linux-kernel - Re: spinlock contention of files->file

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Wed, 2 Oct 2013 07:13:19 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Al Viro <viro@...IV.linux.org.uk>
Cc:	Eric Dumazet <eric.dumazet@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Waiman Long <Waiman.Long@...com>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	"Chandramouleeswaran, Aswin" <aswin@...com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>
Subject: Re: spinlock contention of files->file_lock


* Al Viro <viro@...IV.linux.org.uk> wrote:

> On Tue, Oct 01, 2013 at 02:41:58PM -0700, Eric Dumazet wrote:
> > Maybe I am missing something obvious ?
> 
> Yes.  do_execve_common() starts with unshare_files(); there can be
> no other thread capable of modifying that descriptor table.

Btw., might the Android Binder:

  drivers/staging/android/binder.c:       struct files_struct *files = proc->files;
...
  drivers/staging/android/binder.c:               __fd_install(proc->files, fd, file);
...
  drivers/staging/android/binder.c:       retval = __close_fd(proc->files, fd);

violate that assumption?

Thanks,

	Ingo
--
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/