Re: [PATCH 1/3] intel_sgx: do not use BUG() in sgx_free_page()

From: Andy Shevchenko
Date: Fri Jan 27 2017 - 10:46:03 EST


On Thu, Jan 26, 2017 at 11:20 PM, Jarkko Sakkinen
<jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
> EREMOVE fails on non-EPC page or when a SECS page with children is to be
> removed. These do not happen if the driver is working correctly. Log the
> error but do not crash the driver.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
> drivers/platform/x86/intel_sgx_page_cache.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/intel_sgx_page_cache.c b/drivers/platform/x86/intel_sgx_page_cache.c
> index d073057..7f73ac7 100644
> --- a/drivers/platform/x86/intel_sgx_page_cache.c
> +++ b/drivers/platform/x86/intel_sgx_page_cache.c
> @@ -551,10 +551,8 @@ void sgx_free_page(struct sgx_epc_page *entry,
> ret = __eremove(epc);
> sgx_put_epc_page(epc);
>
> - if (ret) {
> - pr_err("EREMOVE returned %d\n", ret);
> - BUG();
> - }
> + if (ret)
> + sgx_err(encl, "EREMOVE returned %d\n", ret);

Do you have something like critical level? For me seems reasonable to
increase the level of message if BUG() was somehow related to actual
situation.

> }
>
> spin_lock(&sgx_free_list_lock);

--
With Best Regards,
Andy Shevchenko