Re: [PATCH v3 2/8] gdbstub: Try unlinking the unix socket before binding

[Alex Bennée]

Ilya Leoshkevich <iii@linux.ibm.com> writes:

> In case an emulated process execve()s another emulated process, bind()
> will fail, because the socket already exists. So try deleting it.
>
> Note that it is not possible to handle this in do_execv(): deleting
> gdbserver_user_state.socket_path before safe_execve() is not correct,
> because the latter may fail, and afterwards we may lose control.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>  gdbstub/user.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/gdbstub/user.c b/gdbstub/user.c
> index ef52f249ce9..c900d0a52fe 100644
> --- a/gdbstub/user.c
> +++ b/gdbstub/user.c
> @@ -337,6 +337,7 @@ static int gdbserver_open_socket(const char *path)
>  
>      sockaddr.sun_family = AF_UNIX;
>      pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path);
> +    unlink(sockaddr.sun_path);

Should we be checking for errors here? What do we expect when attempting
to unlink a non-existent path? -EIO?

>      ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
>      if (ret < 0) {
>          perror("bind socket");

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro