[yocto] [ptest-runner][PATCH v2 4/4] utils: ensure child can be session leader
Randy MacLeod
randy.macleod at windriver.com
Wed Jun 19 10:49:43 PDT 2019
On 6/14/19 10:48 AM, Randy MacLeod wrote:
> When running the run-execscript bash ptest as a user rather than root, a warning:
> bash: cannot set terminal process group (16036): Inappropriate ioctl for device
> bash: no job control in this shell
> contaminates the bash log files causing the test to fail. This happens only
> when run under ptest-runner and not when interactively testing!
>
> The changes made to fix this include:
> 1. Get the process group id (pgid) before forking,
> 2. Set the pgid in both the parent and child to avoid a race,
> 3. Find, open and set permission on the child tty, and
> 4. Allow the child to attach to controlling tty.
>
> Also add '-lutil' to Makefile. This lib is from libc and provides openpty.
Hmmm, I was making the code compile cleanly under clang using
-Weverything
when I noticed:
1. the 'make check' tests. They still work fine.
2. The './ptest-runner -d tests/data -t 1' tests
which now generate loads of error like:
ERROR: Unable to detach from controlling tty, Inappropriate ioctl
for device
so while this change fixed the bash-ptest, the ptest-runner self-test
it did something wrong.... Ah, I'm calling:
ioctl(0, TIOCNOTTY) == -1)
repeatedly in the parent so that's what's generating the extra logs.
Fixed locally and I'll send a patch but it's not urgent. Phew! :)
Anibal,
If you could reply to explain your plans for Richard's patches
that would help me figure out when to send the clang warning clean-ups
commits and what commit to base my work on.
../Randy
>
> Signed-off-by: Sakib Sajal <sakib.sajal at windriver.com>
> Signed-off-by: Randy MacLeod <Randy.MacLeod at windriver.com>
> ---
> Makefile | 2 +-
> utils.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++------
> 2 files changed, 92 insertions(+), 12 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 1bde7be..439eb79 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -29,7 +29,7 @@ TEST_DATA=$(shell echo `pwd`/tests/data)
> all: $(SOURCES) $(EXECUTABLE)
>
> $(EXECUTABLE): $(OBJECTS)
> - $(CC) $(LDFLAGS) $(OBJECTS) -o $@
> + $(CC) $(LDFLAGS) $(OBJECTS) -lutil -o $@
>
> tests: $(TEST_SOURCES) $(TEST_EXECUTABLE)
>
> diff --git a/utils.c b/utils.c
> index ad737c2..f11ce39 100644
> --- a/utils.c
> +++ b/utils.c
> @@ -1,5 +1,6 @@
> /**
> * Copyright (c) 2016 Intel Corporation
> + * Copyright (C) 2019 Wind River Systems, Inc.
> *
> * This program is free software; you can redistribute it and/or
> * modify it under the terms of the GNU General Public License
> @@ -22,23 +23,27 @@
> */
>
> #define _GNU_SOURCE
> +
> #include <stdio.h>
>
> +#include <dirent.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <grp.h>
> #include <libgen.h>
> -#include <signal.h>
> #include <poll.h>
> -#include <fcntl.h>
> +#include <pty.h>
> +#include <signal.h>
> +#include <stdlib.h>
> +#include <string.h>
> #include <time.h>
> -#include <dirent.h>
> +#include <unistd.h>
> +
> +#include <sys/ioctl.h>
> #include <sys/resource.h>
> +#include <sys/stat.h>
> #include <sys/types.h>
> #include <sys/wait.h>
> -#include <sys/stat.h>
> -#include <unistd.h>
> -#include <string.h>
> -#include <stdlib.h>
> -
> -#include <errno.h>
>
> #include "ptest_list.h"
> #include "utils.h"
> @@ -346,6 +351,53 @@ wait_child(const char *ptest_dir, const char *run_ptest, pid_t pid,
> return status;
> }
>
> +/* Returns an integer file descriptor.
> + * If it returns < 0, an error has occurred.
> + * Otherwise, it has returned the slave pty file descriptor.
> + * fp should be writable, likely stdout/err.
> + */
> +static int
> +setup_slave_pty(FILE *fp) {
> + int pty_master = -1;
> + int pty_slave = -1;
> + char pty_name[256];
> + struct group *gptr;
> + gid_t gid;
> + int slave = -1;
> +
> + if (openpty(&pty_master, &pty_slave, pty_name, NULL, NULL) < 0) {
> + fprintf(fp, "ERROR: openpty() failed with: %s.\n", strerror(errno));
> + return -1;
> + }
> +
> + if ((gptr = getgrnam(pty_name)) != 0) {
> + gid = gptr->gr_gid;
> + } else {
> + /* If the tty group does not exist, don't change the
> + * group on the slave pty, only the owner
> + */
> + gid = -1;
> + }
> +
> + /* chown/chmod the corresponding pty, if possible.
> + * This will only work if the process has root permissions.
> + */
> + if (chown(pty_name, getuid(), gid) != 0) {
> + fprintf(fp, "ERROR; chown() failed with: %s.\n", strerror(errno));
> + }
> +
> + /* Makes the slave read/writeable for the user. */
> + if (chmod(pty_name, S_IRUSR|S_IWUSR) != 0) {
> + fprintf(fp, "ERROR: chmod() failed with: %s.\n", strerror(errno));
> + }
> +
> + if ((slave = open(pty_name, O_RDWR)) == -1) {
> + fprintf(fp, "ERROR: open() failed with: %s.\n", strerror(errno));
> + }
> + return (slave);
> +}
> +
> +
> int
> run_ptests(struct ptest_list *head, const struct ptest_options opts,
> const char *progname, FILE *fp, FILE *fp_stderr)
> @@ -362,6 +414,8 @@ run_ptests(struct ptest_list *head, const struct ptest_options opts,
> int timeouted;
> time_t sttime, entime;
> int duration;
> + int slave;
> + int pgid = -1;
>
> if (opts.xml_filename) {
> xh = xml_create(ptest_list_length(head), opts.xml_filename);
> @@ -379,7 +433,6 @@ run_ptests(struct ptest_list *head, const struct ptest_options opts,
> close(pipefd_stdout[1]);
> break;
> }
> -
> fprintf(fp, "START: %s\n", progname);
> PTEST_LIST_ITERATE_START(head, p);
> char *ptest_dir = strdup(p->run_ptest);
> @@ -388,6 +441,13 @@ run_ptests(struct ptest_list *head, const struct ptest_options opts,
> break;
> }
> dirname(ptest_dir);
> + if (ioctl(0, TIOCNOTTY) == -1) {
> + fprintf(fp, "ERROR: Unable to detach from controlling tty, %s\n", strerror(errno));
> + }
> +
> + if ((pgid = getpgid(0)) == -1) {
> + fprintf(fp, "ERROR: getpgid() failed, %s\n", strerror(errno));
> + }
>
> child = fork();
> if (child == -1) {
> @@ -395,13 +455,33 @@ run_ptests(struct ptest_list *head, const struct ptest_options opts,
> rc = -1;
> break;
> } else if (child == 0) {
> - setsid();
> + close(0);
> + if ((slave = setup_slave_pty(fp)) < 0) {
> + fprintf(fp, "ERROR: could not setup pty (%d).", slave);
> + }
> + if (setpgid(0,pgid) == -1) {
> + fprintf(fp, "ERROR: setpgid() failed, %s\n", strerror(errno));
> + }
> +
> + if (setsid() == -1) {
> + fprintf(fp, "ERROR: setsid() failed, %s\n", strerror(errno));
> + }
> +
> + if (ioctl(0, TIOCSCTTY, NULL) == -1) {
> + fprintf(fp, "ERROR: Unable to attach to controlling tty, %s\n", strerror(errno));
> + }
> +
> run_child(p->run_ptest, pipefd_stdout[1], pipefd_stderr[1]);
> +
> } else {
> int status;
> int fds[2]; fds[0] = pipefd_stdout[0]; fds[1] = pipefd_stderr[0];
> FILE *fps[2]; fps[0] = fp; fps[1] = fp_stderr;
>
> + if (setpgid(child, pgid) == -1) {
> + fprintf(fp, "ERROR: setpgid() failed, %s\n", strerror(errno));
> + }
> +
> sttime = time(NULL);
> fprintf(fp, "%s\n", get_stime(stime, GET_STIME_BUF_SIZE, sttime));
> fprintf(fp, "BEGIN: %s\n", ptest_dir);
>
--
# Randy MacLeod
# Wind River Linux
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