[LTP] [PATCH v4] Remove ltp_clone_quick usage from pidns suite

[LTP] [PATCH v4] Remove ltp_clone_quick usage from pidns suite

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
Usage of checkpoints instead of pipe
Usage of SAFE_* macros
Removed libclone dependency and replaced with SAFE_CLONE
Description formatting

 testcases/kernel/containers/pidns/pidns05.c | 286 ++++++--------------
 1 file changed, 77 insertions(+), 209 deletions(-)

diff --git a/testcases/kernel/containers/pidns/pidns05.c b/testcases/kernel/containers/pidns/pidns05.c
index 79e146e36..f48e9e528 100644
--- a/testcases/kernel/containers/pidns/pidns05.c
+++ b/testcases/kernel/containers/pidns/pidns05.c
@@ -1,256 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
-* Copyright (c) International Business Machines Corp., 2007
-* This program is free software; you can redistribute it and/or modify
-* it under the terms of the GNU General Public License as published by
-* the Free Software Foundation; either version 2 of the License, or
-* (at your option) any later version.
-* This program is distributed in the hope that it will be useful
-* but WITHOUT ANY WARRANTY; without even the implied warranty of
-* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
-* the GNU General Public License for more details.
-* You should have received a copy of the GNU General Public License
-* along with this program; if not, write to the Free Software
-* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
-*
-***************************************************************************
-*
-* Assertion:
-*   a) Create a  container.
-*   b) Create many levels of child containers inside this container.
-*   c) Now do kill -9 init , outside of the container.
-*   d) This should kill all the child containers.
-*      (containers created at the level below)
-*
-* Description:
-* 1. Parent process clone a process with flag CLONE_NEWPID
-* 2. The container will recursively loop and creates 4 more containers.
-* 3. All the container init's  goes into sleep(), waiting to be terminated.
-* 4. The parent process will kill child[3] by passing SIGKILL
-* 5. Now parent process, verifies the child containers 4 & 5 are destroyed.
-* 6. If they are killed then
-*	Test passed
-*  else Test failed.
-*
-* Test Name: pidns05
-*
-* History:
-*
-* FLAG DATE		NAME				DESCRIPTION
-* 31/10/08  Veerendra C <vechandr@in.ibm.com>	Verifies killing of NestedCont's
-*
-*******************************************************************************/
-#define _GNU_SOURCE 1
+ * Copyright (c) Veerendra C <vechandr@in.ibm.com>, 2008
+ * Copyright (C) 2023 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Clone a process with CLONE_NEWPID flag and create many levels of child
+ * containers. Then kill container init process from parent and check if all
+ * containers have been killed.
+ */
+
 #include <sys/wait.h>
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <errno.h>
-#include "pidns_helper.h"
-#include "test.h"
-#include "safe_macros.h"
+#include "tst_test.h"
+#include "lapi/sched.h"
 
-#define INIT_PID	1
-#define CINIT_PID	1
-#define PARENT_PID	0
 #define MAX_DEPTH	5
 
-char *TCID = "pidns05";
-int TST_TOTAL = 1;
-int fd[2];
+static struct tst_clone_args clone_args = {
+	.flags = CLONE_NEWPID,
+	.exit_signal = SIGCHLD
+};
+static pid_t pid_max;
 
-int max_pid(void)
+static void child_func(int *level)
 {
-	FILE *fp;
-	int ret;
+	pid_t cpid, ppid;
+
+	cpid = getpid();
+	ppid = getppid();
+
+	TST_EXP_EQ_LI(cpid, 1);
+	TST_EXP_EQ_LI(ppid, 0);
 
-	fp = fopen("/proc/sys/kernel/pid_max", "r");
-	if (fp != NULL) {
-		fscanf(fp, "%d", &ret);
-		fclose(fp);
-	} else {
-		tst_resm(TBROK, "Cannot open /proc/sys/kernel/pid_max");
-		ret = -1;
+	if (*level >= MAX_DEPTH) {
+		TST_CHECKPOINT_WAKE(0);
+		return;
 	}
-	return ret;
+
+	(*level)++;
+
+	if (!SAFE_CLONE(&clone_args)) {
+		child_func(level);
+		return;
+	}
+
+	pause();
 }
 
-/* find_cinit_pids() iteratively finds the pid's having same PGID as its parent.
- * Input parameter - Accepts pointer to pid_t : To copy the pid's matching.
- * Returns - the number of pids matched.
-*/
-int find_cinit_pids(pid_t * pids)
+static int find_cinit_pids(pid_t *pids)
 {
-	int next = 0, pid_max, i;
+	int i;
+	int next = 0;
 	pid_t parentpid, pgid, pgid2;
 
-	pid_max = max_pid();
 	parentpid = getpid();
-	pgid = getpgid(parentpid);
+	pgid = SAFE_GETPGID(parentpid);
 
-	/* The loop breaks, when the loop counter reaches the parentpid value */
 	for (i = parentpid + 1; i != parentpid; i++) {
 		if (i > pid_max)
 			i = 2;
 
 		pgid2 = getpgid(i);
+
 		if (pgid2 == pgid) {
 			pids[next] = i;
 			next++;
 		}
 	}
+
 	return next;
 }
 
-/*
-* create_nested_container() Recursively create MAX_DEPTH nested containers
-*/
-int create_nested_container(void *vtest)
+static void setup(void)
 {
-	int exit_val;
-	int ret, count, *level;
-	pid_t cpid, ppid;
-	cpid = getpid();
-	ppid = getppid();
-	char mesg[] = "Nested Containers are created";
-
-	level = (int *)vtest;
-	count = *level;
-
-	/* Child process closes up read side of pipe */
-	close(fd[0]);
-
-	/* Comparing the values to make sure pidns is created correctly */
-	if (cpid != CINIT_PID || ppid != PARENT_PID) {
-		printf("Got unexpected cpid and/or ppid (cpid=%d ppid=%d)\n",
-		       cpid, ppid);
-		exit_val = 1;
-	}
-	if (count > 1) {
-		count--;
-		ret = do_clone_unshare_test(T_CLONE, CLONE_NEWPID,
-					    create_nested_container,
-					    (void *)&count);
-		if (ret == -1) {
-			printf("clone failed; errno = %d : %s\n",
-			       ret, strerror(ret));
-			exit_val = 1;
-		} else
-			exit_val = 0;
-	} else {
-		/* Sending mesg, 'Nested containers created' through the pipe */
-		write(fd[1], mesg, (strlen(mesg) + 1));
-		exit_val = 0;
-	}
-
-	close(fd[1]);
-	pause();
-
-	return exit_val;
+	SAFE_FILE_SCANF("/proc/sys/kernel/pid_max", "%d\n", &pid_max);
 }
 
-void kill_nested_containers()
+static void run(void)
 {
-	int orig_count, new_count, status = 0, i;
-	pid_t pids[MAX_DEPTH];
+	int i, status, children;
+	int level = 0;
 	pid_t pids_new[MAX_DEPTH];
+	pid_t pids[MAX_DEPTH];
+	pid_t pid;
 
-	orig_count = find_cinit_pids(pids);
-	kill(pids[MAX_DEPTH - 3], SIGKILL);
-	sleep(1);
-
-	/* After killing child container, getting the New PID list */
-	new_count = find_cinit_pids(pids_new);
-
-	/* Verifying that the child containers were destroyed when parent is killed */
-	if (orig_count - 2 != new_count)
-		status = -1;
-
-	for (i = 0; i < new_count; i++) {
-		if (pids[i] != pids_new[i])
-			status = -1;
+	pid = SAFE_CLONE(&clone_args);
+	if (!pid) {
+		child_func(&level);
+		return;
 	}
 
-	if (status == 0)
-		tst_resm(TPASS, "The number of containers killed are %d",
-			 orig_count - new_count);
-	else
-		tst_resm(TFAIL, "Failed to kill the sub-containers of "
-			 "the container %d", pids[MAX_DEPTH - 3]);
+	TST_CHECKPOINT_WAIT(0);
 
-	/* Loops through the containers created to exit from sleep() */
-	for (i = 0; i < MAX_DEPTH; i++) {
-		kill(pids[i], SIGKILL);
-		waitpid(pids[i], &status, 0);
-	}
-}
+	TST_EXP_POSITIVE(find_cinit_pids(pids));
 
-static void setup(void)
-{
-	tst_require_root();
-	check_newpid();
-}
+	SAFE_KILL(pid, SIGKILL);
+	SAFE_WAITPID(0, &status, 0);
 
-int main(void)
-{
-	int ret, nbytes, status;
-	char readbuffer[80];
-	pid_t pid, pgid;
-	int count = MAX_DEPTH;
+	children = find_cinit_pids(pids_new);
 
-	setup();
+	if (children > 0) {
+		tst_res(TFAIL, "%d children left after sending SIGKILL", children);
 
-	/*
-	 * XXX (garrcoop): why in the hell is this fork-wait written this way?
-	 * This doesn't add up with the pattern used for the rest of the tests,
-	 * so I'm pretty damn sure this test is written incorrectly.
-	 */
-	pid = fork();
-	if (pid == -1) {
-		tst_brkm(TBROK | TERRNO, NULL, "fork failed");
-	} else if (pid != 0) {
-		/*
-		 * NOTE: use waitpid so that we know we're waiting for the
-		 * _top-level_ child instead of a spawned subcontainer.
-		 *
-		 * XXX (garrcoop): Might want to mask SIGCHLD in the top-level
-		 * child too, or not *shrugs*.
-		 */
-		if (waitpid(pid, &status, 0) == -1) {
-			perror("wait failed");
+		for (i = 0; i < MAX_DEPTH; i++) {
+			kill(pids[i], SIGKILL);
+			waitpid(pids[i], &status, 0);
 		}
-		if (WIFEXITED(status))
-			exit(WEXITSTATUS(status));
-		else
-			exit(status);
-	}
 
-	/* To make all the containers share the same PGID as its parent */
-	setpgid(0, 0);
-
-	pid = getpid();
-	pgid = getpgid(pid);
-	SAFE_PIPE(NULL, fd);
-
-	TEST(do_clone_unshare_test(T_CLONE, CLONE_NEWPID,
-				   create_nested_container, (void *)&count));
-	if (TEST_RETURN == -1) {
-		tst_brkm(TFAIL | TTERRNO, NULL, "clone failed");
+		return;
 	}
 
-	close(fd[1]);
-	/* Waiting for the MAX_DEPTH number of containers to be created */
-	nbytes = read(fd[0], readbuffer, sizeof(readbuffer));
-	close(fd[0]);
-	if (nbytes > 0)
-		tst_resm(TINFO, " %d %s", MAX_DEPTH, readbuffer);
-	else
-		tst_brkm(TFAIL, NULL, "unable to create %d containers",
-			 MAX_DEPTH);
-
-	/* Kill the container created */
-	kill_nested_containers();
-
-	tst_exit();
+	tst_res(TPASS, "No children left after sending SIGKILL to the first child");
 }
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.needs_root = 1,
+	.needs_checkpoints = 1,
+	.forks_child = 1,
+};
-- 
2.35.3


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

Re: [LTP] [PATCH v4] Remove ltp_clone_quick usage from pidns suite

[Andrea Cervesato via ltp]

Hi,

there's an error on the name of the patch. The correct name is "[PATCH 
v3] Remove libclone dependency from pidns05 test". Beside that, patch is 
the right one.


On 7/31/23 13:49, Andrea Cervesato wrote:
> From: Andrea Cervesato <andrea.cervesato@suse.com>
>
> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
> Usage of checkpoints instead of pipe
> Usage of SAFE_* macros
> Removed libclone dependency and replaced with SAFE_CLONE
> Description formatting
>
>   testcases/kernel/containers/pidns/pidns05.c | 286 ++++++--------------
>   1 file changed, 77 insertions(+), 209 deletions(-)
>
> diff --git a/testcases/kernel/containers/pidns/pidns05.c b/testcases/kernel/containers/pidns/pidns05.c
> index 79e146e36..f48e9e528 100644
> --- a/testcases/kernel/containers/pidns/pidns05.c
> +++ b/testcases/kernel/containers/pidns/pidns05.c
> @@ -1,256 +1,124 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
>   /*
> -* Copyright (c) International Business Machines Corp., 2007
> -* This program is free software; you can redistribute it and/or modify
> -* it under the terms of the GNU General Public License as published by
> -* the Free Software Foundation; either version 2 of the License, or
> -* (at your option) any later version.
> -* This program is distributed in the hope that it will be useful
> -* but WITHOUT ANY WARRANTY; without even the implied warranty of
> -* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> -* the GNU General Public License for more details.
> -* You should have received a copy of the GNU General Public License
> -* along with this program; if not, write to the Free Software
> -* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> -*
> -***************************************************************************
> -*
> -* Assertion:
> -*   a) Create a  container.
> -*   b) Create many levels of child containers inside this container.
> -*   c) Now do kill -9 init , outside of the container.
> -*   d) This should kill all the child containers.
> -*      (containers created at the level below)
> -*
> -* Description:
> -* 1. Parent process clone a process with flag CLONE_NEWPID
> -* 2. The container will recursively loop and creates 4 more containers.
> -* 3. All the container init's  goes into sleep(), waiting to be terminated.
> -* 4. The parent process will kill child[3] by passing SIGKILL
> -* 5. Now parent process, verifies the child containers 4 & 5 are destroyed.
> -* 6. If they are killed then
> -*	Test passed
> -*  else Test failed.
> -*
> -* Test Name: pidns05
> -*
> -* History:
> -*
> -* FLAG DATE		NAME				DESCRIPTION
> -* 31/10/08  Veerendra C <vechandr@in.ibm.com>	Verifies killing of NestedCont's
> -*
> -*******************************************************************************/
> -#define _GNU_SOURCE 1
> + * Copyright (c) Veerendra C <vechandr@in.ibm.com>, 2008
> + * Copyright (C) 2023 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Clone a process with CLONE_NEWPID flag and create many levels of child
> + * containers. Then kill container init process from parent and check if all
> + * containers have been killed.
> + */
> +
>   #include <sys/wait.h>
> -#include <assert.h>
> -#include <stdio.h>
> -#include <stdlib.h>
> -#include <unistd.h>
> -#include <string.h>
> -#include <errno.h>
> -#include "pidns_helper.h"
> -#include "test.h"
> -#include "safe_macros.h"
> +#include "tst_test.h"
> +#include "lapi/sched.h"
>   
> -#define INIT_PID	1
> -#define CINIT_PID	1
> -#define PARENT_PID	0
>   #define MAX_DEPTH	5
>   
> -char *TCID = "pidns05";
> -int TST_TOTAL = 1;
> -int fd[2];
> +static struct tst_clone_args clone_args = {
> +	.flags = CLONE_NEWPID,
> +	.exit_signal = SIGCHLD
> +};
> +static pid_t pid_max;
>   
> -int max_pid(void)
> +static void child_func(int *level)
>   {
> -	FILE *fp;
> -	int ret;
> +	pid_t cpid, ppid;
> +
> +	cpid = getpid();
> +	ppid = getppid();
> +
> +	TST_EXP_EQ_LI(cpid, 1);
> +	TST_EXP_EQ_LI(ppid, 0);
>   
> -	fp = fopen("/proc/sys/kernel/pid_max", "r");
> -	if (fp != NULL) {
> -		fscanf(fp, "%d", &ret);
> -		fclose(fp);
> -	} else {
> -		tst_resm(TBROK, "Cannot open /proc/sys/kernel/pid_max");
> -		ret = -1;
> +	if (*level >= MAX_DEPTH) {
> +		TST_CHECKPOINT_WAKE(0);
> +		return;
>   	}
> -	return ret;
> +
> +	(*level)++;
> +
> +	if (!SAFE_CLONE(&clone_args)) {
> +		child_func(level);
> +		return;
> +	}
> +
> +	pause();
>   }
>   
> -/* find_cinit_pids() iteratively finds the pid's having same PGID as its parent.
> - * Input parameter - Accepts pointer to pid_t : To copy the pid's matching.
> - * Returns - the number of pids matched.
> -*/
> -int find_cinit_pids(pid_t * pids)
> +static int find_cinit_pids(pid_t *pids)
>   {
> -	int next = 0, pid_max, i;
> +	int i;
> +	int next = 0;
>   	pid_t parentpid, pgid, pgid2;
>   
> -	pid_max = max_pid();
>   	parentpid = getpid();
> -	pgid = getpgid(parentpid);
> +	pgid = SAFE_GETPGID(parentpid);
>   
> -	/* The loop breaks, when the loop counter reaches the parentpid value */
>   	for (i = parentpid + 1; i != parentpid; i++) {
>   		if (i > pid_max)
>   			i = 2;
>   
>   		pgid2 = getpgid(i);
> +
>   		if (pgid2 == pgid) {
>   			pids[next] = i;
>   			next++;
>   		}
>   	}
> +
>   	return next;
>   }
>   
> -/*
> -* create_nested_container() Recursively create MAX_DEPTH nested containers
> -*/
> -int create_nested_container(void *vtest)
> +static void setup(void)
>   {
> -	int exit_val;
> -	int ret, count, *level;
> -	pid_t cpid, ppid;
> -	cpid = getpid();
> -	ppid = getppid();
> -	char mesg[] = "Nested Containers are created";
> -
> -	level = (int *)vtest;
> -	count = *level;
> -
> -	/* Child process closes up read side of pipe */
> -	close(fd[0]);
> -
> -	/* Comparing the values to make sure pidns is created correctly */
> -	if (cpid != CINIT_PID || ppid != PARENT_PID) {
> -		printf("Got unexpected cpid and/or ppid (cpid=%d ppid=%d)\n",
> -		       cpid, ppid);
> -		exit_val = 1;
> -	}
> -	if (count > 1) {
> -		count--;
> -		ret = do_clone_unshare_test(T_CLONE, CLONE_NEWPID,
> -					    create_nested_container,
> -					    (void *)&count);
> -		if (ret == -1) {
> -			printf("clone failed; errno = %d : %s\n",
> -			       ret, strerror(ret));
> -			exit_val = 1;
> -		} else
> -			exit_val = 0;
> -	} else {
> -		/* Sending mesg, 'Nested containers created' through the pipe */
> -		write(fd[1], mesg, (strlen(mesg) + 1));
> -		exit_val = 0;
> -	}
> -
> -	close(fd[1]);
> -	pause();
> -
> -	return exit_val;
> +	SAFE_FILE_SCANF("/proc/sys/kernel/pid_max", "%d\n", &pid_max);
>   }
>   
> -void kill_nested_containers()
> +static void run(void)
>   {
> -	int orig_count, new_count, status = 0, i;
> -	pid_t pids[MAX_DEPTH];
> +	int i, status, children;
> +	int level = 0;
>   	pid_t pids_new[MAX_DEPTH];
> +	pid_t pids[MAX_DEPTH];
> +	pid_t pid;
>   
> -	orig_count = find_cinit_pids(pids);
> -	kill(pids[MAX_DEPTH - 3], SIGKILL);
> -	sleep(1);
> -
> -	/* After killing child container, getting the New PID list */
> -	new_count = find_cinit_pids(pids_new);
> -
> -	/* Verifying that the child containers were destroyed when parent is killed */
> -	if (orig_count - 2 != new_count)
> -		status = -1;
> -
> -	for (i = 0; i < new_count; i++) {
> -		if (pids[i] != pids_new[i])
> -			status = -1;
> +	pid = SAFE_CLONE(&clone_args);
> +	if (!pid) {
> +		child_func(&level);
> +		return;
>   	}
>   
> -	if (status == 0)
> -		tst_resm(TPASS, "The number of containers killed are %d",
> -			 orig_count - new_count);
> -	else
> -		tst_resm(TFAIL, "Failed to kill the sub-containers of "
> -			 "the container %d", pids[MAX_DEPTH - 3]);
> +	TST_CHECKPOINT_WAIT(0);
>   
> -	/* Loops through the containers created to exit from sleep() */
> -	for (i = 0; i < MAX_DEPTH; i++) {
> -		kill(pids[i], SIGKILL);
> -		waitpid(pids[i], &status, 0);
> -	}
> -}
> +	TST_EXP_POSITIVE(find_cinit_pids(pids));
>   
> -static void setup(void)
> -{
> -	tst_require_root();
> -	check_newpid();
> -}
> +	SAFE_KILL(pid, SIGKILL);
> +	SAFE_WAITPID(0, &status, 0);
>   
> -int main(void)
> -{
> -	int ret, nbytes, status;
> -	char readbuffer[80];
> -	pid_t pid, pgid;
> -	int count = MAX_DEPTH;
> +	children = find_cinit_pids(pids_new);
>   
> -	setup();
> +	if (children > 0) {
> +		tst_res(TFAIL, "%d children left after sending SIGKILL", children);
>   
> -	/*
> -	 * XXX (garrcoop): why in the hell is this fork-wait written this way?
> -	 * This doesn't add up with the pattern used for the rest of the tests,
> -	 * so I'm pretty damn sure this test is written incorrectly.
> -	 */
> -	pid = fork();
> -	if (pid == -1) {
> -		tst_brkm(TBROK | TERRNO, NULL, "fork failed");
> -	} else if (pid != 0) {
> -		/*
> -		 * NOTE: use waitpid so that we know we're waiting for the
> -		 * _top-level_ child instead of a spawned subcontainer.
> -		 *
> -		 * XXX (garrcoop): Might want to mask SIGCHLD in the top-level
> -		 * child too, or not *shrugs*.
> -		 */
> -		if (waitpid(pid, &status, 0) == -1) {
> -			perror("wait failed");
> +		for (i = 0; i < MAX_DEPTH; i++) {
> +			kill(pids[i], SIGKILL);
> +			waitpid(pids[i], &status, 0);
>   		}
> -		if (WIFEXITED(status))
> -			exit(WEXITSTATUS(status));
> -		else
> -			exit(status);
> -	}
>   
> -	/* To make all the containers share the same PGID as its parent */
> -	setpgid(0, 0);
> -
> -	pid = getpid();
> -	pgid = getpgid(pid);
> -	SAFE_PIPE(NULL, fd);
> -
> -	TEST(do_clone_unshare_test(T_CLONE, CLONE_NEWPID,
> -				   create_nested_container, (void *)&count));
> -	if (TEST_RETURN == -1) {
> -		tst_brkm(TFAIL | TTERRNO, NULL, "clone failed");
> +		return;
>   	}
>   
> -	close(fd[1]);
> -	/* Waiting for the MAX_DEPTH number of containers to be created */
> -	nbytes = read(fd[0], readbuffer, sizeof(readbuffer));
> -	close(fd[0]);
> -	if (nbytes > 0)
> -		tst_resm(TINFO, " %d %s", MAX_DEPTH, readbuffer);
> -	else
> -		tst_brkm(TFAIL, NULL, "unable to create %d containers",
> -			 MAX_DEPTH);
> -
> -	/* Kill the container created */
> -	kill_nested_containers();
> -
> -	tst_exit();
> +	tst_res(TPASS, "No children left after sending SIGKILL to the first child");
>   }
> +
> +static struct tst_test test = {
> +	.test_all = run,
> +	.setup = setup,
> +	.needs_root = 1,
> +	.needs_checkpoints = 1,
> +	.forks_child = 1,
> +};

Andrea


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Re: [LTP] [PATCH v4] Remove ltp_clone_quick usage from pidns suite

[Cyril Hrubis]

Hi!
> -int find_cinit_pids(pid_t * pids)
> +static int find_cinit_pids(pid_t *pids)
>  {
> -	int next = 0, pid_max, i;
> +	int i;
> +	int next = 0;
>  	pid_t parentpid, pgid, pgid2;
>  
> -	pid_max = max_pid();
>  	parentpid = getpid();
> -	pgid = getpgid(parentpid);
> +	pgid = SAFE_GETPGID(parentpid);
>  
> -	/* The loop breaks, when the loop counter reaches the parentpid value */
>  	for (i = parentpid + 1; i != parentpid; i++) {
>  		if (i > pid_max)
>  			i = 2;

Can we please, as I asked for in v1 review, just do loop from 2 to
pid_max here instead? It's effectively the same we do here but much
clearer code...

The rest looks good to me.

With the change to the loop above:

Reviewed-by: Cyril Hrubis <chrubis@suse.cz>

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Cyril Hrubis
chrubis@suse.cz

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