From mboxrd@z Thu Jan  1 00:00:00 1970
From: oleg@redhat.com (Oleg Nesterov)
Date: Mon, 3 Mar 2014 21:50:39 +0100
Subject: [PATCH v6 00/14] uprobes: Add uprobes support for ARM
In-Reply-To: <53131DBE.7020500@linaro.org>
References: <1392017945-4507-1-git-send-email-dave.long@linaro.org>
 <20140301123026.GD21483@n2100.arm.linux.org.uk> <53131DBE.7020500@linaro.org>
Message-ID: <20140303205039.GA8949@redhat.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 03/02, David Long wrote:
>
> Oleg,
>
> I've been looking at arch/Kconfig and kernel/trace/Kconfig where they
> deal with uprobes.  The relevant items are CONFIG_UPROBES and
> CONFIG_UPROBE_EVENT.  It just doesn't look right to me.

Yes, this looks strange. I never understood these dependencies. In fact
I even never tried. And I do not really understand kbuild, unfortunately...

>> --- a/arch/Kconfig
>> +++ b/arch/Kconfig
>> @@ -87,7 +87,8 @@ config KPROBES_ON_FTRACE
>>
>>  config UPROBES
>>  	bool "Transparent user-space probes (EXPERIMENTAL)"
>> -	depends on UPROBE_EVENT && PERF_EVENTS
>> +	depends on ARCH_SUPPORTS_UPROBES
>> +	depends on PERF_EVENTS

And why CONFIG_UPROBES should depend on PERF_EVENTS? uprobes can be
used by (say) systemtap without UPROBE_EVENT/PERF_EVENTS.

But as Russell pointed out the events directory is only built if
CONFIG_PERF_EVENTS=y, so it should depend on it or select...


I dunno. Personally I vote for the patch from Srikar in

	http://article.gmane.org/gmane.linux.kernel/1017186

This is what we currently have, currently CONFIG_UPROBES is not
user-selectable anyway.

Oleg.