[yocto] [meta-oe][PATCH] utils.c: close all file descriptors after completing a ptest

[Randy MacLeod]

Thanks Sakib.

Next time please use --prefix to add the ptest-runner tag:
so you'll have a subject line like:

[meta-oe][ptest-runner] utils.c: close all file descriptors after 
completing a ptest

The subject line is wrongg since we are closing the fds
*before* the tests. Resend with something like:
    utils.c: close all fds in child for each ptest


Wait to see if Anibal has any comment then send a v2
with a 'v2' prefix in the subject like:
    [yocto] [ptest-runner][PATCHv2 1/3] Makefile: libcheck now requires 
to link subunit

Thanks,
../Randy

On 5/31/19 1:44 PM, Sakib Sajal wrote:
> vredir ptest fails since too many file descriptors were open.
> 
>  From the failed ptest log:
>     run-vredir
>     87,88c87,88
>     < ./vredir6.sub: line 10: /dev/null: Too many open files
>     < ./vredir6.sub: line 13: /dev/null: Too many open files
>     FAIL: run-vredir
> 
> Added function to close file descriptors before starting a new process.
> 
> Signed-off-by: Sakib Sajal <sakib.sajal at windriver.com>
> Signed-off-by: Randy Macleod <randy.macleod at windriver.com>
> ---
>   utils.c | 19 +++++++++++++++++++
>   1 file changed, 19 insertions(+)
> 
> diff --git a/utils.c b/utils.c
> index 504df0b..05c2bfe 100644
> --- a/utils.c
> +++ b/utils.c
> @@ -28,6 +28,7 @@
>   #include <fcntl.h>
>   #include <time.h>
>   #include <dirent.h>
> +#include <sys/resource.h>
>   #include <sys/types.h>
>   #include <sys/wait.h>
>   #include <sys/stat.h>
> @@ -240,6 +241,23 @@ filter_ptests(struct ptest_list *head, char **ptests, int ptest_num)
>   	return head_new;
>   }
>   
> +/* Close all fds from 3 up to 'ulimit -n'
> + * i.e. do not close STDIN, STDOUT, STDERR.
> + * Typically called in in a child process after forking
> + * but before exec as a good policy especially for security.
> + */
> +static void
> +close_fds(void)
> +{
> +	struct rlimit curr_lim;
> +	getrlimit(RLIMIT_NOFILE, &curr_lim);
> +
> +	int fd;
> +	for (fd=3; fd < curr_lim.rlim_cur; fd++) {
> +		(void) close(fd);
> +   	}
> +}
> +
>   static inline void
>   run_child(char *run_ptest, int fd_stdout, int fd_stderr)
>   {
> @@ -252,6 +270,7 @@ run_child(char *run_ptest, int fd_stdout, int fd_stderr)
>   	dup2(fd_stdout, STDOUT_FILENO);
>   	// XXX: Redirect stderr to stdout to avoid buffer ordering problems.
>   	dup2(fd_stdout, STDERR_FILENO);
> +	close_fds();
>   	execv(run_ptest, argv);
>   
>   	exit(1);
> 


-- 
# Randy MacLeod
# Wind River Linux