linux-kernel - Re: [PATCH] mm: honor FOLL_GET flag in follow_hugetlb

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: <CAH3drwbt_YX-jWrwsp0X2CH3t9ms65fX40cvumr4FyRhKBcbyw@mail.gmail.com>
Date:	Tue, 7 May 2013 20:51:08 -0400
From:	Jerome Glisse <j.glisse@...il.com>
To:	KOSAKI Motohiro <kosaki.motohiro@...il.com>
Cc:	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Jerome Glisse <jglisse@...hat.com>
Subject: Re: [PATCH] mm: honor FOLL_GET flag in follow_hugetlb_page v2

On Tue, May 7, 2013 at 8:47 PM, KOSAKI Motohiro
<kosaki.motohiro@...il.com> wrote:
> On Tue, May 7, 2013 at 6:58 PM,  <j.glisse@...il.com> wrote:
>> From: Jerome Glisse <jglisse@...hat.com>
>>
>> Do not increase page count if FOLL_GET is not set. None of the
>> current user can trigger the issue because none of the current
>> user call __get_user_pages with both the pages array ptr non
>> NULL and the FOLL_GET flags non set in other word all caller
>> of __get_user_pages that don't set the FOLL_GET flags also call
>> with pages == NULL.
>
> Because, __get_user_pages() doesn't allow pages==NULL and FOLL_GET is on.

Yes but this allow pages != NULL and FOLL_GET not set and as i said
there is no such user of that yet and this is exactly what i was
trying to use.

Cheers,
Jerome

>
> long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
> {
> (snip)
>     VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET));
--
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/