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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-24 04:52:22 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-24 04:52:22 +0000 |
commit | 7f3caba522f4d24764f29d83aa2de9198bb7f01c (patch) | |
tree | 66b798ea74302325d6a5c11df044cbe4bb845af1 /man2/pidfd_getfd.2 | |
parent | Adding upstream version 6.7. (diff) | |
download | manpages-upstream.tar.xz manpages-upstream.zip |
Adding upstream version 6.8.upstream/6.8upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man2/pidfd_getfd.2')
-rw-r--r-- | man2/pidfd_getfd.2 | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/man2/pidfd_getfd.2 b/man2/pidfd_getfd.2 deleted file mode 100644 index 918f1d2..0000000 --- a/man2/pidfd_getfd.2 +++ /dev/null @@ -1,144 +0,0 @@ -.\" Copyright (c) 2020 by Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH pidfd_getfd 2 2023-10-31 "Linux man-pages 6.7" -.SH NAME -pidfd_getfd \- obtain a duplicate of another process's file descriptor -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" -.B #include <unistd.h> -.P -.BI "int syscall(SYS_pidfd_getfd, int " pidfd ", int " targetfd , -.BI " unsigned int " flags ); -.fi -.P -.IR Note : -glibc provides no wrapper for -.BR pidfd_getfd (), -necessitating the use of -.BR syscall (2). -.SH DESCRIPTION -The -.BR pidfd_getfd () -system call allocates a new file descriptor in the calling process. -This new file descriptor is a duplicate of an existing file descriptor, -.IR targetfd , -in the process referred to by the PID file descriptor -.IR pidfd . -.P -The duplicate file descriptor refers to the same open file description (see -.BR open (2)) -as the original file descriptor in the process referred to by -.IR pidfd . -The two file descriptors thus share file status flags and file offset. -Furthermore, operations on the underlying file object -(for example, assigning an address to a socket object using -.BR bind (2)) -can equally be performed via the duplicate file descriptor. -.P -The close-on-exec flag -.RB ( FD_CLOEXEC ; -see -.BR fcntl (2)) -is set on the file descriptor returned by -.BR pidfd_getfd (). -.P -The -.I flags -argument is reserved for future use. -Currently, it must be specified as 0. -.P -Permission to duplicate another process's file descriptor -is governed by a ptrace access mode -.B PTRACE_MODE_ATTACH_REALCREDS -check (see -.BR ptrace (2)). -.SH RETURN VALUE -On success, -.BR pidfd_getfd () -returns a file descriptor (a nonnegative integer). -On error, \-1 is returned and -.I errno -is set to indicate the error. -.SH ERRORS -.TP -.B EBADF -.I pidfd -is not a valid PID file descriptor. -.TP -.B EBADF -.I targetfd -is not an open file descriptor in the process referred to by -.IR pidfd . -.TP -.B EINVAL -.I flags -is not 0. -.TP -.B EMFILE -The per-process limit on the number of open file descriptors has been reached -(see the description of -.B RLIMIT_NOFILE -in -.BR getrlimit (2)). -.TP -.B ENFILE -The system-wide limit on the total number of open files has been reached. -.TP -.B EPERM -The calling process did not have -.B PTRACE_MODE_ATTACH_REALCREDS -permissions (see -.BR ptrace (2)) -over the process referred to by -.IR pidfd . -.TP -.B ESRCH -The process referred to by -.I pidfd -does not exist -(i.e., it has terminated and been waited on). -.SH STANDARDS -Linux. -.SH HISTORY -Linux 5.6. -.\" commit 8649c322f75c96e7ced2fec201e123b2b073bf09 -.SH NOTES -For a description of PID file descriptors, see -.BR pidfd_open (2). -.P -The effect of -.BR pidfd_getfd () -is similar to the use of -.B SCM_RIGHTS -messages described in -.BR unix (7), -but differs in the following respects: -.IP \[bu] 3 -In order to pass a file descriptor using an -.B SCM_RIGHTS -message, -the two processes must first establish a UNIX domain socket connection. -.IP \[bu] -The use of -.B SCM_RIGHTS -requires cooperation on the part of the process whose -file descriptor is being copied. -By contrast, no such cooperation is necessary when using -.BR pidfd_getfd (). -.IP \[bu] -The ability to use -.BR pidfd_getfd () -is restricted by a -.B PTRACE_MODE_ATTACH_REALCREDS -ptrace access mode check. -.SH SEE ALSO -.BR clone3 (2), -.BR dup (2), -.BR kcmp (2), -.BR pidfd_open (2) |