Re: [PATCH] testpmd: fix early exit from signal

[David Marchand <david.marchand@redhat.com>]

On Thu, Oct 26, 2023 at 7:11 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> Other signals may occur causing read to get interrupted.
> Loop until quit flag is set by signal, a character is entered,
> or end of file. This fixes bug where testpmd would exit early
> because of signal used by TAP device.
>
> Bugzilla ID: 1305
> Fixes: 0fd1386c30c3 ("app/testpmd: cleanup cleanly from signal")

We need this fix in LTS.
Cc: stable@dpdk.org


> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
>  app/test-pmd/testpmd.c | 26 +++++++++-----------------
>  1 file changed, 9 insertions(+), 17 deletions(-)
>
> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
> index 595b77748c2a..619a59f5b891 100644
> --- a/app/test-pmd/testpmd.c
> +++ b/app/test-pmd/testpmd.c
> @@ -11,7 +11,6 @@
>  #include <fcntl.h>
>  #ifndef RTE_EXEC_ENV_WINDOWS
>  #include <sys/mman.h>
> -#include <sys/select.h>
>  #endif
>  #include <sys/types.h>
>  #include <errno.h>
> @@ -4743,25 +4742,18 @@ main(int argc, char** argv)
>                         }
>                 } else {
>                         char c;
> -                       fd_set fds;
>
>                         printf("Press enter to exit\n");
> +                       while (f_quit == 0) {
> +                               /* end-of-file or any character exits loop */
> +                               if (read(0, &c, 1) >= 0)
> +                                       break;
>
> -                       FD_ZERO(&fds);
> -                       FD_SET(0, &fds);
> -
> -                       /* wait for signal or enter */
> -                       ret = select(1, &fds, NULL, NULL, NULL);
> -                       if (ret < 0 && errno != EINTR)
> -                               rte_exit(EXIT_FAILURE,
> -                                        "Select failed: %s\n",
> -                                        strerror(errno));
> -
> -                       /* if got enter then consume it */
> -                       if (ret == 1 && read(0, &c, 1) < 0)
> -                               rte_exit(EXIT_FAILURE,
> -                                        "Read failed: %s\n",
> -                                        strerror(errno));
> +                               if (errno == EINTR)
> +                                       continue;
> +                               rte_exit(EXIT_FAILURE, "Read failed: %s\n",
> +                                                strerror(errno));

Just a nit here.
Indent seems odd, I see an extra whitespace.

Otherwise the fix lgtm and resolves the issue reported in bz.
Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand