The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=c20558e5c9dadfdddc879ee50a65d14beb4992b9
commit c20558e5c9dadfdddc879ee50a65d14beb4992b9 Author: Konstantin Belousov <[email protected]> AuthorDate: 2026-05-22 10:09:01 +0000 Commit: Konstantin Belousov <[email protected]> CommitDate: 2026-07-07 22:03:53 +0000 pdfork.2: document pddupfd() Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D57163 --- lib/libsys/Makefile.sys | 3 ++- lib/libsys/pdfork.2 | 57 +++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 55 insertions(+), 5 deletions(-) diff --git a/lib/libsys/Makefile.sys b/lib/libsys/Makefile.sys index c362258b89f4..5924abb43a39 100644 --- a/lib/libsys/Makefile.sys +++ b/lib/libsys/Makefile.sys @@ -500,7 +500,8 @@ MLINKS+=pdfork.2 pdgetpid.2 \ pdfork.2 pdopenpid.2 \ pdfork.2 pdkill.2 \ pdfork.2 pdrfork.2 \ - pdfork.2 pdwait.2 + pdfork.2 pdwait.2 \ + pdfork.2 pddupfd.2 MLINKS+=pipe.2 pipe2.2 MLINKS+=poll.2 ppoll.2 MLINKS+=rctl_add_rule.2 rctl_get_limits.2 \ diff --git a/lib/libsys/pdfork.2 b/lib/libsys/pdfork.2 index 18dff970be1f..a6bf8534003d 100644 --- a/lib/libsys/pdfork.2 +++ b/lib/libsys/pdfork.2 @@ -39,7 +39,8 @@ .Nm pdopenpid , .Nm pdgetpid , .Nm pdkill , -.Nm pdwait +.Nm pdwait , +.Nm pddupfd .Nd System calls to manage process descriptors .Sh LIBRARY .Lb libc @@ -63,6 +64,8 @@ .Fa "struct __wrusage *wrusage" .Fa "struct __siginfo *info" .Fc +.Ft int +.Fn pddupfd "int fd" "int remotefd" "int flags" .Sh DESCRIPTION Process descriptors are special file descriptors that represent processes, and are created using @@ -176,6 +179,23 @@ See the description of the .Xr wait6 system call for the behavior specification. .Pp +The +.Fn pddupfd +allows the caller to duplicate a file descriptor across the process +boundaries. +The function returns the new file descriptor that points to the same file +as the file descriptor +.Fa remotefd +in the process specified by the +.Fa fd +process descriptor. +The returned file descriptor has the +.Va O_CLOEXEC +flag set. +The +.Fa flags +argument is reserved and must be zero. +.Pp The following system calls also have effects specific to process descriptors: .Pp .Xr fstat 2 @@ -228,8 +248,9 @@ does. .Fn pdopenpid , .Fn pdgetpid , .Fn pdkill , +.Fn pdwait , and -.Fn pdwait +.Fn pddupfd return 0 on success and -1 on failure. .Sh ERRORS These functions may return the same error numbers as their PID-based equivalents @@ -306,6 +327,30 @@ which executes all actions performed by .Xr close 2 on it. .El +.Pp +The +.Fn pddupfd +returns the following errors: +.Bl -tag -width Er +.It Bq Er EINVAL +The +.Fa flags +argument is not zero. +.It Bq Er ESRCH +The process specified by the file descriptor +.Fa fd +exited. +.It Bq Er EBADF +The file descriptor +.Fa fd +is not a process file descriptor. +.It Bq Er EBADF +The file descriptor +.Fa remotefd +is not a valid file descriptor in the specified process. +.It Bq Er ENOENT +The specified process does not have a file descriptor table. +.El .Sh SEE ALSO .Xr close 2 , .Xr fork 2 , @@ -332,7 +377,9 @@ system calls first appeared in .Fx 15.1 . The .Fn pdopenpid -system call first appeared in +and +.Fn pddupfd +system calls first appeared in .Fx 16.0 . .Pp Support for process descriptors mode was developed as part of the @@ -356,5 +403,7 @@ with input from .An Alan Somers Aq Mt [email protected] . The .Fn pdopenpid -function was developed by +and +.Fn pddupfd +functions were developed by .An Konstantin Belousov Aq Mt [email protected] .
