linux-kernel - Re: [PATCH 2/4] uml: helper.c warning corrections

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAGTPOqebcT_Dd5nPSNEkrDvnCgYhqcU=ayjEA8L7Zh0Wr_pj5w@mail.gmail.com>
Date:	Tue, 5 Jul 2011 14:45:06 +0300
From:	Vitaliy Ivanov <vitalivanov@...il.com>
To:	Richard Weinberger <richard@....at>
Cc:	Jeff Dike <jdike@...toit.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
	"user-mode-linux-devel@...ts.sourceforge.net" 
	<user-mode-linux-devel@...ts.sourceforge.net>,
	lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/4] uml: helper.c warning corrections

Richard,

On Tue, Jul 5, 2011 at 12:42 PM, Richard Weinberger <richard@....at> wrote:
> Am Dienstag 05 Juli 2011, 01:15:47 schrieb Vitaliy Ivanov:
>> From 7296c5b9770e95cd6ad4e9e71d2d14c972abdfe1 Mon Sep 17 00:00:00 2001
>> From: Vitaliy Ivanov <vitalivanov@...il.com>
>> Date: Tue, 5 Jul 2011 02:03:06 +0300
>> Subject: [PATCH 2/4] uml: helper.c warning corrections
>> MIME-Version: 1.0
>> Content-Type: text/plain; charset=UTF-8
>> Content-Transfer-Encoding: 8bit
>>
>> arch/um/os-Linux/helper.c: In function ‘helper_child’:
>> arch/um/os-Linux/helper.c:38:7: warning: ignoring return value of ‘write’,
>> declared with attribute warn_unused_result
>
> Same question as before...

Same answer is here:)

>> Signed-off-by: Vitaliy Ivanov <vitalivanov@...il.com>
>> ---
>>  arch/um/os-Linux/helper.c |    4 ++--
>>  1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
>> index b6b1096..feff22d 100644
>> --- a/arch/um/os-Linux/helper.c
>> +++ b/arch/um/os-Linux/helper.c
>> @@ -28,14 +28,14 @@ static int helper_child(void *arg)
>>  {
>>       struct helper_data *data = arg;
>>       char **argv = data->argv;
>> -     int err;
>> +     int err, ret;
>>
>>       if (data->pre_exec != NULL)
>>               (*data->pre_exec)(data->pre_data);
>>       err = execvp_noalloc(data->buf, argv[0], argv);
>>
>>       /* If the exec succeeds, we don't get here */
>> -     write(data->fd, &err, sizeof(err));
>> +     CATCH_EINTR(ret = write(data->fd, &err, sizeof(err)));
>
> Is there really a realistic chance that this write() can be interrupted?
> helper_child() gets called via clone() in run_helper().

It's always better not to think whether it's possible but simply kill
all the chances for this to happen.
In this case that's pretty trivial thing and also it solves issue with warning.

Vitaliy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/