From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Ingo Molnar <mingo@redhat.com>,
Arjan van de Ven <arjan@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH, RFC] shmat: introduce flag SHM_MAP_HINT
Date: Tue, 7 Oct 2008 09:57:03 +0300 [thread overview]
Message-ID: <20081007065701.GA5012@localhost.localdomain> (raw)
In-Reply-To: <20081006192923.GJ3180@one.firstfloor.org>
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On Mon, Oct 06, 2008 at 09:29:23PM +0200, Andi Kleen wrote:
> On Mon, Oct 06, 2008 at 05:37:59PM +0300, Kirill A. Shutemov wrote:
> > It allows interpret attach address as a hint, not as exact address.
>
> First you should also do a patch for the manpage and send to
> the manpage maintainer.
I'll do it if the patch is ok.
> > #define SHM_LOCK 11
> > diff --git a/ipc/shm.c b/ipc/shm.c
> > index e77ec69..19462bb 100644
> > --- a/ipc/shm.c
> > +++ b/ipc/shm.c
> > @@ -819,7 +819,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
> > if (shmid < 0)
> > goto out;
> > else if ((addr = (ulong)shmaddr)) {
> > - if (addr & (SHMLBA-1)) {
> > + if (!(shmflg & SHM_MAP_HINT) && (addr & (SHMLBA-1))) {
> > if (shmflg & SHM_RND)
> > addr &= ~(SHMLBA-1); /* round down */
> > else
> > @@ -828,7 +828,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
> > #endif
> > goto out;
> > }
> > - flags = MAP_SHARED | MAP_FIXED;
> > + flags = (shmflg & SHM_MAP_HINT ? 0 : MAP_FIXED) | MAP_SHARED;
>
>
> IMHO you need at least make the
>
> if (find_vma_intersection(current->mm, addr, addr + size))
> goto invalid;
>
> test above conditional too.
Since it's a hint, we shouldn't call find_vma_intersection() at all.
I'll send fixed patch soon.
--
Regards, Kirill A. Shutemov
+ Belarus, Minsk
+ ALT Linux Team, http://www.altlinux.com/
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next prev parent reply other threads:[~2008-10-07 6:56 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-03 7:04 [PATCH] x86_64: Implement personality ADDR_LIMIT_32BIT Kirill A. Shutemov
2008-10-03 8:02 ` Ingo Molnar
2008-10-03 9:25 ` Kirill A. Shutemov
2008-10-03 12:44 ` Arjan van de Ven
2008-10-03 12:58 ` Kirill A. Shutemov
2008-10-06 6:13 ` Andi Kleen
2008-10-06 8:17 ` Kirill A. Shutemov
2008-10-06 8:42 ` Andi Kleen
2008-10-06 9:17 ` Kirill A. Shutemov
2008-10-06 9:56 ` Andi Kleen
2008-10-06 10:12 ` Kirill A. Shutemov
2008-10-06 13:26 ` Andi Kleen
2008-10-06 14:37 ` [PATCH, RFC] shmat: introduce flag SHM_MAP_HINT Kirill A. Shutemov
2008-10-06 19:29 ` Andi Kleen
2008-10-07 6:57 ` Kirill A. Shutemov [this message]
2008-10-07 6:57 ` [PATCH, RFC, v2] " Kirill A. Shutemov
2008-10-07 8:20 ` Andi Kleen
2008-10-07 10:09 ` Kirill A. Shutemov
2008-10-07 11:26 ` Andi Kleen
2008-10-07 11:23 ` Kirill A. Shutemov
2008-10-07 14:38 ` Hugh Dickins
2008-10-07 15:10 ` Andi Kleen
2008-10-07 11:08 ` [PATCH, RFC] " KOSAKI Motohiro
2008-10-07 11:21 ` Andi Kleen
2008-10-07 11:21 ` Kirill A. Shutemov
2008-10-07 11:26 ` KOSAKI Motohiro
2008-10-07 11:30 ` Kirill A. Shutemov
2008-10-07 11:50 ` Andi Kleen
2008-10-07 11:24 ` Kirill A. Shutemov
2008-10-07 12:31 ` Alan Cox
2008-10-07 13:14 ` Andi Kleen
2008-10-03 9:33 ` [PATCH] x86_64: Implement personality ADDR_LIMIT_32BIT Kirill A. Shutemov
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