Re: [PATCH] selftests/sgx: retry the ioctls returned with EAGAIN

[Jarkko Sakkinen <jarkko@kernel.org>]

On Fri, Aug 12, 2022 at 01:13:31PM -0700, Haitao Huang wrote:
> For EMODT and EREMOVE ioctls with a large range, kernel
> may not finish in one shot and return EAGAIN error code
> and count of bytes of EPC pages on that operations are
> finished successfully.
> 
> Change the unclobbered_vdso_oversubscribed_remove test
> to rerun the ioctls in a loop, updating offset and length
> using the byte count returned in each iteration.
> 
> Signed-off-by: Haitao Huang <haitao.huang@intel.com>
> ---
>  tools/testing/selftests/sgx/main.c | 39 +++++++++++++++++++++++-------
>  1 file changed, 30 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
> index 9820b3809c69..ff66ce2bbcac 100644
> --- a/tools/testing/selftests/sgx/main.c
> +++ b/tools/testing/selftests/sgx/main.c
> @@ -391,7 +391,7 @@ TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
>  	unsigned long total_mem;
>  	int ret, errno_save;
>  	unsigned long addr;
> -	unsigned long i;
> +	unsigned long i, count;
>  
>  	/*
>  	 * Create enclave with additional heap that is as big as all
> @@ -453,16 +453,27 @@ TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
>  	modt_ioc.offset = heap->offset;
>  	modt_ioc.length = heap->size;
>  	modt_ioc.page_type = SGX_PAGE_TYPE_TRIM;
> -
> +	count = 0;
>  	TH_LOG("Changing type of %zd bytes to trimmed may take a while ...",
>  	       heap->size);
> -	ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc);
> -	errno_save = ret == -1 ? errno : 0;
> +	do {
> +		ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc);
> +		errno_save = ret == -1 ? errno : 0;
> +		if (errno_save == EAGAIN) {
> +			count += modt_ioc.count;
> +			modt_ioc.offset += modt_ioc.count;
> +			modt_ioc.length -= modt_ioc.count;
> +			modt_ioc.result= 0;
> +			modt_ioc.count = 0;
> +		} else
> +			break;
> +	} while(modt_ioc.length != 0);
>  
>  	EXPECT_EQ(ret, 0);
>  	EXPECT_EQ(errno_save, 0);
>  	EXPECT_EQ(modt_ioc.result, 0);
> -	EXPECT_EQ(modt_ioc.count, heap->size);
> +	count += modt_ioc.count;
> +	EXPECT_EQ(count, heap->size);
>  
>  	/* EACCEPT all removed pages. */
>  	addr = self->encl.encl_base + heap->offset;
> @@ -490,15 +501,25 @@ TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
>  
>  	remove_ioc.offset = heap->offset;
>  	remove_ioc.length = heap->size;
> -
> +	count = 0;
>  	TH_LOG("Removing %zd bytes from enclave may take a while ...",
>  	       heap->size);
> -	ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc);
> -	errno_save = ret == -1 ? errno : 0;
> +    do {
> +		ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc);
> +		errno_save = ret == -1 ? errno : 0;
> +		if (errno_save == EAGAIN) {
> +			count += remove_ioc.count;
> +			remove_ioc.offset += remove_ioc.count;
> +			remove_ioc.length -= remove_ioc.count;
> +			remove_ioc.count = 0;
> +		} else
> +			break;
> +	} while(remove_ioc.length != 0);
>  
>  	EXPECT_EQ(ret, 0);
>  	EXPECT_EQ(errno_save, 0);
> -	EXPECT_EQ(remove_ioc.count, heap->size);
> +	count += remove_ioc.count;
> +	EXPECT_EQ(count, heap->size);
>  }
>  
>  TEST_F(enclave, clobbered_vdso)
> -- 
> 2.25.1
> 

Thank you.

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko