/* * 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" #include "os.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(int 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: */