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6952a4f646
We recently regressed (cf. [1] and its corresponding fix in [2]) returning ENOMEM when trying to create a process in a pid namespace whose init process/child subreaper has already died. This has caused confusion at least once before that (cf. [3]). Let's add a simple regression test to catch this in the future. [1]:49cb2fc42c("fork: extend clone3() to support setting a PID") [2]:b26ebfe12f("pid: Fix error return value in some cases") [3]:35f71bc0a0("fork: report pid reservation failure properly") Cc: Corey Minyard <cminyard@mvista.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Adrian Reber <areber@redhat.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
99 lines
1.8 KiB
C
99 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __PIDFD_H
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#define __PIDFD_H
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#define _GNU_SOURCE
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#include <errno.h>
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#include <fcntl.h>
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#include <sched.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <syscall.h>
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#include <sys/mount.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include "../kselftest.h"
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#ifndef P_PIDFD
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#define P_PIDFD 3
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#endif
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#ifndef CLONE_PIDFD
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#define CLONE_PIDFD 0x00001000
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#endif
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#ifndef __NR_pidfd_open
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#define __NR_pidfd_open -1
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#endif
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#ifndef __NR_pidfd_send_signal
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#define __NR_pidfd_send_signal -1
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#endif
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#ifndef __NR_clone3
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#define __NR_clone3 -1
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#endif
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#ifndef __NR_pidfd_getfd
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#define __NR_pidfd_getfd -1
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#endif
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/*
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* The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
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* That means, when it wraps around any pid < 300 will be skipped.
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* So we need to use a pid > 300 in order to test recycling.
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*/
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#define PID_RECYCLE 1000
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/*
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* Define a few custom error codes for the child process to clearly indicate
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* what is happening. This way we can tell the difference between a system
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* error, a test error, etc.
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*/
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#define PIDFD_PASS 0
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#define PIDFD_FAIL 1
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#define PIDFD_ERROR 2
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#define PIDFD_SKIP 3
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#define PIDFD_XFAIL 4
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int wait_for_pid(pid_t pid)
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{
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int status, ret;
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again:
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ret = waitpid(pid, &status, 0);
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if (ret == -1) {
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if (errno == EINTR)
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goto again;
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return -1;
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}
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if (!WIFEXITED(status))
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return -1;
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return WEXITSTATUS(status);
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}
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static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
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{
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return syscall(__NR_pidfd_open, pid, flags);
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}
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static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
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unsigned int flags)
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{
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return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
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}
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static inline int sys_pidfd_getfd(int pidfd, int fd, int flags)
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{
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return syscall(__NR_pidfd_getfd, pidfd, fd, flags);
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}
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#endif /* __PIDFD_H */
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