alloc_hugepages.2, arch_prctl.2, capget.2, clone.2, delete_module.2, exit_group.2, get_robust_list.2, getunwind.2, init_module.2: Add note about the use of syscall(2)

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/alloc_hugepages.2

@@ -35,6 +35,11 @@ alloc_hugepages, free_hugepages \- allocate or free huge pages
 .BI "int syscall(SYS_free_hugepages, void *" addr );
 .\" asmlinkage int sys_free_hugepages(unsigned long addr);
 .fi
+.PP
+.IR Note :
+glibc provides no wrappers for these system calls,
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 The system calls
 .BR alloc_hugepages ()

man2/arch_prctl.2

@@ -34,6 +34,12 @@ arch_prctl \- set architecture-specific thread state
 .BI "int syscall(SYS_arch_prctl, int " code ", unsigned long " addr );
 .BI "int syscall(SYS_arch_prctl, int " code ", unsigned long *" addr );
 .fi
+.PP
+.IR Note :
+glibc provides no wrapper for
+.BR arch_prctl (),
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 .BR arch_prctl ()
 sets architecture-specific process or thread state.

man2/capget.2

@@ -28,6 +28,11 @@ capget, capset \- set/get capabilities of thread(s)
 .BI "int syscall(SYS_capset, cap_user_header_t " hdrp ,
 .BI "            const cap_user_data_t " datap );
 .fi
+.PP
+.IR Note :
+glibc provides no wrappers for these system calls,
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 These two system calls are the raw kernel interface for getting and
 setting thread capabilities.

man2/clone.2

@@ -63,6 +63,12 @@ clone, __clone2, clone3 \- create a child process
 .PP
 .BI "long syscall(SYS_clone3, struct clone_args *" cl_args ", size_t " size );
 .fi
+.PP
+.IR Note :
+glibc provides no wrapper for
+.BR clone3 (),
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 These system calls
 create a new ("child") process, in a manner similar to

man2/delete_module.2

@@ -33,6 +33,12 @@ delete_module \- unload a kernel module
 .PP
 .BI "int syscall(SYS_delete_module, const char *" name ", unsigned int " flags );
 .fi
+.PP
+.IR Note :
+glibc provides no wrapper for
+.BR delete_module (),
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 The
 .BR delete_module ()

man2/exit_group.2

@@ -32,6 +32,12 @@ exit_group \- exit all threads in a process
 .PP
 .BI "noreturn void syscall(SYS_exit_group, int " status );
 .fi
+.PP
+.IR Note :
+glibc provides no wrapper for
+.BR exit_group (),
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 This system call is equivalent to
 .BR _exit (2)

man2/get_robust_list.2

@@ -42,6 +42,11 @@ get_robust_list, set_robust_list \- get/set list of robust futexes
 .BI "long syscall(SYS_set_robust_list,"
 .BI "             struct robust_list_head *" head ", size_t " len );
 .fi
+.PP
+.IR Note :
+glibc provides no wrappers for these system calls,
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 These system calls deal with per-thread robust futex lists.
 These lists are managed in user space:

man2/getunwind.2

@@ -35,6 +35,12 @@ getunwind \- copy the unwind data to caller's buffer
 .PP
 .BI "long syscall(SYS_getunwind, void " *buf ", size_t " buf_size );
 .fi
+.PP
+.IR Note :
+glibc provides no wrapper for
+.BR getunwind (),
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 .I Note: this system call is obsolete.
 .PP

man2/init_module.2

@@ -38,6 +38,11 @@ init_module, finit_module \- load a kernel module
 .BI "int syscall(SYS_finit_module, int " fd ", const char *" param_values ,
 .BI "            int " flags );
 .fi
+.PP
+.IR Note :
+glibc provides no wrappers for these system calls,
+necessitating the use of
+.BR syscall (2).
 .SH DESCRIPTION
 .BR init_module ()
 loads an ELF image into kernel space,