From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KtjvR-0006Z9-My for qemu-devel@nongnu.org; Sat, 25 Oct 2008 10:15:33 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KtjvP-0006Yg-9j for qemu-devel@nongnu.org; Sat, 25 Oct 2008 10:15:32 -0400 Received: from [199.232.76.173] (port=55302 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KtjvP-0006YX-4A for qemu-devel@nongnu.org; Sat, 25 Oct 2008 10:15:31 -0400 Received: from rv-out-0708.google.com ([209.85.198.244]:59468) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KtjvO-0004to-1F for qemu-devel@nongnu.org; Sat, 25 Oct 2008 10:15:30 -0400 Received: by rv-out-0708.google.com with SMTP id f25so1204569rvb.22 for ; Sat, 25 Oct 2008 07:15:27 -0700 (PDT) Message-ID: Date: Sat, 25 Oct 2008 16:15:27 +0200 From: "andrzej zaborowski" Subject: Re: [Qemu-devel] [5532] Replace uses of strndup (a GNU extension) with Qemu pstrdup In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 2008/10/25 Blue Swirl : > On 10/25/08, andrzej zaborowski wrote: >> 2008/10/25 Blue Swirl : >> > On 10/25/08, andrzej zaborowski wrote: >> >> 2008/10/25 Blue Swirl : >> >> >> >> > Revision: 5532 >> >> > http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5532 >> >> > Author: blueswir1 >> >> > Date: 2008-10-25 11:23:27 +0000 (Sat, 25 Oct 2008) >> >> > >> >> > Log Message: >> >> > ----------- >> >> > Replace uses of strndup (a GNU extension) with Qemu pstrdup >> >> > >> >> > Modified Paths: >> >> > -------------- >> >> > trunk/cutils.c >> >> > trunk/hw/bt-hci.c >> >> > trunk/qemu-common.h >> >> > >> >> > Modified: trunk/cutils.c >> >> > =================================================================== >> >> > --- trunk/cutils.c 2008-10-25 11:21:28 UTC (rev 5531) >> >> > +++ trunk/cutils.c 2008-10-25 11:23:27 UTC (rev 5532) >> >> > @@ -50,6 +50,18 @@ >> >> > return buf; >> >> > } >> >> > >> >> > +/* strdup with a limit */ >> >> > +char *pstrdup(const char *str, size_t buf_size) >> >> > +{ >> >> > + size_t len; >> >> > + char *buf; >> >> > + >> >> > + len = MIN(buf_size, strlen(str)); >> >> > + buf = qemu_malloc(len); >> >> > + pstrcpy(buf, len, str); >> >> > + return buf; >> >> > +} >> >> >> >> >> >> I think here also pstrcpy will only copy up to buf_size - 1 characters >> >> while strndup would copy buf_size chars. >> > >> > That is actually safer if we always want the strings to be NUL terminated. >> >> >> strndup also always NUL terminates the string so it's just as safe, >> the length is just different. >> >> >> > >> > But the allocation length is wrong, it should be MIN(buf_size, strlen(str) + 1). >> >> >> By my reading of the manual, it should rather be MIN(buf_size, strlen(str)) + 1. > > But then the length could be incorrect: buf_size + 1. That's what it should be in case lmp_name is 248 chars long. I think the confusion is because you called the parameter buf_size while strndup calls it n (the number of characters.. not buffer size). Note that you can use memcpy instead of pstrcpy because the length is known so there's no need for the overhead. Cheers