", HEADER_CHAR);
+		}
+	}
+	printf("\n");
+}
+
+static void output_comp_headers(enum resfmt fmt)
+{
+	static const char *table_sfxs[3] = {" (A)", " (B)", " (DIFF)"};
+	static const char *name_sfxs[3] = {"_base", "_comp", "_diff"};
+	int i, j, len;
+
+	for (i = 0; i < env.output_spec.spec_cnt; i++) {
+		int id = env.output_spec.ids[i];
+		/* key stats don't have A/B/DIFF columns, they are common for both data sets */
+		int max_j = is_key_stat(id) ? 1 : 3;
+
+		for (j = 0; j < max_j; j++) {
+			int *max_len = &env.output_spec.lens[3 * i + j];
+			bool last = (i == env.output_spec.spec_cnt - 1) && (j == max_j - 1);
+			const char *sfx;
+
+			switch (fmt) {
+			case RESFMT_TABLE_CALCLEN:
+				sfx = is_key_stat(id) ? "" : table_sfxs[j];
+				len = snprintf(NULL, 0, "%s%s", stat_defs[id].header, sfx);
+				if (len > *max_len)
+					*max_len = len;
+				break;
+			case RESFMT_TABLE:
+				sfx = is_key_stat(id) ? "" : table_sfxs[j];
+				printf("%s%-*s%s", i + j == 0 ? "" : COLUMN_SEP,
+				       *max_len - (int)strlen(sfx), stat_defs[id].header, sfx);
+				if (last)
+					printf("\n");
+				break;
+			case RESFMT_CSV:
+				sfx = is_key_stat(id) ? "" : name_sfxs[j];
+				printf("%s%s%s", i + j == 0 ? "" : ",", stat_defs[id].names[0], sfx);
+				if (last)
+					printf("\n");
+				break;
+			}
+		}
+	}
+
+	if (fmt == RESFMT_TABLE)
+		output_comp_header_underlines();
+}
+
+static void output_comp_stats(const struct verif_stats *base, const struct verif_stats *comp,
+			      enum resfmt fmt, bool last)
+{
+	char base_buf[1024] = {}, comp_buf[1024] = {}, diff_buf[1024] = {};
+	int i;
+
+	for (i = 0; i < env.output_spec.spec_cnt; i++) {
+		int id = env.output_spec.ids[i], len;
+		int *max_len_base = &env.output_spec.lens[3 * i + 0];
+		int *max_len_comp = &env.output_spec.lens[3 * i + 1];
+		int *max_len_diff = &env.output_spec.lens[3 * i + 2];
+		const char *base_str = NULL, *comp_str = NULL;
+		long base_val = 0, comp_val = 0, diff_val = 0;
+
+		prepare_value(base, id, &base_str, &base_val);
+		prepare_value(comp, id, &comp_str, &comp_val);
+
+		/* normalize all the outputs to be in string buffers for simplicity */
+		if (is_key_stat(id)) {
+			/* key stats (file and program name) are always strings */
+			if (base != &fallback_stats)
+				snprintf(base_buf, sizeof(base_buf), "%s", base_str);
+			else
+				snprintf(base_buf, sizeof(base_buf), "%s", comp_str);
+		} else if (base_str) {
+			snprintf(base_buf, sizeof(base_buf), "%s", base_str);
+			snprintf(comp_buf, sizeof(comp_buf), "%s", comp_str);
+			if (strcmp(base_str, comp_str) == 0)
+				snprintf(diff_buf, sizeof(diff_buf), "%s", "MATCH");
+			else
+				snprintf(diff_buf, sizeof(diff_buf), "%s", "MISMATCH");
+		} else {
+			snprintf(base_buf, sizeof(base_buf), "%ld", base_val);
+			snprintf(comp_buf, sizeof(comp_buf), "%ld", comp_val);
+
+			diff_val = comp_val - base_val;
+			if (base == &fallback_stats || comp == &fallback_stats || base_val == 0) {
+				snprintf(diff_buf, sizeof(diff_buf), "%+ld (%+.2lf%%)",
+					 diff_val, comp_val < base_val ? -100.0 : 100.0);
+			} else {
+				snprintf(diff_buf, sizeof(diff_buf), "%+ld (%+.2lf%%)",
+					 diff_val, diff_val * 100.0 / base_val);
+			}
+		}
+
+		switch (fmt) {
+		case RESFMT_TABLE_CALCLEN:
+			len = strlen(base_buf);
+			if (len > *max_len_base)
+				*max_len_base = len;
+			if (!is_key_stat(id)) {
+				len = strlen(comp_buf);
+				if (len > *max_len_comp)
+					*max_len_comp = len;
+				len = strlen(diff_buf);
+				if (len > *max_len_diff)
+					*max_len_diff = len;
+			}
+			break;
+		case RESFMT_TABLE: {
+			/* string outputs are left-aligned, number outputs are right-aligned */
+			const char *fmt = base_str ? "%s%-*s" : "%s%*s";
+
+			printf(fmt, i == 0 ? "" : COLUMN_SEP, *max_len_base, base_buf);
+			if (!is_key_stat(id)) {
+				printf(fmt, COLUMN_SEP, *max_len_comp, comp_buf);
+				printf(fmt, COLUMN_SEP, *max_len_diff, diff_buf);
+			}
+			if (i == env.output_spec.spec_cnt - 1)
+				printf("\n");
+			break;
+		}
+		case RESFMT_CSV:
+			printf("%s%s", i == 0 ? "" : ",", base_buf);
+			if (!is_key_stat(id)) {
+				printf("%s%s", i == 0 ? "" : ",", comp_buf);
+				printf("%s%s", i == 0 ? "" : ",", diff_buf);
+			}
+			if (i == env.output_spec.spec_cnt - 1)
+				printf("\n");
+			break;
+		}
+	}
+
+	if (last && fmt == RESFMT_TABLE)
+		output_comp_header_underlines();
+}
+
+static int cmp_stats_key(const struct verif_stats *base, const struct verif_stats *comp)
+{
+	int r;
+
+	r = strcmp(base->file_name, comp->file_name);
+	if (r != 0)
+		return r;
+	return strcmp(base->prog_name, comp->prog_name);
+}
+
+static int handle_comparison_mode(void)
+{
+	struct stat_specs base_specs = {}, comp_specs = {};
+	enum resfmt cur_fmt;
+	int err, i, j;
+
+	if (env.filename_cnt != 2) {
+		fprintf(stderr, "Comparison mode expects exactly two input CSV files!\n");
+		argp_help(&argp, stderr, ARGP_HELP_USAGE, "veristat");
+		return -EINVAL;
+	}
+
+	err = parse_stats_csv(env.filenames[0], &base_specs,
+			      &env.baseline_stats, &env.baseline_stat_cnt);
+	if (err) {
+		fprintf(stderr, "Failed to parse stats from '%s': %d\n", env.filenames[0], err);
+		return err;
+	}
+	err = parse_stats_csv(env.filenames[1], &comp_specs,
+			      &env.prog_stats, &env.prog_stat_cnt);
+	if (err) {
+		fprintf(stderr, "Failed to parse stats from '%s': %d\n", env.filenames[1], err);
+		return err;
+	}
+
+	/* To keep it simple we validate that the set and order of stats in
+	 * both CSVs are exactly the same. This can be lifted with a bit more
+	 * pre-processing later.
+	 */
+	if (base_specs.spec_cnt != comp_specs.spec_cnt) {
+		fprintf(stderr, "Number of stats in '%s' and '%s' differs (%d != %d)!\n",
+			env.filenames[0], env.filenames[1],
+			base_specs.spec_cnt, comp_specs.spec_cnt);
+		return -EINVAL;
+	}
+	for (i = 0; i < base_specs.spec_cnt; i++) {
+		if (base_specs.ids[i] != comp_specs.ids[i]) {
+			fprintf(stderr, "Stats composition differs between '%s' and '%s' (%s != %s)!\n",
+				env.filenames[0], env.filenames[1],
+				stat_defs[base_specs.ids[i]].names[0],
+				stat_defs[comp_specs.ids[i]].names[0]);
+			return -EINVAL;
+		}
+	}
+
+	qsort(env.prog_stats, env.prog_stat_cnt, sizeof(*env.prog_stats), cmp_prog_stats);
+	qsort(env.baseline_stats, env.baseline_stat_cnt, sizeof(*env.baseline_stats), cmp_prog_stats);
+
+	/* for human-readable table output we need to do extra pass to
+	 * calculate column widths, so we substitute current output format
+	 * with RESFMT_TABLE_CALCLEN and later revert it back to RESFMT_TABLE
+	 * and do everything again.
+	 */
+	if (env.out_fmt == RESFMT_TABLE)
+		cur_fmt = RESFMT_TABLE_CALCLEN;
+	else
+		cur_fmt = env.out_fmt;
+
+one_more_time:
+	output_comp_headers(cur_fmt);
+
+	/* If baseline and comparison datasets have different subset of rows
+	 * (we match by 'object + prog' as a unique key) then assume
+	 * empty/missing/zero value for rows that are missing in the opposite
+	 * data set
+	 */
+	i = j = 0;
+	while (i < env.baseline_stat_cnt || j < env.prog_stat_cnt) {
+		bool last = (i == env.baseline_stat_cnt - 1) || (j == env.prog_stat_cnt - 1);
+		const struct verif_stats *base, *comp;
+		int r;
+
+		base = i < env.baseline_stat_cnt ? &env.baseline_stats[i] : &fallback_stats;
+		comp = j < env.prog_stat_cnt ? &env.prog_stats[j] : &fallback_stats;
+
+		if (!base->file_name || !base->prog_name) {
+			fprintf(stderr, "Entry #%d in '%s' doesn't have file and/or program name specified!\n",
+				i, env.filenames[0]);
+			return -EINVAL;
+		}
+		if (!comp->file_name || !comp->prog_name) {
+			fprintf(stderr, "Entry #%d in '%s' doesn't have file and/or program name specified!\n",
+				j, env.filenames[1]);
+			return -EINVAL;
+		}
+
+		r = cmp_stats_key(base, comp);
+		if (r == 0) {
+			output_comp_stats(base, comp, cur_fmt, last);
+			i++;
+			j++;
+		} else if (comp == &fallback_stats || r < 0) {
+			output_comp_stats(base, &fallback_stats, cur_fmt, last);
+			i++;
+		} else {
+			output_comp_stats(&fallback_stats, comp, cur_fmt, last);
+			j++;
+		}
+	}
+
+	if (cur_fmt == RESFMT_TABLE_CALCLEN) {
+		cur_fmt = RESFMT_TABLE;
+		goto one_more_time; /* ... this time with feeling */
+	}
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int err = 0, i;
+
+	if (argp_parse(&argp, argc, argv, 0, NULL, NULL))
+		return 1;
+
+	if (env.verbose && env.quiet) {
+		fprintf(stderr, "Verbose and quiet modes are incompatible, please specify just one or neither!\n");
+		argp_help(&argp, stderr, ARGP_HELP_USAGE, "veristat");
+		return 1;
+	}
+	if (env.verbose && env.log_level == 0)
+		env.log_level = 1;
+
+	if (env.output_spec.spec_cnt == 0)
+		env.output_spec = default_output_spec;
+	if (env.sort_spec.spec_cnt == 0)
+		env.sort_spec = default_sort_spec;
+
+	if (env.comparison_mode)
+		err = handle_comparison_mode();
+	else
+		err = handle_verif_mode();
+
+	free_verif_stats(env.prog_stats, env.prog_stat_cnt);
+	free_verif_stats(env.baseline_stats, env.baseline_stat_cnt);
+	for (i = 0; i < env.filename_cnt; i++)
+		free(env.filenames[i]);
+	free(env.filenames);
+	for (i = 0; i < env.allow_filter_cnt; i++) {
+		free(env.allow_filters[i].file_glob);
+		free(env.allow_filters[i].prog_glob);
+	}
+	free(env.allow_filters);
+	for (i = 0; i < env.deny_filter_cnt; i++) {
+		free(env.deny_filters[i].file_glob);
+		free(env.deny_filters[i].prog_glob);
+	}
+	free(env.deny_filters);
+	return -err;
+}