[LTP] [PATCH v2] crypto/af_alg02: fixed read() being stuck

[Christian Amann]

@ Li Wang

Okay, I think I understand it now. It looks much cleaner when done like
you suggested. Thanks!

Regards,

Christian


On 07/05/2019 13:38, Christian Amann wrote:
> On kernels < 4.14 (missing commit 2d97591ef43d) reading from
> the request socket does not return and the testcase does not
> finish.
>
> This fix moves the logic to a child thread in order for the
> parent to handle the timeout and report a message to the user.
>
> Signed-off-by: Christian Amann <camann@suse.com>
> ---
>  testcases/kernel/crypto/Makefile   |  2 ++
>  testcases/kernel/crypto/af_alg02.c | 29 ++++++++++++++++++++++++++++-
>  2 files changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/testcases/kernel/crypto/Makefile b/testcases/kernel/crypto/Makefile
> index 76f9308c2..6547e1cb6 100644
> --- a/testcases/kernel/crypto/Makefile
> +++ b/testcases/kernel/crypto/Makefile
> @@ -20,3 +20,5 @@ include $(top_srcdir)/include/mk/testcases.mk
>  CFLAGS			+= -D_GNU_SOURCE
>  
>  include $(top_srcdir)/include/mk/generic_leaf_target.mk
> +
> +af_alg02: CFLAGS += -pthread
> diff --git a/testcases/kernel/crypto/af_alg02.c b/testcases/kernel/crypto/af_alg02.c
> index a9e820423..7f8c81b66 100644
> --- a/testcases/kernel/crypto/af_alg02.c
> +++ b/testcases/kernel/crypto/af_alg02.c
> @@ -7,12 +7,20 @@
>   * Regression test for commit ecaaab564978 ("crypto: salsa20 - fix
>   * blkcipher_walk API usage"), or CVE-2017-17805.  This test verifies that an
>   * empty message can be encrypted with Salsa20 without crashing the kernel.
> + *
> + * read() fix:
> + * Calls read() in child thread in order to manually kill it after a timeout.
> + * With kernels missing commit 2d97591ef43d ("crypto: af_alg - consolidation
> + * of duplicate code") read() does not return.
>   */
>  
>  #include "tst_test.h"
>  #include "tst_af_alg.h"
> +#include "tst_safe_pthread.h"
> +#include <pthread.h>
> +#include <errno.h>
>  
> -static void run(void)
> +void *verify_encrypt(void *arg)
>  {
>  	char buf[16];
>  	int reqfd = tst_alg_setup_reqfd("skcipher", "salsa20", NULL, 16);
> @@ -22,8 +30,27 @@ static void run(void)
>  		tst_res(TPASS, "Successfully \"encrypted\" an empty message");
>  	else
>  		tst_res(TBROK, "read() didn't return 0");
> +	return arg;
> +}
> +
> +static void run(void)
> +{
> +	pthread_t thr;
> +
> +	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
> +	SAFE_PTHREAD_CREATE(&thr, NULL, verify_encrypt, NULL);
> +
> +	while (pthread_kill(thr, 0) != ESRCH) {
> +		if (tst_timeout_remaining() <= 10) {
> +			pthread_cancel(thr);
> +			tst_brk(TBROK,
> +				"Timed out while reading from request socket.");
> +		}
> +		usleep(1000);
> +	}
>  }
>  
>  static struct tst_test test = {
>  	.test_all = run,
> +	.timeout = 20,
>  };