[v5,11/35] clone.2: Use syscall(SYS_...); for system calls without a wrapper
Commit Message
The CLONE_* constants seem to be available from either
<linux/sched.h> or <sched.h>, and since clone3() already
includes <linux/sched.h> for 'struct clone_args', <sched.h>
is not really needed, AFAICS; however, to avoid confussion,
I also included <sched.h> for clone3() for consistency:
clone() is getting CLONE_* from <sched.h>, and it would confuse
the reader if clone3() got the same CLONE_* constants from a
different header.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
---
man2/clone.2 | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
Comments
Hi Alex,
On 4/4/21 1:58 PM, Alejandro Colomar wrote:
> The CLONE_* constants seem to be available from either
> <linux/sched.h> or <sched.h>, and since clone3() already
> includes <linux/sched.h> for 'struct clone_args', <sched.h>
> is not really needed, AFAICS; however, to avoid confussion,
> I also included <sched.h> for clone3() for consistency:
I think that's a good decision.
> clone() is getting CLONE_* from <sched.h>, and it would confuse
> the reader if clone3() got the same CLONE_* constants from a
> different header.
Agreed.
Patch applied.
Thanks,
Michael
>
> Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
> ---
> man2/clone.2 | 17 ++++++-----------
> 1 file changed, 6 insertions(+), 11 deletions(-)
>
> diff --git a/man2/clone.2 b/man2/clone.2
> index fa7d1103e..f455c97d8 100644
> --- a/man2/clone.2
> +++ b/man2/clone.2
> @@ -56,13 +56,13 @@ clone, __clone2, clone3 \- create a child process
> .PP
> /* For the prototype of the raw clone() system call, see NOTES */
> .PP
> -.BI "long clone3(struct clone_args *" cl_args ", size_t " size );
> -.fi
> +.BR "#include <linux/sched.h>" " /* Definition of " "struct clone_args" " */"
> +.BR "#include <sched.h>" " /* Definition of " CLONE_* " constants */"
> +.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */"
> +.B #include <unistd.h>
> .PP
> -.IR Note :
> -There is no glibc wrapper for
> -.BR clone3 ();
> -see NOTES.
> +.BI "long syscall(SYS_clone3, struct clone_args *" cl_args ", size_t " size );
> +.fi
> .SH DESCRIPTION
> These system calls
> create a new ("child") process, in a manner similar to
> @@ -1541,11 +1541,6 @@ One use of these systems calls
> is to implement threads: multiple flows of control in a program that
> run concurrently in a shared address space.
> .PP
> -Glibc does not provide a wrapper for
> -.BR clone3 ();
> -call it using
> -.BR syscall (2).
> -.PP
> Note that the glibc
> .BR clone ()
> wrapper function makes some changes
>
@@ -56,13 +56,13 @@ clone, __clone2, clone3 \- create a child process
.PP
/* For the prototype of the raw clone() system call, see NOTES */
.PP
-.BI "long clone3(struct clone_args *" cl_args ", size_t " size );
-.fi
+.BR "#include <linux/sched.h>" " /* Definition of " "struct clone_args" " */"
+.BR "#include <sched.h>" " /* Definition of " CLONE_* " constants */"
+.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */"
+.B #include <unistd.h>
.PP
-.IR Note :
-There is no glibc wrapper for
-.BR clone3 ();
-see NOTES.
+.BI "long syscall(SYS_clone3, struct clone_args *" cl_args ", size_t " size );
+.fi
.SH DESCRIPTION
These system calls
create a new ("child") process, in a manner similar to
@@ -1541,11 +1541,6 @@ One use of these systems calls
is to implement threads: multiple flows of control in a program that
run concurrently in a shared address space.
.PP
-Glibc does not provide a wrapper for
-.BR clone3 ();
-call it using
-.BR syscall (2).
-.PP
Note that the glibc
.BR clone ()
wrapper function makes some changes