Re: [PATCH v3 1/2] x86/sgx: Do not fail on incomplete sanitization on premature stop of ksgxd

[Huang, Kai]

On Tue, 2022-09-06 at 03:02 +0300, 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@xxxxxxxxxx/T/#u
> Fixes: 51ab30eb2ad4 ("x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list")
> Cc: stable@xxxxxxxxxxxxxxx # v5.13+
> Reported-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>

(Given the idea of moving sgx_page_reclaimer_init() to the end of sgx_init() is
considered too big to fix this bug:)

Acked-by: Kai Huang <kai.huang@xxxxxxxxx>

-- 
Thanks,
-Kai