linux-kernel - Re: [PATCH v2 1/2] x86/sgx: Do not update sgx_nr_free_pages in sgx_setup_epc

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Message-ID: <20210408085640.GD10192@zn.tnic>
Date:   Thu, 8 Apr 2021 10:56:40 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Jarkko Sakkinen <jarkko@...nel.org>
Cc:     linux-sgx@...r.kernel.org,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] x86/sgx: Do not update sgx_nr_free_pages in
 sgx_setup_epc_section()

On Thu, Apr 08, 2021 at 11:48:46AM +0300, Jarkko Sakkinen wrote:
> The regression is that the sgx_nr_free_pages is also incremented by
> sgx_free_epc_pages(), and thus it ends up having double the number of
> pages available.

So when you add a new EPC section with sgx_setup_epc_section(), those
new pages in "nr_pages" are initially not going to be accounted
anywhere? Or is that sgx_nr_all_pages? And you do that in your second
patch...

But those new pages coming in *are* free pages so they should be in the
free pages count too, IMHO.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette