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Date:   Fri, 12 Mar 2021 17:24:01 +0000
From:   Qais Yousef <qais.yousef@arm.com>
To:     Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: Re: [PATCH v7 2/2] ARM: ftrace: Add MODULE_PLTS support
Message-ID: <20210312172401.36awjh4hmj4cs6ot@e107158-lin.cambridge.arm.com>
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Hi Alexander

On 03/10/21 18:17, Alexander Sverdlin wrote:
> Hi!
> 
> On 10/03/2021 17:14, Florian Fainelli wrote:
> >>>>> I tried on 5.12-rc2 and 5.11 but couldn't reproduce the problem using your
> >>> I still can't reproduce on 5.12-rc2.
> >>>
> >>> I do have CONFIG_ARM_MODULE_PLTS=y. Do you need to do something else after
> >>> loading the module? I tried starting ftrace, but maybe there's a particular
> >>> combination required?
> >> You need to load a BIG module, so big that it has no place in the modules area
> >> any more and goes to vmalloc area.
> > You absolutely need a very big module maybe more than one. When I tested
> > this, I could use the two proprietary modules (*sigh*) that I needed to
> > exercise against and loading one but not the other was not enough to
> > make the second module loading spill into vmalloc space.
> 
> Here is what I use instead of these real world "proprietary" modules (which of course
> were the real trigger for the patch):
> 
> https://www.spinics.net/lists/arm-kernel/msg878599.html

I am testing with your module. I can't reproduce the problem you describe with
it as I stated.

I will try to spend more time on it on the weekend.

Thanks

--
Qais Yousef