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Date:   Thu, 8 Sep 2022 12:53:55 -0700
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Subject: Re: [PATCH v3 1/2] x86/sgx: Do not fail on incomplete sanitization on
 premature stop of ksgxd
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To:     Jarkko Sakkinen <jarkko@kernel.org>, <linux-sgx@vger.kernel.org>
CC:     Haitao Huang <haitao.huang@linux.intel.com>,
        Vijay Dhanraj <vijay.dhanraj@intel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "Kai Huang" <kai.huang@intel.com>, <stable@vger.kernel.org>,
        Paul Menzel <pmenzel@molgen.mpg.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" 
        <linux-kernel@vger.kernel.org>
References: <20220906000221.34286-1-jarkko@kernel.org>
 <20220906000221.34286-2-jarkko@kernel.org>
From:   Reinette Chatre <reinette.chatre@intel.com>
In-Reply-To: <20220906000221.34286-2-jarkko@kernel.org>
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On 9/5/2022 5:02 PM, Jarkko Sakkinen wrote:
> Unsanitized pages trigger WARN_ON() unconditionally, which can panic the
> whole computer, if /proc/sys/kernel/panic_on_warn is set.
> 
> In sgx_init(), if misc_register() fails or misc_register() succeeds but
> neither sgx_drv_init() nor sgx_vepc_init() succeeds, then ksgxd will be
> prematurely stopped. This may leave unsanitized pages, which will result a
> false warning.
> 
> Refine __sgx_sanitize_pages() to return:
> 
> 1. Zero when the sanitization process is complete or ksgxd has been
>    requested to stop.
> 2. The number of unsanitized pages otherwise.
> 
> Link: https://lore.kernel.org/linux-sgx/20220825051827.246698-1-jarkko@kernel.org/T/#u
> Fixes: 51ab30eb2ad4 ("x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list")
> Cc: stable@vger.kernel.org # v5.13+
> Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette