linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Davidlohr Bueso <dave@stgolabs.net>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: fix lockdep build in rcu-protected get_mm_exe_file()
Date: Tue, 24 Mar 2015 07:38:34 -0700	[thread overview]
Message-ID: <1427207914.2412.17.camel@stgolabs.net> (raw)
In-Reply-To: <20150323191055.GA10212@redhat.com>

On Mon, 2015-03-23 at 20:10 +0100, Oleg Nesterov wrote:
> "atomic_read(&mm->mm_users) <= 1" looks a bit more "safe". But again,
> I won't insist.

Agreed, it is nicer to do that check, but I have no strong preference
either, perhaps Konstantin or akpm do. Anyway, here's the change that
can be folded in if you guys want to.

Thanks.

8<-------------------------------------------------
diff --git a/kernel/fork.c b/kernel/fork.c
index 98858b5..0c3de2b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -697,7 +697,7 @@ EXPORT_SYMBOL_GPL(mmput);
 void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
 {
 	struct file *old_exe_file = rcu_dereference_protected(mm->exe_file,
-			!atomic_read(&mm->mm_users) || current->in_execve);
+			atomic_read(&mm->mm_users) <= 1);
 
 	if (new_exe_file)
 		get_file(new_exe_file);


--
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>

  reply	other threads:[~2015-03-24 14:38 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-20 14:47 Konstantin Khlebnikov
2015-03-23 18:11 ` Davidlohr Bueso
2015-03-23 19:10   ` Oleg Nesterov
2015-03-24 14:38     ` Davidlohr Bueso [this message]
2015-03-24 17:13     ` Konstantin Khlebnikov
2015-03-24 18:10       ` Oleg Nesterov
2015-03-24 18:15         ` Konstantin Khlebnikov
2015-03-24 19:02           ` Oleg Nesterov
2015-03-25  1:30             ` [PATCH v2] prctl: avoid using mmap_sem for exe_file serialization Davidlohr Bueso
2015-03-25  9:21               ` Konstantin Khlebnikov
2015-03-25 10:42                 ` [PATCH v3] " Davidlohr Bueso
2015-03-25 11:08                   ` Konstantin Khlebnikov
2015-03-25 12:50                     ` Davidlohr Bueso
2015-03-25 12:53                   ` Oleg Nesterov

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=1427207914.2412.17.camel@stgolabs.net \
    --to=dave@stgolabs.net \
    --cc=akpm@linux-foundation.org \
    --cc=khlebnikov@yandex-team.ru \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=oleg@redhat.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox