From: Andi Kleen <andi@firstfloor.org>
To: ebiederm@xmission.com (Eric W. Biederman)
Cc: paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [4/9] SYSCTL: Use RCU strings for core_pattern sysctl
Date: Tue, 05 Jan 2010 12:49:34 +0100 [thread overview]
Message-ID: <87aawsdb5d.fsf@basil.nowhere.org> (raw)
In-Reply-To: <m1zl4t82f8.fsf@fess.ebiederm.org> (Eric W. Biederman's message of "Mon, 04 Jan 2010 22:56:59 -0800")
ebiederm@xmission.com (Eric W. Biederman) writes:
>>
>> @@ -1421,7 +1421,7 @@ EXPORT_SYMBOL(set_binfmt);
>> static int format_corename(char *corename, long signr)
>> {
>> const struct cred *cred = current_cred();
>> - const char *pat_ptr = core_pattern;
>> + const char *pat_ptr = rcu_dereference(core_pattern);
>
> rcu_dereference should aways be between rcu_read_lock()
> and rcu_read_unlock();
It is, see the call site below:
>> - * lock_kernel() because format_corename() is controlled by sysctl, which
>> - * uses lock_kernel()
>> + * Protect corename by RCU vs proc_rcu_string()
>> */
>> - lock_kernel();
>> + rcu_read_lock();
>> ispipe = format_corename(corename, signr);
>> - unlock_kernel();
>> + rcu_read_unlock();
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2010-01-05 11:49 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-05 2:15 [PATCH] [0/9] SYSCTL: Use RCU to avoid races with string sysctls v2 Andi Kleen
2010-01-05 2:15 ` [PATCH] [1/9] Add rcustring ADT for RCU protected strings v2 Andi Kleen
2010-01-05 5:32 ` Paul E. McKenney
2010-01-05 10:47 ` Andi Kleen
2010-01-05 14:11 ` Paul E. McKenney
2010-01-05 14:19 ` Andi Kleen
2010-01-08 23:50 ` Andrew Morton
2010-01-11 12:12 ` Bert Wesarg
2010-01-11 14:26 ` Andi Kleen
2010-01-05 2:15 ` [PATCH] [2/9] Add a kernel_address() that works for data too Andi Kleen
2010-01-05 8:44 ` Russell King
2010-01-05 8:58 ` Sam Ravnborg
2010-01-05 19:04 ` Russell King
2010-01-05 19:15 ` Andi Kleen
2010-01-08 23:51 ` Andrew Morton
2010-01-05 2:15 ` [PATCH] [3/9] SYSCTL: Add proc_rcu_string to manage sysctls using rcu strings Andi Kleen
2010-01-05 2:15 ` [PATCH] [4/9] SYSCTL: Use RCU strings for core_pattern sysctl Andi Kleen
2010-01-05 6:56 ` Eric W. Biederman
2010-01-05 11:49 ` Andi Kleen [this message]
2010-01-05 2:15 ` [PATCH] [5/9] SYSCTL: Add call_usermodehelper_cleanup() Andi Kleen
2010-01-05 2:15 ` [PATCH] [6/9] SYSCTL: Convert modprobe_path to proc_rcu_string() Andi Kleen
2010-01-05 2:15 ` [PATCH] [7/9] SYSCTL: Convert poweroff_command to proc_rcu_string Andi Kleen
2010-01-05 2:15 ` [PATCH] [8/9] SYSCTL: Convert hotplug helper string to proc_rcu_string() Andi Kleen
2010-01-05 2:15 ` [PATCH] [9/9] SYSCTL: Use RCU protected sysctl for ocfs group add helper Andi Kleen
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