[src/trunk]: src/sys/arch/usermode/usermode rearrange ptrace_getregs and have...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0f87c8c3ecc9
branches:  trunk
changeset: 769277:0f87c8c3ecc9
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Mon Sep 05 13:28:17 2011 +0000

description:
rearrange ptrace_getregs and have the child raise(SIGSTOP) instead of wait()

diffstat:

 sys/arch/usermode/usermode/urkelvisor.c |  29 +++++++++++++++--------------
 1 files changed, 15 insertions(+), 14 deletions(-)

diffs (95 lines):

diff -r cd9cd8d42374 -r 0f87c8c3ecc9 sys/arch/usermode/usermode/urkelvisor.c
--- a/sys/arch/usermode/usermode/urkelvisor.c   Mon Sep 05 12:49:33 2011 +0000
+++ b/sys/arch/usermode/usermode/urkelvisor.c   Mon Sep 05 13:28:17 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: urkelvisor.c,v 1.4 2011/09/05 12:49:33 jmcneill Exp $ */
+/* $NetBSD: urkelvisor.c,v 1.5 2011/09/05 13:28:17 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2011 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -32,13 +32,14 @@
 
 #include <sys/cdefs.h>
 #ifdef __NetBSD__
-__RCSID("$NetBSD: urkelvisor.c,v 1.4 2011/09/05 12:49:33 jmcneill Exp $");
+__RCSID("$NetBSD: urkelvisor.c,v 1.5 2011/09/05 13:28:17 jmcneill Exp $");
 #endif
 
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/ptrace.h>
 #include <sys/wait.h>
+#include <sys/syscall.h>
 
 #ifdef __linux__
 #include <sys/user.h>
@@ -50,6 +51,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <signal.h>
 #include <unistd.h>
 
 #include "../include/urkelvisor.h"
@@ -98,27 +100,24 @@
 static void
 ptrace_getregs(pid_t urkel_pid, struct reg_struct *puregs)
 {
+       errno = 0;
 #ifdef __linux__
        ptrace(PT_GETREGS, urkel_pid, NULL, puregs);
 #else
        ptrace(PT_GETREGS, urkel_pid, puregs, 0);
 #endif
+       if (errno)
+               err(EXIT_FAILURE, "ptrace(PT_GETREGS, %d, &uregs, 0) failed",
+                   urkel_pid);
 }
 
 static int
-handle_syscall(pid_t urkel_pid)
+handle_syscall(struct reg_struct *puregs, pid_t urkel_pid)
 {
-       struct reg_struct uregs;
        int sig = 0;
 
-       errno = 0;
-       ptrace_getregs(urkel_pid, &uregs);
-       if (errno)
-               err(EXIT_FAILURE, "ptrace(PT_GETREGS, %d, &uregs, 0) failed",
-                   urkel_pid);
-
-       if (R_PC(&uregs) >= kmem_user_start && R_PC(&uregs) < kmem_user_end) {
-               fprintf(stderr, "caught syscall %d\n", (int)R_SYSCALL(&uregs));
+       if (R_PC(puregs) >= kmem_user_start && R_PC(puregs) < kmem_user_end) {
+               fprintf(stderr, "caught syscall %d\n", (int)R_SYSCALL(puregs));
                errno = 0;
                ptrace(PT_SYSCALLEMU, urkel_pid, NULL, 0);
                if (errno)
@@ -134,6 +133,7 @@
 static int
 urkelvisor(pid_t urkel_pid)
 {
+       struct reg_struct uregs;
        int status, insyscall, sig;
 
        insyscall = 0;
@@ -156,7 +156,8 @@
                if (WSTOPSIG(status) == SIGTRAP) {
                        insyscall = !insyscall;
                        if (insyscall) {
-                               sig = handle_syscall(urkel_pid);
+                               ptrace_getregs(urkel_pid, &uregs);
+                               sig = handle_syscall(&uregs, urkel_pid);
                                if (sig)
                                        insyscall = !insyscall;
                        }
@@ -191,7 +192,7 @@
                if (errno)
                        err(EXIT_FAILURE,
                            "ptrace(PT_TRACE_ME, 0, NULL, 0) failed");
-               wait(&status);
+               raise(SIGSTOP);
                break;
        default:
                status = urkelvisor(child_pid);