Hi Marko,
On Thu, 17 Sep 2020 at 07:34, Marko Hrastovec <marko.hrasto...@gmail.com> wrote:
>
> Hi,
>
> examples in freeaddrinfo.3 have a memory leak, which is replicated in many
> real world programs copying an example from manual pages. The two examples
> should have different order of lines, which is done in the following patch.
>
> diff --git a/man3/getaddrinfo.3 b/man3/getaddrinfo.3
> index c9a4b3e43..4d383bea0 100644
> --- a/man3/getaddrinfo.3
> +++ b/man3/getaddrinfo.3
> @@ -711,13 +711,13 @@ main(int argc, char *argv[])
> close(sfd);
> }
>
> + freeaddrinfo(result); /* No longer needed */
> +
> if (rp == NULL) { /* No address succeeded */
> fprintf(stderr, "Could not bind\en");
> exit(EXIT_FAILURE);
> }
>
> - freeaddrinfo(result); /* No longer needed */
> -
> /* Read datagrams and echo them back to sender */
>
> for (;;) {
> @@ -804,13 +804,13 @@ main(int argc, char *argv[])
> close(sfd);
> }
>
> + freeaddrinfo(result); /* No longer needed */
> +
> if (rp == NULL) { /* No address succeeded */
> fprintf(stderr, "Could not connect\en");
> exit(EXIT_FAILURE);
> }
>
> - freeaddrinfo(result); /* No longer needed */
> -
> /* Send remaining command\-line arguments as separate
> datagrams, and read responses from server */
>
When you say "memory leak", do you mean that something like valgrind
complains? I mean, strictly speaking, there is no memory leak that I
can see that is fixed by that patch, since the if-branches that the
freeaddrinfo() calls are shifted above terminates the process in each
case.
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
