From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexei Starovoitov <ast@plumgrid.com>
Subject: Re: [PATCH v2 net-next] fix unsafe set_memory_rw from softirq
Date: Thu, 3 Oct 2013 16:10:58 -0700
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	<1380841333.19002.259.camel@edumazet-glaptop.roam.corp.google.com>
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Cc: "David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	James Morris <jmorris@namei.org>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Patrick McHardy <kaber@trash.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Daniel Borkmann <dborkman@redhat.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Xi Wang <xi.wang@gmail.com>, x86@kernel.org,
	Eric Dumazet <edumazet@google.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	linux-kernel@vger.kernel.org
To: Eric Dumazet <erdnetdev@gmail.com>
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On Thu, Oct 3, 2013 at 4:02 PM, Eric Dumazet <erdnetdev@gmail.com> wrote:
> On Thu, 2013-10-03 at 15:47 -0700, Alexei Starovoitov wrote:
>> on x86 system with net.core.bpf_jit_enable = 1
>>
>
>> --- a/net/core/filter.c
>> +++ b/net/core/filter.c
>> @@ -644,7 +644,9 @@ void sk_filter_release_rcu(struct rcu_head *rcu)
>>       struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
>>
>>       bpf_jit_free(fp);
>> +#if !defined(CONFIG_X86_64) /* x86_64 has a deferred free */
>>       kfree(fp);
>> +#endif
>
> Sorry this is not very nice.
>
> Make bpf_jit_free(fp) a bool ?  true : caller must free, false : caller
> must not free ?
>
> if (bpf_jit_free(fp))
>         kfree(fp);
>
> Or move the kfree() in bpf_jit_free()

I think it's cleaner too, just didn't want to touch all architectures.
Will do then.