Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932875Ab1DZBpy (ORCPT ); Mon, 25 Apr 2011 21:45:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56976 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932783Ab1DZBpv (ORCPT ); Mon, 25 Apr 2011 21:45:51 -0400 From: Eric Paris Subject: [PATCH 3/3] flex_array: allow 0 length elements To: dave@linux.vnet.ibm.com Cc: steffen.klassert@secunet.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov, sds@tycho.nsa.gov Date: Mon, 25 Apr 2011 21:45:43 -0400 Message-ID: <20110426014543.1740.89115.stgit@paris.rdu.redhat.com> In-Reply-To: <20110426014531.1740.24077.stgit@paris.rdu.redhat.com> References: <20110426014531.1740.24077.stgit@paris.rdu.redhat.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3423 Lines: 111 allow elements of 0 length. We already allow flex_arrays with 0 elements, but this patch allow us to have elements that are 0 bytes long. Based-on-patch-by: Steffen Klassert Signed-off-by: Eric Paris --- lib/flex_array.c | 26 ++++++++++++++++++++------ 1 files changed, 20 insertions(+), 6 deletions(-) diff --git a/lib/flex_array.c b/lib/flex_array.c index 2554a5f..dcd91d5 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -88,8 +88,11 @@ struct flex_array *flex_array_alloc(int element_size, unsigned int total, gfp_t flags) { struct flex_array *ret; - int max_size = FLEX_ARRAY_NR_BASE_PTRS * - FLEX_ARRAY_ELEMENTS_PER_PART(element_size); + int max_size = 0; + + if (element_size) + max_size = FLEX_ARRAY_NR_BASE_PTRS * + FLEX_ARRAY_ELEMENTS_PER_PART(element_size); /* max_size will end up 0 if element_size > PAGE_SIZE */ if (total > max_size) @@ -183,15 +186,18 @@ __fa_get_part(struct flex_array *fa, int part_nr, gfp_t flags) int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src, gfp_t flags) { - int part_nr = fa_element_to_part_nr(fa, element_nr); + int part_nr; struct flex_array_part *part; void *dst; if (element_nr >= fa->total_nr_elements) return -ENOSPC; + if (!fa->element_size) + return 0; if (elements_fit_in_base(fa)) part = (struct flex_array_part *)&fa->parts[0]; else { + part_nr = fa_element_to_part_nr(fa, element_nr); part = __fa_get_part(fa, part_nr, flags); if (!part) return -ENOMEM; @@ -211,15 +217,18 @@ EXPORT_SYMBOL(flex_array_put); */ int flex_array_clear(struct flex_array *fa, unsigned int element_nr) { - int part_nr = fa_element_to_part_nr(fa, element_nr); + int part_nr; struct flex_array_part *part; void *dst; if (element_nr >= fa->total_nr_elements) return -ENOSPC; + if (!fa->element_size) + return 0; if (elements_fit_in_base(fa)) part = (struct flex_array_part *)&fa->parts[0]; else { + part_nr = fa_element_to_part_nr(fa, element_nr); part = fa->parts[part_nr]; if (!part) return -EINVAL; @@ -264,6 +273,8 @@ int flex_array_prealloc(struct flex_array *fa, unsigned int start, if (end >= fa->total_nr_elements) return -ENOSPC; + if (!fa->element_size) + return 0; if (elements_fit_in_base(fa)) return 0; start_part = fa_element_to_part_nr(fa, start); @@ -291,14 +302,17 @@ EXPORT_SYMBOL(flex_array_prealloc); */ void *flex_array_get(struct flex_array *fa, unsigned int element_nr) { - int part_nr = fa_element_to_part_nr(fa, element_nr); + int part_nr; struct flex_array_part *part; + if (!fa->element_size) + return NULL; if (element_nr >= fa->total_nr_elements) return NULL; if (elements_fit_in_base(fa)) part = (struct flex_array_part *)&fa->parts[0]; else { + part_nr = fa_element_to_part_nr(fa, element_nr); part = fa->parts[part_nr]; if (!part) return NULL; @@ -353,7 +367,7 @@ int flex_array_shrink(struct flex_array *fa) int part_nr; int ret = 0; - if (!fa->total_nr_elements) + if (!fa->total_nr_elements || !fa->element_size) return 0; if (elements_fit_in_base(fa)) return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/