1 files changed, 278 insertions, 0 deletions
diff --git a/arch/um/kernel/tt/gdb.c b/arch/um/kernel/tt/gdb.c
new file mode 100644
index 000000000000..19a0ad7b35b3
--- /dev/null
+++ b/arch/um/kernel/tt/gdb.c
@@ -0,0 +1,278 @@
+/* 
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/types.h>
+#include "ptrace_user.h"
+#include "uml-config.h"
+#include "kern_constants.h"
+#include "chan_user.h"
+#include "init.h"
+#include "user.h"
+#include "debug.h"
+#include "kern_util.h"
+#include "user_util.h"
+#include "tt.h"
+#include "sysdep/thread.h"
+
+extern int debugger_pid;
+extern int debugger_fd;
+extern int debugger_parent;
+
+int detach(int pid, int sig)
+{
+	return(ptrace(PTRACE_DETACH, pid, 0, sig));
+}
+
+int attach(int pid)
+{
+	int err;
+
+	err = ptrace(PTRACE_ATTACH, pid, 0, 0);
+	if(err < 0) return(-errno);
+	else return(err);
+}
+
+int cont(int pid)
+{
+	return(ptrace(PTRACE_CONT, pid, 0, 0));
+}
+
+#ifdef UML_CONFIG_PT_PROXY
+
+int debugger_signal(int status, pid_t pid)
+{
+	return(debugger_proxy(status, pid));
+}
+
+void child_signal(pid_t pid, int status)
+{
+	child_proxy(pid, status);
+}
+
+static void gdb_announce(char *dev_name, int dev)
+{
+	printf("gdb assigned device '%s'\n", dev_name);
+}
+
+static struct chan_opts opts = {
+	.announce  	= gdb_announce,
+	.xterm_title 	= "UML kernel debugger",
+	.raw 		= 0,
+	.tramp_stack 	= 0,
+	.in_kernel  	= 0,
+};
+
+/* Accessed by the tracing thread, which automatically serializes access */
+static void *xterm_data;
+static int xterm_fd;
+
+extern void *xterm_init(char *, int, struct chan_opts *);
+extern int xterm_open(int, int, int, void *, char **);
+extern void xterm_close(int, void *);
+
+int open_gdb_chan(void)
+{
+	char stack[UM_KERN_PAGE_SIZE], *dummy;
+
+	opts.tramp_stack = (unsigned long) stack;
+	xterm_data = xterm_init("", 0, &opts);
+	xterm_fd = xterm_open(1, 1, 1, xterm_data, &dummy);
+	return(xterm_fd);
+}
+
+static void exit_debugger_cb(void *unused)
+{
+	if(debugger_pid != -1){
+		if(gdb_pid != -1){
+			fake_child_exit();
+			gdb_pid = -1;
+		}
+		else kill_child_dead(debugger_pid);
+		debugger_pid = -1;
+		if(debugger_parent != -1)
+			detach(debugger_parent, SIGINT);
+	}
+	if(xterm_data != NULL) xterm_close(xterm_fd, xterm_data);
+}
+
+static void exit_debugger(void)
+{
+	initial_thread_cb(exit_debugger_cb, NULL);
+}
+
+__uml_exitcall(exit_debugger);
+
+struct gdb_data {
+	char *str;
+	int err;
+};
+
+static void config_gdb_cb(void *arg)
+{
+	struct gdb_data *data = arg;
+	void *task;
+	int pid;
+
+	data->err = -1;
+	if(debugger_pid != -1) exit_debugger_cb(NULL);
+	if(!strncmp(data->str, "pid,", strlen("pid,"))){
+		data->str += strlen("pid,");
+		pid = strtoul(data->str, NULL, 0);
+		task = cpu_tasks[0].task;
+		debugger_pid = attach_debugger(TASK_EXTERN_PID(task), pid, 0);
+		if(debugger_pid != -1){
+			data->err = 0;
+			gdb_pid = pid;
+		}
+		return;
+	}
+	data->err = 0;
+	debugger_pid = start_debugger(linux_prog, 0, 0, &debugger_fd);
+	init_proxy(debugger_pid, 0, 0);
+}
+
+int gdb_config(char *str)
+{
+	struct gdb_data data;
+
+	if(*str++ != '=') return(-1);
+	data.str = str;
+	initial_thread_cb(config_gdb_cb, &data);
+	return(data.err);
+}
+
+void remove_gdb_cb(void *unused)
+{
+	exit_debugger_cb(NULL);
+}
+
+int gdb_remove(char *unused)
+{
+	initial_thread_cb(remove_gdb_cb, NULL);
+	return(0);
+}
+
+void signal_usr1(int sig)
+{
+	if(debugger_pid != -1){
+		printf("The debugger is already running\n");
+		return;
+	}
+	debugger_pid = start_debugger(linux_prog, 0, 0, &debugger_fd);
+	init_proxy(debugger_pid, 0, 0);
+}
+
+int init_ptrace_proxy(int idle_pid, int startup, int stop)
+{
+	int pid, status;
+
+	pid = start_debugger(linux_prog, startup, stop, &debugger_fd);
+	status = wait_for_stop(idle_pid, SIGSTOP, PTRACE_CONT, NULL);
+ 	if(pid < 0){
+		cont(idle_pid);
+		return(-1);
+	}
+	init_proxy(pid, 1, status);
+	return(pid);
+}
+
+int attach_debugger(int idle_pid, int pid, int stop)
+{
+	int status = 0, err;
+
+	err = attach(pid);
+	if(err < 0){
+		printf("Failed to attach pid %d, errno = %d\n", pid, -err);
+		return(-1);
+	}
+	if(stop) status = wait_for_stop(idle_pid, SIGSTOP, PTRACE_CONT, NULL);
+	init_proxy(pid, 1, status);
+	return(pid);
+}
+
+#ifdef notdef /* Put this back in when it does something useful */
+static int __init uml_gdb_init_setup(char *line, int *add)
+{
+	gdb_init = uml_strdup(line);
+	return 0;
+}
+
+__uml_setup("gdb=", uml_gdb_init_setup, 
+"gdb=<channel description>\n\n"
+);
+#endif
+
+static int __init uml_gdb_pid_setup(char *line, int *add)
+{
+	gdb_pid = strtoul(line, NULL, 0);
+	*add = 0;
+	return 0;
+}
+
+__uml_setup("gdb-pid=", uml_gdb_pid_setup, 
+"gdb-pid=<pid>\n"
+"    gdb-pid is used to attach an external debugger to UML.  This may be\n"
+"    an already-running gdb or a debugger-like process like strace.\n\n"
+);
+
+#else
+
+int debugger_signal(int status, pid_t pid){ return(0); }
+void child_signal(pid_t pid, int status){ }
+int init_ptrace_proxy(int idle_pid, int startup, int stop)
+{
+	printf("debug requested when CONFIG_PT_PROXY is off\n");
+	kill_child_dead(idle_pid);
+	exit(1);
+}
+
+void signal_usr1(int sig)
+{
+	printf("debug requested when CONFIG_PT_PROXY is off\n");
+}
+
+int attach_debugger(int idle_pid, int pid, int stop)
+{
+	printf("attach_debugger called when CONFIG_PT_PROXY "
+	       "is off\n");
+	return(-1);
+}
+
+int config_gdb(char *str)
+{
+	return(-1);
+}
+
+int remove_gdb(void)
+{
+	return(-1);
+}
+
+int init_parent_proxy(int pid)
+{
+	return(-1);
+}
+
+void debugger_parent_signal(int status, int pid)
+{
+}
+
+#endif
+
+/*
+ * 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:
+ */