linux-kernel - Re: [PATCH v2 04/13] uprobes: allow arch-specific initialization

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]

Message-ID: <20131028185818.GB12863@redhat.com>
Date:	Mon, 28 Oct 2013 19:58:18 +0100
From:	Oleg Nesterov <oleg@...hat.com>
To:	David Long <dave.long@...aro.org>
Cc:	linux-arm-kernel@...ts.infradead.org, Rabin Vincent <rabin@....in>,
	"Jon Medhurst (Tixy)" <tixy@...aro.org>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 04/13] uprobes: allow arch-specific initialization

On 10/22, David Long wrote:
>
> On 10/19/13 12:42, Oleg Nesterov wrote:
>> On 10/15, David Long wrote:
>>>
>>> Add a weak function for any architecture-specific initialization.  ARM
>>> will use this to register the handlers for the undefined instructions it
>>> uses to implement uprobes.
>>
>> Could you explain why ARM can't simply do the necessary initialization in
>> arch/arm/kernel/uprobes-arm.c ?
>>
>>
>>> +int __weak __init arch_uprobes_init(void)
>>> +{
>>> +	return 0;
>>> +}
>>> +
>>>   static int __init init_uprobes(void)
>>>   {
>>> +	int ret;
>>>   	int i;
>>>
>>>   	for (i = 0; i < UPROBES_HASH_SZ; i++)
>>> @@ -1870,6 +1876,10 @@ static int __init init_uprobes(void)
>>>   	if (percpu_init_rwsem(&dup_mmap_sem))
>>>   		return -ENOMEM;
>>>
>>> +	ret = arch_uprobes_init();
>>> +	if (ret)
>>> +		return ret;
>>> +
>>>   	return register_die_notifier(&uprobe_exception_nb);
>>>   }
>>>   module_init(init_uprobes);
>>
>> IOW, why do we need to call arch_uprobes_init() from init_uprobes().
>>
>> Oleg
>>
>
> I don't know how you would do the initialization without invoking it
> through the module_init function, which I think you can only have one
> of.  Could you explain in more detail what you had in mind?

I simply do not understand why uprobes.c uses module_init/module_exit,
it can't be compiled as a module.

I think that module_exit/exit_uprobes should be killed, and module_init()
should be turned into __initcall(). uprobes-arm.c can have another one.

Oleg.

--
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/