From: Bart Van Assche Date: Wed, 14 Aug 2019 20:10:08 +0000 (-0700) Subject: Optimize the code that copies strings X-Git-Tag: fio-3.16~30 X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=36833fb04b5f9a734e96a571dfb52fc54b5b95e7 Optimize the code that copies strings Using strncpy() to copy strings is suboptimal because strncpy writes a bunch of additional unnecessary null bytes. Use snprintf() instead of strncpy(). An additional advantage of snprintf() is that it guarantees that the output string is '\0'-terminated. This patch is an improvement for commit 32e31c8c5f7b ("Fix string copy compilation warnings"). Cc: Damien Le Moal Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe --- diff --git a/cconv.c b/cconv.c index 50e45c63..0e657246 100644 --- a/cconv.c +++ b/cconv.c @@ -13,10 +13,9 @@ static void string_to_cpu(char **dst, const uint8_t *src) static void __string_to_net(uint8_t *dst, const char *src, size_t dst_size) { - if (src) { - dst[dst_size - 1] = '\0'; - strncpy((char *) dst, src, dst_size - 1); - } else + if (src) + snprintf((char *) dst, dst_size, "%s", src); + else dst[0] = '\0'; } diff --git a/client.c b/client.c index 43cfbd43..e0047af0 100644 --- a/client.c +++ b/client.c @@ -520,7 +520,7 @@ static void probe_client(struct fio_client *client) sname = server_name(client, buf, sizeof(buf)); memset(pdu.server, 0, sizeof(pdu.server)); - strncpy((char *) pdu.server, sname, sizeof(pdu.server) - 1); + snprintf((char *) pdu.server, sizeof(pdu.server), "%s", sname); fio_net_send_cmd(client->fd, FIO_NET_CMD_PROBE, &pdu, sizeof(pdu), &tag, &client->cmd_list); } @@ -574,7 +574,8 @@ static int fio_client_connect_sock(struct fio_client *client) memset(addr, 0, sizeof(*addr)); addr->sun_family = AF_UNIX; - strncpy(addr->sun_path, client->hostname, sizeof(addr->sun_path) - 1); + snprintf(addr->sun_path, sizeof(addr->sun_path), "%s", + client->hostname); fd = socket(AF_UNIX, SOCK_STREAM, 0); if (fd < 0) { diff --git a/diskutil.c b/diskutil.c index 7be4c022..f0744015 100644 --- a/diskutil.c +++ b/diskutil.c @@ -181,8 +181,7 @@ static int get_device_numbers(char *file_name, int *maj, int *min) /* * must be a file, open "." in that path */ - tempname[PATH_MAX - 1] = '\0'; - strncpy(tempname, file_name, PATH_MAX - 1); + snprintf(tempname, ARRAY_SIZE(tempname), "%s", file_name); p = dirname(tempname); if (stat(p, &st)) { perror("disk util stat"); @@ -314,7 +313,8 @@ static struct disk_util *disk_util_add(struct thread_data *td, int majdev, sfree(du); return NULL; } - strncpy((char *) du->dus.name, basename(path), FIO_DU_NAME_SZ - 1); + snprintf((char *) du->dus.name, ARRAY_SIZE(du->dus.name), "%s", + basename(path)); du->sysfs_root = strdup(path); du->major = majdev; du->minor = mindev; @@ -435,8 +435,7 @@ static struct disk_util *__init_per_file_disk_util(struct thread_data *td, log_err("unknown sysfs layout\n"); return NULL; } - tmp[PATH_MAX - 1] = '\0'; - strncpy(tmp, p, PATH_MAX - 1); + snprintf(tmp, ARRAY_SIZE(tmp), "%s", p); sprintf(path, "%s", tmp); } diff --git a/engines/net.c b/engines/net.c index ca6fb344..91f25774 100644 --- a/engines/net.c +++ b/engines/net.c @@ -1105,8 +1105,7 @@ static int fio_netio_setup_connect_unix(struct thread_data *td, struct sockaddr_un *soun = &nd->addr_un; soun->sun_family = AF_UNIX; - memset(soun->sun_path, 0, sizeof(soun->sun_path)); - strncpy(soun->sun_path, path, sizeof(soun->sun_path) - 1); + snprintf(soun->sun_path, sizeof(soun->sun_path), "%s", path); return 0; } @@ -1135,9 +1134,8 @@ static int fio_netio_setup_listen_unix(struct thread_data *td, const char *path) mode = umask(000); - memset(addr, 0, sizeof(*addr)); addr->sun_family = AF_UNIX; - strncpy(addr->sun_path, path, sizeof(addr->sun_path) - 1); + snprintf(addr->sun_path, sizeof(addr->sun_path), "%s", path); unlink(path); len = sizeof(addr->sun_family) + strlen(path) + 1; diff --git a/engines/sg.c b/engines/sg.c index c46b9aba..a1a6de4c 100644 --- a/engines/sg.c +++ b/engines/sg.c @@ -1181,8 +1181,8 @@ static char *fio_sgio_errdetails(struct io_u *io_u) } if (!(hdr->info & SG_INFO_CHECK) && !strlen(msg)) - strncpy(msg, "SG Driver did not report a Host, Driver or Device check", - MAXERRDETAIL - 1); + snprintf(msg, MAXERRDETAIL, "%s", + "SG Driver did not report a Host, Driver or Device check"); return msg; } diff --git a/filesetup.c b/filesetup.c index 17fa31fb..57eca1bf 100644 --- a/filesetup.c +++ b/filesetup.c @@ -805,8 +805,7 @@ static unsigned long long get_fs_free_counts(struct thread_data *td) } else if (f->filetype != FIO_TYPE_FILE) continue; - buf[255] = '\0'; - strncpy(buf, f->file_name, 255); + snprintf(buf, ARRAY_SIZE(buf), "%s", f->file_name); if (stat(buf, &sb) < 0) { if (errno != ENOENT) @@ -829,8 +828,7 @@ static unsigned long long get_fs_free_counts(struct thread_data *td) continue; fm = calloc(1, sizeof(*fm)); - strncpy(fm->__base, buf, sizeof(fm->__base)); - fm->__base[255] = '\0'; + snprintf(fm->__base, ARRAY_SIZE(fm->__base), "%s", buf); fm->base = basename(fm->__base); fm->key = sb.st_dev; flist_add(&fm->list, &list); diff --git a/gclient.c b/gclient.c index 04275a13..64324177 100644 --- a/gclient.c +++ b/gclient.c @@ -318,7 +318,7 @@ static void gfio_update_thread_status(struct gui_entry *ge, static char message[100]; const char *m = message; - strncpy(message, status_message, sizeof(message) - 1); + snprintf(message, sizeof(message), "%s", status_message); gtk_progress_bar_set_text(GTK_PROGRESS_BAR(ge->thread_status_pb), m); gtk_progress_bar_set_fraction(GTK_PROGRESS_BAR(ge->thread_status_pb), perc / 100.0); gtk_widget_queue_draw(ge->ui->window); @@ -330,7 +330,7 @@ static void gfio_update_thread_status_all(struct gui *ui, char *status_message, static char message[100]; const char *m = message; - strncpy(message, status_message, sizeof(message) - 1); + strncpy(message, sizeof(message), "%s", status_message); gtk_progress_bar_set_text(GTK_PROGRESS_BAR(ui->thread_status_pb), m); gtk_progress_bar_set_fraction(GTK_PROGRESS_BAR(ui->thread_status_pb), perc / 100.0); gtk_widget_queue_draw(ui->window); diff --git a/init.c b/init.c index c9f6198e..63f2168e 100644 --- a/init.c +++ b/init.c @@ -1273,8 +1273,7 @@ static char *make_filename(char *buf, size_t buf_size,struct thread_options *o, for (f = &fpre_keywords[0]; f->keyword; f++) f->strlen = strlen(f->keyword); - buf[buf_size - 1] = '\0'; - strncpy(buf, o->filename_format, buf_size - 1); + snprintf(buf, buf_size, "%s", o->filename_format); memset(copy, 0, sizeof(copy)); for (f = &fpre_keywords[0]; f->keyword; f++) { @@ -1353,7 +1352,7 @@ static char *make_filename(char *buf, size_t buf_size,struct thread_options *o, if (post_start) strncpy(dst, buf + post_start, dst_left); - strncpy(buf, copy, buf_size - 1); + snprintf(buf, buf_size, "%s", copy); } while (1); } @@ -2029,20 +2028,12 @@ static int __parse_jobs_ini(struct thread_data *td, */ if (access(filename, F_OK) && (ts = strrchr(file, '/'))) { - int len = ts - file + - strlen(filename) + 2; - - if (!(full_fn = calloc(1, len))) { + if (asprintf(&full_fn, "%.*s%s", + (int)(ts - file + 1), file, + filename) < 0) { ret = ENOMEM; break; } - - strncpy(full_fn, - file, (ts - file) + 1); - strncpy(full_fn + (ts - file) + 1, - filename, - len - (ts - file) - 1); - full_fn[len - 1] = 0; filename = full_fn; } diff --git a/ioengines.c b/ioengines.c index aa4ccd27..40fa75c3 100644 --- a/ioengines.c +++ b/ioengines.c @@ -125,8 +125,7 @@ static struct ioengine_ops *__load_ioengine(const char *name) { char engine[64]; - engine[sizeof(engine) - 1] = '\0'; - strncpy(engine, name, sizeof(engine) - 1); + snprintf(engine, sizeof(engine), "%s", name); /* * linux libaio has alias names, so convert to what we want diff --git a/options.c b/options.c index f4c9bedf..447f231e 100644 --- a/options.c +++ b/options.c @@ -4902,8 +4902,7 @@ char *fio_option_dup_subs(const char *opt) return NULL; } - in[OPT_LEN_MAX] = '\0'; - strncpy(in, opt, OPT_LEN_MAX); + snprintf(in, sizeof(in), "%s", opt); while (*inptr && nchr > 0) { if (inptr[0] == '$' && inptr[1] == '{') { diff --git a/parse.c b/parse.c index a7d4516e..c4fd4626 100644 --- a/parse.c +++ b/parse.c @@ -602,8 +602,7 @@ static int __handle_option(const struct fio_option *o, const char *ptr, if (!is_time && o->is_time) is_time = o->is_time; - tmp[sizeof(tmp) - 1] = '\0'; - strncpy(tmp, ptr, sizeof(tmp) - 1); + snprintf(tmp, sizeof(tmp), "%s", ptr); p = strchr(tmp, ','); if (p) *p = '\0'; @@ -829,8 +828,7 @@ static int __handle_option(const struct fio_option *o, const char *ptr, char tmp[128]; char *p1, *p2; - tmp[sizeof(tmp) - 1] = '\0'; - strncpy(tmp, ptr, sizeof(tmp) - 1); + snprintf(tmp, sizeof(tmp), "%s", ptr); /* Handle bsrange with separate read,write values: */ p1 = strchr(tmp, ','); diff --git a/server.c b/server.c index 23e549a5..e7846227 100644 --- a/server.c +++ b/server.c @@ -865,7 +865,8 @@ static int handle_probe_cmd(struct fio_net_cmd *cmd) strcpy(me, (char *) pdu->server); gethostname((char *) probe.hostname, sizeof(probe.hostname)); - strncpy((char *) probe.fio_version, fio_version_string, sizeof(probe.fio_version) - 1); + snprintf((char *) probe.fio_version, sizeof(probe.fio_version), "%s", + fio_version_string); /* * If the client supports compression and we do too, then enable it @@ -1470,12 +1471,10 @@ void fio_server_send_ts(struct thread_stat *ts, struct group_run_stats *rs) memset(&p, 0, sizeof(p)); - strncpy(p.ts.name, ts->name, FIO_JOBNAME_SIZE); - p.ts.name[FIO_JOBNAME_SIZE - 1] = '\0'; - strncpy(p.ts.verror, ts->verror, FIO_VERROR_SIZE); - p.ts.verror[FIO_VERROR_SIZE - 1] = '\0'; - strncpy(p.ts.description, ts->description, FIO_JOBDESC_SIZE); - p.ts.description[FIO_JOBDESC_SIZE - 1] = '\0'; + snprintf(p.ts.name, sizeof(p.ts.name), "%s", ts->name); + snprintf(p.ts.verror, sizeof(p.ts.verror), "%s", ts->verror); + snprintf(p.ts.description, sizeof(p.ts.description), "%s", + ts->description); p.ts.error = cpu_to_le32(ts->error); p.ts.thread_number = cpu_to_le32(ts->thread_number); @@ -1666,8 +1665,7 @@ static void convert_dus(struct disk_util_stat *dst, struct disk_util_stat *src) { int i; - dst->name[FIO_DU_NAME_SZ - 1] = '\0'; - strncpy((char *) dst->name, (char *) src->name, FIO_DU_NAME_SZ - 1); + snprintf((char *) dst->name, sizeof(dst->name), "%s", src->name); for (i = 0; i < 2; i++) { dst->s.ios[i] = cpu_to_le64(src->s.ios[i]); @@ -1977,8 +1975,7 @@ int fio_send_iolog(struct thread_data *td, struct io_log *log, const char *name) else pdu.compressed = 0; - strncpy((char *) pdu.name, name, FIO_NET_NAME_MAX); - pdu.name[FIO_NET_NAME_MAX - 1] = '\0'; + snprintf((char *) pdu.name, sizeof(pdu.name), "%s", name); /* * We can't do this for a pre-compressed log, but for that case, @@ -2195,9 +2192,8 @@ static int fio_init_server_sock(void) mode = umask(000); - memset(&addr, 0, sizeof(addr)); addr.sun_family = AF_UNIX; - strncpy(addr.sun_path, bind_sock, sizeof(addr.sun_path) - 1); + snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", bind_sock); len = sizeof(addr.sun_family) + strlen(bind_sock) + 1; @@ -2247,9 +2243,9 @@ static int fio_init_server_connection(void) if (p) strcat(p, port); else - strncpy(bind_str, port, sizeof(bind_str) - 1); + snprintf(bind_str, sizeof(bind_str), "%s", port); } else - strncpy(bind_str, bind_sock, sizeof(bind_str) - 1); + snprintf(bind_str, sizeof(bind_str), "%s", bind_sock); log_info("fio: server listening on %s\n", bind_str); diff --git a/stat.c b/stat.c index bf87917c..33637900 100644 --- a/stat.c +++ b/stat.c @@ -1828,10 +1828,11 @@ void __show_run_stats(void) /* * These are per-group shared already */ - strncpy(ts->name, td->o.name, FIO_JOBNAME_SIZE - 1); + snprintf(ts->name, sizeof(ts->name), "%s", td->o.name); if (td->o.description) - strncpy(ts->description, td->o.description, - FIO_JOBDESC_SIZE - 1); + snprintf(ts->description, + sizeof(ts->description), "%s", + td->o.description); else memset(ts->description, 0, FIO_JOBDESC_SIZE); @@ -1868,12 +1869,12 @@ void __show_run_stats(void) if (!td->error && td->o.continue_on_error && td->first_error) { ts->error = td->first_error; - ts->verror[sizeof(ts->verror) - 1] = '\0'; - strncpy(ts->verror, td->verror, sizeof(ts->verror) - 1); + snprintf(ts->verror, sizeof(ts->verror), "%s", + td->verror); } else if (td->error) { ts->error = td->error; - ts->verror[sizeof(ts->verror) - 1] = '\0'; - strncpy(ts->verror, td->verror, sizeof(ts->verror) - 1); + snprintf(ts->verror, sizeof(ts->verror), "%s", + td->verror); } } diff --git a/verify.c b/verify.c index f79ab43a..48ba051d 100644 --- a/verify.c +++ b/verify.c @@ -1635,8 +1635,7 @@ struct all_io_list *get_all_io_list(int save_mask, size_t *sz) s->rand.state32.s[3] = 0; s->rand.use64 = 0; } - s->name[sizeof(s->name) - 1] = '\0'; - strncpy((char *) s->name, td->o.name, sizeof(s->name) - 1); + snprintf((char *) s->name, sizeof(s->name), "%s", td->o.name); next = io_list_next(s); }