From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Amann Date: Fri, 14 Jun 2019 09:28:29 +0200 Subject: [LTP] [PATCH v3 4/4] syscalls/pidfd_send_signal03 In-Reply-To: <20190614072829.24529-1-camann@suse.com> References: <20190614072829.24529-1-camann@suse.com> Message-ID: <20190614072829.24529-4-camann@suse.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it 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 Reviewed-by: Petr Vorel --- 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 + */ +/* + * 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 +#include +#include +#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