[LTP] [PATCH v1] crypto/af_alg02: fixed read() being stuck

[Li Wang <liwang@redhat.com>]

Hi Christian,

On Tue, May 7, 2019 at 2:56 PM Christian Amann <camann@suse.com> 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 | 36
> +++++++++++++++++++++++++++++++++++-
>  2 files changed, 37 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..056511993 100644
> --- a/testcases/kernel/crypto/af_alg02.c
> +++ b/testcases/kernel/crypto/af_alg02.c
> @@ -7,12 +7,23 @@
>   * 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
> 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 <time.h>
> +#include <errno.h>
>
> -static void run(void)
> +#define VERIFY_TIMEOUT (time(NULL) + 5)
>

It is very neccessary to take some action before process being killed in
timeout. In LTP, we have an tst_timeout_remaining() function. Have a look?

> +
> +void *verify_encrypt(void *arg)
>  {
>         char buf[16];
>         int reqfd = tst_alg_setup_reqfd("skcipher", "salsa20", NULL, 16);
> @@ -22,6 +33,29 @@ 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;
> +       int join_ret;
> +       struct timespec read_timeout;
> +
> +       read_timeout.tv_sec  = VERIFY_TIMEOUT;
> +       read_timeout.tv_nsec = 0;
> +
> +       SAFE_PTHREAD_CREATE(&thr, NULL, verify_encrypt, NULL);
> +       join_ret = pthread_timedjoin_np(thr, NULL, &read_timeout);
> +
> +       if (join_ret != 0) {
> +               if (join_ret == ETIMEDOUT)
> +                       tst_brk(TBROK,
> +                               "Timed out while reading from request
> socket.");
> +               else
> +                       tst_brk(TBROK | TTERRNO,
> +                               "Error while joining child thread");
> +       }
>  }
>
>  static struct tst_test test = {
> --
> 2.16.4
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>


-- 
Regards,
Li Wang
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