Re: [dpdk-dev] [PATCH v2] test: fix process dup fd close

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

On Mon, Sep 2, 2019 at 11:50 AM <kkanas@marvell.com> wrote:
>
> From: Krzysztof Kanas <kkanas@marvell.com>
>
> process_dup was intending to close it's own fd's but failed to do so

Please, explain how you caught the issue and what the impact was on your system.

>
> Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org

>
> Signed-off-by: Krzysztof Kanas <kkanas@marvell.com>
> ---
> v2:
> * remove unnecessary commit msg information
>
>  app/test/process.h | 40 +++++++++++++++++++++++++++++++++++-----
>  1 file changed, 35 insertions(+), 5 deletions(-)
>
> diff --git a/app/test/process.h b/app/test/process.h
> index 128ce41219a1..2a6428f104e1 100644
> --- a/app/test/process.h
> +++ b/app/test/process.h
> @@ -11,6 +11,7 @@
>  #include <stdlib.h> /* NULL */
>  #include <string.h> /* strerror */
>  #include <unistd.h> /* readlink */
> +#include <dirent.h>
>  #include <sys/wait.h>
>
>  #include <rte_string_fns.h> /* strlcpy */
> @@ -40,8 +41,12 @@ process_dup(const char *const argv[], int numargs, const char *env_value)
>  {
>         int num;
>         char *argv_cpy[numargs + 1];
> -       int i, fd, status;
> +       int i, fd, fdir, status;
> +       struct dirent *dirent = NULL;

No need to initialise to NULL.

> +       const char *procdir = "/proc/self/fd/";

self is a Linux thing.
This won't work on FreeBSD.


>         char path[32];
> +       char *endptr;
> +       DIR *dir = NULL;

Idem, no need to initialize.

>  #ifdef RTE_LIBRTE_PDUMP
>         pthread_t thread;
>  #endif
> @@ -58,11 +63,36 @@ process_dup(const char *const argv[], int numargs, const char *env_value)
>
>                 /* close all open file descriptors, check /proc/self/fd to only
>                  * call close on open fds. Exclude fds 0, 1 and 2*/
> -               for (fd = getdtablesize(); fd > 2; fd-- ) {
> -                       snprintf(path, sizeof(path), "/proc/" exe "/fd/%d", fd);
> -                       if (access(path, F_OK) == 0)
> -                               close(fd);
> +               dir = opendir(procdir);
> +

Remove empty line.


> +               if (dir == NULL) {
> +                       rte_panic("Error opening %s: %s\n", procdir,
> +                                       strerror(errno));
> +               }
> +
> +               fdir = dirfd(dir);
> +               if (fdir < 0) {
> +                       status = errno;

No need to set status, this (forked) process will panic.


> +                       closedir(dir);
> +                       rte_panic("Error %d obtaining fd for dir %s: %s\n",
> +                                       fdir, procdir, strerror(status));
>                 }
> +
> +               while ((dirent = readdir(dir)) != NULL) {
> +                       errno = 0;
> +                       fd = strtol(dirent->d_name, &endptr, 10);
> +                       if (errno != 0 || dirent->d_name == endptr) {

If you want to validate that the entire string is valid:

if (errno != 0 || endptr[0] != '\0')

> +                               printf("Error converint name fd %d %s:\n",
> +                                       fd, dirent->d_name);

converting


> +                               continue;
> +                       }
> +
> +                       if (fd == fdir || fd <= 2)
> +                               continue;
> +
> +                       close(fd);
> +               }

Missing closedir().

> +
>                 printf("Running binary with argv[]:");
>                 for (i = 0; i < num; i++)
>                         printf("'%s' ", argv_cpy[i]);
> --
> 2.21.0
>


-- 
David Marchand