From patchwork Mon Feb 20 14:19:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yauheni Kaliuta X-Patchwork-Id: 9582949 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9332C60578 for ; Mon, 20 Feb 2017 14:20:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8121828680 for ; Mon, 20 Feb 2017 14:20:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 70BF728764; Mon, 20 Feb 2017 14:20:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD69428680 for ; Mon, 20 Feb 2017 14:20:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753273AbdBTOUU (ORCPT ); Mon, 20 Feb 2017 09:20:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42828 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753205AbdBTOUT (ORCPT ); Mon, 20 Feb 2017 09:20:19 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 918F7C05681A; Mon, 20 Feb 2017 14:19:04 +0000 (UTC) Received: from astarta.redhat.com (ovpn-117-254.ams2.redhat.com [10.36.117.254]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1KEIvVj030482 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 20 Feb 2017 09:19:03 -0500 From: Yauheni Kaliuta To: linux-modules Cc: Lucas De Marchi , Mian Yousaf Kaukab , bjorn.andersson@linaro.org Subject: [PATCH RFC v2 2/2] depmod: handle nested loops Date: Mon, 20 Feb 2017 16:19:00 +0200 Message-Id: <20170220141900.8705-3-yauheni.kaliuta@redhat.com> In-Reply-To: <20170220141900.8705-1-yauheni.kaliuta@redhat.com> References: <20170220141900.8705-1-yauheni.kaliuta@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 20 Feb 2017 14:19:04 +0000 (UTC) Sender: owner-linux-modules@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP This is a rework of depmod report cycles logic to make it tolerant to more complex loops. The patch tries to remember own path for vertexes which makes it possible to handle configurations with common edges and non-cyclic modules. It assumes that the previous dependency calculations can not give as input something like mod_a -> mod_b -> , but -> mod_a -> mod_b should be fine. Signed-off-by: Yauheni Kaliuta --- tools/depmod.c | 292 ++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 208 insertions(+), 84 deletions(-) diff --git a/tools/depmod.c b/tools/depmod.c index f2b370f146bb..3fb188f878f8 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -37,7 +37,7 @@ #include #include -#include +#include #include "kmod.h" @@ -785,6 +785,7 @@ static void cfg_free(struct cfg *cfg) /* depmod calculations ***********************************************/ +struct vertex; struct mod { struct kmod_module *kmod; char *path; @@ -800,6 +801,7 @@ struct mod { uint16_t idx; /* index in depmod->modules.array */ uint16_t users; /* how many modules depend on this one */ bool visited; /* helper field to report cycles */ + struct vertex *vertex; /* helper field to report cycles */ char modname[]; }; @@ -1450,105 +1452,228 @@ static void depmod_sort_dependencies(struct depmod *depmod) } } -static void depmod_report_cycles(struct depmod *depmod, uint16_t n_mods, - uint16_t n_roots, uint16_t *users, - uint16_t *stack, uint16_t *edges) +struct vertex { + struct vertex *parent; + struct mod *mod; +}; + +static struct vertex *vertex_new(struct mod *mod, struct vertex *parent) +{ + struct vertex *v; + + v = malloc(sizeof(*v)); + if (v == NULL) + return NULL; + + v->parent = parent; + v->mod = mod; + return v; +} + +static void depmod_list_remove_data(struct kmod_list **list, void *data) +{ + struct kmod_list *l; + + l = kmod_list_remove_data(*list, data); + *list = l; +} + +static void depmod_report_one_cycle(struct depmod *depmod, + struct vertex *vertex, + struct kmod_list **roots, + struct hash *loop_set) { const char sep[] = " -> "; - int ir = 0; - int num_cyclic = 0; + size_t sz; + char *buf; + struct array reverse; + int i; + int n; + struct vertex *v; - while (n_roots > 0) { - int is, ie; + array_init(&reverse, 3); - for (; ir < n_mods; ir++) { - if (users[ir] > 0) { - break; - } + sz = 0; + for (v = vertex->parent, n = 0; + v != NULL; + v = v->parent, n++) { + + sz += v->mod->modnamesz - 1; + array_append(&reverse, v); + hash_add(loop_set, v->mod->modname, NULL); + } + sz += vertex->mod->modnamesz - 1; + + buf = malloc(sz + n * strlen(sep) + 1); + + sz = 0; + for (i = reverse.count - 1; i >= 0; i--) { + size_t len; + + v = reverse.array[i]; + + len = v->mod->modnamesz - 1; + memcpy(buf + sz, v->mod->modname, len); + sz += len; + strcpy(buf + sz, sep); + sz += strlen(sep); + + depmod_list_remove_data(roots, v->mod); + } + strcpy(buf + sz, vertex->mod->modname); + ERR("Cycle detected: %s\n", buf); + + free(buf); + array_free_array(&reverse); +} + +static int depmod_report_cycles_from_root(struct depmod *depmod, + struct mod *root_mod, + struct kmod_list **roots, + void **stack, + size_t stack_size, + struct hash *loop_set) +{ + struct kmod_list *free_list = NULL; /* struct vertex */ + struct kmod_list *l; + struct vertex *root; + struct vertex *vertex; + struct vertex *v; + struct mod *m; + struct mod **itr, **itr_end; + size_t is; + + root = vertex_new(root_mod, NULL); + if (root == NULL) { + ERR("No memory to report cycles\n"); + return -ENOMEM; + } + + l = kmod_list_append(free_list, root); + if (l == NULL) { + ERR("No memory to report cycles\n"); + return -ENOMEM; + } + free_list = l; + + is = 0; + stack[is++] = (void *)root; + + while (is > 0) { + vertex = stack[--is]; + m = vertex->mod; + /* + * because of the topological sort we can start only + * from part of a loop or from a branch after a loop + */ + if (m->visited && m == root->mod) { + depmod_report_one_cycle(depmod, vertex, + roots, loop_set); + continue; } - if (ir >= n_mods) - break; + m->visited = true; + if (m->deps.count == 0) { + /* + * boundary condition: if there is more than one + * single node branch (not a loop), it is + * recognized as a loop by the code above: + * m->visited because more then one, + * m == root->mod since it is a single node. + * So, prevent deeping into the branch second + * time. + */ + depmod_list_remove_data(roots, m); - /* New DFS with ir as root, no edges */ - stack[0] = ir; - ie = 0; - - /* at least one root less */ - n_roots--; - - /* skip this root on next iteration */ - ir++; - - for (is = 1; is > 0;) { - uint16_t idx = stack[--is]; - struct mod *m = depmod->modules.array[idx]; - const struct mod **itr, **itr_end; - - DBG("Cycle report: Trying %s visited=%d users=%d\n", - m->modname, m->visited, users[idx]); - - if (m->visited) { - int i, n = 0, sz = 0; - char *buf; - bool is_cyclic = false; - - for (i = ie - 1; i >= 0; i--) { - struct mod *loop = depmod->modules.array[edges[i]]; - sz += loop->modnamesz - 1; - n++; - if (loop == m) { - sz += loop->modnamesz - 1; - is_cyclic = true; - break; - } - } - /* Current module not found in dependency list. - * Must be a related module. Ignore it. - */ - if (!is_cyclic) - continue; - - num_cyclic += n; - - buf = malloc(sz + n * strlen(sep) + 1); - sz = 0; - for (i = ie - n; i < ie; i++) { - struct mod *loop = - depmod->modules.array[edges[i]]; - memcpy(buf + sz, loop->modname, - loop->modnamesz - 1); - sz += loop->modnamesz - 1; - memcpy(buf + sz, sep, strlen(sep)); - sz += strlen(sep); - } - memcpy(buf + sz, m->modname, m->modnamesz); + continue; + } - ERR("Cycle detected: %s\n", buf); + itr = (struct mod **) m->deps.array; + itr_end = itr + m->deps.count; + for (; itr < itr_end; itr++) { + struct mod *dep = *itr; + v = vertex_new(dep, vertex); + if (v == NULL) { + ERR("No memory to report cycles\n"); + return -ENOMEM; + } + assert(is < stack_size); + stack[is++] = v; - free(buf); - continue; + l = kmod_list_append(free_list, v); + if (l == NULL) { + ERR("No memory to report cycles\n"); + return -ENOMEM; } + free_list = l; - m->visited = true; + } + } + while (free_list) { + v = free_list->data; + l = kmod_list_remove(free_list); + free_list = l; + free(v); + } - if (m->deps.count == 0) { - continue; - } + return 0; +} - edges[ie++] = idx; +static void depmod_report_cycles(struct depmod *depmod, uint16_t n_mods, + uint16_t *users) +{ + int num_cyclic = 0; + struct kmod_list *roots = NULL; /* struct mod */ + struct kmod_list *l; + size_t n_r; /* local n_roots */ + int i; + int err; + void **stack; + struct mod *m; + struct mod *root; + struct hash *loop_set; - itr = (const struct mod **) m->deps.array; - itr_end = itr + m->deps.count; - for (; itr < itr_end; itr++) { - const struct mod *dep = *itr; - stack[is++] = dep->idx; - users[dep->idx]--; - } + for (i = 0, n_r = 0; i < n_mods; i++) { + if (users[i] <= 0) + continue; + m = depmod->modules.array[i]; + l = kmod_list_append(roots, m); + if (l == NULL) { + ERR("No memory to report cycles\n"); + return; } + roots = l; + n_r++; + } + + stack = malloc(n_r * sizeof(void *)); + if (stack == NULL) { + ERR("No memory to report cycles\n"); + return; + } + + loop_set = hash_new(16, NULL); + if (loop_set == NULL) { + ERR("No memory to report cycles\n"); + return; + } + + while (roots != NULL) { + root = roots->data; + l = kmod_list_remove(roots); + roots = l; + err = depmod_report_cycles_from_root(depmod, + root, + &roots, + stack, n_r, loop_set); + if (err < 0) + goto err; } + num_cyclic = hash_get_count(loop_set); ERR("Found %d modules in dependency cycles!\n", num_cyclic); +err: + hash_free(loop_set); } static int depmod_calculate_dependencies(struct depmod *depmod) @@ -1605,8 +1730,7 @@ static int depmod_calculate_dependencies(struct depmod *depmod) } if (n_sorted < n_mods) { - depmod_report_cycles(depmod, n_mods, n_mods - n_sorted, - users, roots, sorted); + depmod_report_cycles(depmod, n_mods, users); ret = -EINVAL; goto exit; }