Date: Fri, 31 Jul 2015 11:13:16 -0500 From: Pedro Giffuni <pfg@FreeBSD.org> To: Bruce Evans <brde@optusnet.com.au> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r286102 - head/usr.bin/wall Message-ID: <55BB9E9C.9030608@FreeBSD.org> In-Reply-To: <20150731162408.M1843@besplex.bde.org> References: <201507310112.t6V1CWh8034232@repo.freebsd.org> <20150731162408.M1843@besplex.bde.org>
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On 07/31/15 02:12, Bruce Evans wrote:
> On Fri, 31 Jul 2015, Pedro F. Giffuni wrote:
>
...
>
>> static char errbuf[1024];
>
> Another static buffer. The function is obviously not reentrant. This
> large static buffer mainly wastes space all the time instead of only
> when the function is called.
>
But if I drop that static I get a bunch of errors:
/usr/src/usr.bin/wall/ttymsg.c:82:11: error: address of stack memory
associated
with local variable 'errbuf' returned [-Werror,-Wreturn-stack-address]
return (errbuf);
^~~~~~
/usr/src/usr.bin/wall/ttymsg.c:94:11: error: address of stack memory
associated
with local variable 'errbuf' returned [-Werror,-Wreturn-stack-address]
return (errbuf);
^~~~~~
/usr/src/usr.bin/wall/ttymsg.c:134:13: error: address of stack memory
associated
with local variable 'errbuf' returned [-Werror,-Wreturn-stack-address]
return (errbuf);
^~~~~~
/usr/src/usr.bin/wall/ttymsg.c:160:11: error: address of stack memory
associated
with local variable 'errbuf' returned [-Werror,-Wreturn-stack-address]
return (errbuf);
^~~~~~
...
>> char *p;
>> int forked;
>> @@ -71,8 +71,8 @@ ttymsg(struct iovec *iov, int iovcnt, co
>> if (iovcnt > (int)(sizeof(localiov) / sizeof(localiov[0])))
>> return ("too many iov's (change code in wall/ttymsg.c)");
>>
>> + strlcat(device, line, sizeof(device));
>
> This depends on the slow reinitialization on every entry. The combined
> initialization (initializer + strlcat) is an obfuscated way of
> concatenating 2 strings. The clearest way is snprintf with %s%s format.
>
I will do that, thanks.
Pedro.
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