Hi Michael, On Mon, Oct 30, 2017 at 01:47:31PM +0100, Michael Kerrisk (man-pages) wrote: > On 10 August 2017 at 20:46, Andrei Vagin <avagin@xxxxxxxxxx> wrote: > > It is a hybrid of process_vm_readv() and vmsplice(). > > > > vmsplice can map memory from a current address space into a pipe. > > process_vm_readv can read memory of another process. > > > > A new system call can map memory of another process into a pipe. > > > > ssize_t process_vmsplice(pid_t pid, int fd, const struct iovec *iov, > > unsigned long nr_segs, unsigned int flags) > > > > All arguments are identical with vmsplice except pid which specifies a > > target process. > > Can we have a man page for this new syscall please? I think we can add a description for process_vmsplice into man2/vmsplice.2. The patch is attached. Thanks, Andrei > > Thanks, > > Michael > >
>From 923cbd38805f8017b6d86ac6a12c8f45a4117399 Mon Sep 17 00:00:00 2001 From: Andrei Vagin <avagin@xxxxxxxxxx> Date: Wed, 1 Nov 2017 10:26:06 -0700 Subject: [PATCH] vmsplice.2: add description for process_vmsplice Signed-off-by: Andrei Vagin <avagin@xxxxxxxxxx> --- man2/vmsplice.2 | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/man2/vmsplice.2 b/man2/vmsplice.2 index e3e61cf27..8b28b6fff 100644 --- a/man2/vmsplice.2 +++ b/man2/vmsplice.2 @@ -25,7 +25,7 @@ .\" .TH VMSPLICE 2 2014-10-02 "Linux" "Linux Programmer's Manual" .SH NAME -vmsplice \- splice user pages into a pipe +vmsplice, process_vmsplice \- splice user pages into a pipe .SH SYNOPSIS .nf .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" @@ -34,6 +34,8 @@ vmsplice \- splice user pages into a pipe .BI "ssize_t vmsplice(int " fd ", const struct iovec *" iov , .BI " unsigned long " nr_segs ", unsigned int " flags ); +.BI "ssize_t process_vmsplice(pid_t " pid ", int " fd ", const struct iovec *" iov , +.BI " unsigned long " nr_segs ", unsigned int " flags ); .fi .\" Return type was long before glibc 2.7 .SH DESCRIPTION @@ -55,6 +57,12 @@ The file descriptor .I fd must refer to a pipe. +The +.BR process_vmsplice() +system call maps user memory from the process identified by +.I pid +to the local pipe. + The pointer .I iov points to an array of @@ -114,6 +122,7 @@ Data must also be properly page aligned, both in memory and length. .\" commit bd1a68b59c8e3bce45fb76632c64e1e063c3962d .\" .\" .... if we expect to later SPLICE_F_MOVE to the cache. + .SH RETURN VALUE Upon successful completion, .BR vmsplice () @@ -145,6 +154,15 @@ set. .TP .B ENOMEM Out of memory. +.TP +.B ESRCH +No process with ID +.I pid +exists. +.TP +.B EPERM +The caller does not have permission to access the address space of the process +.IR pid . .SH VERSIONS The .BR vmsplice () -- 2.13.6
