From: ebiederm@xmission.com (Eric W. Biederman)
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: gorcunov@openvz.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, xemul@openvz.org, xemul@parallels.com,
avagin@openvz.org, kosaki.motohiro@gmail.com, mingo@elte.hu,
hpa@zytor.com, tglx@linutronix.de, glommer@parallels.com,
andi@firstfloor.org, tj@kernel.org, matthltc@us.ibm.com,
penberg@kernel.org, eric.dumazet@gmail.com, segoon@openwall.com,
adobriyan@gmail.com, Valdis.Kletnieks@vt.edu
Subject: Re: [RFC c/r 2/4] [RFC] syscalls, x86: Add __NR_kcmp syscall v7
Date: Fri, 27 Jan 2012 12:33:07 -0800 [thread overview]
Message-ID: <m1aa5828e4.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <4F2306BB.5090907@jp.fujitsu.com> (KOSAKI Motohiro's message of "Fri, 27 Jan 2012 15:19:07 -0500")
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> writes:
> On 1/27/2012 12:53 PM, Cyrill Gorcunov wrote:
>> + switch (type) {
>> + case KCMP_FILE: {
>> + struct file *filp1, *filp2;
>> +
>> + filp1 = get_file_raw_ptr(task1, idx1);
>> + filp2 = get_file_raw_ptr(task2, idx2);
>> +
>> + if (filp1 && filp2)
>> + ret = kcmp_ptr((long)filp1, (long)filp2, KCMP_FILE);
>> + else
>> + ret = -ENOENT;
>
> If my remember is correct, Andrew pointed out EINVAL is better than ENOENT.
Ah yes. And really what it should be is
if (!filp1 || !filp2)
return -EBADF;
At least EBADF is what you return if it is your process that doesn't
have the filedescriptor.
>> + break;
>> + case KCMP_SYSVSEM:
>> +#ifdef CONFIG_SYSVIPC
>> + ret = kcmp_ptr((long)task1->sysvsem.undo_list,
>> + (long)task2->sysvsem.undo_list,
>> + KCMP_SYSVSEM);
>> +#else
>> + ret = -EINVAL;
>
> ENOTSUP is better, I think. because of, EINVAL implicitly mean _caller_ is wrong.
> but in this case, it is not bad. only the kernel doesn't have enough
> feature.
Careful a type compiled out should in principle match a type whose
support has not been implemented. That is the default case should match
what happens when you don't compile in sysvipc support.
>
>> + goto err;
>
> you don't need err label at all.
>
>
>> +#endif
>> + break;
>> + default:
>> + ret = -EINVAL;
>> + goto err;
>> + }
>> +
>> +err:
>> + put_task_struct(task1);
>> + put_task_struct(task2);
>> +
>> + return ret;
>> +}
Eric
next prev parent reply other threads:[~2012-01-27 20:30 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-27 17:53 [RFC c/r 0/4] [RFC c/r 0/@total@] A pile in c/r sake Cyrill Gorcunov
2012-01-27 17:53 ` [RFC c/r 1/4] fs, proc: Introduce /proc/<pid>/task/<tid>/children entry v9 Cyrill Gorcunov
2012-01-27 17:53 ` [RFC c/r 2/4] [RFC] syscalls, x86: Add __NR_kcmp syscall v7 Cyrill Gorcunov
2012-01-27 18:05 ` H. Peter Anvin
2012-01-27 18:11 ` Cyrill Gorcunov
2012-01-27 18:15 ` Andi Kleen
2012-01-27 18:24 ` Cyrill Gorcunov
2012-01-27 18:30 ` H. Peter Anvin
2012-01-28 17:19 ` Michael Kerrisk
2012-01-28 17:34 ` Cyrill Gorcunov
2012-01-28 17:36 ` Cyrill Gorcunov
2012-01-27 18:31 ` Andi Kleen
2012-01-27 18:40 ` Cyrill Gorcunov
2012-01-27 19:40 ` Andi Kleen
2012-01-27 20:55 ` Eric W. Biederman
2012-01-27 18:40 ` Eric W. Biederman
2012-01-27 18:45 ` Cyrill Gorcunov
2012-01-27 19:10 ` Cyrill Gorcunov
2012-01-27 19:37 ` Vasiliy Kulikov
2012-01-27 19:59 ` hpanvin@gmail.com
2012-01-27 20:07 ` Cyrill Gorcunov
2012-01-27 20:19 ` KOSAKI Motohiro
2012-01-27 20:33 ` Eric W. Biederman [this message]
2012-01-27 20:50 ` Cyrill Gorcunov
2012-01-27 21:19 ` Eric W. Biederman
2012-01-27 20:34 ` Glauber Costa
2012-01-27 20:37 ` H. Peter Anvin
2012-01-27 20:47 ` Cyrill Gorcunov
2012-01-27 17:53 ` [RFC c/r 3/4] c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat Cyrill Gorcunov
2012-01-27 18:29 ` Kees Cook
2012-01-27 20:00 ` KOSAKI Motohiro
2012-01-27 20:10 ` Cyrill Gorcunov
2012-01-27 17:53 ` [RFC c/r 4/4] c/r: prctl: Extend PR_SET_MM to set up more mm_struct entries Cyrill Gorcunov
2012-01-27 18:37 ` Kees Cook
2012-01-27 18:43 ` Cyrill Gorcunov
2012-01-27 20:31 ` KOSAKI Motohiro
2012-01-27 20:28 ` KOSAKI Motohiro
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