Extend the support for exempting processes from being killed when swap is

exhausted.
- Add a new protect(1) command that can be used to set or revoke protection
  from arbitrary processes.  Similar to ktrace it can apply a change to all
  existing descendants of a process as well as future descendants.
- Add a new procctl(2) system call that provides a generic interface for
  control operations on processes (as opposed to the debugger-specific
  operations provided by ptrace(2)).  procctl(2) uses a combination of
  idtype_t and an id to identify the set of processes on which to operate
  similar to wait6().
- Add a PROC_SPROTECT control operation to manage the protection status
  of a set of processes.  MADV_PROTECT still works for backwards
  compatability.
- Add a p_flag2 to struct proc (and a corresponding ki_flag2 to kinfo_proc)
  the first bit of which is used to track if P_PROTECT should be inherited
  by new child processes.

Reviewed by:	kib, jilles (earlier version)
Approved by:	re (delphij)
MFC after:	1 month

3 files changed, 31 insertions, 0 deletions

diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h
index aa08432..e6644f6 100644
--- a/sys/compat/freebsd32/freebsd32.h
+++ b/sys/compat/freebsd32/freebsd32.h
@@ -342,6 +342,7 @@ struct kinfo_proc32 {
 	char	ki_loginclass[LOGINCLASSLEN+1];
 	char	ki_sparestrings[50];
 	int	ki_spareints[KI_NSPARE_INT];
+	int	ki_flag2;
 	int	ki_fibnum;
 	u_int	ki_cr_flags;
 	int	ki_jid;
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index dbdafeb..deb03f3 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -56,6 +56,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/mutex.h>
 #include <sys/namei.h>
 #include <sys/proc.h>
+#include <sys/procctl.h>
 #include <sys/reboot.h>
 #include <sys/resource.h>
 #include <sys/resourcevar.h>
@@ -3000,3 +3001,23 @@ convert_sigevent32(struct sigevent32 *sig32, struct sigevent *sig)
 	}
 	return (0);
 }
+
+int
+freebsd32_procctl(struct thread *td, struct freebsd32_procctl_args *uap)
+{
+	void *data;
+	int error, flags;
+
+	switch (uap->com) {
+	case PROC_SPROTECT:
+		error = copyin(PTRIN(uap->data), &flags, sizeof(flags));
+		if (error)
+			return (error);
+		data = &flags;
+		break;
+	default:
+		return (EINVAL);
+	}
+	return (kern_procctl(td, uap->idtype, PAIR32TO64(id_t, uap->id),
+	    uap->com, data));
+}
diff --git a/sys/compat/freebsd32/syscalls.master b/sys/compat/freebsd32/syscalls.master
index c52256a..90c3e75 100644
--- a/sys/compat/freebsd32/syscalls.master
+++ b/sys/compat/freebsd32/syscalls.master
@@ -1056,3 +1056,12 @@
 542	AUE_PIPE	NOPROTO	{ int pipe2(int *fildes, int flags); }
 543	AUE_NULL	NOSTD	{ int freebsd32_aio_mlock( \
 				    struct aiocb32 *aiocbp); }
+#ifdef PAD64_REQUIRED
+544	AUE_NULL	STD	{ int freebsd32_procctl(int idtype, int pad, \
+				    uint32_t id1, uint32_t id2, int com, \
+				    void *data); }
+#else
+544	AUE_NULL	STD	{ int freebsd32_procctl(int idtype, \
+				    uint32_t id1, uint32_t id2, int com, \
+				    void *data); }
+#endif