Date: Thu, 21 Jun 2012 02:27:23 +1000 (EST) From: Bruce Evans <brde@optusnet.com.au> To: Eitan Adler <eadler@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r237286 - head/lib/libc/gen Message-ID: <20120621015220.J2636@besplex.bde.org> In-Reply-To: <201206200638.q5K6cg7u024024@svn.freebsd.org> References: <201206200638.q5K6cg7u024024@svn.freebsd.org>
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On Wed, 20 Jun 2012, Eitan Adler wrote:
> Log:
> Don't close an uninitialized descriptor. [1]
> Add a sanity check for the validity of the passed fd.
Library functions shouldn't use assert() or abort().
The fd is not passed, but is a static variable under syslog()'s control.
In libc, only the following use assert.h:
- stdio/xprintf*.c. Very nonstd.
- rpc/*.c (perhaps not everything)
- db/*.c (but partly under DEBUG. Not the standard use where assert() is
controlled by NDEBUG)
- nameser/ns_print.c
- ia64/gen/unwind.c (but under SANITY. The standard NDEBUG is too hard to
use here too)
- gen/getgrent.c.
- regex/grot/main.c (test program. Not part of libc)
- regex/regex/utils.h (but ifdefed, and I think turned off in production.
Spencer knows how to use NDEBUG)
- regex/regcomp.c (ifdefed)
- include/isc/list.h
- net/*.c (just 2 files)
- posix1e/acl*.c (perhaps not everything)
- inet/inet_net_pton.c
- iconv/*.c (perhaps not everything).
The list was only short enough to be described by "only" in not very old
versions of FreeBSD. posix1e and iconv doubled the number of files.
> Modified: head/lib/libc/gen/syslog.c
> ==============================================================================
> --- head/lib/libc/gen/syslog.c Wed Jun 20 04:11:34 2012 (r237285)
> +++ head/lib/libc/gen/syslog.c Wed Jun 20 06:38:41 2012 (r237286)
> @@ -41,6 +41,7 @@ __FBSDID("$FreeBSD$");
> #include <sys/un.h>
> #include <netdb.h>
>
> +#include <assert.h>
> #include <errno.h>
> #include <fcntl.h>
> #include <paths.h>
> @@ -413,8 +414,11 @@ void
> closelog(void)
> {
> THREAD_LOCK();
> - (void)_close(LogFile);
> - LogFile = -1;
> + assert(LogFile >= -1);
Since this assert() can't fail (unless the CPU has a parity error or
or the memory behind Logfile has a parity error or another memory error
or was clobbered by a buffer overrun), this assert() doesn't break the
library but just wastes space.
> + if (LogFile != -1) {
> + (void)_close(LogFile);
> + LogFile = -1;
> + }
> LogTag = NULL;
> status = NOCONN;
> THREAD_UNLOCK();
Bruce
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