From: Badari Pulavarty <pbadari@us.ibm.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Albert Cahalan <acahalan@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
torvalds@linux-foundation.org
Subject: Re: [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid
Date: Fri, 08 Jun 2007 09:07:54 -0700 [thread overview]
Message-ID: <46697EDA.9000209@us.ibm.com> (raw)
In-Reply-To: m1ir9zrtwe.fsf@ebiederm.dsl.xmission.com
Eric W. Biederman wrote:
>
>At this point given that we actually have a small user space dependency
>and the fact that after I have reviewed the code it looks harmless to
>change the inode number of those inodes, in both cases they are just
>anonymous inodes generated with new_inode, and anything that we wrap
>is likely to be equally so.
>
>So it looks to me like we need to do three things:
>- Fix the inode number
>
Okay. its already done.
>
>- Fix the name on the hugetlbfs dentry to hold the key
>
I don't see need for doing this for hugetlbfs inodes. Currently, they
don't base their
name on "key" + basing on the "key" is kind of useless anyway (its not
unique).
>
>- Add a big fat comment that user space programs depend on this
> behavior of both the dentry name and the inode number.
>
I don't think, the user-space can depend on the dentry-name. It can only
depend
on inode# to match shmid. (since key is not unique esp. for key=0x00000000).
BTW, I agree that shmid is not unique even without namespaces as its
based on
seq# and we wrap seq#.
Thanks,
Badari
WARNING: multiple messages have this Message-ID (diff)
From: Badari Pulavarty <pbadari@us.ibm.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Albert Cahalan <acahalan@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
torvalds@linux-foundation.org
Subject: Re: [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid
Date: Fri, 08 Jun 2007 09:07:54 -0700 [thread overview]
Message-ID: <46697EDA.9000209@us.ibm.com> (raw)
In-Reply-To: m1ir9zrtwe.fsf@ebiederm.dsl.xmission.com
Eric W. Biederman wrote:
>
>At this point given that we actually have a small user space dependency
>and the fact that after I have reviewed the code it looks harmless to
>change the inode number of those inodes, in both cases they are just
>anonymous inodes generated with new_inode, and anything that we wrap
>is likely to be equally so.
>
>So it looks to me like we need to do three things:
>- Fix the inode number
>
Okay. its already done.
>
>- Fix the name on the hugetlbfs dentry to hold the key
>
I don't see need for doing this for hugetlbfs inodes. Currently, they
don't base their
name on "key" + basing on the "key" is kind of useless anyway (its not
unique).
>
>- Add a big fat comment that user space programs depend on this
> behavior of both the dentry name and the inode number.
>
I don't think, the user-space can depend on the dentry-name. It can only
depend
on inode# to match shmid. (since key is not unique esp. for key=0x00000000).
BTW, I agree that shmid is not unique even without namespaces as its
based on
seq# and we wrap seq#.
Thanks,
Badari
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2007-06-08 16:08 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-07 3:27 [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid Albert Cahalan
2007-06-07 3:27 ` Albert Cahalan
2007-06-07 3:44 ` Andrew Morton
2007-06-07 3:44 ` Andrew Morton
2007-06-07 4:53 ` Albert Cahalan
2007-06-07 4:53 ` Albert Cahalan
2007-06-07 16:20 ` Serge E. Hallyn
2007-06-07 16:20 ` Serge E. Hallyn
2007-06-08 3:45 ` Eric W. Biederman
2007-06-08 3:45 ` Eric W. Biederman
2007-06-08 4:41 ` Albert Cahalan
2007-06-08 4:41 ` Albert Cahalan
2007-06-08 5:55 ` Eric W. Biederman
2007-06-08 5:55 ` Eric W. Biederman
2007-06-08 6:51 ` Albert Cahalan
2007-06-08 6:51 ` Albert Cahalan
2007-06-08 22:31 ` [PATCH] Restore shmid as inode# to fix /proc/pid/maps ABI breakage Badari Pulavarty
2007-06-08 22:31 ` Badari Pulavarty
2007-06-08 16:07 ` Badari Pulavarty [this message]
2007-06-08 16:07 ` [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid Badari Pulavarty
2007-06-08 23:43 ` [PATCH] shm: Fix the filename of hugetlb sysv shared memory Eric W. Biederman
2007-06-08 23:43 ` Eric W. Biederman
2007-06-08 23:55 ` Andrew Morton
2007-06-08 23:55 ` Andrew Morton
2007-06-09 4:32 ` Badari Pulavarty
2007-06-09 4:32 ` Badari Pulavarty
2007-06-09 8:01 ` Eric W. Biederman
2007-06-09 8:01 ` Eric W. Biederman
2007-06-11 18:11 ` Andrew Morton
2007-06-11 18:11 ` Andrew Morton
2007-06-11 19:55 ` Badari Pulavarty
2007-06-11 19:55 ` Badari Pulavarty
2007-06-11 19:00 ` Adam Litke
2007-06-11 19:00 ` Adam Litke
2007-06-11 20:53 ` Ken Chen
2007-06-11 20:53 ` Ken Chen
2007-06-07 16:23 ` [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid Badari Pulavarty
2007-06-07 16:23 ` Badari Pulavarty
2007-06-07 16:43 ` Albert Cahalan
2007-06-07 16:43 ` Albert Cahalan
2007-06-07 17:06 ` Badari Pulavarty
2007-06-07 17:06 ` Badari Pulavarty
2007-06-07 19:48 ` Andrew Morton
2007-06-07 19:48 ` Andrew Morton
2007-06-07 19:59 ` Badari Pulavarty
2007-06-07 19:59 ` Badari Pulavarty
2007-06-07 20:37 ` Serge E. Hallyn
2007-06-07 20:37 ` Serge E. Hallyn
2007-06-07 20:51 ` Serge E. Hallyn
2007-06-07 20:51 ` Serge E. Hallyn
2007-06-07 21:16 ` Badari Pulavarty
2007-06-07 21:16 ` Badari Pulavarty
2007-06-07 22:08 ` Serge E. Hallyn
2007-06-07 22:08 ` Serge E. Hallyn
2007-06-07 22:21 ` Badari Pulavarty
2007-06-07 22:21 ` Badari Pulavarty
2007-06-07 22:22 ` Serge E. Hallyn
2007-06-07 22:22 ` Serge E. Hallyn
2007-06-07 23:57 ` Badari Pulavarty
2007-06-07 23:57 ` Badari Pulavarty
-- strict thread matches above, loose matches on Subject: below --
2007-06-06 16:07 Badari Pulavarty
2007-06-06 16:07 ` Badari Pulavarty
2007-06-06 17:02 ` Eric W. Biederman
2007-06-06 17:02 ` Eric W. Biederman
2007-06-06 17:37 ` Badari Pulavarty
2007-06-06 17:37 ` Badari Pulavarty
2007-06-06 18:24 ` Eric W. Biederman
2007-06-06 18:24 ` Eric W. Biederman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=46697EDA.9000209@us.ibm.com \
--to=pbadari@us.ibm.com \
--cc=acahalan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=ebiederm@xmission.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=serge@hallyn.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.