Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:44696 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752812AbdECQE4 (ORCPT ); Wed, 3 May 2017 12:04:56 -0400 Subject: [PATCH 1/9] Provide a function to create a NUL-terminated string from unterminated data From: David Howells To: viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, dhowells@redhat.com, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, mszeredi@redhat.com Date: Wed, 03 May 2017 17:04:42 +0100 Message-ID: <149382748241.30481.12971647975706869540.stgit@warthog.procyon.org.uk> In-Reply-To: <149382747487.30481.15428192741961545429.stgit@warthog.procyon.org.uk> References: <149382747487.30481.15428192741961545429.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: Provide a function, kstrcreate(), that will create a NUL-terminated string from an unterminated character array where the length is known in advance. This is better than kstrndup() in situations where we already know the string length as the strnlen() in kstrndup() is superfluous. Signed-off-by: David Howells --- include/linux/string.h | 1 + mm/util.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index 26b6f6a66f83..5596ae56ce0a 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -122,6 +122,7 @@ extern void kfree_const(const void *x); extern char *kstrdup(const char *s, gfp_t gfp) __malloc; extern const char *kstrdup_const(const char *s, gfp_t gfp); extern char *kstrndup(const char *s, size_t len, gfp_t gfp); +extern char *kstrcreate(const char *s, size_t len, gfp_t gfp); extern void *kmemdup(const void *src, size_t len, gfp_t gfp); extern char **argv_split(gfp_t gfp, const char *str, int *argcp); diff --git a/mm/util.c b/mm/util.c index 656dc5e37a87..01887bbdb11e 100644 --- a/mm/util.c +++ b/mm/util.c @@ -103,6 +103,28 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp) EXPORT_SYMBOL(kstrndup); /** + * kstrcreate - Create a NUL-terminated string from unterminated data + * @s: The data to stringify + * @len: The size of the data + * @gfp: the GFP mask used in the kmalloc() call when allocating memory + */ +char *kstrcreate(const char *s, size_t len, gfp_t gfp) +{ + char *buf; + + if (!s) + return NULL; + + buf = kmalloc_track_caller(len + 1, gfp); + if (buf) { + memcpy(buf, s, len); + buf[len] = '\0'; + } + return buf; +} +EXPORT_SYMBOL(kstrcreate); + +/** * kmemdup - duplicate region of memory * * @src: memory region to duplicate