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From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>, Salman <sqazi@google.com>
Cc: mingo@elte.hu, linux-kernel@vger.kernel.org,
	peterz@infradead.org, tytso@google.com,
	torvalds@linux-foundation.org, walken@google.com
Subject: [PATCH 0/1] (Was: Fix a race in pid generation that causes pids to be reused immediately.)
Date: Tue, 15 Jun 2010 20:35:25 +0200	[thread overview]
Message-ID: <20100615183525.GA24577@redhat.com> (raw)
In-Reply-To: <20100611224902.5039.60134.stgit@bumblebee1.mtv.corp.google.com>

On 06/11, Salman wrote:
>
> A program that repeatedly forks and waits is susceptible to having the
> same pid repeated,

I agree this patch should fix this.

But the kernel still can use the same pid twice in a row, I am wondering
if there a simple solution to prevent this. Probably not, and this case
is unlikely.

While we are here, and given that many reviewers recently inspected
alloc_pidmap(), probably someone can explain the mysterious checks
in do/while loop ?

See the patch I am going to send, it is on top on Salman's fix but doesn't
really depend on it.

Oleg.


  parent reply	other threads:[~2010-06-15 18:37 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-11 17:17 [PATCH] Fix a race in pid generation that causes pids to be reused immediately Salman
2010-06-11 17:44 ` Linus Torvalds
2010-06-11 22:49   ` Salman
2010-06-11 23:07     ` Linus Torvalds
2010-06-14 23:58     ` Andrew Morton
2010-06-15  0:56       ` tytso
2010-06-15  1:55         ` Andrew Morton
2010-06-15  3:26           ` Paul Mackerras
2010-06-15  4:21             ` Andrew Morton
2010-06-15  4:38               ` Eric Dumazet
2010-06-15  6:57               ` Benjamin Herrenschmidt
2010-06-15  7:25               ` Paul Mackerras
2010-06-15 12:56           ` tytso
2010-06-15 13:06             ` Kyle McMartin
2010-06-15 14:35           ` Peter Zijlstra
2010-06-15 19:37             ` Andrew Morton
2010-06-15 18:35     ` Oleg Nesterov [this message]
2010-06-15 18:35       ` [PATCH 1/1] pids: alloc_pidmap: remove the unnecessary boundary checks Oleg Nesterov

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