blob: 58800c50b10e5a58e43bef19518232f866a4d9a0 [file] [log] [blame]
/**********************************************************************
proxy.c
Copyright (C) 1999 Lars Brinkhoff. See the file COPYING for licensing
terms and conditions.
Jeff Dike (jdike@karaya.com) : Modified for integration into uml
**********************************************************************/
/* XXX This file shouldn't refer to CONFIG_* */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <termios.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <asm/unistd.h>
#include "ptrace_user.h"
#include "ptproxy.h"
#include "sysdep.h"
#include "wait.h"
#include "user_util.h"
#include "user.h"
#include "os.h"
#include "tempfile.h"
static int debugger_wait(debugger_state *debugger, int *status, int options,
int (*syscall)(debugger_state *debugger, pid_t child),
int (*normal_return)(debugger_state *debugger,
pid_t unused),
int (*wait_return)(debugger_state *debugger,
pid_t unused))
{
if(debugger->real_wait){
debugger->handle_trace = normal_return;
syscall_continue(debugger->pid);
debugger->real_wait = 0;
return(1);
}
debugger->wait_status_ptr = status;
debugger->wait_options = options;
if((debugger->debugee != NULL) && debugger->debugee->event){
syscall_continue(debugger->pid);
wait_for_stop(debugger->pid, SIGTRAP, PTRACE_SYSCALL,
NULL);
(*wait_return)(debugger, -1);
return(0);
}
else if(debugger->wait_options & WNOHANG){
syscall_cancel(debugger->pid, 0);
debugger->handle_trace = syscall;
return(0);
}
else {
syscall_pause(debugger->pid);
debugger->handle_trace = wait_return;
debugger->waiting = 1;
}
return(1);
}
/*
* Handle debugger trap, i.e. syscall.
*/
int debugger_syscall(debugger_state *debugger, pid_t child)
{
long arg1, arg2, arg3, arg4, arg5, result;
int syscall, ret = 0;
syscall = get_syscall(debugger->pid, &arg1, &arg2, &arg3, &arg4,
&arg5);
switch(syscall){
case __NR_execve:
/* execve never returns */
debugger->handle_trace = debugger_syscall;
break;
case __NR_ptrace:
if(debugger->debugee->pid != 0) arg2 = debugger->debugee->pid;
if(!debugger->debugee->in_context)
child = debugger->debugee->pid;
result = proxy_ptrace(debugger, arg1, arg2, arg3, arg4, child,
&ret);
syscall_cancel(debugger->pid, result);
debugger->handle_trace = debugger_syscall;
return(ret);
#ifdef __NR_waitpid
case __NR_waitpid:
#endif
case __NR_wait4:
if(!debugger_wait(debugger, (int *) arg2, arg3,
debugger_syscall, debugger_normal_return,
proxy_wait_return))
return(0);
break;
case __NR_kill:
if(!debugger->debugee->in_context)
child = debugger->debugee->pid;
if(arg1 == debugger->debugee->pid){
result = kill(child, arg2);
syscall_cancel(debugger->pid, result);
debugger->handle_trace = debugger_syscall;
return(0);
}
else debugger->handle_trace = debugger_normal_return;
break;
default:
debugger->handle_trace = debugger_normal_return;
}
syscall_continue(debugger->pid);
return(0);
}
/* Used by the tracing thread */
static debugger_state parent;
static int parent_syscall(debugger_state *debugger, int pid);
int init_parent_proxy(int pid)
{
parent = ((debugger_state) { .pid = pid,
.wait_options = 0,
.wait_status_ptr = NULL,
.waiting = 0,
.real_wait = 0,
.expecting_child = 0,
.handle_trace = parent_syscall,
.debugee = NULL } );
return(0);
}
int parent_normal_return(debugger_state *debugger, pid_t unused)
{
debugger->handle_trace = parent_syscall;
syscall_continue(debugger->pid);
return(0);
}
static int parent_syscall(debugger_state *debugger, int pid)
{
long arg1, arg2, arg3, arg4, arg5;
int syscall;
syscall = get_syscall(pid, &arg1, &arg2, &arg3, &arg4, &arg5);
if((syscall == __NR_wait4)
#ifdef __NR_waitpid
|| (syscall == __NR_waitpid)
#endif
){
debugger_wait(&parent, (int *) arg2, arg3, parent_syscall,
parent_normal_return, parent_wait_return);
}
else ptrace(PTRACE_SYSCALL, pid, 0, 0);
return(0);
}
int debugger_normal_return(debugger_state *debugger, pid_t unused)
{
debugger->handle_trace = debugger_syscall;
syscall_continue(debugger->pid);
return(0);
}
void debugger_cancelled_return(debugger_state *debugger, int result)
{
debugger->handle_trace = debugger_syscall;
syscall_set_result(debugger->pid, result);
syscall_continue(debugger->pid);
}
/* Used by the tracing thread */
static debugger_state debugger;
static debugee_state debugee;
void init_proxy (pid_t debugger_pid, int stopped, int status)
{
debugger.pid = debugger_pid;
debugger.handle_trace = debugger_syscall;
debugger.debugee = &debugee;
debugger.waiting = 0;
debugger.real_wait = 0;
debugger.expecting_child = 0;
debugee.pid = 0;
debugee.traced = 0;
debugee.stopped = stopped;
debugee.event = 0;
debugee.zombie = 0;
debugee.died = 0;
debugee.wait_status = status;
debugee.in_context = 1;
}
int debugger_proxy(int status, int pid)
{
int ret = 0, sig;
if(WIFSTOPPED(status)){
sig = WSTOPSIG(status);
if (sig == SIGTRAP)
ret = (*debugger.handle_trace)(&debugger, pid);
else if(sig == SIGCHLD){
if(debugger.expecting_child){
ptrace(PTRACE_SYSCALL, debugger.pid, 0, sig);
debugger.expecting_child = 0;
}
else if(debugger.waiting)
real_wait_return(&debugger);
else {
ptrace(PTRACE_SYSCALL, debugger.pid, 0, sig);
debugger.real_wait = 1;
}
}
else ptrace(PTRACE_SYSCALL, debugger.pid, 0, sig);
}
else if(WIFEXITED(status)){
tracer_panic("debugger (pid %d) exited with status %d",
debugger.pid, WEXITSTATUS(status));
}
else if(WIFSIGNALED(status)){
tracer_panic("debugger (pid %d) exited with signal %d",
debugger.pid, WTERMSIG(status));
}
else {
tracer_panic("proxy got unknown status (0x%x) on debugger "
"(pid %d)", status, debugger.pid);
}
return(ret);
}
void child_proxy(pid_t pid, int status)
{
debugee.event = 1;
debugee.wait_status = status;
if(WIFSTOPPED(status)){
debugee.stopped = 1;
debugger.expecting_child = 1;
kill(debugger.pid, SIGCHLD);
}
else if(WIFEXITED(status) || WIFSIGNALED(status)){
debugee.zombie = 1;
debugger.expecting_child = 1;
kill(debugger.pid, SIGCHLD);
}
else panic("proxy got unknown status (0x%x) on child (pid %d)",
status, pid);
}
void debugger_parent_signal(int status, int pid)
{
int sig;
if(WIFSTOPPED(status)){
sig = WSTOPSIG(status);
if(sig == SIGTRAP) (*parent.handle_trace)(&parent, pid);
else ptrace(PTRACE_SYSCALL, pid, 0, sig);
}
}
void fake_child_exit(void)
{
int status, pid;
child_proxy(1, W_EXITCODE(0, 0));
while(debugger.waiting == 1){
CATCH_EINTR(pid = waitpid(debugger.pid, &status, WUNTRACED));
if(pid != debugger.pid){
printk("fake_child_exit - waitpid failed, "
"errno = %d\n", errno);
return;
}
debugger_proxy(status, debugger.pid);
}
CATCH_EINTR(pid = waitpid(debugger.pid, &status, WUNTRACED));
if(pid != debugger.pid){
printk("fake_child_exit - waitpid failed, "
"errno = %d\n", errno);
return;
}
if(ptrace(PTRACE_DETACH, debugger.pid, 0, SIGCONT) < 0)
printk("fake_child_exit - PTRACE_DETACH failed, errno = %d\n",
errno);
}
char gdb_init_string[] =
"att 1 \n\
b panic \n\
b stop \n\
handle SIGWINCH nostop noprint pass \n\
";
int start_debugger(char *prog, int startup, int stop, int *fd_out)
{
int slave, child;
slave = open_gdb_chan();
child = fork();
if(child == 0){
char *tempname = NULL;
int fd;
if(setsid() < 0) perror("setsid");
if((dup2(slave, 0) < 0) || (dup2(slave, 1) < 0) ||
(dup2(slave, 2) < 0)){
printk("start_debugger : dup2 failed, errno = %d\n",
errno);
exit(1);
}
if(ioctl(0, TIOCSCTTY, 0) < 0){
printk("start_debugger : TIOCSCTTY failed, "
"errno = %d\n", errno);
exit(1);
}
if(tcsetpgrp (1, os_getpid()) < 0){
printk("start_debugger : tcsetpgrp failed, "
"errno = %d\n", errno);
#ifdef notdef
exit(1);
#endif
}
fd = make_tempfile("/tmp/gdb_init-XXXXXX", &tempname, 0);
if(fd < 0){
printk("start_debugger : make_tempfile failed,"
"err = %d\n", -fd);
exit(1);
}
os_write_file(fd, gdb_init_string, sizeof(gdb_init_string) - 1);
if(startup){
if(stop){
os_write_file(fd, "b start_kernel\n",
strlen("b start_kernel\n"));
}
os_write_file(fd, "c\n", strlen("c\n"));
}
if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
printk("start_debugger : PTRACE_TRACEME failed, "
"errno = %d\n", errno);
exit(1);
}
execlp("gdb", "gdb", "--command", tempname, prog, NULL);
printk("start_debugger : exec of gdb failed, errno = %d\n",
errno);
}
if(child < 0){
printk("start_debugger : fork for gdb failed, errno = %d\n",
errno);
return(-1);
}
*fd_out = slave;
return(child);
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/