[LTP] [PATCH v3 1/4] Add Syscall numbers for pidfd_send_signal

[LTP] [PATCH v3 1/4] Add Syscall numbers for pidfd_send_signal

[Christian Amann]

Signed-off-by: Christian Amann <camann@suse.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
---
 include/lapi/syscalls/aarch64.in   | 1 +
 include/lapi/syscalls/arm.in       | 1 +
 include/lapi/syscalls/hppa.in      | 1 +
 include/lapi/syscalls/i386.in      | 1 +
 include/lapi/syscalls/ia64.in      | 1 +
 include/lapi/syscalls/powerpc.in   | 1 +
 include/lapi/syscalls/powerpc64.in | 1 +
 include/lapi/syscalls/s390.in      | 1 +
 include/lapi/syscalls/s390x.in     | 1 +
 include/lapi/syscalls/sh.in        | 1 +
 include/lapi/syscalls/sparc.in     | 1 +
 include/lapi/syscalls/sparc64.in   | 1 +
 include/lapi/syscalls/x86_64.in    | 1 +
 13 files changed, 13 insertions(+)

diff --git a/include/lapi/syscalls/aarch64.in b/include/lapi/syscalls/aarch64.in
index 177dd0115..ce6080894 100644
--- a/include/lapi/syscalls/aarch64.in
+++ b/include/lapi/syscalls/aarch64.in
@@ -265,4 +265,5 @@ mlock2 284
 copy_file_range 285
 preadv2 286
 pwritev2 287
+pidfd_send_signal 424
 _sysctl 1078
diff --git a/include/lapi/syscalls/arm.in b/include/lapi/syscalls/arm.in
index f4adedb2c..33168889f 100644
--- a/include/lapi/syscalls/arm.in
+++ b/include/lapi/syscalls/arm.in
@@ -350,3 +350,4 @@ copy_file_range (__NR_SYSCALL_BASE+391)
 preadv2 (__NR_SYSCALL_BASE+392)
 pwritev2 (__NR_SYSCALL_BASE+393)
 statx (__NR_SYSCALL_BASE+397)
+pidfd_send_signal (__NR_SYSCALL_BASE+424)
diff --git a/include/lapi/syscalls/hppa.in b/include/lapi/syscalls/hppa.in
index a0dd2307f..4cdd109fb 100644
--- a/include/lapi/syscalls/hppa.in
+++ b/include/lapi/syscalls/hppa.in
@@ -25,3 +25,4 @@ mlock2 345
 copy_file_range 346
 preadv2 347
 pwritev2 348
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/i386.in b/include/lapi/syscalls/i386.in
index af5254f77..3355b9127 100644
--- a/include/lapi/syscalls/i386.in
+++ b/include/lapi/syscalls/i386.in
@@ -348,3 +348,4 @@ copy_file_range 377
 preadv2 378
 pwritev2 379
 statx 383
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/ia64.in b/include/lapi/syscalls/ia64.in
index c0aeed08b..9ac81e91e 100644
--- a/include/lapi/syscalls/ia64.in
+++ b/include/lapi/syscalls/ia64.in
@@ -305,3 +305,4 @@ mlock2 1346
 copy_file_range 1347
 preadv2 1348
 pwritev2 1349
+pidfd_send_signal 1448
diff --git a/include/lapi/syscalls/powerpc.in b/include/lapi/syscalls/powerpc.in
index 6b6be58a7..488d6dfa9 100644
--- a/include/lapi/syscalls/powerpc.in
+++ b/include/lapi/syscalls/powerpc.in
@@ -355,3 +355,4 @@ copy_file_range 379
 preadv2 380
 pwritev2 381
 statx 383
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/powerpc64.in b/include/lapi/syscalls/powerpc64.in
index 6b6be58a7..488d6dfa9 100644
--- a/include/lapi/syscalls/powerpc64.in
+++ b/include/lapi/syscalls/powerpc64.in
@@ -355,3 +355,4 @@ copy_file_range 379
 preadv2 380
 pwritev2 381
 statx 383
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/s390.in b/include/lapi/syscalls/s390.in
index 2a2ffe223..69b49eac0 100644
--- a/include/lapi/syscalls/s390.in
+++ b/include/lapi/syscalls/s390.in
@@ -338,3 +338,4 @@ mlock2 374
 copy_file_range 375
 preadv2 376
 pwritev2 377
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/s390x.in b/include/lapi/syscalls/s390x.in
index 4c36ce17c..685c16f68 100644
--- a/include/lapi/syscalls/s390x.in
+++ b/include/lapi/syscalls/s390x.in
@@ -337,3 +337,4 @@ mlock2 374
 copy_file_range 375
 preadv2 376
 pwritev2 377
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/sh.in b/include/lapi/syscalls/sh.in
index a942fb506..132492922 100644
--- a/include/lapi/syscalls/sh.in
+++ b/include/lapi/syscalls/sh.in
@@ -369,3 +369,4 @@ mlock2 390
 copy_file_range 391
 preadv2 392
 pwritev2 393
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/sparc.in b/include/lapi/syscalls/sparc.in
index 20dc37b01..e74b48170 100644
--- a/include/lapi/syscalls/sparc.in
+++ b/include/lapi/syscalls/sparc.in
@@ -343,3 +343,4 @@ mlock2 356
 copy_file_range 357
 preadv2 358
 pwritev2 359
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/sparc64.in b/include/lapi/syscalls/sparc64.in
index c100b8e3e..577aa9b35 100644
--- a/include/lapi/syscalls/sparc64.in
+++ b/include/lapi/syscalls/sparc64.in
@@ -319,3 +319,4 @@ mlock2 356
 copy_file_range 357
 preadv2 358
 pwritev2 359
+pidfd_send_signal 424
diff --git a/include/lapi/syscalls/x86_64.in b/include/lapi/syscalls/x86_64.in
index 87849e5c0..99d387277 100644
--- a/include/lapi/syscalls/x86_64.in
+++ b/include/lapi/syscalls/x86_64.in
@@ -315,3 +315,4 @@ copy_file_range 326
 preadv2 327
 pwritev2 328
 statx 332
+pidfd_send_signal 424
-- 
2.16.4

[LTP] [PATCH v3 2/4] syscalls/pidfd_send_signal01

[Christian Amann]

Add testcase to check if pidfd_send_signal() can provide
the same functionality as rt_sigqueueinfo().

Signed-off-by: Christian Amann <camann@suse.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
---
 configure.ac                                       |   2 +
 runtest/syscalls                                   |   2 +
 .../kernel/syscalls/pidfd_send_signal/.gitignore   |   1 +
 .../kernel/syscalls/pidfd_send_signal/Makefile     |  14 +++
 .../syscalls/pidfd_send_signal/pidfd_send_signal.h |  28 ++++++
 .../pidfd_send_signal/pidfd_send_signal01.c        | 104 +++++++++++++++++++++
 6 files changed, 151 insertions(+)
 create mode 100644 testcases/kernel/syscalls/pidfd_send_signal/.gitignore
 create mode 100644 testcases/kernel/syscalls/pidfd_send_signal/Makefile
 create mode 100644 testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal.h
 create mode 100644 testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal01.c

diff --git a/configure.ac b/configure.ac
index 5ecc92781..65fc2a232 100644
--- a/configure.ac
+++ b/configure.ac
@@ -71,6 +71,7 @@ AC_CHECK_FUNCS([ \
     mkdirat \
     mknodat \
     openat \
+    pidfd_send_signal \
     preadv \
     preadv2 \
     profil \
@@ -238,6 +239,7 @@ else
 fi
 AC_DEFINE_UNQUOTED(NUMA_ERROR_MSG, ["$numa_error_msg"], [Error message when no NUMA support])
 
+
 LTP_CHECK_SYSCALL_PERF_EVENT_OPEN
 LTP_CHECK_SYSCALL_QUOTACTL
 LTP_CHECK_SYSCALL_SIGNALFD
diff --git a/runtest/syscalls b/runtest/syscalls
index 702d6a8c7..ac6000065 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -833,6 +833,8 @@ pause03 pause03
 personality01 personality01
 personality02 personality02
 
+pidfd_send_signal01 pidfd_send_signal01
+
 pipe01 pipe01
 pipe02 pipe02
 pipe03 pipe03
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/.gitignore b/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
new file mode 100644
index 000000000..7ccbf2d80
--- /dev/null
+++ b/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
@@ -0,0 +1 @@
+/pidfd_send_signal01
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/Makefile b/testcases/kernel/syscalls/pidfd_send_signal/Makefile
new file mode 100644
index 000000000..23e4ec478
--- /dev/null
+++ b/testcases/kernel/syscalls/pidfd_send_signal/Makefile
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#
+#   Copyright (c) 2019 SUSE LLC
+#
+#   Author: Christian Amann <camann@suse.com>
+#
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
+
+pidfd_send_signal01: CFLAGS += -pthread
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal.h b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal.h
new file mode 100644
index 000000000..dc17fe058
--- /dev/null
+++ b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal.h
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 SUSE LLC
+ * Author: Christian Amann <camann@suse.com>
+ */
+
+#ifndef PIDFD_SEND_SIGNAL_H
+#define PIDFD_SEND_SIGNAL_H
+
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+
+static void check_syscall_support(void)
+{
+	/* allow the tests to fail early */
+	tst_syscall(__NR_pidfd_send_signal);
+}
+
+#ifndef HAVE_PIDFD_SEND_SIGNAL
+static int pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
+				 unsigned int flags)
+{
+	tst_res(TINFO, "Testing syscall(__NR_pidfd_send_signal)");
+	return tst_syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
+}
+#endif /* HAVE_PIDFD_SEND_SIGNAL */
+
+#endif /* PIDFD_SEND_SIGNAL_H */
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal01.c b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal01.c
new file mode 100644
index 000000000..f03905894
--- /dev/null
+++ b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal01.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 SUSE LLC
+ * Author: Christian Amann <camann@suse.com>
+ */
+/*
+ * Tests if the pidfd_send_signal syscall behaves
+ * like rt_sigqueueinfo when a pointer to a siginfo_t
+ * struct is passed.
+ */
+
+#include <signal.h>
+#include <stdlib.h>
+#include "tst_safe_pthread.h"
+#include "pidfd_send_signal.h"
+
+#define SIGNAL  SIGUSR1
+#define DATA	777
+
+static struct sigaction *sig_action;
+static int sig_rec;
+static siginfo_t *uinfo;
+static int pidfd;
+
+static void received_signal(int sig, siginfo_t *info, void *ucontext)
+{
+	if (info && ucontext) {
+		if (sig == SIGNAL && uinfo->si_value.sival_int == DATA) {
+			tst_res(TPASS, "Received correct signal and data!");
+			sig_rec = 1;
+		} else {
+			tst_res(TFAIL, "Received wrong signal and/or data!");
+		}
+	} else {
+		tst_res(TFAIL, "Signal handling went wrong!");
+	}
+}
+
+static void *handle_thread(void *arg)
+{
+	SAFE_SIGACTION(SIGNAL, sig_action, NULL);
+	TST_CHECKPOINT_WAKE_AND_WAIT(0);
+	return arg;
+}
+
+static void verify_pidfd_send_signal(void)
+{
+	pthread_t thr;
+
+	SAFE_PTHREAD_CREATE(&thr, NULL, handle_thread, NULL);
+
+	TST_CHECKPOINT_WAIT(0);
+
+	TEST(pidfd_send_signal(pidfd, SIGNAL, uinfo, 0));
+	if (TST_RET != 0) {
+		tst_res(TFAIL | TTERRNO, "pidfd_send_signal() failed");
+		return;
+	}
+
+	TST_CHECKPOINT_WAKE(0);
+	SAFE_PTHREAD_JOIN(thr, NULL);
+
+	if (sig_rec) {
+		tst_res(TPASS,
+			"pidfd_send_signal() behaved like rt_sigqueueinfo()");
+	}
+}
+
+static void setup(void)
+{
+	check_syscall_support();
+
+	pidfd = SAFE_OPEN("/proc/self", O_DIRECTORY | O_CLOEXEC);
+
+	sig_action = SAFE_MALLOC(sizeof(struct sigaction));
+
+	memset(sig_action, 0, sizeof(*sig_action));
+	sig_action->sa_sigaction = received_signal;
+	sig_action->sa_flags = SA_SIGINFO;
+
+	uinfo = SAFE_MALLOC(sizeof(siginfo_t));
+
+	memset(uinfo, 0, sizeof(*uinfo));
+	uinfo->si_signo = SIGNAL;
+	uinfo->si_code = SI_QUEUE;
+	uinfo->si_pid = getpid();
+	uinfo->si_uid = getuid();
+	uinfo->si_value.sival_int = DATA;
+}
+
+static void cleanup(void)
+{
+	free(uinfo);
+	free(sig_action);
+	if (pidfd > 0)
+		SAFE_CLOSE(pidfd);
+}
+
+static struct tst_test test = {
+	.test_all = verify_pidfd_send_signal,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_checkpoints = 1,
+};
-- 
2.16.4

[LTP] [PATCH v3 3/4] syscalls/pidfd_send_signal02

[Christian Amann]

Add test to check basic error handling of the syscall.

Signed-off-by: Christian Amann <camann@suse.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
---
 runtest/syscalls                                   |   1 +
 .../kernel/syscalls/pidfd_send_signal/.gitignore   |   1 +
 .../pidfd_send_signal/pidfd_send_signal02.c        | 104 +++++++++++++++++++++
 3 files changed, 106 insertions(+)
 create mode 100644 testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal02.c

diff --git a/runtest/syscalls b/runtest/syscalls
index ac6000065..aa192b517 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -834,6 +834,7 @@ personality01 personality01
 personality02 personality02
 
 pidfd_send_signal01 pidfd_send_signal01
+pidfd_send_signal02 pidfd_send_signal02
 
 pipe01 pipe01
 pipe02 pipe02
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/.gitignore b/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
index 7ccbf2d80..6ea6401a8 100644
--- a/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
+++ b/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
@@ -1 +1,2 @@
 /pidfd_send_signal01
+/pidfd_send_signal02
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal02.c b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal02.c
new file mode 100644
index 000000000..c933ada84
--- /dev/null
+++ b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal02.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 SUSE LLC
+ * Author: Christian Amann <camann@suse.com>
+ */
+/*
+ * Tests basic error handling of the pidfd_send_signal
+ * system call.
+ *
+ * 1) Pass invalid flag value to syscall (value chosen
+ *    to be unlikely to collide with future extensions)
+ *    -> EINVAL
+ * 2) Pass a file descriptor that is corresponding to a
+ *    regular file instead of a pid directory
+ *    -> EBADF
+ * 3) Pass a signal that is different from the one used
+ *    to initialize the siginfo_t struct
+ *    -> EINVAL
+ * 4) Try to send signal to other process (init) with
+ *    missing privileges
+ *    -> EPERM
+ */
+
+#include <pwd.h>
+#include <signal.h>
+#include "tst_safe_pthread.h"
+#include "pidfd_send_signal.h"
+
+#define CORRECT_SIGNAL		SIGUSR1
+#define DIFFERENT_SIGNAL	SIGUSR2
+
+static siginfo_t info;
+static int pidfd;
+static int init_pidfd;
+static int dummyfd;
+
+static struct tcase {
+	int		*fd;
+	siginfo_t	*siginf;
+	int		signal;
+	int		flags;
+	int		exp_err;
+} tcases[] = {
+	{&pidfd, &info, CORRECT_SIGNAL, 99999, EINVAL},
+	{&dummyfd, &info, CORRECT_SIGNAL, 0, EBADF},
+	{&pidfd, &info, DIFFERENT_SIGNAL, 0, EINVAL},
+	{&init_pidfd, &info, CORRECT_SIGNAL, 0, EPERM},
+};
+
+static void verify_pidfd_send_signal(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+
+	TEST(pidfd_send_signal(*tc->fd, tc->signal, tc->siginf, tc->flags));
+	if (tc->exp_err != TST_ERR) {
+		tst_res(TFAIL | TTERRNO,
+			"pidfd_send_signal() did not fail with %s but",
+			tst_strerrno(tc->exp_err));
+		return;
+	}
+
+	tst_res(TPASS | TTERRNO,
+		"pidfd_send_signal() failed as expected");
+}
+
+static void setup(void)
+{
+	struct passwd *pw;
+
+	check_syscall_support();
+
+	pidfd = SAFE_OPEN("/proc/self", O_DIRECTORY | O_CLOEXEC);
+	init_pidfd = SAFE_OPEN("/proc/1", O_DIRECTORY | O_CLOEXEC);
+	dummyfd = SAFE_OPEN("dummy_file", O_RDWR | O_CREAT, 0664);
+
+	if (getuid() == 0) {
+		pw = SAFE_GETPWNAM("nobody");
+		SAFE_SETUID(pw->pw_uid);
+	}
+
+	memset(&info, 0, sizeof(info));
+	info.si_signo = CORRECT_SIGNAL;
+	info.si_code = SI_QUEUE;
+	info.si_pid = getpid();
+	info.si_uid = getuid();
+}
+
+static void cleanup(void)
+{
+	if (dummyfd > 0)
+		SAFE_CLOSE(dummyfd);
+	if (init_pidfd > 0)
+		SAFE_CLOSE(init_pidfd);
+	if (pidfd > 0)
+		SAFE_CLOSE(pidfd);
+}
+
+static struct tst_test test = {
+	.test = verify_pidfd_send_signal,
+	.tcnt = ARRAY_SIZE(tcases),
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_tmpdir = 1,
+};
-- 
2.16.4

[LTP] [PATCH v3 4/4] syscalls/pidfd_send_signal03

[Christian Amann]

Add testcase to check if the syscall will send a signal
to a process with the same PID as the targeted process.

Signed-off-by: Christian Amann <camann@suse.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
---
 runtest/syscalls                                   |   1 +
 .../kernel/syscalls/pidfd_send_signal/.gitignore   |   1 +
 .../pidfd_send_signal/pidfd_send_signal03.c        | 138 +++++++++++++++++++++
 3 files changed, 140 insertions(+)
 create mode 100644 testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal03.c

diff --git a/runtest/syscalls b/runtest/syscalls
index aa192b517..c3e144fc6 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -835,6 +835,7 @@ personality02 personality02
 
 pidfd_send_signal01 pidfd_send_signal01
 pidfd_send_signal02 pidfd_send_signal02
+pidfd_send_signal03 pidfd_send_signal03
 
 pipe01 pipe01
 pipe02 pipe02
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/.gitignore b/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
index 6ea6401a8..cba7d50a4 100644
--- a/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
+++ b/testcases/kernel/syscalls/pidfd_send_signal/.gitignore
@@ -1,2 +1,3 @@
 /pidfd_send_signal01
 /pidfd_send_signal02
+/pidfd_send_signal03
diff --git a/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal03.c b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal03.c
new file mode 100644
index 000000000..27dbc6626
--- /dev/null
+++ b/testcases/kernel/syscalls/pidfd_send_signal/pidfd_send_signal03.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 SUSE LLC
+ * Author: Christian Amann <camann@suse.com>
+ */
+/*
+ * This test checks if the pidfd_send_signal syscall wrongfully sends
+ * a signal to a new process which inherited the PID of the actual
+ * target process.
+ * In order to do so it is necessary to start a process with a pre-
+ * determined PID. This is accomplished by writing to the
+ * /proc/sys/kernel/ns_last_pid file.
+ * By utilizing this, this test forks two children with the same PID.
+ * It is then checked, if the syscall will send a signal to the second
+ * child using the pidfd of the first one.
+ */
+
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+#include "pidfd_send_signal.h"
+#include "tst_safe_pthread.h"
+
+#define PIDTRIES	3
+
+static char *last_pid_file;
+static int pidfd, new_pidfd;
+static int old_inode, new_inode;
+
+static int get_inode_number(int fd)
+{
+	struct stat file_stat;
+
+	SAFE_FSTAT(fd, &file_stat);
+	return file_stat.st_ino;
+}
+
+static void verify_pidfd_send_signal(void)
+{
+	pid_t pid, new_pid;
+	char pid_filename[32];
+	char pid_str[16];
+	int i, fail;
+
+	fail = 1;
+	for (i = 0; i < PIDTRIES; i++) {
+		pid = SAFE_FORK();
+		if (pid == 0) {
+			TST_CHECKPOINT_WAIT(0);
+			return;
+		}
+
+		sprintf(pid_filename, "/proc/%d", pid);
+		pidfd = SAFE_OPEN(pid_filename, O_DIRECTORY | O_CLOEXEC);
+		old_inode = get_inode_number(pidfd);
+
+		TST_CHECKPOINT_WAKE(0);
+		tst_reap_children();
+
+		/* Manipulate PID for next process */
+		sprintf(pid_str, "%d", pid - 1);
+		SAFE_FILE_PRINTF(last_pid_file, pid_str);
+
+		new_pid = SAFE_FORK();
+		if (new_pid == 0) {
+			TST_CHECKPOINT_WAIT(0);
+			return;
+		}
+
+		if (new_pid == pid) {
+			new_pidfd = SAFE_OPEN(pid_filename,
+					O_DIRECTORY | O_CLOEXEC);
+			new_inode = get_inode_number(new_pidfd);
+			SAFE_CLOSE(new_pidfd);
+			fail = 0;
+			break;
+		}
+
+		if (i < PIDTRIES) {
+			tst_res(TINFO,
+				"Failed to set correct PID, trying again...");
+		}
+		SAFE_CLOSE(pidfd);
+		TST_CHECKPOINT_WAKE(0);
+		tst_reap_children();
+	}
+	if (fail) {
+		tst_brk(TBROK,
+			"Could not set new child to same PID as the old one!");
+	}
+	if (old_inode == new_inode) {
+		tst_res(TWARN,
+			"File descriptor of new process points to the inode of the old process!");
+	}
+
+	TEST(pidfd_send_signal(pidfd, SIGUSR1, NULL, 0));
+	if (TST_RET == -1 && TST_ERR == ESRCH) {
+		tst_res(TPASS,
+			"Did not send signal to wrong process with same PID!");
+	} else {
+		tst_res(TFAIL | TTERRNO,
+			"pidf_send_signal() ended unexpectedly - return value: %ld, error",
+			TST_RET);
+	}
+	TST_CHECKPOINT_WAKE(0);
+	tst_reap_children();
+
+	SAFE_CLOSE(pidfd);
+}
+
+static void setup(void)
+{
+	check_syscall_support();
+
+	last_pid_file = "/proc/sys/kernel/ns_last_pid";
+	if (access(last_pid_file, F_OK) == -1) {
+		tst_brk(TCONF, "%s does not exist, cannot set PIDs",
+			last_pid_file);
+	}
+}
+
+static void cleanup(void)
+{
+	tst_reap_children();
+	if (new_pidfd > 0)
+		SAFE_CLOSE(new_pidfd);
+	if (pidfd > 0)
+		SAFE_CLOSE(pidfd);
+}
+
+static struct tst_test test = {
+	.test_all = verify_pidfd_send_signal,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_root = 1,
+	.needs_checkpoints = 1,
+	.forks_child = 1,
+};
-- 
2.16.4

[LTP] [PATCH v3 4/4] syscalls/pidfd_send_signal03

[Petr Vorel]

Hi Christian,

> Add testcase to check if the syscall will send a signal
> to a process with the same PID as the targeted process.

> Signed-off-by: Christian Amann <camann@suse.com>
> Reviewed-by: Petr Vorel <pvorel@suse.cz>

Whole patchset merged, thx!

Kind regards,
Petr