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

2 files changed, 11 insertions, 1 deletions

diff --git a/usr.bin/truss/syscall.h b/usr.bin/truss/syscall.h
index ce7d2e9..b0d3461 100644
--- a/usr.bin/truss/syscall.h
+++ b/usr.bin/truss/syscall.h
@@ -40,7 +40,7 @@ enum Argtype { None = 1, Hex, Octal, Int, Name, Ptr, Stat, Ioctl, Quad,
 	Fd_set, Sigaction, Fcntl, Mprot, Mmapflags, Whence, Readlinkres,
 	Umtx, Sigset, Sigprocmask, Kevent, Sockdomain, Socktype, Open,
 	Fcntlflag, Rusage, BinString, Shutdown, Resource, Rlimit, Timeval2,
-	Pathconf, Rforkflags, ExitStatus, Waitoptions, Idtype };
+	Pathconf, Rforkflags, ExitStatus, Waitoptions, Idtype, Procctl };
 
 #define	ARG_MASK	0xff
 #define	OUT	0x100
diff --git a/usr.bin/truss/syscalls.c b/usr.bin/truss/syscalls.c
index 5369dec..06c2511 100644
--- a/usr.bin/truss/syscalls.c
+++ b/usr.bin/truss/syscalls.c
@@ -41,6 +41,7 @@ static const char rcsid[] =
 
 #include <sys/types.h>
 #include <sys/mman.h>
+#include <sys/procctl.h>
 #include <sys/ptrace.h>
 #include <sys/socket.h>
 #include <sys/time.h>
@@ -270,6 +271,8 @@ static struct syscall syscalls[] = {
 	{ .name = "wait6", .ret_type = 1, .nargs = 6,
 	  .args = { { Idtype, 0 }, { Int, 1 }, { ExitStatus | OUT, 2 },
 		    { Waitoptions, 3 }, { Rusage | OUT, 4 }, { Ptr, 5 } } },
+	{ .name = "procctl", .ret_type = 1, .nargs = 4,
+	  .args = { { Idtype, 0 }, { Int, 1 }, { Procctl, 2 }, { Ptr, 3 } } },
 	{ .name = 0 },
 };
 
@@ -399,6 +402,10 @@ static struct xlat idtype_arg[] = {
 	X(P_CTID) X(P_CPUID) X(P_PSETID) XEND
 };
 
+static struct xlat procctl_arg[] = {
+	X(PROC_SPROTECT) XEND
+};
+
 #undef X
 #undef XEND
 
@@ -1198,6 +1205,9 @@ print_arg(struct syscall_args *sc, unsigned long *args, long retval,
 	case Idtype:
 		tmp = strdup(xlookup(idtype_arg, args[sc->offset]));
 		break;
+	case Procctl:
+		tmp = strdup(xlookup(procctl_arg, args[sc->offset]));
+		break;
 	default:
 		errx(1, "Invalid argument type %d\n", sc->type & ARG_MASK);
 	}